Cornell Aniversity Library THE GIFT OF s PA QRBZD IM occcsnsnnnnnninnrnnnnaTl [TEE (1404, 3513-2 W34_ University Library iin ( engr | TN 24.V8W 4 THE VIRGINIA JAMESTOWN EXPOSITION COMMISSION MINERAL RESOURCES OF VIRGINIA BY THOMAS LEONARD WATSON, Ph. D. Professor of Economic Geology in the University of Virginia LYNCHBURG, VA.: J. P. Bett Company, Printers and Binders 1907 D CONTENTS AND SCHEME OF CLASSIFICATION PaGE ILLUSTRATIONS .cy-5 Good duiauwisalson hangin ces & A RA Rng DA meee MeN eT aun MeeeS xix PREFACE! go eco eales got he See ea Nele 4 wie ks Melee es RE Te ee ee See a xxix Part I. GENERAL GEOLOGY OF VIRGINIA.......... 00sec cee e cece ence eens 1 Geographic position of Virginia............. 000s cece een e eee eeees 1 Surface features ..ccosoic.d eek sales greelie eed aed era ee aes dee 1 The Coastal Plain province............ 0. cece cece cee eee tees eenees . 8 Formations of Virginia Coastal Plain.................cceeee eee eeee 4 The Piedmont Plateau province............. 0.0 c cece e ee ce eect en eeeees 5 The Appalachian Mountain province............. 0.0.0. e eee eee e eee 7 Diversity’ of resources sé ncccs edie dues gees ads eGae Pislan cae sugien HRs 15 Value of resources... sis sa ccamecg odes Owhes weve ee dated Lames owed naeRs 15 Part II. Burzpine Stones; CEMENT AND CEMENT MATERIALS; AND CLAYS.. 16 I. BUILDING AND ORNAMENTAL STONES.......... 0 0c e cece e cence eeeenees 16 Introduction. esis s vised wesey Ge Vewdia a yg sedis ae bea Teese ees ORS ES 16 Siliceous crystalline rocks........ 0.0 cece cee eee e nent ee eenees 17 Vs GRA NTTEB 5565 os rdse oie ais shee foaled ae wetaal ae aera Gane yaw Oe Rig OG Sle SS 17 Definition: chained sueacsnng sees tees Gale Gtkel sd el Gale Mamet 17 Distribution of the granites........... 00. ccc cee eee eee eeeee 17 Mineral composition.........0. 0000 c cece eee e eee ee eeees 18 Kinds. of granite ssi. sca oc eens. cimpeeden es eae sae a veeee 18 Description of granite areaS......... 60. cece ee een erwin 19 The Petersburg aread........ 6. cece cece eee e eee e eens 19 The Richmond area........... ee ec eee eens Bc Guievean Suess a ageaie: wie 21 The Fredericksburg area............ see cece cece cnet eeteee 26 The Fairfax county area........... eee cece ee eee ete eeneee 28 The Nottoway-Prince Edward counties area.............+... 29 The Blue Ridge area........... cee eee cece eect eee teen tees 30 Unakite: s.ss2 cise eres s One cased ta ned eee oe eee ese ee eet 30 2... BYWINTTE: jo on diane caianese ois yee 86 naan tis Sennen een nett e ene e ene ee 31 B. GNHISSES 1... eee ee eee eee eee ee eee eee teen ence ee eeee es 33 The Lynchburg area........ se ce cece eee e eee teen ence eeees 33 The Fairfax-Alexandria counties area.............seeceereee 34 Other gneiss areas........ 6 eee eee eee eet eect e eee eeaes 34 4, MICK SCHIST 2: need tines Gees Hake tase RGU See a eae OT ES 35 ProductiOn: -< 51 Production: siwoi ness sue wa nuie oe oxcere 6 gig ooo dane ae ok see Sa 51 References! ....06c .0ascer ee eae soasiod parame eerenareweateies 52 7. SANDSTONES AND QUARTZITES......... 0000 ccc cece eee tenes 52 General properties.... 0.0.0.6. cece eee ete teen eens 52 General’ ‘statements 625. dues oa giqiiag ae satan aoa HERA tees 53 The Coastal Plain region............ Aorta gun dlidhe/ eel ah een mee evet es 54 The Juro-Cretaceous sandstones.......... 0... e cee eee eres 54 Piedmont Plateau region........... 6. cece cece tenes 55 The older crystalline quartzites........... 0... cece eee eee 55 The Newark (Jura-Trias) sandstones.................0000- 58 The Appalachian Mountain region..............6. 0. cee ee eee 59 Introductory statement......... 0... ccc eee cee terete eee 59 The Cambrian sandstones.......... 00.060. cece eee eae 60 The Silurian sandstones............ 0... cece eee cece 61 The Devonian sandstones.......... 0... cece cece een eee 61 The Carboniferous sandstones............... 0.000 e eee eee 62 Mississippian :STOUP wc. yo iscngajas soo we gents toe see ges decide sida s 62 Pennsylvanian g6oup .s)..0d 844 aw ba oie es Hee es Se DERE ESA 62 USCS: i tuaeensees stows cyeh seer eN ER dee ae eee 63 PPROGUCEION. se'scassai sees. ibaa Neues d ear a pets Sie Acasa) fuk lanes graaveaded: Siena CAGE 64 RROLCTONCESS ® sscsise a9 un te bies Sug aads ded guard @ Hughesle HSRMRG Meaae aimee aaeale Ne 64 8. LIMESTONES AND MARBLES........ 000.00 c ccc cece cece nents 65 General properties, composition, and occurrence............... 65 Distribution in Virginia.......... 0.0... ccc cee eee 65 The Coastal Plain limestones..................00.0..0 ccc eeeee 66 The Piedmont Plateau limestones...............0.0 00. cease 66 The older crystalline limestones.................. 0000 eee 67 General, Properties, : 5 waiesc-nasdie omahesauealeyis duh ad easun 67 Distribution, occurrence, and general characters........... 67 Marble: 2 ccvaiscoeseeriies a ateanlers teaver date aie AOS aan acct acace suena 69 Verd antique marble.............. 0... cee cece cece ee aee 70 The Newark (Jura-Trias) limestones..................00005 73 The Mountain province (Paleozoic) limestones................ 73 The Shenandoah (Valley) limestone........................ 74 The Chickamauga limestone..................... cece eee 76 The Lewistown limestone...............0. 000 cece eee cee 77 The Greenbrier limestone.............. 0.000 e cece cece 80 Math ler ase eterageaaaneaatsnes gerne alae oa Men Wed EN salle onues oddest 82 CONTENTS AND SCHEME OF CLASSIFICATION. Vv PacE S68) ig sirsies ax ey motte Sata es wi Nn eadera leet egidiag bo sais bnanbe de Wale 83 Production : sai iaioire dnd nxeiasewtad Metaaheu Ota arueet ye suas Oe ana tdieans oat 547 References: sons hasud.gu tie sca toad ed Leas dae alae boa ee ee 547 XVili VI. CONTENTS AND SCHEME OF CLASSIFICATION. Pace GOLD AND SILVER... 6... 0c ccc ec ere eee e ee teen tenet ene eees 549 HIStoritall! oo g.g ayiantacgactde eee eae eerse 244 RE A he Pe POE TES 549 DIStribution! wzs2325 seserde aan Sense ORs HaRS SA eR hes Eee ata 549 General. gedlogy' icc ica necks Giese teenie gad ca ea ee R EEE AE eo ees 551 The country rockS...... 0... eet eens 551 TG VEINS: caaina reer geet ieomege Oo EMSS eG ee Ae Rode eee ee ee 551 The gangue minerals........ 0.0... cece eee een tte eens 552 Description of mines.......... 00. eee e eens 553 Fauquier county sissies ccees coe cane vee we ata seep ame dene See Rees 553 Staflord, COUNtY......003 coe cao nee tae es ed De a Ea Eee ES 553 Culpeper cotinty. ss cd aioe vend eo ee ead Kae Ones ea ian eee SS PEE 554 Spottsylvania county ....... 0... ene ete e eens 554 Orange county: icnscs nasties cateeeeder eae en ai pore were thee. oe 555 Louisa. cOunty 34 << Secess geerae ee de EN eK Rds ds ee ye eee Rye eee eee 557 Fluvanna and Goochland counties............06 ccc eee eee eee eens 559 Buckingham County sis. cieoecng. decks ted tered ssa ahaeweb eet eae 562 eI PAR COUME Yi. oc sleet 55 6 At tannin hy BOG sath oy a ase ea NO a feel ues atensoas Sopa tae 563 Montgomery and Floyd counties.............. 0. 6c cece ee eee eens 564 PYOdUCtION jo vsiciaty ss Hew wiedeet ae Nee PARE RES se PO aeuaY Heme aN aM 564 References: sec: vieevined sss terssde vee ded epee yee ge peace eR eee ote 566 DDN sapere BMG bae ISH Hy se ai bres WR eats ah Aah welase ays Ribs wea sec ne ans ease eRe 567 Mineralogical and chemical character.......... 0.0.0.0 cee eee eee eee 567 Hstori¢al! coc caw sigmcbue Wee terete eels demoed ReameR ei 568 OGQUETENCE ere iacs tAagen ona aS pS he Ness eedun aealai ge phi s Mapeeane 568 Other localities!:.: ssc cwey weer Sed ons MOREE NEE FOSTER EERO OE SS 577 References, avec sc wace oxnden dev tis Se Soe hehe RH aa Ree ay ae aeade sah ee 577 NICKEL; AND COBALT ji. sis tetieiein dai soe ge ses par emuad gone EARLE ae eS 578 General “statement. :i030. ican cas ees eek Mase aed Saw oe 4 bane aoe 578 The Floyd county area... 0... 6... cece cece cece n eee eeeaes 580 PLATE II. III. IV. VI. VII. VITI. IX. XI. XII. XIII. XIV. ILLUSTRATIONS. Facina Pacp HigH AND LOW WATER STAGES IN JAMES ‘RIVER AT RICHMOND.... 4 Fig. 1—Flood stage in James river........... 00. cc ceca eeeeee 4 Fig. 2.—Low water stage in James river................00005 4 GRANITE QUARRIES IN THE PETERSBURG AND RICHMOND AREAS.... 20 Fig. 1—Cook’s granite quarry, north of Petersburg............ 20 Fig. 2.—Granite quarry near Richmond..................00005 20 Map oF THE RICHMOND GRANITE AREA SHOWING LOCATION OF QUARRIES ...........-..4. act eas aa Sera ec Uane once Bhi fea eae 23 GRANITE QUARRIES IN THE RICHMOND ARBA..........-0.eeeceeees 24 Fig. 1—McGowan quarry south of Richmond................. 24 Fig. 2.—Granite quarry near Richmond, showing jointing...... 24 GRANITE QUARRIES IN THE RICHMOND AREA...............20000- 26 Fig. 1—Granite quarry near Richmond, showing joint structure 26 Fig. 2.—McGowan quarry near Richmond, showing gneiss in- CLUSION: gids wis pareiy in aig snk A Naw BaD SA ws RA Ow eae Leelee aeees 26 GRANITE AND GNEISS QUARRIES...........0 eee eeceeeveeens shakes 34 Fig. 1—McGowan quarry and dressing yard................4. 34 Fig. 2.—Gneiss quarry southeast limits of Lynchburg.......... 34 SLATE QUARRIES, ARVONIA, BUCKINGHAM COUNTY...........000005 42 Fig. 1—Slate quarry in the Arvonia area.................... 42 Fig. 2.—Slate quarry in the Arvonia area................0005 42 SLATE QUARRIES, ARVONIA, BUCKINGHAM COUNTY.............0005 45 Fig. 1—Williams Slate Company’s quarry, Arvonia............ 45 Fig. 2.—Abandoned slate quarry, Arvonia.............000eeeeee 45 SLATE QUARRIES, SNOWDEN, AMHERST COUNTY.............0.005- 48 Fig. 1—Williams Brothers slate quarry, near Snowden........ 48 Hig) 2— Same as Nig. Ves insee teases, deans emaghes wee aed sedan 48 CRYSTALLINE SCHIST AND MARBLE QUARRIES............00eeeeeee 70 Fig. 1——Quarry in crystalline schist, Faber, Nelson county..... 70 Fig. 2.—Opening in marble, Grayson county.................5- 70 Map oF THE GREATER VALLEY BEGION OF VIRGINIA, SHOWING DIS- TRIBUTION OF ORDOVICIAN........... cece cece cette eens 91 NATURAL BRIDGE, ROCKBRIDGE COUNTY......-... 02. c cee eecececcees 94 ANTICLINAL FOLD IN MASSANUTTEN SANDSTONE.........0-eeseee- 102 House MounNTAINS AND FOLDED MASSANUTIEN SANDSTONE........ 103 Fig. 1—House Mountains, Rockbridge county...............645 103 Fig. 2—Fold in Massanutten sandstone..................0000 103 PLATE XV. XVI. XVII. XVIII. XIX. XX. XXI. XXII. XXITI. XXIV. XXV XXVL XXVII. XXVIII. XXIX. ILLUSTRATIONS. \ Facine Page OVERTHRUST FAULT AND LIMESTONE DECAY......---eeeeeeerereree 119 Fig. 1—Overthrust fault in Tuscarora sandstone, near Panther Gap acceded cs doses desu gee eae re eee mee ene ee gaa s 119 Fig. 2.—Fields of residual decay near Natural Bridge.........-- 119 NATURAL BRIDGE LIMESTOND.... 0.0000 cece cee eee een ene eens 121 Fig. 1—Upper part Natural Bridge limestone weathering into Chert: bands ses asec. cane gees Hew ee Ra Kee ea Red ee HE SE Te 121 Fig. 2—Same as Fig. 1........ 200-2 e eee eee e eens 121 LOWER CAMBRIAN QUARTZITE AND SHERWOOD FORMATION........-.- 123 Fig. 1—Balcony Rock, composed of Lower Cambrian quartzite, Balcony Falls........ 0. cece cece eee e eee te n eee e eee nees 123 Fig. 2.—Cliff of Sherwood dolomite, near Sherwood, Natural Bridge station c ss 5444 6c ded a een sas en esac eae ee eee 123 BuENA VISTA SHALES AND LEWISTOWN LIMESTONE......-.-.++-+> 149 Fig. 1—Buena Vista, Virginia.............. sees eee eee ee eee 149 Fig. 2.—Quarry in Lewistown limestone, Longdale............. 149 ANTICLINAL FOLD IN LEWISTOWN LIMESTONE........--..-++e+eeee 152 PORTLAND CEMENT PLANT, FoRDWICK, AUGUSTA COUNTY........... 163 LIMESTONE WEATHERING, BRICK PLANT AND CLAY PIT.........-.-. 169 Fig. 1—Weathering of limestone, near Christiansburg.......... 169 Fig. 2—Oldfield Brick Co’s plant, Oldfield.................... 169 KAOLIN PIT AND WASHING PLANT, HENRY COUNTY............00-- 170 Fig. 1—Kaolin pit near Oak Level, Henry county............. 170 Fig. 2.—Kaolin washing plant near Oak Level, Henry county... 170 Map OF THE VIRGINIA COASTAL PLAIN, SHOWING CLAY LOCALITIES 174 THE PowHATAN CLAY MANUFACTURING Co’S PLANT, CLAYVILLE.. 178 CLAY BANK AND BRICK YARD ON APPOMATTOX RIVER............4. 183 Fig. 1—Keeler’s brick yard at Broadway on the Appomattox PIV ER acest c eink Reta ead amie ieee Melina teed 183 Fig. 2.—Keeler’s clay bank at Broadway on the Appomattox EVER, 24 sialsins paomhite aos dpocag meee ace, ates ee andi eines we ea 183 WASHINGTON HypRAULIC PRESS BRICK Co’s WORKS, VIRGINIA..... 186 PYRITE MINES IN VIRGINIA.........0.0. 0000 c cece eee e eee eee eens 200 Fig. 1.—Arminius pyrite mines, near Mineral City............. 200 Fig. 2.—Cabin Branch pyrite mine, near Dumfries............. 200 PYRITP LENSES, LOUISA COUNTY.......... 00.00 ccc cece eeeceeeuee 201 Fig. 1.—Exposure of pyrite ore-body at the Sulphur mines, Louisa COUMLY: sents essen oh hh eeu ranialnit saya as Mh adel dae eee mene 201 Fig: 2.--Saime) as-Big. Wiss. cissly dpa See eae ce Spee deh p aseismic 201 PYRITE MINES IN VIRGINIA............ 0000s ccc cece eee eeeeeees 205 Fig. 1.—Sulphur mines, near Mineral City..............00e000e 205 Fig. 2.—Shaft and dump at Sulphur mines, near Mineral City.. 205 PLATE XXX, XXXI. XXXII. XXXII. XXXIV. XXXV. XXXVI. XXXVII. XXXVIII. XXXIX. XL. XLI. XLII. XLII. XLIV. ILLUSTRATIONS. xxi Facine Pacp PyYRRHOTITE MINE, “GREAT GOSSAN LEAD,” CARROLL COUNTY..... 208 Mar oF workines, U. 8. Arsenic Mines Co., REWALD, FLoyD COUNTY: said 5.5 ha eta t 8 igh salle kets ce Sat eA Sie Sie See agee eh s 210 ARSENIC AND NICKEL MINES, FLOYD COUNTY...........00cceceeeee 211 Fig. 1—Milling plant and mines, U. S. Arsenic Mines Co., near Terry's; Fork siccaskasacerss Gosia daen waves Sag ae ewe vanes ied 211 Fig. 2.—Lick Fork nickel opening, near Hemlock, Floyd county 211 SALT WELLS. AND SALTVILLE. .o6.5..cseecss esas bases ea cetbuetun 212 Fig. 1—Salt wells, Saltville.......... 0... ccc eee e eee eee 212 Fig. 2.—Saltville, Washington county.....................00.. 212 MarTuHipson ALKALI WORKS AND SALT WELLS, SALTVILLE.......... 214 Fig. 1—Mathieson Alkali Works, Saltville.................... 214 Fig. 2.—Salt wells and valley at Saltville..................0.. 214 DIATOMACEOUS EARTH, WILMONT.......... 0.0 e cece eee ete eeeee 221 Fig. 1—Diatomaceous earth overlain by Pleistocene clay at Wil- DOVOTNG sss fidence asa seneden adv ides Sens Wi can tod aledvoyauan e: Bb ayant, eaaaanened aac pie Auaes 221 Fig. 2.—Bluffs of diatomaceous earth southeast of Wilmont.... 221 RUTILE OPENINGS, ROSELAND, NELSON COUNTY................00- 234 Fig. 1—Openings for rutile along Tye river, Roseland.......... 234 Hig; 2-—Same as) Bigs i asssamads vies chm cha dans ee eae aad 234 CRIMORA MANGANESE MILLING PLANT AND MINES, AUGUSTA COUNTY 246 Fig. 1—Crimora manganese milling plant, Crimora, Augusta COUNTY) jocc8 gical caus uaGawe Mosaaee sedis eat iae emcee. 246 Fig. 2.—Crimora manganese mines, Crimora, Augusta county... 246 MINERAL SPRINGS IN VIRGINIA.... 2.0.00 e cece ete e cece eee eeee 259 Fig. 1—The New Homestead, Virginia Hot Springs, Bath county 259 Fig. 2.—Buffalo Lithia Springs, Mecklenburg county........... 259 SECTIONS INDICATING WATER-BEARING HORIZONS IN EASTERN VIRGINIA 268 Map OF EASTERN VIRGINIA, SHOWING DISTRIBUTION OF UNDERGROUND WATERS! oii “man vie taineeis eG sara Daa temam at a8 Dae eM ey aedaued 269 MICA MINE AND DUMP, AMELIA COUNTY......... 000: eee e cece eeeee 283 Fig. 1—Pinchback mica mine, near Amelia court-house........ 283 Fig. 2.—Dump of scrap mica, near Amelia court-house......... 283 Map SHOWING LOCATION OF SOAPSTONE QUARRIES IN ALBEMARLE AND NELSON COUNTIES ici¢ ose esis cou saan nd se ee ERE ous dee 293 SOAPSTONE QUARRIES, NELSON COUNTY........ 0. 000s cee e eee e eee 294 Fig. 1—Soapstone quarry, Nelson county............+..--eee 294 Fig. 2.—Soapstone quarry, Nelson county..........-....--++0- 294 SOAPSTONE QUARRIES, NELSON COUNTY........ 0... cece eee eee eeee 295 Fig. 1—Schuyler Soapstone Co’s plant, Nelson. county.......... 295 Fig. 2.—National Soapstone Co’s quarry, Nelson county........ 295 PLATE XLV. XLVI. XLVII. XLVIII. XLIX. LI. LII. LIII. LIV. LV. LVI. LVII. LVIII. LIX. LX. LXI. ILLUSTRATIONS. Facine Pach SoAPSTONE QUARRIES IN ALBEMARLE COUNTY.....-.-050s eee eeeees 296 Fig. 1.—Alberene soapstone quarry, Albemarle county........--. 296 Fig. 2.—Alberene soapstone quarry, Albemarle county........-- 296 SoAPSTONE AND LIMESTONE QUARRIES IN VIRGINIA......--++-++005 297 Fig. 1—A recently opened soapstone quarry in Nelson county. . 297 Fig. 2—lLimestone quarry of the Mathieson Alkali Works, near Saltville sgascccns dev ance aed Hegel ee bois Slaw Reed OEE Re oes Ge i 297 BARITE MINES, PRINCE WILLIAM COUNTY......-.-. 0200s eee e eens 308 Fig. 1—Barite mine near Catlett station.......-.....--.+.e00, 308 Fig. 2—Shaft at barite mine near Catlett station..........-.. 308 BaRITE AND GYPSUM MINES IN VIRGINIA.......-2 00 eee eee sees eres 314 Fig. 1—Bennett’s barite mine, Pittsylvania county............ 314 Fig. 2—Gypsum opening, near salt plant, Saltville............ 314 BARITE, MILT AD BRISTOL: i506 5.c:5 end citenda waa eee 48 GS OSS AE 324 BARITE MILL AT RICHLANDS......... 0 ccc ccc e cece eee nee neees 326 GYPSUM MINES AND MILL, WASHINGTON COUNTY............+.04. 328 Fig. 1—Saltville valley at Plasterco, showing mined gypsum TU ASSES. 2 saudi Peed aniydeis Lauectced dae soe aunt sam Acca atatadn iis itn SaeBuamta toners Se Aas 328 Fig. 2—Buena Vista Plaster and Mining Co’s plant, Plasterco.. 328 Map OF THE SALT AND GYPSUM DEPOSITS IN SOUTHWEST VIRGINIA.. 330 Map oF THE RICHMOND COAL BASIN.......-. 00 cece eee reece eeee 340 QoAL MINES AND BREAKER OF THE VIRGINIA ANTHRACITE CoaL Com- PANY, NEAR CHRISTIANSBURG..........0...0 202 e cece cece eee 351 GENERALIZED SECTIONS FROM DIFFERFNT PORTIONS OF THE BIG STONE CGAP COAT) HERE jc c2ccistgecs die suet ne bins iancus sa: aneeacera ya Dihdun eG Rae Sees 355 GEOLOGIC STRUCTURE SECTIONS, SOUTHWESTERN AND NORTHERN VIR- GTINTAY, chines Geka thinloree ay chal chap a(erG: stants lag Sila ayeen ae eh een bend Soe 356 BiLock OF COAL, POCAHONTAS COAL FIELD, TAZEWELL COUNTY...... 360 CoAL INCLINE AND TIPPLE, Big STONE GAP COAL FIELD........... 364 Fig. 1.—Clinchfield Coal Co’s incline, Dante................... 364 Fig. 2.—Cranes Nest Coal and Coke Co’s tipple, Tom’s Creek... 364 SEABOARD CoaL Co’s TIPPLE, SEABOARD............00 cece eeeees 368 CoaL MINING PLANT, TIPPLE, CRUSHER, AND COKE OVENS, Big STONE GAP GOAL, FIELD ia ss cwevs yee bee B84 ook a Mess hee ba we sw aes 371 Fig. 1.—Stonega coal mining camp...............0ccceeeeeees 371 Fig. 2.—Coal tipple, crusher, and coke ovens, Stonega.......... 371 CoaL TIPPLE AND COKE OVENS, Bic StonE Gap COAL FIELD......... 380 Fig. 1—Osaka No. 1 coal tipple... 2.0.0... 0. ccc cece een eee 380 Fig. 2.—Coke ovens, Osaka.... 02.2.0... ccc cece cece eens 380 PLATE LXII. LXIII. LXIV. LXV. LXVI. LXVII. LXVIII. LXIX. LXX. LXXT. LXXII. LXXIiII. LXXIV. ILLUSTRATIONS. xxiii Factne Pace CoKE OVENS, Big STONE GAP COAL FIELD.......... 0.00 cc eeeeeeee 382 Fig. 1—Coke ovens, Stonega............... 0c: e eee eee ee 382 Fig. 2.—Coke ovens, Imboden.................. 0.00 eee eee ee 382 Map OF PART OF VIRGINIA, SHOWING LOCATION OF PRINCIPAL IRON MAINES 5. WEG si5.2 Saeox Siehasts wisaet eos Goecaracacapdina what Sia aya ae busts Waaceare eae 429 IRON MINES IN THE BLUE RIDGE REGION.............. 0000 eee eeee 436 Fig. 1—Buena Vista iron mine.............. 00. eee eee eee eee 436 Fig. 2.—Dixie iron mines: soos posse sa eek ee one wate ss wee oe 436 TRON ORE OUTCROPS AND WASHER, BLUE RIDGE REGION............. 443 Fig. 1—Adams Peak looking southwest, etc................... 443 Fig. 2.—The Grubb iron mines washer................. 0000 eue 443 IRoN (HEMATITE) MINES, BLUE RIDGE REGION..............+-4-. 445 Fig. 1—Wood iron mine............... 2. cece eee eee ee tenes 445 Fig. 2.—Areadia iron mine...... 64.0 0¢ccaes sve ctinscenee et ees 445 Iron GATE GAP AND ORISKANY IRON MINE, ALLEGHANY COUNTY.... 446 Fig. 1—Iron Gate gap of Jackson river through Rich Patch Mountain a sir cicsds gen he teats dios coded da Ae sens cb aR ae eek 446 Fig. 2. Oriskany irom mine............. 60. cece eee eee teens 446 MINING BY MILLING, New RIveR-CRIPPLE CREEK IRON ORE AREA... 450 Fig. 1—Loeust Hill iron mine............. 0 ccc cece eee eee 450 Fig. 2.—Reed Island iron mine............. 0.2 cece cence 450 HYDRAULIC MINING IN New Rivpr-CRIPPLE CREEK IRON ORE AREA.. 455 Fig, L.—HeMatite MINE. oo. seas ca ewes ot ae ena ene ale 455 Fig. 2.—Rich Hill iron, mines isi. snd cdc eee be wee we as 455 IRON MINES, PITTSYLVANIA COUNTY.......... 0002 cc eee eee e eee 473 Fig. 1—Shaft house of the Barr magnetic mine, near Pittsville 473 Fig. 2.—Barr limonite mine, near Pittsville................... 473 CoPPER ORE, VIRGILINA DISTRICT, VIRGINIA-NORTH CAROLINA........ 495 Fig. 1.—Copper ore (chaleocite and bornite in quartz) Virgilina. COPPER WIStrict: ihc Ga Fcc Sieh rceeshd ae Oa Pirwerh ee ssiate nals oe aes 496 Hig; 2-—Samé a8. Wigs das cucccnasn das ceeds aos op gases aad ees 495 Mar OF THE NORTHERN BLUE RIDGE COPPER DISTRICT, SHOWING LOCA- CATION ‘OF MINES «4 ciciso sess. ge se toe cess eee se RAG Be eeee 503 CoPpPpER MINES IN THE NORTHERN BLUE RIDGE REGION............. 509 Fig. 1—Shaft house, ore dump, and basalt cliffs, Madison county 509 Fig. 2.—Shaft house, Virginia Consolidated Copper Co’s mine, Near Wdais cca wew ss eevee Me Ree eee Ree Cea Ow Yes ee be eae as COS 509 BuiuE RIDGE AND SHAFT OF COPPER MINE.........-.0ee cece ee eeaee 510 Fig. 1.—Blue Ridge from Virginia Consolidated Copper Co’s mine, MIG BE? La wd 5 Sie «Sais sip raya) Pacoraeaeane aia cxahaad be Gaastilan a aner oe Rapa aoe aia aOR 510 Fig. 2.—Shaft No. 3 High Hill copper mines, Halifax county.... 510 xxiv PLATE LXXV. LXXVI. LXXVII. LXXVIII. LXXIX. LXXX. LXXXI. LXXXII. LXXXITI. ILLUSTRATIONS. Facing PAGE PYRRHOTITE MINES CONTAINING copper, “GREAT GossAN LEAD,” CARROLD GOUNDY, ssa prone ce miece eraeate ak wn © cana d sinew tise oo eae Fig. 1—Shaft at Betty Baker mine, west side of road.......... Fig. 2.—Open cut at Betty Baker mine, Carroll county.......... LIMESTONE WEATHERING, ZINC MINES, WYTHE COUNTY...........-- Fig. 1.—Limestone “chimneys” at Bertha zinc mines............ Fig. 2.—Open cut showing limestone “chimneys” at Bertha zinc MINES sein sadid, Bid Gin old Bet ess Gay PRE Ae Ady Gee ok OR Ra LIMESTONE WEATHERING, ZINC MINES, WYTHE COUNTY............ Fig. 1—Weathered limestone surface in open cut, Bertha zine WINGS. seve hea vena seh es es ere eed oP ana dee yaad ea pe ee eee Fig. 2.—Weathered limestone surface, Austinville zinc and lead TOAD GS pcg Bsr auacd, Bupha Sie cue Eel pasha ae Spdenl S odueets aNeieas ot aEec er coe MNS A ZINO MILLING PLANT AND LIMESTONE “CHIMNEYS,” WYTHE COUNTY Fig. 1.—Zine milling plant at Austinville.................44.. Fig. 2.—Weathering of limestone into pinnacled surface, “chim- TLEYS0 «cas tow oie aod tails g, ear ada gon Ridings eS anette Ss BAA Grae Sa aT ONT ZINC SMELTING PLANT AND FURNACE, PULASEI..........-...00005 Fig. 1—Zine smelting plant of Bertha Mineral Co............. Fig. 2.—Dismantled zine furnace................. 0 cee eee eee Map OF PRINCIPAL GOLD BELT IN VIRGINIA, SHOWING DISTRIBUTION OR MINES & :caene Seven aad Myned shige ea aie Sain ces eee hile ep Ane ioe be Belen GOLD-BEARING QUARTZ VEINS, ORANGE COUNTY.......... 0000000005 Fig. 1.—Outcrop of gold-bearing quartz vein on the former “Clark TMA be jo shsevatetenn dceus eusy dete the te tuat eed gap hl gers DA alec e a Need eae alot oa Fig. 2.—Gold-bearing quartz veins, a4 portion of “Smoke-House WCU sac coarsesies Sia Gor. arated Svisveages gue Sheuelaa Sued AE aGlRES EARLS BOS GOLD- AND COPPER-BEARING VEINS AND ORE, ORANGE COUNTY........ Fig. 1—Exposure of gold- and copper-bearing veins, “American PEDAG Ley "bia iesateassesesnvanaaher a sgiacae trations etl dboaetus nis au age ieee eens Fig. 2.—Gold- and copper-bearing quartz ore...............005 GOLD MILLING PLANT AND MINE OPENING, FLUVANNA AND ORANGE COUNTING --oey'uky ete Soa we eR Ae Ro ee aw ha awed aoa Racks & Fig. 1.—Hughes gold milling plant, near Fork Union, Fluvanna COUNLY. sessed dcp: deuivenk stented MERE My aes sarbans ae 6s alee clea Fig. 2.—Open cut, a few feet south of the old Virginia Mining Cais: shaite se sateen decunpieeewes geate-wy co eane lie ged ublacda abe aioe apes 536 547 547 547 553 555 555 555 556 556 556 561 561 ILLUSTRATIONS. XXV FIGuRE PAGE 1. Sketch map of Virginia showing physiographic provinces................ 2 2. Diagrammatic section illustrating relationship between the Piedmont and Coastal. Plain) formations + s:iecicwingie sacs cas cu Bate a wai hig Re sails he Re 3 3. Generalized section of area covered by the Harper’s Ferry folio.......... 8 4, Generalized section of area covered by the Staunton folio................ 9 5. Generalized section of area covered by the Tazewell folio................ 11 6. Generalized section of portion of area covered by the Bristol folio........ 13 7. Map showing location of granite quarries in the Petersburg area......... 19 8. Relations of blue to gray granite at the Netherwood quarry............. 22 9. Map showing location of granite quarries in the Fredericksburg area..... 27 10. Map of the Arvonia slate area, Buckingham county..................... 43 11. Map showing location of Snowden slate quarries, Amherst county........ 47 12. Map of the Fauquier county slate area........ 0... cece eee 49 13. Structure section from the Blue Ridge to Little North Mountain........ 106 14. Structure section across Massanutten Mountain syncline................ 106 15. Structure section from Strasburg to 1 mile west of Strasburg Junction... 106 16. Map of cement materials of northwestern Virginia..................... 108 17. Map of Valley of Virginia from Woodstock to Staunton................. 111 18. Structure section from the Blue Ridge to Little North Mountain, about latitude Of PlarrisOnDur gis ice: ssc ais sina qca cn sas saat ena Oe aw dos ete ae OES 112 19. Structure section in the vicinity of Lexington.....................-.005 112 20. Map of Valley of Virginia from Staunton to Natural Bridge............. 116 21. Structure section south of Stokesville............. 0.0... cece eee ceca ee 120 22. Structure section in the vicinity of Zack, and Little North Mountain..... 120 23. Structure section from Holston Mountain west to Cumberland Mountain.. 125 24. Structure section from Glade Spring to Saltville....................0... 125 25. Map of cement materials of southwest Virginia............... cece eee 143 26. Structure section from Bristol east to Holston Mountain................ 145 27. Structure section from Powell Mountain to Cumberland Mountain....... 145 28. Map of cement materials of New River district.................0000005. 147 29. Sketch map of Virginia showing pyrite and pyrrhotite belts............. 192 30. Plan of pyrite lenses in Louisa county..............- 600 cece e cece e eee 193 31. Plan of pyrite lenses at Sulphur mines, Louisa county................... 194 32. Plan of pyrite lens, showing pyrite stringers in the hanging-wall.......... 195 33. Plan of portion of pyrite lens in Cabin Branch pyrite mine.............. 195 34. Map showing location of pyrite mines in Louisa county................4. 199 35. Plan of pyrite lens on the 620-foot level, Arminius mine................. 200 36. Map showing location of Cabin Branch pyrite mine...................... 203 37. Plan of part of pyrite lens at Cabin Branch pyrite mine................. 204 38. Map showing location of rutile and nelsonite, Nelson county............. 233 39. Section showing occurrence of manganese ore in residual clay............ 237 40. Ground plan of manganese deposits, Crimora, Augusta county........... 247 41. Sections through Crimora manganese deposits................0ee ee eeeee 247 42. Map showing location of mica mines in Amelia county.................. 281 43. Section showing relations of nelsonite to the enclosing schists............ 301 44, Sketch map of Virginia showing worked areas of barite................. 306 45. Map showing location of barite mines in Piedmont Virginia.............. 310 \XV1 ILLUSTRATIONS. FIGURE PAGE 46. Columnar section at Bennett barite mine, near Toshes............++-+++- 312 47. Section in Bennett barite mine, near Toshes............-.0e eres eeeees 313 48. Structure section at Saunders manganese and barite mines, near Evington, Campbell county...... 6... cece teeta 318 49. Section showing occurrence of barite in limestone residual clay........... 321 50. Map and sections of the Russell-Tazewell counties barite belt............ 323 51. Section across the Holston and Saltville valleys..........-...+--- sees ees 329 52. Map of Virginia showing the coal areas............ 2-0 cee e eee eee 337 53. Geologic section of Richmond coal basin.............0:0 eee cence eee eee 341 54. Map showing location of principal coal mines in the Montgomery-Pulaski counties: coal: field... .i6s.cnad nse Gags de Rea gee de ae aed Bae IE TS 350 55. Diagram showing panel system of coal mining..............0eeeeeee eee 373 56. Cross section of Alleghany Mountain anticlinal showing Oriskany ore, etc. 409 57. Diagram illustrating the occurrence of ‘mountain ores” in the New River- Cripple: Creek areas sanvevse us 4 dee 04 Se 84 AE Tea YER EEO eg Ee Ble 411 58. Diagram illustrating the relations of the New River-Cripple Creek limonite to the lower beds of the Shenandoah limestone..................0000- 412 59. Diagram illustrating occurrence of limestone limonite in southwest Vir- OUTL LD: — iy Ac as stapes a estas acess Sia Gy gy Barat WSR aon AA. Ao Seta ich arty a detag ates SN GE TOT 413 60. Section showing the occurrence of Blue Ridge limonite ore.............. 415 61. Diagrammatic cross section of the “Great Gossan Lead”...............-. 420 62. Generalized columnar section of Paleozoic strata showing distribution of TROT: OTE i dactae Be. keb spect ok Mate scek seal eee eben Ts aaah Min aot inte Sata Seana od 424 63. Generalized section across the Valley and Alleghany Mountains in Virginia showing position of iron ore, etc............ cee eee eee ee eee 426 64. Sketch map of Virginia showing the principal iron ore areas............ 427 65. Profile of part of the Blue Ridge at the Dixie iron mine................ 437 66. Section showing the geologic relations of the iron ore in the Holston mine 462 67. Geologic structure section across Poor Valley Ridge, ete................ 465 68. Diagram of the Ewing iron mine................ 2. eee eee eee 467 69. Section in the Barr magnetite mine....................0000 0. cece eee ee 473 70. Diagram illustrating milling of iron ore from face of slope.............. 480 71. Diagram illustrating milling of iron ore (first stage)................... 481 72. Diagram illustrating milling of iron ore (later stage)................... 481 73. Section showing geologic relations of Oriskany ore and method of working Gee pr lyAN 8) “OVE sais sacri aareibl is wut Citgo Soe easde ean ae eta eRe Meet se 483 74, Diagram illustrating method of mining in steeply dipping beds, etc...... 484 75. Diagram illustrating method of mining in flat-lying beds, etc............ 485 76. Map of Virginia showing distribution of copper areas................... 493 77. Diagram illustrating vein structure in the Virgilina copper district...... 495 78. Diagram of High Hill vein at shaft No. 4............0 000 cece cece eee 496 79. Map of the Virgilina copper district, showing location of principal mines 497 80. Concentrating system at the Durgy mine, Virgilina copper district....... 499 81. Brecciated epidotized basalt with ore and quartz, Stony Man peak...... 504 82. Part of basalt shell filled with epidote and rimmed with ore, Warren QOUMUY. cea 35 SHS agen eg nai eas Sek vegas s glahi’ 8 Mictednie danny lee gids hep iene Hare eee Lo 505 83. Quartz with native copper, Fletcher, Greene COUBLY 5 sig ses aie Seem exceeds e308 506 ILLUSTRATIONS. XXVil FIGURE PAGE 84. Asbestiform serpentine with native copper, Ida, Page county............. 506 85. Profile of “Gossan Lead,” Carroll county, from Betty Baker mine to the Karkbride® sini ase. sianehc ens aes aaa LES Ge dhe deee ae aN Geen RE Meee aed 512 86. Pyrrhotite interleaved with talc, Chestnut Yard, Carroll county.......... 513 87. Pyrrhotite with columnar hornblende, Chestnut Yard, Carroll county..... 513 88. Map of Carroll county pyrrhotite area, showing location of mines....... 515 89. Map showing distribution of lead and zine ores, Virginia and Tennessee... 521 90. Section of the Bertha zine mines, showing geologic relations of the ore and TOCKS, Sate jpe sd ndc a Dare BS aie areata Gay ate oe ee eae yaaiges on Adm aes 533 91. Section at the Bertha zinc mines, showing the mode of occurrence of the ore and the method of mining............. 0... ccc cece eee ene 534 92. Section at the Austinville lead and zinc mines, showing geologic relations of the oré: atid TOCKSs.sscu si cpeumeee sage tes as tk Oe RGIS Sea EY eed es ees 535 93. Sketch map of the Austinville lead and zinc mines, Wythe county....... 537 94. Limestone breccia zine ore from Cedar Springs, Wythe county........... 538 95. Limestone breccia zine ore from Cedar Springs, Wythe county............ 539 96. Zinc-lead ore from Sugar Grove, Smyth county.............-... cee eee 540 97. Zinc-lead ore from the Albemarle zinc and lead mines, near Faber....... 542 98. Map of Virginia showing the principal gold ore areas.................-. 550 99. Map showing location of nickel and arsenic mines, Floyd county......... 579 100. Ground plan showing location of nickel openings, near Hemlock, Floyd COUNLY® 3. sees aes Bae ex eee aie aa a kas ered ok Dec oiee exe 580 101. Section showing structural relations of the rocks at the nickel mine in HOV. COUNEY nas 2 ges eee sie eae os he DN de tas ae RE eae 581 PREFACE This volume, Mineral Resources of Virginia, authorized by the Governor of Virginia and the Virginia Jamestown Exposition Commission, has been published in order to direct attention to the economic value, location, and commercial possibilities of Virginia’s varied mineral wealth. The evidence here presented shows that the State is well supplied with a great variety of mineral resources, many of which are being rapidly developed. There is probably no state in the Union of the same area as Virginia that can show a greater diversity in geologic resources. This most important fact taken in connection with the mildness of the climate, which permits of a long season of outdoor work, and the cheapness of labor, are conducive to a very extensive mining industry. The total value of production of the mineral resources of Virginia for the year 1906 has been estimated at $30,000,000. At the July (1906) meeting of the Virginia Jamestown Exposition Commission, it was agreed that a handbook illustrative of the vast mineral resources of Virginia was a necessity. The writer was accordingly authorized to prepare a handbook setting forth, as completely as our present knowledge permitted, the vast and varied mineral resources of the State. He was further authorized to devote several months in the field to a study of the mineral resources in those portions of the State where information was most needed for the purpose of collecting the necessary data for this volume. The work has proved far more exacting than was at first con- templated, in that the widely scattered literature on the geology of Virginia lad to be overhauled in the preparation of the volume. The principal sources of information, forming the basis of this volume, are “A Reprint of the Geology of the Virginias,” by Professor William Barton Rogers, State Geologist of Virginia from 1835 to 1841, inclusive; “The Virginias,” a monthly journal edited by Major Jed Hotchkiss from 1880 to 1885, inclusive (six volumes) ; the numerous excellent publications of the United States Geological Survey; and the published and unpub- lished reports of the recent Geological Survey of Virginia conducted jointly for two years by the Board of Visitors of the Virginia Polytechnic Institute and the State Board of Agriculture. In addition to the above publications much valuable information has been obtained from general treatises on special geologic subjects, such as from Merrill’s “Non-Metallic Minerals,” XXX : PREFACE. and “Stones for Building and Decoration ;” from the large number of separate papers published in the various scientific journals on different aspects of the Virginia geology; and from various private reports pub- lished by individual companies and corporations, either operating at present or have operated in the past in Virginia. The writer has used freely the above publications and all other sources of information, without the insertion of references at the bottom of each page to indicate the portions abstracted, but at the end of each subject treated is appended a list of references arranged alphabetically by authors. This list is not a complete bibliography of the particular subject, but it includes the im- portant publications consulted in the preparation of the subject matter. Unless otherwise stated, all figures of production are taken from the reports of the United States Geological Survey. A brief outline of the General Geology of Virginia with special reference to the mineral resources forms Part I of this volume. The classification into Building and Ornamental Stones, Cements and Cement Materials, and Clays; Non-Metallic Minerals; and Metallic Minerals or Ores, form- ing Parts II, III, and IV, respectively, rather than the more scientific classification into Non-Metallic and Metallic Minerals, has been adopted in the present volume principally, in order to more equally proportion the subject matter presented. Under the latter classification, Parts II and III of the grouping here made would be brought together under the single division Non-Metallic Minerals. In Part III, the writer has followed the classification of Doctor George P. Merrill in his book entitled “Non- Metallic Minerals.” The apparent unequal treatment of some of the subjects in this volume has arisen chiefly from the fact that because of lack of systematic geologic work in the State our present knowledge of these subjects is likewise very unequal—some subjects have been carefully studied and published on while others have received little or no attention. It is regretted that it was found impossible to republish in this volume, without unduly delaying it, the Hotchkiss color geologic map of Virginia, which accompanies Professor Rogers’ “A Reprint of the Geology of the Virginias.” It is with deep obligation that the writer has pleasure in gratefully acknowledging the invaluable contributions so generously made to this volume on Cement and Cement Materials by Doctor R. S. Bassler of the United States National Museum; on Clays by Professor Heinrich Ries of Cornell University; and on Iron by Professor R. J. Holden of the Virginia Polytechnic Institute. These contributions are based on recent PREFACE. Xxxi careful field study of the areas by the authors, made possible by the recent Geological Survey of Virginia in codperation with the United States Geological Survey, especially in the study of the Cement and Cement Materials by Doctor Bassler, and of the Iron Ores by Professor Holden. The contribution on Clays by Professor Ries was extracted by him from his report on the Virginia Clays published as Bulletin No. II of the Geological Survey of Virginia. The general interest manifested in the work by many people in the State, especially the mine and quarry operators, and by many residing outside of the State but who have mining interests in Virginia, aided greatly in the preparation of this volume. To all of these the writer is under deep obligation for many courtesies extended. Acknowledgments are also due to Messrs. Joel H. Watkins and Henry F. Day, former students in geology at the Virginia Polytechnic Institute, for valuable services rendered. Mr. Watkins prepared the line drawings and maps illustrating this volume. Mr. Day assisted the writer in the field during a part of the summer of 1906. To Governor Claude A. Swanson and the members of the Virginia Jamestown Exposition Commission, especially Hon. W. W. Baker of Chesterfield county, who made this work possible and have rendered every assistance during its preparation, the writer makes most grateful acknowl- edgment. With a full realization of the deficiencies in this volume, it is published with the hope that it will supply a widespread and increasing demand among our people and among others for information on the mineral resources of Virginia. THomas LEonaRD WaTSON. University of Virginia, Charlottesville, September 30, 1907. PART I. GENERAL GEOLOGY OF VIRGINIA. GEOGRAPHIC POSITION OF VIRGINIA. The State of Virginia is situated on the Atlantic slope of the Appalachian Mountains, halfway between Maine and Florida. It is included between the parallels 36° 31’ and 39° 27’ north latitude, and between the meridians 75° 13’ and 83° 387’ west longitude, and extending from the sea-coast west- ward beyond the Great Valley to the Alleghany Front. The extreme length of the State from the Atlantic border to Kentucky is 476 miles, and greatest width from north to south is 192 miles; its area is 42,450 square miles. Of this area 2,325 square miles are covered with water, giving 40,125 square miles of land surface. Its principal inland waters are the Chesapeake and Mobjack bays, Hampton Roads, and Lake Drummond. Except in the eastern section no navigable streams traverse the State, and transportation is necessarily limited to railways. SURFACE FEATURES. Considered with reference to its surface features—physiography—Vir- ginia is divided into three major provinces: (1) An eastern plain region usually designated the Coastal Plain or Tidewater region; (2) a central or plateau region, designated the Piedmont Plateau; and (3) a western or mountain region, designated the Appalachian Mountain province. The boundaries of these provinces are indicated on the map, forming figure 1. As is indicated on map, figure 1, the western or Mountain province is divided into three well-marked physiographic belts, which extend the entire length of the province in the State from northeast to southwest. These are, named in order from east to west, (a) the Blue Ridge, (b) the Great Valley or Valley of Virginia, and (c) the Alleghany Ridges, known also as the Alleghany Mountains. The three larger well-defined topographic provinces of the State differ markedly in the nature and origin of surface features, and in the age and kinds of rock. They are intimately related to the geologic ‘sooutaoid o1ydvasorshyd Surmoys viursita jo dem yoyayG—T ‘BLT TONIAOUA Nivid WISYOO] SONIAOUS QUaIVId INGWGSid./7IONINOUd NIWANNOW NVIHOW daw I, TRava: aoe PT VENT OU TSS 3 sipatiion” lM) (Ke ot_ ce ATALWWIXOUddY SITIW OZ=HONI LE 31V9S VINIOUIA. — 10— SAONINOUd DINdWYSOISAHd JHL DNIMOHS dvVW GENERAL GEOLOGY OF VIRGINIA. 3 structure and hence have an important bearing upon the mineral resources of the State. These are therefore considered in order below. THE COASTAL PLAIN PROVINCE. The Virginia Coastal Plain province, the most easterly of the three larger physiographic provinces and comprising approximately one-fourth of the total area of the State, is separated from the higher-lying Piedmont Plateau province on the west and the deep Atlantic Ocean basin on the east. The boundary of the Coastal Plain to the eastward is marked by the steep slope of the continental shelf which lies from 30 to 50 miles east of the present shore line. The western limit of the Coastal Plain is defined by the belt of metamorphic crystalline rocks known as the Piedmont Plateau province. Figure 2 shows the relations of the Coastal Plain sediments along its western margin to the Piedmont crystalline rocks. The Virginia fy \ N SPAS WEY ee = VIS LSI RIAN EYE Fig. 2.—Diagrammatic section illustrating the relationship between the Pied- mont Plateau and the Coastal Plain. A. Crystalline rocks of the Piedmont Plateau. I, II, III, IV, and V. Coastal Plain formations. Coastal Plain region is more than 100 miles wide and includes approxi- mately 9,500 square miles of territory or about one-fourth the area of the State. Because of marked geologic differences in the two provinces, most of the largest streams and many of the smaller ones, are characterized by fails or rapids where they cross the western margin of the Coastal Plain, and they always show a marked decrease in the velocity of their currents from this point eastward. For this reason, the name “fall-line” has been given to this boundary, the position of which is marked on the accompany- ing map, figure 1. The position of the “fall-line,” near the head of navigation and the source of water-power, has been an important factor in determining the location of many of the towns and cities of the Atlantic Coast. In Virginia, the “fall-line” passes near to or through the following important cities or towns: Washington, D. C., Fredericksburg, Richmond, Petersburg, and Emporia. As indicated on the map, figure 1, the line 4 MINERAL RESOURCES OF VIRGINIA. drawn through these places approximately separates the Coastal Plain from the Piedmont Plateau. Outliers of the Coastal Plain are frequent along the eastern margin of the Piedmont province, and the older crystalline rocks of the Piedmont can be followed along the valleys of the larger streams for some distance into the Coastal Plain sediments, where the mantle of the latter has been cut through. The Coastal Plain region, characterized by broad, level-topped stretches of country of low relief, gradually declines in slope from the Piedmont Plateau border to the shore line. In the vicinity of Washington elevations of over 400 feet are reached. Southward the western margin gradually declines in altitude to less than 200 feet in the southern portion of the State. Because of these differences in elevation the topography is more diversified in the northern than in the southern portion of the State. Passing from these elevations along the “fall-line” or western margin, the Coastal Plain declines in slope eastward to sea-level elevations along the Coastal border. Probably the average elevation of the Virginia Coastal Plain is but slightly more than 100 feet above tide. According to Professors Clark and Miller, the formations comprising the Virginia Coastal Plain are given in the following table: Formations of Virginia Coastal Plain. CENZOIC: Quaternary. Recent. Talbot, Pleistocene.............. Wicomico, ~ Columbia group. Sunderland, Tertiary. Z Lafayette Pliocene: .. cvceecces sae { Norfolk. Yorktown, 3 St. Mary’s Miocene...............2 Chopank Chesapeake group. Calvert, Eocene........ .......4-- ie a | Pamunkey group. Mesozoic: Cretaceous. Lower retaceous............ Patapsco, Jurassic? Pot : Arundel omac group. 9 Upper Jurassic?... ..... Patuxent: The deposits of the Joastal Plain consist chiefly of unconsolidated beds of sand, gravel, clay, and marl, which may be locally indurated by a cement either of iron oxide or carbonate of lime. These indurated MINERAL RESOURCES OF VIRGINIA. PLATE I. Fig. 1.—View from Richmond-Manchester bridge looking down the James river in flood. Granite boulders and reefs not entirely covered by the high water. Fig. 2.—View from Richmond-Manchester bridge looking down the James river during low water stage. kocky (granite) character of river bed is con- spicuously shown. HIGH AND LOW WATER STAGES IN JAMES RIVER AT RICHMOND. » GENERAL GEOLOGY OF VIRGINIA. 2 ledges in the vicinity of Acquia creek and, in places, southward along the western margin representing the oldest formation of the Coastal Plain series, have afforded sandstone suitable for building purposes. The beds strike in general from north to south, although some variation occurs, with a low but variable easterly dip. Although not actually horizontal, except locally, the beds generally appear so in any given section, because of this relatively low dip. Figure 2 is a diagrammatic section, which illus- trates the relations of the Coastal Plain beds to each other. In age the Coastal Plain beds range from Lower Cretaceous to Quaternary. The broad and deep estuary of the Chesapeake Bay, which crosses the Coastal Plain region, finds an outlet seaward between the Capes Charles and Henry. This sheet of water affords unparalleled transportation facilities. and its principal tributaries, the Potomac, Rappahannock, York, and James rivers, give access to vessels as far westward as the Piedmont border—the “fall-line.” THE PIEDMONT PLATEAU PROVINCE. The Piedmont Plateau province lies between the Coastal Plain and the Appalachian Mountains. It extends from the eastern slope of the Blue Ridge eastward to the western margin of the Coastal Plain, and it widens southward (map, figure 1). Its width increases from about 40 miles in the northern portion along the Potomac river to nearly 175 miles along the Virginia-Carolina boundary. The nearly horizontal and unconsoli- dated sediments of the Coastal Plain lie across the bevelled edges of the highly crumpled crystalline rocks of the Piedmont, presenting such marked stratigraphic and lithologic contrast that the geologic boundary between the two provinces is sharply defined (figure 2). The transition on the west is less sudden and well-marked. The Piedmont province contains a greater variety of mineral resources than that of either of the other two provinces. In general, the surface of the plateau has a gentle southeastward slope from an average altitude of 1,000 feet along the western margin to from 200 to 400 feet on the east, where the plateau rocks pass beneath the Coastal Plain sediments. The western border of the region is an irregular one, marking the change to the steeper slopes of the Blue Ridge and its outliers. The topography of the plateau is much older and more varied, and its geology more complex than of the Coastal Plain. Its topography is of a more or less smooth, broadly rolling or undulating upland, of moderate elevation into which the streams have rather deeply sunk their channels. Scattering hills and ridges—unreduced residuals—rise in some cases several hundred 6 MINERAL RESOURCES OF VIRGINIA. feet above the general level of the upland surface of the Plateau. Below the upland surface, deep and narrow gorges have been carved by the streams. The drainage of the region is to the southeast into the Atlantic waters, and the major streams which traverse the Plateau are the Potomac, Rappa- hannock, James, and Roanoke rivers. All of these have their sources without the area, and, with the exception of the Rappahannock, they take their rise west of the Blue Ridge. The smaller streams rise within the area and lie between the major rivers, draining either into the latter or directly into the Chesapeake Bay. These streams usually flow in more or less deep rocky gorges, and have rapid currents as far as the eastern border of the Piedmont Plateau, where they debauch on to the Coastal Plain. Lack of systematic study of the Virginia Piedmont region forbids more than a general description of its geology at this time. The rocks com- posing the region are the oldest in the State and, excepting the areas of Newark (Jura-Trias) rocks, they are all crystalline. They comprise both sedimentary and igneous masses so greatly altered from metamorphism, chiefly through pressure and recrystallization, that many of them bear but slight resemblance to the original masses. This metamorphism has induced secondary foliation in the rocks by arranging the mineral con- stituents along somewhat parallel lines or planes; the foliation of which, in many cases, bears little or no relation to the original bedding planes in many of the sedimentary masses. The Plateau region is made up of a complex of schists, gneisses and granites, with, in places, areas of slate, quartzite, and limestone. This complex is further intersected by intrusions of basic eruptive rocks belong- ing, so far as they have been studied, to the diabasic, dioritic, and gabbroic types. To the east of Danville, in the extreme southern portion of the region, is an area of altered volcanic rocks—andesite—which extends southwestward into North Carolina. Over the eastern, northern, central, and southern portions of the Pied- mont are areas of Newark (Jura-Trias) shale, sandstone, and conglomerate, and, in some of the areas, impure thin beds of limestone. These areas of Newark rocks, of which there are seven in number in the Virginia Pied- mont, are shown in the dark brewn convention on the accompanying color geologic map. The northern, southern, and eastern areas of these rocks are quite extensive. The rocks of the Plateau region have a general southeast dip, which varies within rather wide limits, usually between 20° and 70° and, in GENERAL GEOLOGY OF VIRGINIA. 7 cases, steeper, sometimes almost or quite vertical. In general they strike approximately northeast and southwest. Variations, however, in both dip and strike are frequent over the region. The age relations of the rocks of the region are largely unknown. Excepting the areas of Newark rocks, the crystalline rocks were regarded as Archean by the older geologists, and they were so mapped by Professor Rogers. More recent studies, however, based in part on fossil evidence, reveal the fact that a part of them are as late as Ordovician in age. THE APPALACHIAN MOUNTAIN PROVINCE. The Appalachian Mountain province embraces the western portion of the State. Its eastern boundary, the southeastern slope of the Blue Ridge, forms in places not a gradual transition but an abrupt change from plateau to mountain conditions, and is reasonably well-defined. In other places the change is not so abrupt and the boundary is less well-defined. ‘The western limits of the province are artificially drawn in the western boundary of the State. This province, like the Piedmont Plateau and Coastal Plain, extends northeast and southwest far beyond the limits of Virginia. The topography of the Appalachian province is varied and picturesque, and on the basis of topographic types represented, three subdivisions of the province are recognized which, named from east to west, are: (1) The Blue Ridge; (2) the Great Valley; and (3) the Alleghany Ridges. The limits of these subdivisions are indicated on map, figure 1. The Blue Ridge, which forms the eastern boundary of the Appalachian. province, maintains an uneven and knobby crest entirely across the State, in a northeast-southwest direction, and has an average elevation of not less than 2,000 feet above tide-level. At Harper’s Ferry the altitude of the Blue Ridge above tide is less than 1,000 feet, but southward through ‘Virginia the ridge becomes higher and broader, and opposite Luray, Stony Man, and Hawks Bill, 4,031 and 4,066 feet respectively, are the highest summits of the Blue Ridge north of North Carolina. Plate LXV, figure 1, and plate LXXIV, figure 1, indicate the uneven, knobby crestline of the Blue Ridge at different points in Virginia. The Blue Ridge is composed largely of pre-Cambrian rocks, represented in part, at least, by various igneous types, but sandstones and shales of Cambrian age are exposed along the western slope. It is a natural dividing line between the Paleozoic sediments comprising sandstones, limestones, and shales on the west, and the pre-Paleozoic and other rocks on the east. Figure 3, adopted from the Harper’s Ferry folio of the MINERAL RESOURCES OF VIRGINIA. GENERALIZED SECTION, SCALE? 1000 FEET—1 INCH. COLUMNAR |} Tacexess B EACTER OF TOPOGRAPHY AND SOILS. Pumop.| FORMATION NAME. , Sgcrion. || her. CHARACTER OF Rocks. CHARA a 3 $3 Lafayette formation. Gravel and sand. Conglomerate of limestone pebbles and beds Low, wide valleys; deep, red, clayey soil. ‘fred shalo and sandstone. . x g Newark formation. Bege> : Red shale and sandstone with diabase dikes. | Upland plains and broad,rounded hills, dark- > red, sandy soil, | 5 i ' : Conglomerate with quartz pebbles, 1 aa Valleys with many small knobs; thin, yellow || Marnniourg ehale, -1ooo | Gtay.and black shale, caleareous and argilla- alley sata may enna y z = = ec 2 = o }_] TTT! asco: Blue, gray, and dove-colored massive lime- Broad, flat, and slightly rolling valleys; deep, I T I To stone, with bands of slaty limestone and red, clayey soil. = sandy shi — I I I [en Z | Antietam sandstone. aes Fine, white sandstone with beds of eandy shale. | High, rounded hills and mountains; thin, = 90) = rocky oO 2 oO ies Knobs and steep slopes. Haepaw ena, cine | Gray and bluish-gray,sandy shale, with small hed ol gray wendeeene, Rolling valleys; yellowish, sandy soil. H soo- | Massive, gray and white sandstone and con- 4 Woeverton sandstone. || -900 glomerate of quartz pebbles. High mountains and lines of high peaks. [ ‘Ar, us alate, sandy shale, gray san con eas essions and vallays with little ridges; Loudoun formation. = o ets one, quartz conglomerate, blue eee pepe mi ee at d-eandy ig z High ey and mountains with broad, arch- Ww a Wie fe valleys and bye rounded ridge “4 soile, usu a Romney shale. 600-1000] Dark shale, black below valleys usuall: iy contain aiavial de- ei - posits of varying widt ie e ay 7 Knobs and ridges along the base of Monterey sandstone, = -\ 0-800 | Sandstone, in part calcareous. higher hills. . o 00-50 Cherty limestone. Knobby ridges and elevated valleys. | 2 a 0) Pure Ynestone. ‘Thin but Bich soils. Rockwood ‘(ariiation, iol 150-200 Gray quartzite, Mountain slopes, overplaced by sandy Reddish sandstone. fi Maseiniitean nanaatons: Gray quartulte. High rodky ridges, with thin, sandy and gray sandstones. z Low, rounded hills in the Appala- < Gray shale, with sandy beds’ above chian Valley, and the eastern slope @& | Martinsburg shale. 800-1400 and calcareous beds below. of Little North Mountain. Thin, 5 sandy clay-soils. 2 = o Massive fossiliferous limestone. Moderately steep ridges in the Appa- pe Cherty limestone. Tacha, Valley. e PP is it face 1500-4 Te cl Dolomitic (magnesian) limestone, The undulating surface of the App: varying from’ light gray to dark jachian Valley, with clay-soils Pot a: cert gray. ee depth. TI 17 Tae Tell Fig. 4.—Generalized section of area covered by the Staunton folio, U. S. Geol. Survey. (After N. H. Darton.) 10 MINERAL RESOURCES OF VIRGINIA. Alleghany Front, on the southeast and northwest, respectively, are here treated together under the Greater Valley region. These two bounding nearly parallel ranges are separated in Virginia by a distance varying from 75 to more than 100 miles. Considered broadly, the Greater Valley region is composed of narrow valleys and linear ridges arranged in more or less complex relations. Some of the ridges, rising to considerable elevations, are narrow, of even crestlines, and of great length. Others are less persistent and have less regular crests, while others still, which make up the minor irregularities of the surface, such as, the hills, knobs, and lower ridges, are of lower elevations. At Harper’s Ferry on the Potomac the Valley proper is less than 300 feet above tide, but it gradually rises southwestward until it reaches the height of 1,700 feet in southwest. Virginia. It will average from 20 to 30 miles wide and is higher along the western side next to the Alleghany Ridges than on the eastern side. The Alleghany Ridges vary in average elevation from 1,000 to 3,000 feet above tide. Many of the ridges exceed 3,000 feet in height, and Elliots Knob, 20 miles west of Staunton, has an elevation of 4,473 feet. Ordinarily the ridges are unsymmetrical, one slope being much steeper than the other. In some cases the two slopes are more nearly equal and, jn cross-section, the ridge approaches that of symmetry. The Greater Valley region is composed throughout of Paleozoic sedi- ments, which range in age from Cambrian to Carboniferous. The prin- cipal rock-types include limestone, shale, and sandstone. Four generalized sections, adopted from the Geologic folios of the U. 8. Geological Survey, in the northern, central, and southwestern portions of the Greater Valley region, are shown in figures 3, 4,5, and 6. These include formation name, columnar section, thickness in feet, character of rocks, and character of topography and soil. The principal formations of the Greater Valley region or western Virginia, especially those of the Cambrian and Ordovician systems, are described in some detail by Dr. Bassler under Cement and Cement Materials on pages 86-167, to which the reader is referred. The distribution of the formations over the Greater Valley region are shown on the accompanying color geologic map, and in part on the section maps, figures 16, 17, 20, 25, and 28, and on plate XVII. The simple horizontal arrangement of alternating hard and soft beds of the Greater Valley region which prevailed at the time of deposition, have been greatly complicated by folding and faulting. The present attitude of the beds indicates that in general they have been arched into GENERAL GEOLOGY OF VIRGINIA. Foumation Name ‘Tollows formation. ‘Sequoyah formation. (Dismal conglumerate-lentiL) CARBONIFEROUS z < z ° > w ° SILURIAN CAMBRIAN GENERALIZED SEOTION FOR THE TAZEWELL SHEET. pote meen, Cuanactan oF Rocks, “Interbedded sandstone and ahale with one large and foams, ‘several mpall coal coal of moderate Sandstone and shale with many sears of workable con! with Red and greon shale and sandstone mith impure line Mana: very leregular in thelr stratigmphis distelbu- Variegated atulo, red en sandstone, aod impare Tlutoaes provaliog WS Tou, t Sandy shale and thin sandstone. Anpilaceous shale, grading downward toto calearcous ala. and Lupure Ilincatone, Blog lmeatons, thin-bedded towunt the top, becowing wler and cherty toward the base Green sandy sbale ond thin sandstone, contaming locally beds of conglomerate. ‘Sandy shale and thin eandstonv. Groan shale, groding into the formation below shale, ‘Yollow sandy shale, Catcareons shale vith beds of impure limestone Bao Heavy blue limestone containing black chert near tho ‘base. Gray ma cherty horizons, the Giper farlon carries bartenloog Kast Bldg Variegated shale with beds of eandytune and Impure ineaton 11 Cmanacren op Topoonaruy Ax» Sut. Steep slopes and narrow valleys. Poor soll liga on exposed pointe Cliffs whore conglomerate ooeure. Btoep slopes Poor salt. Irregular slopos, depending upon the character of the rocks, Boll good where calcareous beds prevail Arregular slope, dopending apoo tho charter of the Ball good where eatcarsous beds provall. Bleep slopes outer ad tania, by the deeay of the Iimestoncand cal eeu Coves and gentio itopes. Bolt god (n iace, the most noted localities are Horse: pen and Crockett coves. Steep ridges, Soil very poor. Gentle slopes. Vary stoep alopes. Steep a Sentaly ‘Food soll, bat slopes too steep to be farmed ‘va Gentle sloper Gentle slopes. Good soll. g lands In tho area. Chert rid God sollSwbere not cherty. Bolling valley lands Good soll ‘ Sharp hills Fig. 5.—Generalized section of the area covered by the Tazewell folio, U. 8S. Geol. Survey. (After M. R. Campbell.) 12 MINERAL RESOURCES OF VIRGINIA. great folds and troughs whose axes extend, as a rule, in a northeast- southwest direction. Sufficient time has elapsed since the folding and faulting occurred for the rocks to be greatly eroded. The softer or less resistent rocks like shale and limestone were lowered more rapidly by erosion than the harder and more resistent rocks like sandstone, hence the former rocks are in general valley-making while the latter are ridge- forming. The formations are now exposed in long, narrow belts, the widths of which depend on the thickness of the formation and the angle of dip. As a result of the bending into arches and troughs of the beds and of subsequent erosion, the edges of the formations have developed as linear ridges and valleys, developing the well known Appalachian type of topography. This dependence of topography on structure and lithologic character of the rocks is well illustrated in the present surface configuration of the Greater Valley region. As indicated in the recent study of the Greater Valley region of Virginia, certain differences in the general geology of the region are shown, which have resulted in Bassler’s dividing the entire region in Virginia west of the Blue Ridge into three areas, designated as the northwestern, central-western, and southwestern areas. In each of these the geologic sequence differs to some extent and the structure is progressively more complex southwestward. The differences in these three areas are discussed by Dr. Bassler on pages 89-159. Structurally the southwestern Virginia area is more complex than either of the other two by reason of great folds and overthrust faults. Study of the region shows that it is traversed in a northeast-southwest direction by not less than seven major faults and by a number of minor ones. The major faults are, named in order from east to west: (1) The Holston and Iron Mountain fault; (2) the Walker Mountain fault; (3) the Saltville fault; (4) the Copper Creek fault; (5) the Hunter Val- ley fault; (6) the Wallen Valley fault, and (7) the Poor Valley faults. Structure section, figure 23, page 125, shows the relations of these faults to each other and to the folds. The structural relations of the rocks of the Greater Valley region in Virginia are shown in structure sections on pages 106, 112, 120, 125, and 145. As discussed elsewhere in this volume, the mineral resources occur- ring in the region west of the Blue Ridge bear an intimate relation to the structure of the rocks. EFFECTS OF WEATHERING AND EROSION. Through the various atmospheric or external agents grouped under the comprehensive term weathering, all land surfaces when exposed for GENERAL GEOLOGY OF VIRGINIA. GENERALIZED SECTION FOR THE PORTION OF THE QUADRANGLE SOUTH OF CLINCH MOUNTAIN. CALE: 1000 FEET = 1 imCH. roe! FonMarros Name Conumean | teu CuanacrEn oF Roces. Cuanacren oF Toroonaruy amp or. mone of sagan Forms region between Walkor Mountain and Penotngton ahals 8004 Green sandy shale and thin-bodded sandstone. the Noth ork of Holaton River, == Soil very thin an =r Bine calcareous shale, grading downward Into impure limestone 2 2 3 « a a z PpLore a ‘Newman limestone ey 2000-2800 Rough, rolling Jands' with falsly productive soil. g rt Hi blue Umestone, oat ae ncngas ehale with interbedded calcarcousshalo | ‘Tho vajley of the North Fork of Holston River. Sandy shale. Grainger formation. = 1400-1600 Sandstone containing locally bedsot quart conglomerate, | Sharh. terrate ridge wparating the Holston Rivar Valley z = 2 3S Grean shale. a Black carbonaceons shalo which with the green | The Poor Valley © | Chattanooga shale. 300-800 lek cariboos shalo which merges with the Eye |__| “Haneook limestone. =1TS |“ Cherty Gmestone ir re of tine rotor slope of Clinch Mountain. |} Rockwood formation. a. 200-300 | Sandy shalo and ferruginous sandstone. Southern slope of Clinch Mountain. Clinch sandstone. 280-450 | Coaro-grained white sandstone, Sharp mountainous ridges. Bays samicrone. 830-430 | Red sandstone and sandy shale Stoop slopes. Sevier shale. 20+ Gandy shale, Gentle slopes i saa reamed. longs Sandstone and randy shale. Cape tho ighestridgos n the suthenstorn corner of the A =— = 5 Gron isin ‘od thin sandstones with occasional beds of ps of barren hilis io the vicinity of Bristol 3 Athens shale 1000-1200 Sandy ah ala od thlniendacnee. conglomerate. of The Maiti {s oxtremely poor and the hills are generally un- : Dark argillaceous shale at the base SI Blue and gray limestone. Very cherty, along, Walker Mountain bue farcher toward the southeast the a "atiang te peSiecns gsty ei saab wo eda Knox dolomite. SC TET TI) 2900-3500 leapr pears and je formation merges with and "becomes oral purr! ease in lonaker limestone nd the'wole is ealied the Shenandoah lumestona aol erally fel, anos covered with chert Ja 1at—l Jt aL Bige calcareous an sandy shale, Toward the oast 7 Gant) ‘and the northern elope ot Walker Nolichucky shale. (O=000. changes to hmestone, SERRE WBS AR TES | a oar = Pe lonak ond 400 ae ee wen ihe an oe in cart tile formes holo fe et enna nd Rich Vali y ale sng th aottnera aide oY rf 1200-1 Hon 10 6 Knox dolomite, and the whol ley slong the northern sido o St | Heater line : known ag the Shonandoalt limestone. Waiver foun a Paee! « a = é Rumell forination. 400 Red and green ahales and thin-bedded aandstonos. Sharp bills along the north side of Rich Valley. ‘Tho northern slope of Holston Mountain, which pasace Hampton shale 600 Sandy shale throngb the sontheast ccmer of the quadrangle. falda te Fe ths thi fe sles ‘Unico! sandstone. 1000 Quartzsite or fine, blulab, gre sanbord ridge on jace of Hols- Fig. 6.—Generalized section for the portion of the area south of Clinch Mountain covered by the Bristol folio, U. 8. Geol. Survey. Campbell). (After M. R. 14 MINERAL RESOURCES OF VIRGINIA. a sufficient length of time are attacked and gradually lowered in elevation, not equally but unequally, some areas more rapidly than others and some parts of the same area more rapidly than otier parts. All conditions being equal, that area which has been continuously above water for the longest time has suffered the greatest effects from the atmospheric agents. Accordingly an examination of the surface rocks over all parts of Virginia shows some effects from atmospheric action. Of the three major provinces of the State described above, the Coastal Plain, on account of its very recent geologic history,. has suffered the least. The remaining two provinces, on the other hand, Piedmont Plateau and Appalachian mountains, bear striking evidence over all their parts of profound decay and erosion, which have resulted in the removal of vast quantities of rock material. Just how much of their surface has been lowered or what vertical thickness of material has been removed from these land areas and carried seaward, would probably be very difficult to say, but that it has been large cannot be doubted. Because of its greater geologic age and the vast length of time it has been a land area, the Piedmont Plateau has probably suffered the removal of the greatest thickness of material, which contributed in part to the building of the Appalachian province on the northwest, and to the Coastal Plain on the southeast. Through this process of degeneration—weathering—which has been going on for many thousands of years, a mantle of varying thickness of decayed rock material overlies the still fresh or sound rock, except where the erosive action has not been too excessive and the slopes too steep for its accumulation. This decayed product is loose and porous or incoherent, consisting usually of clay, sand, and gravel, and on the immediate surface forms soil. On depth it passes by imperceptible gradation into the hard and fresh unaltered rock. The thickness of this mantle of rock decay in Virginia varies from a few inches to 50, 60, and, in extreme cases, 100 feet. Qver many parts of the State, so profound is this decay, that exposures of the hard rock are rare except along the stream courses where the mantle has been cut through by erosion. This process of rock decay is of very great economic importance. Apart from the consideration of the great variety of soils resulting there- from, which forms perhaps Virginia’s most valuable asset, workable ore- deposits have been formed by it from sparsely disseminated and non- workable mineral matter in the original rocks. This is best illustrated in the manganese deposits, in a part of the iron and zine deposits, and in other ore-deposits described in the following pages of this volume. GENERAL GEOLOGY OF VIRGINIA. 15 DIVERSITY OF RESOURCES. There is probably no state in the Union of the same area as Virginia, that can show a greater diversity in geologic resources. This is confirmed by the actual exploitation thus far made; and it might be naturally inferred from the position which the State occupies with reference to disturbed and undisturbed areas as described above. As indicated above and from an examination of the geologic map, the State stretches from the Atlantic Coast westward nearly entirely across the Appalachian Mountain System. Within this area are found rocks ranging in geologic age from pre-Cambrian to Recent, and representing all the principal divisions of geologic time. Equally as great a variety of rock-types, both sedimentary and igneous, of structure which characterizes both profoundly disturbed and undisturbed rock masses, and of topography, is shown. VALUE OF RESOURCES. The total yearly value of production in mineral resources of Virginia for 1902 to 1906, inclusive, has been estimated as follows: Year Value | re re ee $10,500,000 LOO 3 ia ag. atiate'ecs eee 12,633,000 1904 c6. cee vaca 12,606,000 TQO 5 jects cesececavtss 21,752,000 D906 ies ys eee Beene 30,000,000 The above figures have been compiled from the most authoritative sources, but they must be regarded only as approximate. They probably represent under- rather than over-estimates of the true total value of Virginia’s mineral production. The figures of production for 1906 are based on those of 1905, and when the exact value of the mineral production for 1906 becomes available it may show some variation in either direction from the estimated value given above. A very striking feature in the above compilation is the enormous increase in the value of mineral pro- duction for the years 1905 and 1906 over the preceding years. In 1905 the production nearly doubled that of 1904, and for 1906 a marked increase is shown over that for 1905. PART II. BUILDING AND ORNAMENTAL STONES; CE- MENT AND CEMENT MATERIALS ; AND CLAYS. |. BUILDING AND ORNAMENTAL STONES. GENERAL STATEMENT. The production of building stone has long been an important industry in the State, and the output in some varieties, especially granite, has been used in many notable structures. Among these is the State, War, and Navy Building in Washington. A large variety and abundance of ex- cellent stone, suitable for building, decorative, and other purposes, occur widely distributed over the Piedmont and Mountain provinces of the State. These include granite and gneiss; trappean rocks, some of which are worthy of being included as black granites; slate; sandstone and quartzite; limestone and marble. These different kinds of stone are described below in the order named above. The annual production of each kind of stone quarried in Virginia from 1900 to 1905, inclusive, is given in the following table: Value of various kinds of stone produced annually in Virginia from 1900 to 1905 inclusive. ‘Year Granite Sandstone Slate | Limeston Total 1900 $211,080 $ 6,000 $190,211 $403,318 $ 810,609 1901 275,701 5,803 178,979 986,177 1,416,160 1902 282,046 2,500 160,950 534,113 979,610 1903 299,335 4,471 115,356 569, 205 988,367 1904 510,788 13,522 130,208 442,978 1,097,496 1905 452,390 2,000 146,786 | 212,660 813,836 BUILDING AND ORNAMENTAL STONES. 17 SILICEOUS CRYSTALLINE ROCKS. The siliceous crystalline rocks are confined to the middle province of the State, Piedmont Plateau, east of the Blue Ridge, where they have wide distribution. Over much of the area they form the principal rock-types. These are discussed below under granites, gneisses, schists, and trappean rocks. I, GRANITES. DEFINITION. Under the name granite is included a series of granular igneous rocks composed essentially of an aggregate of the minerals, quartz and feldspar, typically orthoclase, though nearly always carrying in addi- tion some plagioclase feldspar, more or less mica, and sometimes horn- blende or pyroxene. The Virginia granites are largely mica granites, and since this mica is, in most cases, the black variety, biotite, they may be designated as biotite granites. Other varieties occur which will be noted below. Besides the minerals mentioned others occur in very small amount, which exert little or no influence on the rock, and they have no special significance in the present treatment. In texture, granites vary from coarse crystalline, in which the indi- vidual minerals may be an inch or more in length, to fine crystalline, in which the minerals are just visible to the eye. All varieties of texture occur in consequence of the wide variation in the mode of arrangement of the mineral constituents. The color of granite is dependent largely upon the relative abundance of the dark-colored mineral or minerals present, and the character of the feldspars. Those granites containing a large proportion of black mica are of a darker gray color than those containing but little. The pink and red colors are due to the presence of pink and red feldspars. DISTRIBUTION OF THE GRANITES. The granites are limited to the crystalline area, which extends east- ward from the Blue Ridge to the western margin of the Coastal Plain, and they comprise massive and foliated types. The foliated granites or gneisses have very wide distribution over the Piedmont region and they form one of the principal types of rock. The principal areas of producing massive granites are distributed in a 18 MINERAL RESOURCES OF VIRGINIA. north-south direction, along the eastern border of the Piedmont region. They include (1) the Petersburg area; (2) the Richmond area; and (3) the Fredericksburg area. The principal counties composing these areas are Dinwiddie, Chesterfield, Henrico, and Spottsylvania, In addition to these there are several minor areas, chief among which are those of Fairfax, Prince Edward, Fluvanna, and Amherst counties. These are designated minor areas chiefly because of the lack of development in them. Granite occurs in other Piedmont counties but it has not yet been quarried. MINERAL COMPOSITION. In the most important areas, the Virginia granites are mixtures of feldspar, quartz, and biotite, with usually more or less of the white mica, muscovite. Hornblende is an important constituent in a part of the granites in the Falls Church area, near Washington, in Fairfax county. Epidote is a principal constituent in the variety of granite known as unakite, which is found near Luray in Page and Madison counties, and near Troutdale in Grayson county. In addition to the principal feldspar, orthoclase, microcline and plagioclase occur in widely variable amounts. Besides the minerals mentioned, there occur apatite, zircon, sphene, magnetite, and other occasional ones. KINDS OF GRANITE. Based on texture and structure three types of granite occur in Virginia: (1) Massive, even-granular granites; (2) porphyritic granites; and (3) schistose or foliated granites—granite-gneisses. Based on mineral com- position, we have the following types of Virginia granite: (1) Biotite granite, under which a majority of the granites of the State may be grouped; (2) muscovite granite; (3) hornblende-biotite granite; and (4) epidote granite. The granites in the vicinity of Richmond, Petersburg, and Fredericks- burg, are the most important, economically, in the State, and they best illustrate the types of mica granite. I have elsewhere discussed these under the three following types: (1) The Richmond-Fredericksburg light gray; (2) the Richmond-Fredericksburg dark blue-gray; and (3) the Fredericksburg light gray. To these are added the Falls Church dark gray hornblende-biotite type, and the yellowish green and pink epidote type, known as unakite. Granites found but not quarried in other parts of the crystalline area belong to one or the other of the above types. BUILDING AND ORNAMENTAL STONES. 19 DESCRIPTION OF GRANITE AREAS. The Petersburg Area. The Petersburg granite area includes the extreme northeast part of Dinwiddie county and the contiguous southeast corner ARC OR oon -Map showing location of granite quarries in the Petersburg area. Quarries indicated by heavy dots Based on the Bermuda Hundred and Petersburg topographic sheets, U. 8. Geol. Survey. Scale, § inch equals 1 mile, approximately. Contour interval, 20 feet. of Chesterfield. Granite quarries are opened and operated about 2 miles west of the city of Petersburg and at a similar distance north of the city. The principal quarries, shown on the map, figure 7, include the Lassiter and the Petersburg Granite Company’s on the west side of Peters- burg, and the Cook quarry on the north side of the city. The rock from these quarries is a closely similar biotite granite, of 20 MINERAL RESOURCES OF VIRGINIA. medium texture, and gray color. The granite from the Cook quarry con- tains less mica (biotite) than that from the west side quarries, and is accordingly lighter in color. The stone from these quarries is of ex- cellent quality and is used for all purposes made of granite. It is of homogeneous texture, good permanent color, and contains no harmful mineral. ‘The joint-planes are widely spaced, readily admitting of the quarrying of dimension stone. = 7 Cook quarry.—This quarry is located about 2 miles north of Peters- burg, immediately on the west side of the Seaboard Air Line Railway, and within 300 feet of the crossing of this road by the Belt Line. Some stone was quarried as early as 1837, but systematic quarrying was not begun until 1887. Plate II, figure 1, is a view of this quarry. The stone is admirably adapted to the uses made of it, which are for building purposes; in street work of all forms, including blocks and curbing and crushed stone; and in wall, bridge, and culvert work in the rough and dressed state. A crusher is operated at the quarry for working up the quarry-waste, mainly for concrete purposes. The largest size waste is made into paving blocks, the second into rubble paving, and the balance is crushed for concrete work. The granite from this quarry is shipped to the principal points, including New York and as far west as Cincinnati. Practically no shipments are made south of Virginia. The Lassiter quarries—These quarries are located about 1.5 miles west of Petersburg, immediately on the car line of the Virginia Passenger and Power Company, and within a quarter of a mile of the Seaboard Air Line Railway. Three or four openings are made close together which were first worked more than 50 years ago. During the summer of 1906, 2 of the openings were being operated by separate parties. The largest one of these was operated by C. M. Walsh of Petersburg, exclusively for monu- ments. Blocks 20 feet and more in length are constantly being quarried from the Walsh opening. The granite is of medium gray color, the feld- spars of which have a decided pinkish cast. It works well under the hammer and is susceptible of a high polish. It is extensively used in the monument and building trade, principally in the former. The quarry waste is broken up and used for rubble. As monumental stock this granite is marketed over a wide territory, shipments being made as far west as Denver, Colorado. The Petersburg Granite Company’s quarries——The quarries of this company include two large openings several hundred yards apart, located immediately along the car line of the Petersburg Passenger and Power MINERAL RESOURCES OF VIRGINIA. PLATE II. sive ledges of superior Fig. 2—Granite quarry near Richmond, showing monumental granite. GRANITE QUARRIES IN PETERSBURG AND RICHMOND, VIRGINIA, AREAS. BUILDING AND ORNAMENTAL STONES. 21 Company, 2 miles west of Petersburg and a half mile west of the Lassiter quarries. ‘The 2 openings are designated as Quarry No. 1, known as the Asylum quarry, and Quarry No. 2, known as the Dibble quarry. The openings are large and are made in flat surface exposures of the granite. About 5 feet of stripping, comprising sand and gravel of the Coastal Plain and decayed granite, must be removed before the quarrying of fresh granite can be carried on. During the summer of 1906, Quarry No. 1 was being operated under lease by Baltimore parties, and the stone was being used almost exclusive- ly for building purposes in Petersburg. Some of it is used for coping iv cemetery work. Quarry No. 2 has not been operated for four or more years. A large quantity of stone has been quarried and used for the various purposes made of granite. The joint-planes are widely spaced and dimension stone of almost any size can be readily obtained. The Petersburg Passenger and Power Company’s quarry—During the summer of 1905, the Petersburg Passenger and Power Company was operating a quarry at the dam across the Appomattox river, 7 miles west. of Petersburg. The Richmond Area. The Richmond granite area, covering parts of Chesterfield and Henrico counties, in the immediate vicinity of the cities of Richmond and Man- chester, is the largest producing area in the State. The quarrying of granite in this area dates back to the early part of the last century, and a large number of quarries have been worked from time to time. These are opened largely in the granite bluffs along the James river, extending in a general westerly direction from the city of Richmond for a distance of more than 5 miles. To a smaller extent quarries have been opened to the north and south of Richmond in the low granite ledges exposed along smaller streams and in the flat surface exposures on the inter-stream areas. Many of the quarries are very extensive openings, and have been worked to a depth of nearly 200 feet, from which an enormous quantity of excellent stone has been obtained. In some of the larger quarries, the depth reached in quarrying is below that of the river level. The quarries opened are well located with reference to transportation facilities, and admit of easy working. The location of this granite area at the head of navigation in the James river affords cheap transportation of the stone by water north and south. 22 MINERAL RESOURCES OF VIRGINIA. The quarried granites are feldspar-quartz-biotite rocks, which vary from fine to medium granular in texture, and from dark to light gray in color. Near Midlothian, 13 miles west of Richmond, and extending for a north-south distance of about 20 miles, is a beautiful coarse, porphyritic, biotite granite, which has not yet been quarried to any extent. Jointing is usually well developed in the granites but the planes are spaced sufficiently far apart to admit of almost any size stone being quarried. Pegmatite veins or dikes, coarse crystallizations of quartz and feldspar, are not sufficiently numerous to cause waste in quarrying. Two grades of the granite occur and are quarried, one a fine-grained dark blue-gray rock extensively used as monument stock, the other a coarse Fig. 8.—Relations of the blue to the gray granite as shown at the Neth- erwood quarry west of Richmond. Scale, 1 inch equals 150 feet. and lighter gray rock admirably suited for building purposes. Both are homogeneous even-granular granites, possessing good working qualities. The fine-grained dark blue-gray granite is susceptible of high and per- manent polish and is a superior monumental stone, possessing as it does that strong contrast in color between the polished and unpolished rough or dressed surface. Figure 8 shows the structural relations between the two granites as exposed in the Netherwood quarry west of Richmond. The Richmond granites are thoroughly suited for all classes of work in which granite is used. Probably the most elaborate granite structure in the country and the most important building yet constructed of the Virginia granites is the State, War, and Navy building in Washington, built of the Richmond granite. PLATE IIt. MINERAL RESOURCES OF VIRGINIA. opographie our interval, on the Richmond and Goochland t 1 mile, approximately. Cont id. inch uarries indicated by heavy black dots. Base arries. et, 1 inch = 1 mile, approximately; Goochland sheet, % BUILDING AND ORNAMENTAL STONES. 23 The following is a list of the principal quarries in the Richmond area: Name. Location. Belle Isle Quarry, ; Belle Island, above Richmond—Manches- ter bridge. Donald Quarry, Half mile E. of Belt Line Railway, 8. : side of James river. Granite Development Company’s Quarry, One-eighth mile E. of Granite, 8. side of Southern Railway. Hawkins Quarry, North side of So. Railway at Granite. Krim Quarries, Three-eighths mile 8. W. of Granite. McCloy Quarry, One-quarter mile W. of new reservoir. McGranigan Quarry, One-eighth mile W. Belt Line Railway, on James river. McGowan Quarry, Two miles 8S. of Manchester. McIntosh Quarries, Half mile S. W. of Granite. Middendorf Quarries, One-quarter mile S. W. of Granite. Netherwood Quarries, Two miles W. of Richmond, on §. side of James river. Old Dominion Granite Company’s Quarries (Middendorf) , One-fourth mile N. 30° E. of Granite. Philadelphia Quarries, East end of Settling Basin, on N. side of James river. Richmond Granite Company’s Quarries, 4.5 miles N. of Richmond, near R. F. & P. Railway. Smith Quarry, Canal locks W. of Richmond, N. side of James river. Tidewater Quarry Company’s Quarry, Two miles 8. E. of Manchester, on James river. Westham Quarries, 4 miles W. of City Hall in Richmond, on S. side of James river. Winston and Company’s Quarry, North side of James river, at Settling Basin. Wray Quarry, Three miles W. of Richmond, on §. side of James river. Of these, the following quarries were being operated during 1905 and 1906: McCloy, McGowan, McIntosh, Middendorf, Netherwood, Richmond Granite Company, Winston and Company, and Wray. Some of the others have not been operated for some time, and in part they include the most extensive openings in the area. This is particularly true of the Westham quarries out of which stone the War, State, and Navy building in Wash- ington was constructed, and the quarries of the Old Dominion Granite Company, known at present as the Middendorf quarries. Only those quarries which are mentioned above as operating during 1905 and 1906 will be described. The other quarries are equally as important and are capable of producing unlimited quantity of excellent stone, but many of the openings were partially or entirely filled with water at the time of my examination and were not entirely open to study. Map, plate III, shows the distribution and location of granite quarries in the Richmond area. 24 MINERAL RESOURCES OF VIRGINIA. McCloy quarry—The McCloy quarry is opened in a flat surface ex- posure of granite, located about 300 yards from the James river branch of the Richmond, Fredericksburg, and Potomac railroad, and about a quarter of a mile west of the new reservoir. The quarry opening includes about 1 acre of ground. At several places about the edges of the opening the granite is decayed to a depth of 3 or 4 feet, which must be stripped before fresh stone can be obtained. The rock is cut by several well-defined sets of joints which vary in direction, from N. 5° to 85° W. and N. 10° to 75° E., and in dip from vertical to 55° N. W. The rock is a very fine- grained and even-textured, dark blue biotite granite, admirably suited for monumental stock. The principal uses made of it are for monuments and building, and for street purposes as blocks and curbing, The quarry waste is crushed and utilized for street concrete or cement work. It is marketed in a number of states, including Virginia. McGowan quarry—tThis quarry has been worked for about 10 years exclusively for monumental stone. It is located 2 miles south of Man- chester, about 300 yards east of the Petersburg turnpike, and 600 feet west of the Seaboard Air Line Railway, with which the quarry is connected by a spur track for shipping. The opening, which is a large one, is made in a flat surface exposure of granite, and the average depth of stripping, including soil and partially decayed granite, necessary to the quarrying of fresh stone, is about 5 feet. It is a fine-grained dark blue-gray biotite granite, of uniform texture and color, and a most desirable monumental stone. The quarry waste is utilized largely for paving purposes. It has an extensive sale in the monument trade in many states, including Virginia. Views of this quarry are shown in plates IV, V, and VI. McIntosh quarry—The McIntosh quarry, formerly known as “flat- rock,” is probably the most extensive working granite quarry in the State. It is located near Granite, a station on the Southern Railway, 5 miles west of Richmond. A spur track for shipping connects the quarry with the Southern Railway at Granite. It has been operated for about 15 years. About 2 acres have been stripped from the flat ledge exposure to a depth of 37% feet. The fresh rock is exposed at the surface and no stripping of decayed material is necessary. All work is done by compressed air machinery. The stone is of excellent quality and is used for all classes of building and monumental work, and for all purposes for which granite is handled, except in the form of crushed stone. The principal directions of jointing are N. 10° W. and N. 65° E. All the approaches, steps, etc., to the new Capitol building in Richmond are from the granite of this quarry. It has an extensive market in and out of Virginia. MINERAL RESOURCES OF VIRGINEA, PLATE TY. Fig. 1.—McGowan granite quarry, south of Richmond, showine horizontal jointing. Fig. 2.—Granite quarry near Richmond, showing jointing as in Fig. 1. GRANITE QUARRIES IN THE RICHMOND, VIRGINIA, AREA. BUILDING AND ORNAMENTAL STONES. 25 Middendorf quarry—The Middendorf quarry is located on the Belt Line Railway west of Manchester, and 760 feet north of the crossing of the Petersburg turnpike by the above railroad. The rock is a banded biotite granite-gneiss, penetrated by many. pegmatite dikes and veins which vary in width from a fraction of an inch to several feet. Directions of jointing are N. 65° E. and N. 45° W. Strike of the gneissic structure or banding is N. 65° E. Several acres of the gneiss have been stripped to a depth of about 25 feet. The stone is used for ballast and paving blocks, largely the former. Netherwood quarry.—This is one of the most extensive quarries in the Richmond area, and it is reported as having been worked as early as 65 years ago, although operated under the present management for about 8 years. The quarry opening is made in the high granite bluff on the south side of James river and immediately on the Southern Railway, about 2.4 miles southwest of Richmond. The greatest depth reached in quarrying is 65 feet of fresh granite covered by about 2 feet of red clay on top. The ledges of granite average from 20 to 22 feet in thickness. Two grades of granite are produced, a medium coarse light gray for general building purposes, and a fine-grained dark blue-gray for monumental purposes. Neither joints nor pegmatites are too closely spaced nor too numerous to prevent the quarrying of dimension stone—any size blocks of both the gray and the blue stone being readily obtained. It has an extensive market in and out of the State; and is used for general constructional and monumental purposes, curbing and blocks for paving, and crushed stone for all purposes made of granite. Its principal use, however, is for building and city (street) work, which comprises mostly the light gray coarse granite. The Richmond Granite Company's quarries.—The quarries of this com- pany, owned and operated by Copeland and Brown, are located 4.5 miles north of Richmond, near and on the east side of the Richmond, Fredericks- burg, and Potomac Railway. It was first operated about 15 years ago. The dimensions of the principal opening are 500x100 feet and 50 feet deep. A spur track is operated between the opening and the Richmond, Fredericksburg, and Potomac Railway. ‘Two principal sets of joints, spaced at distances of 2, 6, 8, and more feet apart, intersect the granite, with directions varying from N. 10° to 70° W. and N. 30° to 35° E. These dip from the vertical to 35° S. EH. The rock is not sheeted but is perfectly massive, and is an excellent grade of biotite granite. Pegmatite dikes or veins varying in width up to 8 feet occur, but are not numerous 26 MINERAL RESOURCES OF VIRGINIA. and do not interfere with the quarrying of dimension stone. A crusher is operated at the quarry for working up the quarry waste for the various uses made of crushed stone. The principal uses made of the granite are for street work in the form of blocks and curbing, for building and monu- ments, and for crushed stone in its various forms. Winston and Company's quarry.—This quarry, formerly known as the Mitchell and Copeland quarry, under whose management it was first opened and worked for 12 years, many years ago, is located west of Rich- mond at the city settling basin, just completed. The quarry is opened in the granite bluff on the north side of James river, and is of large dimen- sions. The present operators, Winston and Company, contractors for the construction of the settling basin, began working the quarry about 3 years ago to supply crushed stone (concrete) and rip-rap for building the settling basin. The stone was quarried by blasting. The principal joints strike N. 5° W:. and N. 30° to 70° E. Pegmatites are not numerous. The granite is sheeted to the entire depth of working, the sheets being thickest at the bottom and thinnest at the top. Wray quarry—tThis quarry, operated since 1895 for monumental stock exclusively, is opened in the high granite bluffs on the south side of the James river and immediately on the Southern Railway, about 3 miles southwest of Richmond. The stone is of the excellent dark blue-gray biotite granite, of uniform color and texture, and is admirably suited for the use made of it. The joint-planes are widely spaced, admitting of almost any size stone being quarried. The working face in 1905 had a depth of about 75 feet. Occasional pegmatites not exceeding 3 inches in width occur in the granite but give no trouble in quarrying. Its sale is practically limited to the principal cities in the State for monumental stock. The Fredericksburg Area. The Fredericksburg area includes the region to the west and north of the city, in Spottsylvania county, in which granite quarries have been opened. The granite exposed along the Rappahannock river north of Fredericksburg extends into Stafford county, but no quarries have yet been opened in that county. Two types of granite have been quarried in the Fredericksburg area, one a very light gray, medium-textured, muscovite granite, the other a dark blue-gray, very fine-textured, biotite granite. In texture and composition, the latter is identical with the fine-grained dark blue-gray granite quarried in the Richmond area and so extensively used for monument stock. The MINERAL RESOURCES OF VIRGINIA. PLATE V. Fig. 1.—Granite quarry near Richmond, showing joint struc- lig. 2.—MeGowan quarry near Richmond, showing large ture. inclusion of banded gneiss. The hammer spans con- tact between granite and gneiss. GRANITE QUARRIES IN THE RICHMOND, VIRGINIA, AREA, BUILDING AND ORNAMENTAL STONES. 27 Fredericksburg granite is a shade darker in color than the Richmond stone and it is a superb monumental stone for which it has a wide usage. Map, figure 9, shows the location of the quarries in this area. IGS Ree | 25 26 OMCLE TS ANTLA M wet : Fig. 9.—Map showing location of granite quarries in the Fredericksburg area. Quarries indicated by heavy dots. Based on the Fredericksburg topographic sheet, U.S. Geol. Survey. Scale, $ inch equals 1 mile, approximately. Contour interval, 50 feet. Hazel Run light gray granite—-A very light gray muscovite granite of medium texture is exposed along Hazel Run, a tributary of the Rappa- hannock river, and about 1 mile west of Fredericksburg. It somewhat resembles the Stone Mountain light gray muscovite’ granite 16 miles east of Atlanta, Georgia, which is so extensively used for general constructional purposes. In the spring of 1879 an opening was made in the flat ledge 28 MINERAL RESOURCES OF VIRGINIA. immediately on the south side of Hazel Run, about 1 mile west of Fred- ericksburg, and enough stone quarried to build the Presbyterian Memorial Chapel in Fredericksburg. No stone has been quarried since.. The joint- planes are widely spaced, two sets of which strike N. 75° W. and N.-S. Cartwright and Davis quarrics—The quarries of Cartwright and Davis, located along the Rappahannock river 3 miles north of Fredericksburg, are the only ones operating at present in Spottsylvania county. The quarries comprise 8 openings, 6 of which are made in the granite bluffs along the south side of the Rappahannock river, for a distance of nearly half a mile. The granite, an excellent grade of monumental stone, is a massive uniform dark blue-gray colored and fine-textured rock. It is intruded into an irregular banded gneiss of similar mineral composition. Strike of gneissic banding or schistosity is N. 25° to 40° E. The granite is cut by several sets of joints so spaced as to admit of any size blocks of stone being quarried. The principal joint-planes strike N.-S. with a dip of 40° E.; N. 60° to 80° E., dipping 10° to 30°, and N. 20° to 80° W. In places, pegmatites are abundantly developed in the granite, which occa- sion at times considerable waste in quarrying. No dimension stone is sold in the rough but it is all worked up at the “yards” located in the northern limits of Fredericksburg, and is used ex- clusively in the monument trade. The yards are commodious and well equipped with the necessary modern machinery for all grades of polish and dress work. The stone is conveyed from the quarries to the yards, a dis- tance of 3 miles, by canal. A crusher is operated at the yards for sizing the waste which is utilized for local purposes. The monuments made from this granite have an extensive market in and out of the State. The Fairfax County Area, Granite has been quarried in Fairfax county at the following localities: South of Falls Church and west of Annandale. The quarried rock is similar in the two localities and is taken from less schistose portions of the granite mass. It is homogeneous, of even texture and good color. It is not materially effected by schistosity, and works out readily in stones of moderate size. Some of the beds in the Falls Church area are colored by pink feldspar. Many portions of the granite-gneiss furnish good material for foundations and similar rough work. This stone is schistose and con- sequently not obtained in large masses. It is easy to quarry and is strong and durable. Many portions contain pyrite, which unfits it for ornamental use. Many of the more massive beds of mica-gneiss are suitable for BUILDING AND ORNAMENTAL STONES. 29 building and resemble the more schistose portions of the granite mass. They are used locally in the construction of dams and foundations. From the thinner and more micaceous beds flagstone can readily be obtained. The granite quarried in the Fairfax county area has been used entirely for local purposes. . Falls Church area.—The granites in the vicinity of Falls Church are of two varieties. One is a medium- to fine-grained crystalline rock and is a biotite granite carrying a variable quantity of muscovite. The other, a light and dark speckled rock, is a fraction more coarsely crystalline and is a horn- blende-biotite granite. It is the only representative of a hornblende granite yet found in the State and it is closely associated with diorite masses on the one hand and with foliated mica-granites on the other. The Trip quarry, located about 1 mile south of Falls Church, was first opened about 1872, and has supplied considerable stone for local purposes, principally for foundations and buildings. The granite is massive, of medium texture and of variable light gray color, depending upon the amount of mica present. Several sets of joints are developed which usually cut the granite at close intervals and limit the size stone that can be quarried. The directions of these joints vary from N. 10° to 80° E., and N. 10° to 80° W. The Presbyterian and Catholic churches at Falls Church were built of the granite in the rough from this quarry. Annandale area—The Hoffman and Miller quarry, located about 2 miles west of Annandale, directly on the west side of Accotink creek, has not been operated for 12 or 13 years. The opening is made in a boulder ledge exposure on the above stream and at water level. A stripping of 8 to 12 feet of soil and red clay is necessary for the quarrying of fresh granite. The rock is a massive biotite granite of uniform medium texture and light gray color. Good dimension stone can be readily quarried. The joint-planes strike N.-S. and N. 50° to 80° W. The Nottoway—Prince Edward Counties Area. In the northwestern corner of Nottoway county and in the adjacent portion of Prince Edward county is a very promising area of massive gray granite of fine texture and uniform color, which has been opened and a little stone quarried for local use at a single point in both counties. The granite is exposed at the surface in flat-doming masses and as boulders. This area lies close to the Southern, and the Norfolk and Western Railways. 30 MINERAL RESOURCES OF VIRGINIA. The Wingo quarry in Nottoway county, located 3.5 miles north of Jen- nings and 2.5 miles south of Jetersville, on the east side of the Southern Railway, was operated some years ago for ballast. The rock is a fine- grained massive, medium gray, biotite granite, of uniform texture and color. It is a desirable stone and can be used for any purpose made of granite. In the vicinity of Rice’s Depot, Prince Edward county, granite was quarried some years ago for use in bridge construction along the Norfolk and Western Railway. Granite, suitable for general building and other purposes, occurs in other counties of the crystalline area, but in none of these has it been developed. A beautiful coarse-grained granite is found in Buckingham county, near the Court-House, but no quarries have been opened. Likewise a coarse-grained light gray biotite granite occurs 3 miles west of Thaxton, a station on the Norfolk and Western Railway. A red granite, well suited for ornamental and general building purposes, but undeveloped, is reported from Saxe in Charlotte county. The Blue Ridge Area. In the mountain district of Loudoun county, extending northward across the Potomac into Maryland and southward into Fauquier county, Virginia, granite is widely distributed in long belts up to six miles wide. The outcrops increase in extent and number southward from the Potomac in Virginia. According to Keith, the minerals composing the granites are chiefly quartz, and orthoclase and plagioclase feldspar; besides biotite, garnet, epidote, and blue quartz occur, forming four types of granite in different areas. The granite is light gray in color and has been extensively altered by pressure. According to the degree of alteration the rock is a granite, gneiss, or quartz schist. No quarries have been opened in the granite, but where boulders could be obtained without much labor local use has been made of the granite. 7 Unakite. The name unakite was proposed for a unique variety of granite, com- posed of the essential minerals, yellow-green epidote, pink feldspar, and quartz, from the Unaka range of the Great Smoky Mountains, in North Carolina. The effect of the rock in either rock-faced or polished work is BUILDING AND, ORNAMENTAL STONES. 31 quite pleasing and it might be used to good effect in certain forms of ornamental work. Unakite occurs in two localities in Virginia, namely, near Luray, at Milam’s Gap in Page and Madison counties, in the Blue Ridge; and about 2.5 miles south of Troutdale along the Marion-Jefferson public road, in Grayson county. The Milam’s Gap unakite is a moderately coarse but irregular crys- tallization of red feldspar, quartz, and green epidote. Irregular crystal- lization of the rock is shown in the variation of masses composed of more than two-thirds of the red feldspar through all gradations to masses composed of quartz and epidote without feldspar. Thin sections of the unakite from Milam’s Gap show epidote, orthoclase, quartz, iron oxide, zircon, and apatite. The epidote is secondary, replacing pyroxene and feldspar, both plagioclase and orthoclase. ‘The unakite from Grayson county shows deeper colored feldspar and epidote than that from Milam’s Gap. As shown by the analysis below of the Milam’s Gap unakite, made by Phalen, the rock is relatively basic for a granite: Per cent. STICa seh ete en Se wakes hee 58.32 Alumina. sis secs gatas orien sae die 15.77 Ferric oxide...............4. 6.56 Ferrous oxide................ 0.89 Magnesia ..............00005 09 Lime oes ae ie wedcs tess s ewes xe 11.68 Od Bi ioire eis scd ie pinracaed cara auc te 0.32 POtash aiid laa enn cen gor beste 4.01 Water isos ssa sae iarae sa 1.78 Phosphorous pentoxide....... 48 Manganese oxide............. 13 ZATCOMIA! 666-5 ace cis Aale avatar ss trace MOtal adie veces moat abe tay 99.98 2. SYENITE. Under the name syenite is included a crystalline granular rock which consists essentially of orthoclase, with or without one or more of the accessory minerals, mica, hornblende, or augite. It is sold on the market as granite and is used for the same purpose but differs from granite only in the absence of quartz. Most of the known areas of syenite in Virginia 32 MINERAL RESOURCES OF VIRGINIA. contain hornblende as the chief accessory mineral, and the rock is accord- ingly a hornblende syenite. In Charlotte county, an exposure of hornblende syenite has been traced from Drakes Branch, a station on the Southern Railway, to within 2 miles east of Charlotte court-house, a distance of about 5 miles. The rock is entirely massive, varying from gray to deep pink in color, and in texture from medium to coarse-grained. It would make a desirable stone for the various uses to which granite is put. No attempt has been made to quarry this rock. In Carroll county, extending northward from the northwest edge of Sylvatus, is an area of hornblende syenite, the exposures of which show pronounced crushing and shearing from pressure metamorphism. The rock in this vicinity could only be used for the rougher grades of work. Northeastward from Sylvatus along the Carroll county line and on Big Reed Island creek, an area of coarse-grained pink hornblende-biotite syenite, carrying more or less quartz, occurs. Study of this area will probably show the rock to grade into a true granite. Along the west side of the Blue Ridge and topographically below the basalt, a coarse-grained, massive, dark gray syenite has been observed in Warren, Madison, and Greene counties. This rock has been found along the west side of Dickey’s Hill, 4 miles south of Front Royal in Warren county ; at Milam’s Gap in Madison county where it forms the unakite-bearing rock ; and between Elkton and the High Top Copper Company’s mine, in Greene county. Where observed, the syenite appears entirely massive except at one or two points in the Greene county locality, where a schistose structure has been developed in it. In the Warren county area the rock varies from medium to coarse texture. The syenite of the above localities has nowhere been quarried, but it should prove a desirable stone for general construc- tional work and many other purposes for which granite is employed. According to Phalen, the syenite of Milam’s Gap, Madison county, the unakite-bearing rock, a hypersthene-quartz-diallage syenite, is a coarse- grained dark grayish-green aggregate of essentially feldspars and black pyroxenes. The microscope shows the following minerals: Orthoclase, plagioclase, orthorhombic and monoclinc pyroxene, quartz, microcline, iron ore, apatite, and zircon, with the alteration products epidote, chlorite, and sericite. Phalen gives the following analysis of the syenite from Milam’s Gap: BUILDING AND ORNAMENTAL STONES. 83 Per cent. DLLIGH- A sccesiien ama ne eaten hades 60.52 Alumnae 2 soe asacas ou aeeacieles 16.99 Ferric oxide...............05 60 Ferrous oxide..............45 6.53 MG QNESIa. 3. sis. a signer dea aeceiace 1.59 Dime: goss sya one chi eee sects 4.58 ODS ccseers aeans bs eaeseuateald a 4d 2.83 OCHS DN s.c scence wd ates Seeley 3.91 Water’ scans, dae xara eaeea .88 Phosphorus pentoxide........ 74 Manganese oxide............. 25 Chromium oxide............. trace ZIWCONIA, cov os eee Ns See Mea oa trace Ota ee cntvace auemssees eercucmate 99.42 A syenite occurring in the northwestern corner of Floyd county on Lick Fork and Flat Run, and closely similar to the northern Blue Ridge rock, has recently been described by me. The area is a large one, and the rock, both in hand specimens and in thin sections, is strikingly similar to the syenite of Warren, Madison, and Greene counties. The microscope shows the follow- ing minerals: Orthoclase, plagioclase, microcline, pyroxene, biotite, horn- blende, garnet, quartz, and some minor accessories. The rock is typically exposed in the nickel openings on Lick Fork. Additional areas of syenite are referred to by the older writers in a number of other counties in the crystalline area. Although admirably suited for many uses, practically no development of the syenite areas in Virginia has been made. 3. GNEISSES. The Lynchburg Area. On the north and east sides of the city of Lynchburg is an extensive belt of gneiss cut across by the James river and lying partly in Amherst and partly in Campbell county. Excellent exposures of the gneiss are found along the James river and some of its tributaries, near the city, and numerous quarries have been opened and stone supplied for general building and street purposes in Lynchburg. The quarries are located along the north side of James river, in Amherst county, opposite Lynchburg, where the river has cut directly across a broad anticline of gneiss; and to the east of Lynchburg, in Campbell county, along the tributaries of the James river. The stone is a fine-grained dark blue-gray biotite gneiss well suited for the uses made of it. It splits out readily into slabs of any desired 34 MINERAL RESOURCES OF VIRGINIA. thickness, is hard but easily dressed, and very resistant to atmospheric agents. Plate VI, figure 2, is a view in one of the quarries east of Lynch- burg. The Fairfax-Alexandria Counties Area. Extending southward from the Potomac river and covering much of Fairfax and Alexandria counties, are two extensive belts of gneiss, one of which is a metamorphosed granite, the other of doubtful origin. The former rock, known as granite-gneiss, is of fairly uniform color and texture; the latter, which is of doubtful origin, is quite irregular both in color and texture, and composition as well. The granite-gneiss has been quarried quite extensively from time to time for local use, from the ledges along and on the south side of the Potomac river. When fresh the rock is a dark bluish-gray gneiss of rather fine but uniform texture. The principal minerals are quartz, orthoclase, plagio- clase, muscovite, and biotite, with frequently small amounts of garnet, chlorite, hornblende, tourmaline, and pyrite. The gneiss of doubtful origin has been designated by Keith, the Carolina gneiss, and is composed of alternating layers of gneiss and schist of a prevailing gray color, dark bluish-gray when fresh. The bands vary in thickness. Quartz and mica are the predominant minerals in the schist; and quartz, feldspar, and mica, in the gneiss. So far as I am aware the Carolina gneiss has not been quarried in this area. Other Gueiss Areas. Gneisses of granitic composition form one of the most widespread rock- types in the Virginia crystalline area, and large areas occur in many of the Piedmont counties of the State. Like their granite equivalents, from which they have been derived in part, at least, they are usually of the bio- tite type, although hornblende occurs in the gneisses of the Richmond and Fredericksburg areas. Structurally the gneisses vary from irregular banded rocks like those of the Richmond and Fredericksburg areas described above, to regular banded forms like the gneiss of the Lynchburg area. Texturally they vary from fine- to coarse- grained rocks. The more regularly banded ones of uniform texture and color are suitable for general building pur- poses, and all of the Virginia gneisses are well adapted to the pouehes grades of work, such as for all forms of street work, for concreting and ballast, retaining walls, and foundations, and as metal for road construc- tion. MINERAL RESOURCES OF VIRGINIA, PLATE VI Fig. 2.—Gneiss quarry just beyond the southeast limits of Lynchburg, Campbell county. GRANITE AND GNEISS QUARRIES IN VIRGINIA. BUILDING AND ORNAMENTAL STONES. 35 In addition to the quarries of gneiss opened in the Lynchburg area, gneiss has been quarried in Fluvanna, Bedford, and Pittsylvania counties. A gray biotite gneiss has been quarried at Columbia in Fluvanna county, and a large area of dark gray biotite gneiss is exposed for some distance elong the Norfolk and Western railroad at Bellevue. A similar gneiss in color, texture and composition, has been quarried near the depot at Chatham. on Cherrystone creek, in Pittsylvania county. 4, MICA SCHIST. Mica schist is probably the most abundant type of crystalline rock occurring in the Virginia Piedmont region. It is usually thinly foliated, composed essentially of mica and quartz with or without feldspar, and is quite variable in character. Because of its thinly foliated and irregular character, its uses are limited to the lower grades of constructional work. Ordinarily the rock is more or less deeply decayed and fresh exposures of it are not very common. It has been quarried in several localities in the Piedmont region for strictly local use. One of the best grades of mica schist yet quarried in the State is in the vicinity of Rocky Mount, Franklin county. Quarries have been opened in the schist belt, near Rocky Mount, which yields a gray rock well adapted for flagging and other purposes. The stone can be quarried in smooth slabs of any desired thickness. It has been used in Rocky Mount and to some extent in the city of Roanoke for street work. The strike of the schist is 40° east of north, with a dip of 80° to the southeast. Production. Value and uses of granite produced in Virginia from 1900 to 1905 inclusive. mo S 8 a oO mae Ad g ‘ 24 g B bes ; 83 & = “i Yer. | “Sch | gees | mus 3 sg & — as := ° @ 8.2 a Ss 0 ooog | foes | EE 3 Ba geese | Abga moa S ms 1900 $54,225 $76,757 $25,415 $38,850 $15,833 $211,080 1901 49,293 98, 141 25,230 60,008 43,029 275,701 1902 33,658 80,452 45,191 78,275 44,470 282,046 1908 39,785 58,585 38,101 110,005 52,859 299,335 1904 50,933 104,060 67,806 239,335 48,654 510,788 1905 41,639 67,130 30,718 256,899 57,004 452,390 36 MINERAL RESOURCES OF VIRGINIA. 5. TRAPPEAN ROCKS. DIABASE AND BASALT. Trap is the common name given to a class of basic eruptive rocks and it has no distinctive significance in mineralogical composition. It is a useful field name for any dark, finely crystalline, igneous rock. Some of the rocks included under this heading are quarried and known com- mercially as black granite. The ordinary trap rock, such as that com- posing the Palisades of the Hudson in New York, is a crystalline granular mass of plagioclase feldspar (labradorite usually), augite, and magnetite, with or without olivine. It is frequently of finer crystallization than granite and varies in color from dark gray through dark green to almost black. It is exceedingly hard and tough, and on account of its toughness it makes an admirable material for macadamizing roads. In addition to its use as road metal, trap or diabase forms an ex- cellent material for paving blocks and general building and ornamental work, including monumental purposes. Owing to the lack of definite rift in this group of rocks, their compact texture and hardness, they can, as a tule, be worked only with difficulty and usually at a cost greater than that of granite. Diabase has, however, of late years come into more general use for paving purposes, and still more recently for building and monu- mental work. Trap or diabase occurs widely distributed over parts of the Blue Ridge and the crystalline area in Virginia. It occurs in great abundance in the Newark (Jura-Trias) beds, which are shown on the accompany- ing color geological map, and in scattered dikes penetrating the older rocks of the crystalline area. The fissures in the Jura-Trias strata, filled with diabase, are irregular in trend, sometimes following and sometimes crossing the beds of sedimentary rock, and in the Loudoun county area the thickness of the diabase ranges, according to Keith, from 10 feet to possibly 800 feet. The diabase dikes in the crystalline rocks are traced for many miles in extreme cases in the direction of their trend and they vary in width from a few inches up to several hundred feet. One of the best illustrations of the larger dikes in the crystalline rocks is found in Pittsylvania county. The dike is crossed by the Dan river at Neapolis and Danville and is traced northward from the river at Danville along the Southern Railway to and beyond Sycamore Station, a distance of more than 30 miles. Other dikes of the same material and equally as BUILDING AND ORNAMENTAL STONES. 37 large as the Pittsylvania county dike are found in other counties of the crystalline area. The following analyses made by me of the rock from the Pittsylvania county dike, and from nearby smaller ones west of Chatham depot, show their composition : : . Olivine Diabase | Olivine Diabase | Quartz Diabase Constituents. Per cent. Per cent. Per cent. SuG4 se shes taciewces see ceistes 45.73 47.87 52.06 Alumina ..............0066 13.48 14.43 13.67 Ferric oxide... . 11.60 11.55 15.97 Lime...... 9.92 10.45 8.15 Magnesia. 15.40 10.58 5.01 Soda. .... 3.24 3.47 3.36 Potash. 0.47 0.61 0.86 Water .... 0.94 1.82 1.05 Totalisccscs: sees 100.78 100.78 100.13 Specific gravity. ....... 3.026 2.953 In the Blue Ridge region of northern Virginia, extending from the Potomac river southward through parts of Loudoun, Clarke, Fauquier, Warren, Page, Madison, and Greene counties, are extensive sheets or flows of basalt and diabase. The basaltic rock is dense, heavy and dark-colored, and varies texturally from a basalt to a diabase, parts of which are usually altered and sometimes schistose. According to Keith the schistose character prevails in the Harper’s Ferry region, and the rock is known as catoctin schist on account of its great development in Catoctin Mountain in Mary- land. The schistose character of the rock further south in Virginia, from Front Royal southward, is much less well-defined. As a whole it appears more massive than schistose, though in places it is sheeted vertically from close jointing along shear zones. Two varieties of thé basic rocks are recognized near Harper’s Ferry by Keith, a lower diabase sheet, and an upper basaltic sheet, both altered, with the upper one largely epidotized. Thin sections of the rock show variations from fine-grained basalt to, in the coarser varieties, diabase with pronounced ophitic or diabasic texture. The principal minerals are augite, plagioclase, magnetite, some olivine, much secondary epidote and chlorite, and in many of the sections leucoxene. The following analysis 38 MINERAL RESOURCES OF VIRGINIA. made by C. H. Henderson of specimens of the rock from South Mountain, Maryland, shows the chemical composition : Per cent. SilIGAS aid dona ob eace ea se Bee 41.280 SATAN: cg seyite'as & Soar sontie dare, aoe set 18.480 Ferric oxide..............008 9.440 Ferrous oxide................ 8.200 TMG: cane aed cee ees cues 7.040 Magnesia, wis canes s cnn vee oan ss 7.486 SOda .c0ces gus ndeed nearrae es 3.523 POCAS IW, Gee tessa eaueua ten. cuesa ees 2.208 TONItON - renee sen csct Sue teow aaa tc 2.740 Total vcs heed carne esies dens 100.397 The silica was determined by George Steiger of the U. 8. Geological Survey in 2 samples of the basaltic rocks, collected from the following localities in Virginia: 6 miles southeast of Harper’s Ferry, and east of Browntown. The results were 45.66 per cent. and 46.04 per cent., respectively. According to Campbell and Brown, about 3 miles north of Rapidan, a station on the Southern Railway, are to be seen two rounded knolls of similar shape and size, forming rather conspicuous objects in the landscape. These are sometimes called the “Twins,” although known by other names in the neighborhood. On top of the knob nearest to the railroad, beautiful perpendicular, pentagonal and hexagonal basaltic columns form the face of a cliff. Some of these columns are 60 feet high and from 20 to 25 feet in diameter. The stone from the side of the “Twins” is quarried under the name of granite, but it is in reality a hypersthene diabase. Along the railroad, between Rapidan and Mitchell stations, for a mile or more, the same rock appears in the cuts. A few miles east of Culpeper court-house, Mount Pony, an isolated peak, stands out so prominently that. it has been used as a signal station upon various occasions. The greater part of this peak is composed of rock of the same character as the “Twins.” Other knobs and dikes of diabase occur in this region. The composition of the diabase from the quarry on the “Twins,” and from a dike in the railroad cut not far from the “Twins,” is shown in the following analyses, made by W. G. Brown: I II Per cent. Per cent. STIG s aeexnd aaa arth ox a bea aoinaeh Ae a eden 51.31 50.88 AMUN! Yoyo ger etee hans eee nae aatae 13.64 13.17 Ferric: OXide@y.3 6g! bad ados Hewe ew RaeE 0.52 1.11 BUILDING AND ORNAMENTAL STONES. 39 Manganous oxide................... trace trace LAME soak essasia do keaeelaewanes 4 12.41 10.19 Magnesia a5.i.0c8scus resets seed sas 12.73 13.05 OLAS? «aos tnetadmn tas Ge tases eee 0.32 0.31 Oda: sev cean cei eee eee ae heniis 1.40 1.17 Titanium oxide............. 0.0.00, trace — Phosphoric oxide................00. trace — TAMION iocs oo Oa aera wanys eade bee — 0.14 Totals wes as aie ge way es Kanes Hem ee Ae 100.82 99.67 | Specific Gravity.................00. 3.09 3.10 I. Hypersthene diabase from the “Twins” quarry. II. Olivine-hypersthene diabase from dike in railroad cut not far from the “Twins.” Notwithstanding the wealth of diabase of excellent quality found in Virginia, only a few quarries have as yet been opened. The principal quarries opened in this rock are in Loudoun, Fauquier, and Culpeper counties. In the former county, Loudoun, diabase has been quarried near Goose creek, about 3 miles from Leesburg. Excellent stone was found at the surface and few natural joints appear, the rock splitting with ease in any direction. Its texture is coarse and uniform, but it is darker in color than ordinary granite. The stone from this locality has been found to stand a pressure of 23,000 pounds per square inch, and, according to Merrill, the stone undergoes no change on an exposure of 25 years, other than a slight and in no way objectionable darkening of color. In Fauquier county, near the Prince William county line a short dis- tance east of Catlett, a station on the Southern Railway, diabase has been quarried. The rock is of coarse texture, dark gray color, very strong, and apparently durable. As yet the stone quarried at the above dowels has only been used for paving purposes and for bridge abutments, although it is apparently well adapted to all kinds of work for which its color and hardness qualifies it. In other parts of the crystalline area surface boulders of diabase have been worked up for strictly local use. Apart from the utilization of this stone in the better grades of work for which it is well adapted, it should have an extensive use, on account of its general excellence, as road metal, in the construction of permanent good roadways over the crystalline area. DIORITE. Diorite is the name given to a granitoid igneous rock consisting essentially of plagioclase feldspar and hornblende. More or less black 40 MINERAL RESOURCES OF VIRGINIA. mica (biotite) is present, and quartz is a constituent in the more acid varieties when the rock is called quartz-diorite. Diorite occurs east of the Blue Ridge in the crystalline area in the form of dikes of varying width penetrating the crystalline rocks. It is less abundant in Virginia than diabase. The only locality in the State known to the writer where this rock has been quarried at all is in the vicinity of Annandale and Falls Church in Fairfax county. The quarrying of diorite in this locality has been extremely limited, although it readily works out into blocks on account of its more or less gneissoid structure. GABBRO. The word gabbro is employed to designate a granitoid igneous rock composed of plagioclase feldspar and pyroxene. As yet very little is known of the occurrence of this rock in Virginia. Like diorite it is limited in its occurrence to the crystalline area east of the Blue Ridge. It has been found in Amherst county, east of Lynchburg, and in the northwestern corner of Floyd county, but so far as the writer is aware it has not been quarried at any point in the State. References. Campbell and Brown. Composition of Certain Mesozoic Igneous Rocks of Virginia. Bulletin, Geological Society of Am- erica, 1891, II, 339-348. Darton, N. H. On the Occurrence of Basalt Dikes in the Upper Paleozic Series in Central Appalachian Virginia. With notes on the Petrography by J. S. Diller. American Journal of Science, 1890, XXXIX, 269- 271. Geologic Atlas of the United State. Fredericksburg Folio, No. 13. U. 8. Geological Survey, 1894. Darton, N. H. and Keith, A. On Dikes of Felsophyre and Basalt in Paleozoic Rocks in Central Appalachian Virginia. American Journal of Science, 1898, VI, 305-315. Geologic Atlas of the United States. Washington Folio, No. 70. U. 8. Geological Survey, 1901. Keith, A. Geology of the Catoctin Belt. 14th Annual Report, U.S. Geological Survey, 1892-93, Part II, 285-395. Geologic Atlas of the United States. Harper’s Ferry Folio, No. 10. U. S. Geological Survey, 1894. BUILDING AND ORNAMENTAL STONES. 41 Merrill, G. P. Stones for Building and Decoration. New York, 189%. For Virginia granite, see pages 263-264. Phalen, W. C. A New Occurrence of Unakite. ‘Smithsonian Mis- cellaneous Collections, 1904, XLV, 306-316. Rogers, W. B. Geology of the Virginias. (A Reprint of the Annual Reports and Other Papers on the Geology of the Virginias.) New York, 1884. Watson, Thomas L. Weathering of Diabase near Chatham, Virginia. American Geologist, 1898, XXII, 85-101. Some Further Notes on the Weathering of Diabase in the Vicinity of Chatham, Virginia. American Geologist, 1899, XXIV, 355-369. Occurrence of Unakite in a New Locality in Virginia. American Journal of Science, 1906, XXII, 248. Lithological Characters of the Virginia Granites. Bulletin Geological Society of America, 1906, XXVIII, 523-540. Williams, G. H. General Relations of the Granitic Rocks in the Middle Atlantic Piedmont Plateau. 15th Annual Report, U. 8. Geological Survey, 1895, 657-684. Geology of the Crystalline Rocks. Washington Sheet. Maryland, District of Columbia, and Virginia. U. S. Geological Survey. Guide to Washington, pre- pared for the International Congress of Geologists, 5th Session, Washington, 1891. 6. SLATE. INTRODUCTION. Slate suitable for roofing and other purposes is found in many localities in Virginia, and quarries have been opened and worked in Buckingham, Albemarle, Amherst, and Fauquier counties. Slate of commercial value but of which no producing quarries have been opened is found in Prince William, Stafford, Fluvanna, and Craig counties. Along the northeastern base of Massanutten Mountain in the upper or northern part of the Shen- andoah valley a little prospecting in the Paleozoic black shales encourages the possibility of obtaining a reasonably good grade of black slate. Of the slate areas worked, that of the Arvonia belt in Buckingham county is the most important. The several slate belts are separately described in some detail below. 42 MINERAL RESOURCES OF VIRGINIA. DESCRIPTION OF SLATE AREAS. The Buckingham-Fluvanna Counties Belt. In his annual reports of the Virginia Survey from 1835 to 1841, Professor W. B. Rogers called attention to the slate deposits east of the Blue Ridge in Buckingham, Fluvanna, and Fauquier counties. His reference to the Buckingham-Fluvanna slate belt follows: “This [roofing slate] makes its appearance on both sides of the James river, dipping east at an angle of about eighty degrees with the ‘horizon. In Buck- ingham. the bed is largely exposed in the neighbourhood of New Canton on Slate river. . . . In texture, density and capacity of resisting atmospheric agents, it can scarcely be excelled by a similar material in any part of the world. This quarry was first opened to procure slate for roofing the capitol; and notwithstanding it has been thus long known, and its value established, but little further use has been made of it, until the activity of the present proprietor has again brought it into notice. The buildings of the University will soon be furnished with a complete covering of slate from this quarry.” Map, figure 10, in part adopted from Dale, shows some of the important features of this belt. The belt is crossed by the James river a short distance west of Bremo and lies partly on the north side of the river in Fluvanna county and partly on the south side in Buckingham county. On the north side of the river the belt is approximately 1.5 miles wide and strikes N. 20° E. On the south side of the river at Arvonia, in Bucking- ham county, the belt of commercial slate is less than 1 mile in width and strikes N. 35° H. On the north and south sides of the river the slate belt is limited on the east by a micaceous quartzite interbedded in places with thin leaves of slate. Slate also occurs on the east side of the quartzite. The strike of the quartzite is N. 13° to 23° E. and dips 65° to 90° E. On the west side of the belt at Virginia mills there are schists largely chloritic, sericitic and quartzose in composition, which strike N. 25° E. and dip 90°. The belt is frequently traversed by dikes of olivine diabase which range in thickness up to 12 feet. Several of these larger dikes are exposed in some of the larger quarries at Arvonia. The finding of fossils (crinoids, brachiopods, and trilobites) in the slate by Darton at some of the Arvonia quarries shows it to be of Ordo- vician age. Ulrich referred the slate on the above fossil evidence to the Upper Ordovician. The dikes of diabase are of Mesozoic age. MINERAL RESOURCES OF VIRGINIA PLATE VII. CE ATE te) 4 Fig. 1—Slate quarry in the Arvonia area, Buckingham county, showing the nearly vertical slaty cleavage. Fig. 2.—Slate quarry in the Arvonia area, Buckingham county. SLATE QUARRIES, ARVONIA, BUCKINGHAM COUNTY, VIRGINIA. BUILDING AND ORNAMENTAL STONES. Bs wy h Vy K CESK IM Sale Sea 4 ANS os SKS ff = Fig. 10.—Map of the Arvonia slate area, Buckingham county. Quarri shown by heavy dots; strike of commercial slate by arrows. Based o the Palmyra topographic sheet, U. 8S. Geol. Survey. Scale, 3 in equals 1 mile, approximately. Contour interval, 5C feet. 44 MINERAL RESOURCES OF VIRGINIA. Arvonia.—Arvonia, a station on the Buckingham branch of the Chesapeake and Ohio Railway, is in the midst of the producing parts of the slate belt and is the shipping point. The quarries are distributed along Hunts creek for some distance north-northeast and south-southwest of Arvonia. The following companies were operating quarries at and near Arvonia during 1906: The Williams Slate Company. The A. L. Pitts Quarries. The Arvonia Slate Company. The Buckingham Slate Company. The Richmond Slate Company. The LeSeur Slate Company. The Virginia Slate Company. The Penlen Slate Company. Excepting the quarries of the Penlen Slate Company all the operating slate quarries are located on the east side of the belt. The quarries of the Richmond Slate Company are the most easterly ones and are situated about 100 yards west of the slate-quartzite contact. The quarries are very extensive, the largest averaging about 500 feet along the cleavage, 350 feet across, and 350 feet deep. The bedding and cleavage of the slate are identical, striking N. 33° to 37° E. and dipping 70° to 90° southeast, with a probable average of about 85°. ‘Three sets of joints cut the slate, namely, dip joints striking northwest and dipping about vertical; strike joints striking northeast and dipping southeast 70° to 80°; and diagonal joints one set of which dips about 30° east, the other about 50° to 60° west. ; The slate from the Arvonia quarries is a very dark gray, with a faint greenish hue; is of minutely granular crystalline texture and very lustrous surface. According to Dale it is slightly graphitic and magnetitic, does not effervesce in cold dilute hydrochloric acid, and is very sonorous. Dale gives the constituents of the slate in order of their abundance as muscovite and sericite, quartz, biotite, carbonate, graphite (or carbonaceous matter), pyrite, chlorite, magnetite, with accessory plagioclase, zircon, hematite, tourmaline, and rutile. Dale gives the following microscopic description of the slate from the Williams quarries, which may be taken as representative of the belt, as follows: “Under the microscope it shows a matrix of minute, alternating beds, chiefly of fine muscovite, with coarser ones, chiefly of quartz, the former with a brilliant aggregate polarization, the latter with a faint one. These beds are parallel to the cleavage. The quartz fragments measure up to 0.085 millimeter. Scattered throughout both the more MINERAL RESOURCES OF VIRGINTA, PLATE VIII. Fig. 1. View in one of the Williams Slate Company’s quarries at Arvonia, Buckingham county. Fig. 2.—View in abandoned slate quarry at Arvonia, Buckingham county. SLATE QUARRIES, ARVONIA, BUCKINGHAM COUNTY. VIRGINIA. BUILDING AND ORNAMENTAL STONES. 45 micaceous and the more quartzose beds are crystals, lenses, and particles of pyrite, numbering about 25 to each square millimeter and measuring up to 0.09 millimeter, rarely 0.15 and 0.42, with their longer axes parallel to the cleavage. These probably include a little magnetite. There are also biotite scales transverse to the cleavage, about 22 per square millimeter, and measuring up to 0.12, rarely 0.2 millimeter. Almost, if not quite, as abundant are plates and rhombs of carbonate. There are occasional scales of chlorite interleaved with muscovite, a few grains of plagioclase feldspar 0.047 millimeter, rarely one of zircon, some tourmaline prisms 0.014 millimeter long, much extremely fine graphitic (or carbonaceous?) material, a few particles of hematite, and some rutile needles. Sections parallel to the cleavage are unusually brilliant in polarized light, owing to the abun- dance of quartz, biotite, and carbonate.” . Recent tests made by Professor Merriman on the slate from the Williams and Pitts quarries are given by Dale as follows: 3 £ a 2 ° Poa © 23 3 ' a s lt om eh a g Qo Sw Sez [2223/2 | 2222 | 23 | 5828 Color and . a5 4 soaa| as ay Bak |oeus aad ~H ¥ Dey ~ Sm sees om Peg eo firm oo |ga& | eogs a eo Bh meo |B a : 8 (meg |Stad| PS agree) eee lesig Mg eos A Me? g caer cet s8eon ed Soc Hg [eX ee|See5| Se | Stee | BFS | Begs Sa |A8a8/SH8R| Gh | ware | aes |S8es Blue. wi 8,590 0.17 2.788 0.073 0.105 0.281 Williams Ww 2 8,250 19 2.754 .038 .090 .801 Slate W 3 10,700 .ol 2.795 097 . 209 223 Company W4 8,620 24 2.788 . 033 .167 .270 Means 9,040 .227 | 2.781 . 060 143 894 Blue. Pil 8,540 0.25 2.805 0.095 0.332 0.248 A. L. Pitts P 2 9,010 0.18 2.790 .159 —- 0.552 Quarries P3 11,970 .25 2.788 .138 154 275 P4 9,880 22 2.781 . 038 .163 .218 Means 9,850 . 225 2.791 .108 .216 823 Although Dale’s results on the microscopic study of the Arvonia slates show the presence of some carbonate, an appreciable amount of ferrous carbonate cannot be present, for the use of these slates on buildings in Richmond more than 60 years ago, and on buildings near the quarries for more than a century, show no discoloration whatever. Strength and dura- bility would naturally follow from the highly crystalline character of this slate. 46 MINERAL RESOURCES OF VIRGINIA. Bremo.—Slate has been prospected at several places north of the James river several miles west-northwest from Bremo in Fluvanna county. The strike and dip of the slate are approximately the same as south of the river at Arvonia—the strike being N. 18° to 23° E. and dip nearly 90°. A dike of olivine diabase about 10 feet wide cuts the slate about 2 miles northwest of Bremo. The slate from near the surface is dark gray, which color will probably prove darker on depth. It differs from the Arvonia slate in finer texture, possibly lighter shade, and slightly increased pyrite; but less biotite and no carbonate. It contains a little graphite, does not effervesce in cold dilute hydrochloric acid, is sonorous, and very fissile. Arranged in order of abundance the chief constituents are, according to Dale, muscovite, quartz, pyrite, kaolin, chlorite, graphite (or carbonaceous material), rutile, with accessory tourmaline, zircon, biotite, and hematite. A microscopic examination of this slate by Dale gave: “There are abundant quartz grains up to 0.09 by 0.03 and 0.13 millimeter long, the larger ones surrounded by secondary quartz, radiating along the cleavage; about 50 lenses and crystals of pyrite per square millimeter, measuring up to 0.09 by 0.02 (exceptionally the lenses are 1.5 millimeter long), with their longer axes in the cleavage. There are also square and rhombic spaces lined with secondary quartz, measuring up to 0.6 millimeter, left by the dissolution of cubes or distorted cubes of pyrite. In some speci- mens there are 65 such cavities to the square inch, in others none. There are lenses up to 0.56 by 0.11 millimeter, consisting of quartz and musco- vite or of these and chlorite and pyrite, or of chlorite and muscovite, the folia of muscovite and chlorite lying across the cleavage; also muscovite scales up to 0.09 by 0.02 millimeter. Throughout the matrix much dark gray material occurs in exceedingly fine dots (graphite?). There are also some dots of hematite. Rutile needles are not very plentiful up to 0.01 millimeter long; also a number of very irregular particles of rutile up to 0.05 millimeter, consisting of a network of crystals (“sagenite twin- ning”) forming angles of 120° and 60°. A few fragments of zircon, an occasional crystal of dark tourmaline up to 0.05 by 0.02 millimeter, rare flakes of biotite, no carbonate.” The Albemarle County Belt. The Albemarle county slate belt lies about 20 miles west-northwest of the Arvonia belt. It is reported as being crossed by the James river at Manteo, a station on the Chesapeake and Ohio Railway, and near the BUILDING AND ORNAMENTAL STONES. 47 Nelson and Buckingham county line. It has been opened at Keswick, Hs- mont, and Buck Island creek. At the latter place the Albemarle slate quarries were operated many years ago. Slate has recently been prospected near Keswick. During the summer of 1906 a company begun operating a quarry near Esmont. Slate of black, green and red colors is reported from the Esmont quarry. The Amherst County (Snowden) Belt. An extensive belt of slate is found on the southeast side of the Blue Ridge, in the vicinity of Snowden station in the southwest part of Amherst OS % r let a Lees ‘ 1s ° 150 IX a. 7 S \ O. A _ Sees q > Showden Fr NEN i oS Fig. 11.—Map showing location of Snowden slate quarries, Amherst county. Quarries shown by black dots; strike of commercial slate by arrows. Based on the Lexington typographic sheet of the U.S. Geol. Survey. Scale, 3 inch equals 1 mile, approximately. Contour interval, 500 feet. county. The belt has been prospected in a number of places in the county but only one quarry was operating during 1906, located about 3 miles north-northwest of Snowden. It is known as the Williams Brothers slate quarry on the property of the Virginia Slate Mining Company. The quarry is further situated on the southwest side of Rocky Row Mountain just under Saddle Gap and about 1,200 feet above the James river, as shown on the accompanying map, figure 11. The slate strikes 48 MINERAL RESOURCES OF VIRGINIA. N. 65° E. and has quartzite southeast of it which has been referred to the Cambrian. The structure, a flat-topped anticline, indicates a possible overturn. : The Williams Brothers’ quarry was opened in 1880. The production was steady from 1893 until the burning of the mill in October, 1904. Rebuilding of the mill was in progress during the summer of 1906 and the production was expected to begin by September of the same year. The cleavage strikes N. 45° E. and dips 30° S. 60° E. The bedding is strongly marked by finely plicated ribbons of quartz and calcite several inches wide and is cut by the cleavage at an angle of 45° and more, as shown in figure 1, plate IX. Joints are well developed, striking N. 15° to 20° EH. and dipping about 70° W., and a second set intersecting the first at approxi- mately right angles, and dipping at about 65° east. The slate is very dark gray, has a minutely granular texture, moderate- ly smooth cleavage, but with little luster. It resembles the Arvonia slate in not effervescing with cold dilute hydrochloric acid and in being quite sonorous, but differs from it in not being graphitic nor magnetitic. Ar- ranged in order of abundance, the chief constituents of this slate are, according to Dale, muscovite (sericite), quartz, chlorite, kaolin, pyrite, carbonate, rutile, and carbonaceous matter. It is used exclusively for roofing and is a superior slate though less crystalline than the Arvonia slate. Dale gives the following results of a microscopic examination of this slate: “Under the microscope it shows a matrix of muscovite (sericite), with aggregate polarization not very brilliant owing partly to the coarse- ness of many of the other constituents. Quartz fragments measure up to 0.08 millimeter; chlorite scales and lenses up to 0.28 in length, rarely 0.42 by 0.2 millimeter, numbering about 6 per square millimeter; also mus- covite scales up to 0.09 millimeter; some carbonate, but in exceedingly min- ute rhombs and plates ; grayish gachonatenus (?) matter ; about 55 spherules and pyritohedrons of pyrite per square millimeter, measuring up to 0.005 millimeter; abundant rutile needles, and occasional fragments of zircon.” Slate was prospected some years ago on the Thompson property, less than 2 miles northeast of the Williams Brothers quarry. ‘The slate closely resembles that of the latter quarry. According to Dale the’ strike of bed- ding is N. 58° E. and dips 20° E., with cleavage nearly horizontal; strike of joints N. 38° E. and dips 20° W. MINERAL RESOURCES OF VIRGINIA. PLATE IX. eet “Spt Poe Sie ~ NS KS 10 J. Natural Bridge dolomite; ;9. Massive 9 10 ft.; 5. Nodular dark blue lime- 52ft.; 8. Thin bedded dove limestone, 60 ft. showing strata in detail : d calcareous shale, 40 ft.; 12. Martinsburg shales. 4, Crinoidal limestone, , SSS, +6. Argil 65 ft; Stones River limestone; stone, 30 ft.; dove limestone, 2. 1 CEMENT AND CEMENT MATERIALS. 107 of this band. The Stones River strata here are especially characterized by the growth of cedar trees along their outcrop. The purer portion of this formation is made up of dove or bluish limestones often showing outlines of small gastropods upon worn surfaces. The argillaceous materials are very similar to those described later in the Strasburg section, and, as the analysis shows, have a favorable composition: Analysis of argillaceous limestone, just east of Winchester, Va. (J. H. Gibboney, Analyst) Per cent. TSOMUDIE io sse-sietss sea de scessnbsd sa seca: 8. penadk ad austen 8S ays 14.78 Iron oxide (Fe,0O;) and alumina (AI,0;)....... 2.72 Lime: (CaQ): s gisavss ssaa's eatey ex wags a0 ard ane aes. o 3 shee 8 44.94 Caleium carbonate (CaCO,).............0e eae 80.25 Magnesia (MgO) .......... cece cece cece eee 0.34 Magnesium carbonate (MgCO;)............... 0.71 Total sire cared, Hananece espe ice gacsieed miners bee aa Hie 98.46 Middletown.—This and the neighboring towns of Stephens City and Meadow Mills are favorably located so far as transportation facilities and abundance of cement materials are concerned. The following section taken along the street west from the depot at Middletown gives the sequence of rocks in the region. Section of Ordovician rocks in the vicinity of Middletown, Virginia. Feet 9. Mainly covered but apparently all calcareous shale...............+.+5-- 100: 8. Mainly covered but showing traces of earthy limestone.................- 150 7. Partially covered, with bluish limestone at the top and earthy or nodular limestone at intervals...... 0... cece cece eee ete 100 6. Nodular limestone with specimens of Echinosphrites near the base...... 20: 5, Améniaceoits; Shale viz. c cece a sayedce aig ann dee MSE MEENA PTE Eee ah En wee 20 4: “Unexposed) siies acta gain rean es MEET HO RG See A Mele dane Rea Hee tesa TES 30: 3. Dark gray to black limestone with chert.......-.......ss cece eee eens 38 2. Massive dove limestone, apparently the same bed as that quarried for lime at Strasburg ..... 22... eee cee teeta n eens +40 1. Mainly magnesian limestone but with a few layers of pure limestone..... 300: This section then continues westward, the magnesian and pure lime- stones of the Stones River formation being shown in a small anticline between Middletown and Meadow Mills, until in the vicinity of the latter place, the higher pure and argillaceous limestones are again exposed in a small syncline. Strasburg—The abundant pure and clayey limestones in the vicinity of Strasburg combined with the railroad facilities, makes this one of the most promising sites for cement manufacture. As shown on the map, 108 MINERAL RESOURCES OF VIRGINIA. figure 16 (this page), the line of outcrop of Martinsburg shales passes through Strasburg so that to the east of the town an abundance of shale may be found, while to the west occur the various limestones. The rocks of economic importance outcrop between the town and Strasburg Junction, a mile or more to the west, where the upper part of the Stones River n limestones == Ordovician shales Fig. 16.—Map showing distribution of cement materials of northwestern Virginia. formation is being quarried and burned into lime. The section printed on page 106 is found exposed mainly between the two localities mentioned, although the lower beds of the Stones River and the Natural Bridge dolomites outcrop west of Strasburg Junction. The rocks dip to the east and are encountered in ascending order as Strasburg is approached. CEMENT AND CEMENT MATERIALS. 109 The Strasburg section is so complete that it has been employed as a type section for northwestern Virginia. For this reason, the various strata likely to be employed as cement materials were carefully sampled and analyzed. The results of these analyses are given in the following table: Analyses of limestones and shales, vicinity of Strasburg, Virginia. (J. H. Gibboney, Analyst) : I II Ill 1V Vv VI | VIL Per ct. | Per ct. | Per ct. | Per ct. | Per ct. | Per ct. | Per ct. ie oeide (ies ee ore 2.32) 43.50) 19.78) 12.10} 8.68) 12.00) 27.60 ron oxide (Fe,O3)... .....eese eens. 0.24 on Miyowinn (ALO, a s0.c0ee casa seatones hedateees }5.50 1.88, 1.48) 1.82) 2.26) 3.36 Dime! (Ca) cc ccitoesccs os baed seukcaies 54.04/ 26.80) 41.60) 47.40) 49.68) 47.16) 37.40 Calcium carbonate (CaCO,).......... 96.43) 47.86) 74.28) 84.64) 88.71] 84.21) 66.97 Magnesia (MgO).......-.....-0 eee eee 0.52) 1.04] 0.39) 0.80) 0.64) 0.54) 0.58 Magnesium carbonate (MgCO,)....... 1.09} 2.18) 0.82} 1.68) 1.34) 1.13) 1.22 Total see scaieaaaaae ceive gua 100.08] 99.04; 99.76] 99.90}100.05} 99.60) 99.15 I. Blue limestone, lower part of bed 3a, Chambersburg formation. II. Siliceous blue limestone, upper part of bed 3a, Chambersburg formation. III. Dark gray, argillaceous limestone, bed 3e, Chambersburg formation. IV. Thin bedded dove limestone, bed 3f, Chambersburg formation. V. Massive dove limestone, bed 3g, Chambersburg formation. VI. Gray earthy limestone, bed 3i, of Chambersburg formation. VII. Calcareous shales at base of Martinsburg shales. Woodstock and vicinity—About 350 feet of argillaceous limestones of the Chambersburg formation may be found exposed just east of Wood- stock before the Martinsburg shales are encountered. These limestones and the overlying shales dip at an angle of about 40° southeast. Practi- cally the same thickness of cement rock is exposed to the northeast and southwest of Woodstock, but although the outcrops are not as good as those noted in the Strasburg area, essentially the same section may be found. As this line of outcrops is paralleled by the Southern Railroad, which is at no place more than 2 miles distant, favorable sites for cement plants are offered. The most promising location, however, is in the immediate vicinity of Woodstock, since here the cement rocks outcrop on the western side of the North Fork of the Shenandoah river. Farther south the river flows between the railroad and the cement rock outcrop, and the cost of a spur Tine would thus be greatly increased. Pure limestones for mixture with the cement rock can be found in the immediate vicinity, west of the line of the outcrop of the argillaceous 110 MINERAL RESOURCES OF VIRGINIA. rock. Limestone strata, high in calcium carbonate and low in magnesia, were found interbedded with the dolomites west of Woodstock, and more extended search would no doubt reveal an ample supply. The following analyses are of the pure and argillaceous limestones in this vicinity: Analyses of limestones, Woodstock, Virgunia. (J. H. Gibboney, Analyst) I II Ili Fer cent. Per cent. Per cent. Insolublésicswivwe-cs oxat saaeesd ete ves Saanion 56.26 14.88 10.04 Iron oxide (Fe,O,) and alumina (A],0,)....... 4.82 2.38 1.46 Lime (CaQ)iin ca uess Antec a br ensoas woes seen 18.96 45.00 48 48 ‘Calcium carbonate (CaCO )........-. 0.002 sees 33.88 80.36 86.57 Magnesia (MgO)... ......... 2c eee ee cee ee 91 1.04 0.73 Magnesium carbonate (MgCO,)............05- 1.91 2.18 1.54 TOtall scstedtescasitrecsdte cise, ceases Sale Senne 29-wine ocnaea a eaten oneness 5.92 Iron oxide (Fe,O;) and alumina (AI,0;)........ 62 Linié (CaO) sic tsaeaw saddened co6 ghee tees ees 50.62 Calcium carbonate (CaCO,)...........000e eee 90.40 Magnesia (MgO) sis iet se suidge sta ee a on ee ae ee 30 Magnesium carbonate (MgCO;)................ -63 Motel! pects ey nce negecen.s Pages aeds ue 97.57 NATURAL CEMENT. The relation of natural cements to other cements has been oriefly noted on a previous page. An extended and valuable treatise on this subject is presented by Mr. Eckel in his “Cements, Limes and Plasters.” In the present article, the writer wishes to point out briefly the distribution of the limestones suitable for this kind of cement, to give analyses, and to indi- cate the present status of the natural cement industry in Virginia. Under ordinary circumstances the value of natural cement is too small to allow it to be shipped any distance with profit. Therefore. the manufacturer must have a home market and little competition. The raw material is an argillaceous limestone carrying from 13 to 35 per cent. of clayey material, of which about 10 to 22 per cent. is silica, while alumina and iron oxide together may vary from 4 to 16 per cent. Unlike Portland cement rock, the percentage of magnesium carbonate may run high, the reason for this being, that in natural cements the magnesium and lime are regarded as interchangeable. The hydraulic properties do not depend upon the percentage of lime but upon the clayey materials, which therefore are the important factors to consider in the rock analysis. Juimestones having a composition within the limits just indicated are more or less abundant at several horizons in western Virginia, but probably the only one which will meet all the requirements and prove of economic importance is the argillaceous magnesian limestone of the lower part of the Shenan- doah group. This rock, although often very similar in lithologic characters to the dolomitic limestone found higher in the Shenandoah, can be recog- nized as containing argillaceous matter by the clayey odor given forth when breathed upon. These limestones (Sherwood) and shales (Buena Vista) have been de- scribed on page 94, where their use in the making of natural cement was noted. These strata may be found at various points along the eastern side CEMENT AND CEMENT MATERIALS. 161 of the Appalachian Valley so that a considerable supply of the necessary materials should be available. The clayey magnesian Cambrian limestone used by the James River Cement Company at Balcony Falls, Rockbridge county, Virginia, in mak- ing natural cement, gave the following results upon analyses: Analyses of natural cement rock, Balcony Falls, Virginia. I II Ill Per cent. Per cent. Per cent. en Jobe Weed edesedeatenpybences aeeee 17.38 17.21 17.30 amina (AI,O5) ccsvscsewses cteewene: ccscsaedivcvscesive tr. 6.18 Iron orld (Be,0,)-- a pee eA anse } ee { 8 82 ime (CaQ).......sesesseee sue Sass bos : : : Magnesia (Mg0Q)........ . 9.51 16.58 13.05 Carbon dioxide (CO,).... 30.40 37.95 34.17 I. E. C. Boynton, analyst. Gillmore, “Limes, Cements, and Mortars,” p. 125. II. C. L. Allen, analyst. “The Virginias,” vol. 3, p. 88. IlI. Average of preceding two analyses. This same belt of magnesian limestones and shales of Cambrian age crosses Virginia into West Virginia and Maryland. Several small natural cement plants have been established in this district at various times, par- ticularly near Antietam, Maryland, and Shepherdstown, West Virginia. Analyses of natural cements, Shepherdstown-Antietam District, West Virginia-Maryland. I II Ill IV Per cent. Per cent. Per cent. Per cent. Silica (SiO,) ......000seresseeereeees sees 33.42 36.51 33.50 15.97 Alumina (A1,05) 05 cree seeeeteereeees 10.04 9.36 10.44 759 a Teo \ Cs Og) desve sats desies-ceehs ss a sei aes Aes se ime (CaQ)......ccscceeeesereseeeeceee: i : : : Magnesia (MgO).......06: essere Resets: 9.59 11.33 13.37 15.60 Alkalies (K,0, Na,O)...... s+ 0.50 1.25 n. d. n. d. queens eee (SO, ): sserssvvnse os n. d. 1.49 1.15 0.71 arbon dioxide......... " "Waber: sa evvteavsecarsctaeettencnci siti } 7.86 5.18 aoe ee I. Shepherdstown, W. Va. Quoted by Cummings. “American Cements,” p 35. II. Shepherdstown, W. Va. C. Richardson, analyst. Brickbuilder, vol. 6, p. 229 Ill. Antietam, Md. C. Richardson, analyst. Brickbuilder, vol. 6, p. 229. IV. Antietam, Md. C. Richardson, analyst. Brickbuilder, vol. 6, p. 151. Limestones suitable for the manufacture of natural cement occur in southwestern Virginia, particularly along the eastern half of the Appa: 162 MINERAL RESOURCES OF VIRGINIA. lachian Valley. Geologically, these succeed the siliceous deposits of Lower Cambrian age and form the base of the great Shenandoah limestone group. Geographically, however, these particular areas cannot be indicated with- out detailed mapping, requiring long field work. During the progress of his work on the lead and zinc deposits of Virginia, Dr. T. L. Watson col- lected samples of these limestones for analysis. The results were published in Bulletin No. 1 of the Virginia Geological Survey, and analyses selected from this publication are quoted below. Analyses of Shenandoah limestone. I II Ill IV | Per cent. | Per cent. | Per cent. | Per cent. 2.90 0.594 0.45 0.20 trace .073 trace trace none none none none 0.43 0.344 0.24 0.37 0.94 0.19 0.17 0.22 none 0.1938 0.37 trace 30.06 29.085 | 29.50 30.71 18,41 20.54 19.93 21.56 none none trace none 0.24 0.22 0.56 0.12 Na,O 0.21 0.38 1.03 0.10 H,O 100°C- HO 100°C 3.30 2.58 3.73 3.92 COs secnsiscnansstiaen Covvseaeuses 43.98 45.40 44.01 43.88 PO, «.. - ..{ none none none none Og: cue baenaser: eevsusstizevecs, abbeedee-ssvegeocevanddeee vous: none none none none Total isco hacen tap einig nutans ine 100.47 99.599 | 99.99 | 101.08 I. Limestone. Massive grayish black fine granular, crushed and recemented with stringers of pure white calcite. Martin property, two and three- quarter miles southwest of Roanoke City, Roanoke county, Virginia. Dr. W. E. Barlow, analyst. II. Limestone. Grayish white and moderately coarse crystalline. Specimens taken from the 190-foot level in the Austinville zinc and lead mines, Wythe county, Virginia. Dr. W. E. Barlow, analyst. III. Limestone. White, coarsely crystalline, and crushed. Specimens taken from the 80-foot level at bottom of open cut, in the Austinville zinc and. lead mines, Wythe county, Virginia. Dr. W. E. Barlow, analyst. IV. Limestone. White and medium crystalline. Specimens taken from the 80- foot level at bottom of open cut, in the Austinville zinc and lead mines, Wythe county, Virginia. Dr. W. £. Barlow, analyst. CEMENT INDUSTRY IN VIRGINIA. Although the cement industry may be said to be in its infancy in western Virginia, yet the manufacture of this important economic pro- ‘VINIDUIA ‘ALNNOO VISODNAV ‘INVId INANWHO GNVILYOd ‘OTASsIVIN “TINT JUSeMaD puryjiog uoiumnuoqg pig XN DLV Id VINISUIA TO STOMIOSM TWAIN CEMENT AND CEMENT MATERIALS. 163 duct has been carried on for many years at one locality, and for a less time at another. Natural cement has been burned near Balcony Falls, Rock- bridge county, for over half a century. The demand for a cheap and trust- worthy cement for use in the construction of masonry, locks, and walls on the James River Canal, led to the discovery of the hydraulic properties of the rock used at this plant. Since that time a natural cement has been manufactured at this locality almost continuously, the James River Cement Company operating the plant at the present time. The rock used is a steel blue, argillaceous limestone of Lower Cambrian age, with an average thick- ness of twelve feet. For a description and history of this cement plant, the reader is referred to an anonymous article published in the Engineer, September 29, 1899. But a single plant for the manufacture of Portland cement is in opera- tion in Virginia, namely, that of the Virginia Portland Cement Company at Craigsville, Augusta county. The geologic section at Craigsville and analyses of the rock employed have been given on a previous page. As the methods employed by the Virginia Portland Cement Company are those of a large, modern plant, a description of the process of manufacture is here introduced. The materials used in the manufacture of the Old Dominion cement are Lewistown limestone and shale. The principal limestone quarry is lo- cated a mile and one-eighth from the plant, and the shale quarry three- quarters of a mile. The shale is crushed at the quarry and brought down on a standard gauge track to the scale house, where it is elevated into bins over the scales. The limestone is brought to the scale house on a narrow gauge track in cars containing about 3,000 pounds of limestone. The limestone cars are weighed and the proper percentage of shale is dropped from the bins onto the limestone, and the narrow gauge car is then picked up by a cable and carried to a 7-14 Gates crusher, through which the limestone and shale pass together. The output of the crusher goes through a revolving screen and the rejections from the screen are passed through a No. 3 crusher. From the crushers, the raw material is elevated on a belt conveyer to 12 tanks con- taining about 70 tons each. The material is drawn from the bottom of these tanks into a belt conveyer, which carries it to the rotary dryers, J in number. From the dryers, the material is carried on a belt conveyer to the raw material mill, where it receives its preliminary grinding in ball 164 MINERAL RESOURCES OF VIRGINIA. mills, and its fine grinding in pebble mills. The outfit of this raw material mill consists of 3 Krupp ball mills, 2 Smidth kominuters, 3 Krupp pebble mills and 3 Smidth pebble mills. The ground material is conveyed by means of belt conveyers, elevators and screw conveyers to tanks over the kilns, and is fed into the kilns by conveyers in the bottom of tanks. The rotary kilns are 10 in number, 60 feet long, 6 feet in diameter, slightly inclined from the feed end to the discharge end. Powdered coal is used as fuel for burning the raw ma- terial. It is blown in by a low pressure blast of air and ignites instantly. The heat generated is about 2,600°. The coal is first dried in rotary dryers and passed through pebble mills similar to those used for grinding the raw material. The material passes from the kilns in the form of clinker and is ele- vated into coolers through which a blast of air is forced. From the bottom of the coolers, it is drawn by means of a belt conveyer to the clinker storage, where it is allowed to age for about three weeks. Underneath the floor of the clinker storage are belt conveyers, which convey the clinker to the cement mill. The process in the cement mill is a repetition of that in the raw mate- rial mill. The cement grinding machinery consists of 2 Krupp ball mills, 3 Smidth kominuters, 2 Krupp pebble mills, and 4 Smidth pebble mills. From the cement mill, the finished cement is conveyed by belt conveyers to the 2 stockhouses, where it is stored in bins until such time as it is shipped out. The cement is drawn from the bins into screw conveyers, elevated into bins over the bag packers and barrel packers. The bag packers are operated by hand and the barrels are packed by power. The storage capacity is 100,000 barrels. The present output of the plant is between 1,800 and 1,900 barrels per day. Construction work is at ‘present under way to increase the capacity of the plant to 3,000 barrels per day. The power equipment of the plant includes 8 Sterling water tube boil- ers, 1 Hamilton Corlis engine of 750 H. P., 1 Cooper Corlis engine of 1,100 H. P., and 1 Westinghouse engine of 250 H. P. Electric generators located in the power house furnish current to motors which operate the kilns and a large part of the conveying machinery. The grinding ma- chinery is belted to shafting. As the mill is located so far away from any city, it was necessary for the company to provide homes for its employees. The company has ac- commodations for some 200 families, runs a commissary store, village CEMENT AND CEMENT MATERIALS. 165 water works, etc. The company employs a physician, maintains a hos- pital, and close attention is paid to sanitary inspection. The number of employees is about 425. References. Reports treating of the limestones and shales of Virginia with refer- ence to their use as cement materials have been few. Numerous papers treating of the geology of Appalachian Virginia, particularly of the south- western part, have been published, but few of these have direct bearing on, or are of use in, the location of cement rock. Those which may be found of value in this respect are noted in the following bibliographic list. The U. 8. Geological Survey has mapped all of western Virginia geo- graphically, this area being included in 27 quadrangles. However, only 8 folios of the Geologic Atlas of the United States touching this region have been published. These are the Harper’s Ferry folio for northwestern Virginia; the Staunton, Franklin, and Monterey folios for central western Virginia; and the Pocahontas, Tazewell, Bristol, and Estillville folios for southwestern Virginia. These folios contain topographic sheets, areal and economic geologic sheets, and structure sections of the areas studied, with text descriptions of the geology and mineral resources. However, only the 4 last mentioned give maps in which the argillaceous and pure limestones of Ordovician age are separated from the impure Cambro-Ordovician series. Natural Cement. Anonymous. James River, Virginia, Cement Co. Engineer (Lon- don), September 29. 1899. Fekel, E. C. Natural cement resources of Virginia. U.S. Geologi- cal Survey, Bulletin No. 225, 1904, 457-461. Portland Cement. Bassler, R. 8. Cement materials of the Valley of Virginia. U. S. Geological Survey, Bulletin No. 260, 1905, 531-534. Portland cement resource of Virginia. U. 8. Geolog- ical Survey, Bulletin No. 243, 1905, 212-323. Catlett, C. Cement resources of the Valley of Virginia. U. 8. Geological Survey, Bulletin No. 225, 1904, 457-461. Vredenburg, W. The Virginia Portland Cement Company’s Works, Craigsville, Wa. Engineering Record, July 28, 1900. Cement Industry, 1900, 132-141. 166 MINERAL RESOURCES OF VIRGINIA. Miscellaneous. Analyses of the rocks, references, maps, or descriptions of the limestones and shales of western Virginia are given in the following works: Boyd, Charles R. The Mineral Resources of Southwestern Virginia. Wiley and Sons, New York, 1881, 381 pages. Campbell, H. D. The Cambro-Ordovician Limestones of the Middle Portion of the Valley of Virginia. American Journal Science (4), 1905, XX, 445-447. Campbell, M. R. Paleozoic Overlaps in Montgomery and_ Pulaski Counties, Virginia. Bulletin Geological Society America, 1894, V, 171-190. Campbell, J. L. Silurian Formations in Virginia. American Journal Science, (3), 1879, XVIII, 16-29, 119-128. Campbell, J. L. and H. D. William B. Rogers’ Geology of the Virginias. A Review. American Journal of Science (3), 1885, XXX, 357-374; 1886, XXXT, 193-202. Darton, N. H. Notes on the Stratigraphy of a portion of Central Appalachian Virginia. American Geologist, 1892. X, 10-18. Eckel, E. C. Cement Materials and Industry of the United States. U. 8. Geological Survey, Bulletin No. 243, 1905. Cements, Limes and Plasters. Wiley and Sons, New York, 1905, 712 pages. McCreath, A. §., and d’Invilliers, E. V. The New River-Cripple Creek Mineral Region of Virginia. Harrisburg, Pa., 1887, 18, 24, 40, 51, 54-58, 70-76, 82, 89. ~ Rogers, W. B. Reports of the Progress of the Geological Survey of the State of Virginia (1836-1841). A Reprint of the Geology of the Virginias. New York. 1884. Spencer, Arthur Coe. The Geology of Massanutten Mountain in Virginia. Washington, D. C., 1897. Stevenson, John J. Notes on the Geology of Wise, Lee and Scott Counties, Virginia. Proceedings American Philosophical Society, 1880, XIX, 88-107. A Geological Reconnaissance of Parts of Lee, Wise, Scott and Washington Counties, Virginia. Pro- ceeding American Philosophical Society, 1881, XIX, 219-262. CLAYS. 167 Notes on the Geological Structure of Tazewell. Russell, Wise, Smyth and Washington Counties of Virginia. Proceedings American Philosophical Society, 1885, XXII, 114-116. A Geological Reconnaissance of Bland, Giles, Wythe and portions of Pulaski and Montgomery Counties, Virginia. Proceedings American Philosophical Society, 1887, XXIV, 61-108. Stose, G. W. The Sedimentary Rocks of South Mountain, Pennsyl- vania. Journal of Geology, 1906, XIV, 211. Watson, Thomas L. Lead and Zine Deposits of Virginia. Virginia Geological Survey, Bulletin No. 1, 1905, 156 pages. Ill. CLAYS. BY HEINRICH RIES. DEFINITION AND PROPERTIES OF CLAY. Clay is one of the most curious and least understood of our common mineral products, and various investigators have spent much time in attempts to discover the causes of its peculiar properties. In some cases they have partially succeeded; in others it must be admitted that while they have partly solved the problem, they are nevertheless still very far from a complete and satisfactory interpretation of the phenomena dis- cussed. Man at a very early period in the earth’s history discovered the peculiar qualities of the common substance known as clay. That its use- fulness has steadily increased is evidenced by the fact that in 1904, the value of clay products made in the United States alone exceeded $130,- 000,000, which was greater than the value of other important products such as gold, silver, copper, and petroleum, and was only outranked by iron and coal. This being the case, we can justly regard clay as one of our most important mineral resources, although up to a few years ago it was quite neglected by both government and state surveys. To the unaided eye, clay usually appears so fine-grained that most of its component grains cannot be identified, although some particles of quartz, or small scales of mica are not infrequently recognizable. Micro- scopic examination, however, reveals the presence of a number of small mineral grains, many of which are under one one-thousandth of an inch in diameter. In addition to these there are particles of organic matter as 168 MINERAL RESOURCES OF VIRGINIA. well as other small bodies of non-crystalline character, which are classed as colloids, and may be of either organic or inorganic origin. The mineral fragments making up the bulk of the clay represent a variety of com- pounds in all stages of decomposition, but their properties and effect on the clay will be left until a later page. ORIGIN OF CLAY. So far as we know clay results primarily from the decomposition of other rocks, and very often from rocks containing an appreciable amount of the mineral, feldspar. There are some rocks, however, that contain practically no feldspar which, on weathering, yield a most plastic clay. In all of these clays there is found a variable amount of the mineral kaolinite, which is of secondary origin, 7. ¢., it is derived from other minerals by decomposition. This is termed the clay base. In order to trace the process of clay formation, let us take the case of granite, a rock which is commonly composed of three minerals, namely, quartz, feldspar, and mica. When such a mass of rock is exposed to the weather, minute cracks are formed in it, due to the rock expanding when heated by the sun and contracting when cooled at night; or there may be joint-planes formed by the contraction of the rock as it is cooled from a molten condition. Into these cracks the rain water percolates and, when it freezes in cold weather, it expands, thereby exerting a prying action, which further opens the fissures, or may even wedge off fragu.ents of the stone. Plant roots force their way into these cracks and as they expand in growth, supplement the action of the frost, thus further aiding in the breaking up of the mass. This process alone, if kept up, may reduce the rock to a mass of small angular fragments. CLASSIFICATION OF CLAYS. The state of Virginia contains a variety of clays, which are adapted no doubt to a wide variety of uses, but many of the deposits have remained undeveloped, because little is known regarding them, the only ones which have been systematically studied being those of the Coastal Plain or the Tidewater belt. In discussing the clays of Virginia it might perhaps seem more prac- tical to group them according to kinds, but since one type of clay may be often used for the manufacture of several types of clay-products, such a mode of treatment does not form a satisfactory basis and therefore a grouping by formations is adopted. MINERAL RESOURCES Of VIRGQINEA. PLATE XXI. Fig. 1.—General view in railroad cut near Christiansburg. Virginia, showing weathering of limestone. Fig. 2.—General view of Oldfield Brick Company's plant, Oldfield, on James River. Clay pit at rear of yard. LIMESTONE WEATHERING, BRICK PLANT ANJ) CLAY PIT. CLAYS. 169 The clays of Virginia can be divided into two groups, namely, residual and sedimentary. The residual clays have been formed by the weathering of rocks, involving processes of disintegration and decomposition. As a result of this we find the residual clay overlying the parent rock from which it was derived, plate XXI, figure 1. These deposits are of variable thickness depending partly on the depth to which the rock has been changed, and partly on the amount of erosion which they have suffered since their formation. Knowing this we should expect to find heavier deposits on a flat surface, than on a sloping one where the rain-wash is more active. The sedimentary clays represent deposits which have been laid down under water, one layer on another, the materials composing them consisting of the products of rock decay, which have been removed by erosion from the land surface, and washed down into the lakes, or seas, where they have finally settled. Residual Clays. These predominate in the belt underlain by the crystalline rocks. The crystalline rocks, consisting of granite, gneisses, and schists, with some intrusives, extend across the State from north to south in a belt of increasing width, whose western boundary follows approximately a line running from Harper’s Ferry, southwestward. The eastern edge coincides somewhat closely with the “fall-line.” Residual clays are not uncommon throughout this area, but they are usually quite ferruginous and therefore red-burning. Their main use is for the manufacture of brick and drain tile, and some of the smoother deposits have been employed for making smoking pipes. Here and there the decomposition of pegmatite veins has yielded clays of high grade, free from iron, and sometimes sufficiently white to be used for the manufacture of white-ware products. Deposits of this type known as kaolins have been found in Henry, Nelson, Patrick, and other counties in the Piedmont region. In the former county, Henry, a kaolin deposit is being worked near Oak Level station, by John Sant and Company of East Liverpool, Ohio. (Plate XXII.) The clay occurs as a’ series of veins, cutting across the schists of that region. It is mined by circular pits and, before shipment to market, it is put through a washing process in order to free it from grains of sand, mica, and other mineral impurities, which are present in small quantities. 170 MINERAL RESOURCES OF VIRGINIA. The following analyses give the composition of the crude (1) and washed (II) kaolin from this locality: I II Per cent. Per cent. Silica (SiOz). accascc ee ea eecscaed aie 66.82 45.70 Alumina (AI,03;).............. 0008 24.00 39.18 Ferric oxide (Fe,0;)............-.. 94 78 Lime) (CaQ)he ea-nci ac centeeea sakes 28 44 Magnesia (MgO).............-065. ll 05 Potash (KO) esses eedinge sate aeelsee ape 2.59 1.78 Soda; (NaiO)i«.aas-0 4 oe vanes bass 16 .20 Titanic oxide (TiO,).............. 12 .28 Water (TiO). deca cece aes eeu ates 5.52? 12.097 TO6ta] cxiwavwemaee ea ee Melee vate 100.54 100.50 (*) Ineludes 1.98 per cent. of moisture. (7) Includes 2.00 per cent. of moisture. A deposit of refractory residual clay is said to occur at Bon Air, 9 miles west of Richmond, and is well exposed in the cut of the Southern Railway. The following analysis of a washed sample is given by Dr- Froehling : Per cent. Siliea, (SiO,)......-.......6. 46.71 Alumina (AI,0,)............ 37.62 Ferrie oxide (Fe,0;)......... 1.10 Ihame > (CaQ)) id wasps we Si 9 sas 25 Magnesia (MgO)............ 14 Alkalies (Na,O, K,0)........ trace Loss on ignition............. 14.10 Total...... ce aN Res Re 99.92 This deposit is said to have been worked for several years. A bed of refractory clay has also been exploited near Clayville, but the deposit is now exhausted. A second deposit reported by Dr. Froehling occurs on the land of F. B. Deitrick, at Lorraine, in Henrico county. This clay is said to be quite free from grit, very plastic, and to have an air and fire shrinkage of 12 and 7 per cent., respectively. It burns to a dense hard brick of bright red color at 1750° Fahr. The same analyst gives its chemical composi- tion as follows: Per cent. Silica (Si0,).............04. 62.80 Alumina (AI,0;) ............ 21.30 Ferrie oxide (Fe.0;)......... 4.80 Lime (CaO) s.0.¢ 58002063 505 54 Magnesia (MgO)............ 57 Potash (K,O)............... 2.35 Soda (Na,O)............-... 83 Loss on ignition............. 7.00 MINERAL RESOURCES Ol VIRGINLA PLATE NXIL Fig. 1.—View of kaolin-pit near Qak Level. Henry county, The ferruginous clay walls are clearly contrasted to the white kaolin. Fig. 2.—General view of kaolin washing plant near Oak Level, Henry county. The crude clay is washed down the trough from the mine. KAOLIN PIT AND WASHING PLANT, HENRY COUNTY, VIRGINIA. CLAYS. 171 Additional localities are given by the same analyst as follows: A deposit of crude kaolin occurs on the property of the Kaolin Mining and Manufacturing Company near Abbeyville, Mecklenburg county. The deposit is said to be of considerable size, and is in 3 layers, separated by thin bands of ocher. The following analyses give the composition of the individual layers: Ist layer 2nd layer 3rd layer 4 feet thick. 2 feet thick. 30 feet thick. Per cent. Per cent. Per cent. Milicas ‘Roly O9fIAg pus ploy ule V/ : Vv " J ofl Ni eee “SV3UV BLILOHYYAd ONY BLIMAd TWdIONIYd po AS J he vai 3HL JO NOILVDO71 SNIMOHS LS 7 VINIDYIA JO dv Ko / 7 SULPHIDES AND SULPHARSENIDES. 193 including mica schists without quartz largely altered to chlorite, quartz- sericite schists, talcose and chloritic schists, and hornblendic schists. In many places these various varieties of schist are garnetiferous, in others garnet is essentially or entirely absent. The impure limestone bands carry both black lustrous folia of biotite and large fibrous crystals of green- black hornblende. The schists are completely and thinly foliated, so much so that the straighter thin-banded ones are locally called slates. Certain varieties of the schist, especially the highly micaceous ones, are frequently more or less distinctly crinkled. In the Prince William county area, a wide belt of true slates lies a short distance to the east of the ore-bearing schist series. Darton has designated this belt of slate the Quantico slate and it marks the position of the “fall-line” to the east of the Cabin Branch mine between the overlapping of the Coastal Plain sediments onto the crystalline rocks of the Piedmont region. MAY LLY) LLL Fig. 30.—Plan of pyrite lenses in the Louisiana county area. a. Pyrite lens; b. Micaceous schists. The general strike of the schist belt is N. 10° to 20° E. In Louisa county the schists dip from 60° to 65° southeast with flatter dips shown in places. In Prince William county, at the Cabin Branch mine, the dip of the schists ig to the northwest, varying from 25° to 64°. The rocks, as well as the ore-bodies, are penetrated by several well-developed sets of joints and in the Cabin Branch mine cross-faulting is observed. THE ORE. General character and mode of occurrence—-As mined the pyrite consists of massive-granular ore which varies in texture from very fine- to moderately coarse-grained. The very fine ore is ordinarily composed of minute irregular grains without crystal boundaries but may be admixed with much or little pyrite in distinct crystals. On the other hand, the 194 MINERAL RESOURCES OF VIRGINIA. coarser types of ore are made up chiefly of pyrite cubes and their crystal- lographic modifications. Some of the ore is very hard and non-friable, but. much of it is quite friable, and in some mines practically all of the ore is of the latter type. Much of the ore contains little or no admixed small crystalline grains of white calcite and quartz distributed through the inass, but usually more or less of these two minerals is present, the cal- cite greatly preponderating, and nearly all gradations are traceable from much calcite and less pyrite to practically all pyrite with little or no calcite and quartz. The associated metallic minerals are mentioned below. Fig. 31.—Plan of pyrite lenses at Sulphur mines, Louisa county. The ore-bodies consist of a series of lens-shaped bodies conformable to the structure of the enclosing schists. (Figures 30 and 31.) The lenses follow each other in the direction of strike, and may or may not be connected by thin and lean stringers of ore. The spacing between the ends of lenses is variable. In a few instances, a partial overlap of the lenses has been observed as shown in figure 30. The lenses vary much in size. In the Louisa county mines, they usually measure several hundred feet long (700 feet being the longest one yet known) and in thickness as much as 60 to 80 feet. At the Cabin Branch mine, in Prince William county, the maximum thickness is probably 10 feet and one lens had the enormous length of approximately 1,000 feet. As developed by the extensive mining operations, the ore-bodies are marked in places by rolls and swells and by pinching and narrowing. In the change from flatter to steeper dips, no indication was shown of unconformity of the lenses to the structure of the enclosing rocks or suggesting a vein that unmistakably cuts the rocks. In the Louisa county deposits, the strike of the ore-bodies is N. 10° to 20° E. with an average dip of 60° to 65° to the southeast. In several SULPHIDES AND SULPHARSENIDES. 195 places, measurements showed dips as flat as 35° on the 620-foot level in the Arminius mine. In Prince William county, at the Cabin Branch mine, the general strike of the lenses is the same as for those of Louisa county, but the dip is toward the northwest varying from 25° to 55°. ae AZ XX Ze Fig. 32.—Plan of pyrite lens, showing stringers of pyrite interleaved with : schists on the hanging-wall. u. Pyrite; b Crystalline schists, chiefly mica- ceous. Arminius mine, Louisa county, Virginia. The contact between the ore-bodies and the wall-rock is usually sharply defined but some grading into the country-rock by the ore is noted at times. Parallel interleaved thin stringers of solid ore, and of lean ore, to the large lenses characterize the walls of all the mines and are especially marked in the hanging-wall, as shown in figures 32, 33, and 36. Some post-mineral movement is shown in the ore-bodies, especially those of Louisa county, in the highly polished and slickened-sided surfaces along some of the fracture planes. Fig. 33.—Portion of pyrite lens in Cabin Branch mine, Prince William county, showing pyrite stringers interleaved with schists on hanging-wall, and in- closures of sheet masses in the lens. a. Pyrite; 6. Mica schist. 196 MINERAL RESOURCES OF VIRGINIA. Composition of the pyrite—The following analyses will show the general character of the Louisa county pyrite : I II Ill IV Vv Per cent. | Per cent. | Per cent. | Per cent. | Per cent. Sulphur (S)............ a 48 .02 50.00 46.40 50.00 49.27 Tron (Fe)..........0.0005 42.01 43.00 43.62 Tron oxide (Fe.0;)........ 1.93 Iron sulphide (FeS,)...... — —- 93.80 = Silica (SiO.)............. 7.60 Insoluble ................ 6.02 ——_ 6.20 4,23 Sulphur trioxide (SO,)...., 0.44 eet (aay \ Seeivadeanies AE none tae none none 1.50 Aa. — 0.38 1.32 Lime (CaO) Magnesia (MgO) I. Dr. A. Volcker, analyst. II. Sulphur mines reported by W. H. Adams. III. Dr. W. H. Taylor, analyst. IV. Charles Tennant and Company, analysts. V. Arminius mine reported by W. H. Adams. Adams reports that many analyses of the Louisa county pyrite ores give results from 46 per cent. to 51.5 per cent. of sulphur, copper from 0.5 per cent. to 9.72 per cent., and traces of gold and silver, but no arsenic. I am reliably informed, however, by the present management that analyses of the ore mined at present show traces of arsenic. Accord- ing to Adams, there are easily traceable quartz veins in the hanging- and foot-walls in all of the properties, which are gold-bearing to the extent of from $4.00 to $15.00 per ton; but these veins are always narrow, ranging from 3 to 7 inches in thickness. More or less copper, usually a small fraction of 1 per cent. in the form of chalcopyrite, is invariably present, inextricably intermingled with the pyrite. This is obtained from time to time from the mine water as cement copper by precipitation upon scrap iron and is dried, screened, and barreled for market. Lead and zinc are present in traces at times and occasionally they are appreciable in smal] masses of the ore. The form in which these are present is mentioned below under associated minerals. The average in sulphur content of all ore shipped from these mines ranges from 43 to 45 per cent. Associated minerals——The mineral species associated with the pyrite SULPHIDES AND SULPHARSENIDES. 19% lenses or ore-bodies include both metallic and non-metallic com- pounds. Named in the order of their importance the metallic minerals are blende (zinc sulphide), chalcopyrite (copper-iron sulphide), galena (lead sulphide), pyrrhotite (magnetic iron sulphide), and magnetite (magnetic iron oxide). Some of these are only occasionally met with and are limited more to some mines than to others, failing entirely in one or two, while others are usually present to some extent in all. The two commonest non-metallic minerals are calcite and quartz, the small grains and crystals of which are intimately admixed with the crystals of pyrite, forming a more or less friable type of ore. Both minerals are occasionally met with filling fractures and cavities or vuggs in the massive-granular ore and in such cases are clearly of post-mineral forma- tion. In addition to these two, dark green hornblende and red garnet are extensively developed in some of the mines. As a rule, these are not found to any extent in the ore-lenses proper but are usually found near the margins of the pyrite bodies in the wall-rock. Garnet was observed in every instance in the latter position, while hornblende does occur in the ore-bodies proper, but more often is found as the garnet. Garnet is less common than hornblende and in the Cabin Branch mine, in Prince William county, it is but rarely met with. It is always in perfect large and small rhombic dodecahedrons of deep red color. In the Arminius and Sulphur mines, in Louisa county, thin layers of a grayish-white limestone occur in the walls and in places is close to the ore-body, as evidenced by masses on the dump with stringers of pyrite attached to them. This limestone is banded with the dark ferromagnesian silicates, principally hornblende. Similar conditions are observed in the Cabin Branch mine in Prince William county. The limestone is impure, consisting of purer bands of limestone, an inch or more in thickness, interlaminated with bands of mica-schist and containing scattered crystals of hornblende. GENESIS OF THE ORE-BODIES. Without entering into a discussion in this volume of the evidence for or against any particular theory as to the genesis or origin of these ore-bodies, it may be stated that the facts gathered by me from a careful study of the belt strongly suggest a replacement of limestone by the sulphides. This is discussed at length by me in a paper shortly to be published elsewhere. 198 MINERAL RESOURCES OF VIRGINIA. THE LOUISA AND PRINCE WILLIAM COUNTIES PYRITE DEPOSITS. Louisa County. Location—The pyrite deposits of Louisa county are situated near Mineral City, formerly known as Tolersville, a station on the Chesapeake and Ohio Railway, and include three mines, two of which are extensively operated at present. (Map, figure 34.) The mines are located N. 20° E. from Mineral City at a distance of from 1.5 to 3.5 miles. Named in the order of their nearness to the station these are: the Arminius, Smith, and Sulphur mines. The pyrite belt is crossed by the Chesapeake and Ohio Railway to the west of Mineral City and has been prospected for pyrite for a distance of 10 miles southwest of the Arminius mine, or about 8.5 miles southwest of Mineral City, Nothing, however, that seemed profitable in pyrite concentration has been found south of the railroad. A goodly number of gold mines have been worked at different points in the belt. Historical—The Louisa county pyrite mines were worked at different times for iron, copper, and pyrite. They were first opened and worked for iron in 1834 when the gossan or limonite cap, overlying the pyrite to a depth of from 40 to 60 feet, was mined for iron-making in the local furnaces. The gossan at the Arminius mine was practically exhausted in 1861, but that at the Sulphur mines was worked during the Civil War. The gossan ore mined on the Arminius property is reported to have been furnaced in the old Rough and Ready furnace, located about 1.5 miles north of Tolersville, now Mineral City; that from the Sulphur mines was furnaced in the Victoria furnace situated on the present mines property. Both of these furnaces are now entirely destroyed. According to Adams the Arminius mine was opened for copper as early as 1847. It was operated for copper at a later date and prior to the mining of pyrite by the Virginia Central Copper Mines Company; and at a still later date, by the Arminius Copper Mine Company. The total production of copper from the Louisa county mines is reported as not being large, and represented chiefly ores of secondary enrichment be- neath the gossan and at the surface of the pyrite. According to the same writer the Arminius mine was first opened for pyrite mining in 1865. It was purchased in 1865 by a New York Com- pany which worked it until 1877 for copper and pyrite. In 1883, it was purchased by W. H. Adams and was continuously worked for pyrite until June, 1894, when the present company assumed control. SULPHIDES AND SULPHARSENIDES. 199 THE ARMINIUS MINE. This mine is located about 1.5 miles N. 20° E. of Mineral City and has been variously worked for iron, copper, and pyrite since 1834, Pyrite mining was begun at a much later date, 1865, after the working off of os : oo se De bap ; Fig. 34.—Map showing location of pyrite mines in Louisa county. Mines indi- cated by heavy black dots; strike of schistosity rrows topographic sheets, U. 8. Geol. Survey. Scale, $ inch equals 1 proximately. Contour interval, 50 feet. 200 MINERAL RESOURCES OF VIRGINIA. the iron-cap or gossan ore. The mine has been constantly worked for pyrite for 23 years. The ore-bodies are quite extensive and they conform to the structure of the enclosing schists, with local changes noted in both strike and dip of the ore-lenses and the rock. Both hard lump and friable ore are mined, only the latter being milled, which is sold as “fine” The lump ore is cobbed but not milled. The ore is massive-granular, the individual pyrite grains largely possessing crystal form, cubes and their crystallographic modifications. White granular calcite is the most abundant gangue mineral, with some quartz and less dark green hornblende. Sphalerite, chalcopyrite and galena, named in the order of their abundance, are frequent accompaniments in small amounts of the pyrite. Some pyrrhotite and much magnetite are admixed with the pyrite locally. The ore is reported to contain traces of arsenic, gold, and silver. Of the associated metalliferous minerals, only copper is saved and this only occa- sionally. LLL LMMMMSSELEE ee La SS Se Fig. 35.—Plan of pyrite lens on 620-foot level, Arminius mine, Louisa county, showing feathering out at northeast end by interleaving of pyrite and schist. a. Pyrite; 6. Schist. The pyrite lenses vary in size but are usually very large, the largest one yet found measuring 61 feet wide by 700 feet long. The lenses will usually average about 20 feet wide and several hundred feet long. ‘The mine has produced large quantities of ore; is developed by 4 inclined shafts worked on more than 8 principal levels run from opposite sides of the shaft and following the direction of the lenses. The slope of the shafts will average about 63° to the southeast. Of the 4 shafts, 2 were working during the summer of 1904; No. 3 shaft which has reached a depth of 875 feet, and No. 4 shaft which has reached a depth of 250 feet. The property has been extensively tested beyond the working area by much diamond drilling. The lenses do not follow each other along an entirely straight line, but are offset both northeast and southwest without real overlapping, except MINERAL RESOURCES Ob VIRGUINTA, PLATE. NAVI Fig. 1—The Arminius pyrite mines, near Mineral City, Louisa county. Fig. 2—The Cabin Branch pyrite mine, near Dumfries, Prince William county. PYRITE MINES IN VIRGINTA. MINERAL RESOURCES OF VIRGINIA. PLATE XXVIII. Fig. 1—View of a part of pyrite lens in opening at the Sulphur mines, Louisa county. Pyrite lens is exposed in right half of picture. Fig. 2.—View in same opening as Fig. 1, showing crystalline schists on hanging-wall of pyrite lens. PYRITE LENS, LOUISA COUNTY, VIRGINIA. SULPHIDES AND SULPHARSENIDES. 201 im one or two cases. Figure 35 shows feathering out of one of the ore- bodies at the northeast end, on the 620-foot level, by interleaving of the pyrite and schist. The surface plant of the Arminius mine, shown in plate XX VII, figure 1, is large and commodious, and is well equipped with all necessary modern machinery for the mining and milling of pyrite. The total output of ore from this mine is utilized for the manufacture of sulphuric acid. The average sulphur content of the ore shipped from this mine is from 43 to 44 per cent. THE SMITH MINE. The Smith mine, now owned by the Mining Department of the United States Fidelity and Guaranty Company of Baltimore, Maryland, is located three-quarters of a mile N. 20° E. from the Arminius mine. At the time of my visit to this mine, in the summer of 1906, operations were suspended pending litigation. The mine is reported to have been first opened about 20 years ago. It has been developed by 3 shafts and numerous drifts, the deepest being 300 feet, the other two 100 feet and more in depth. Ore has been mined on the following levels: 100, 150, 200,.250, and 300 feet. The ore is of the friable type and of excellent quality, of which a large total output has been produced. The surface plant comprises a mill and all necessary machinery for pyrite mining and milling. THE SULPHUR MINES. The Sulphur mines are located 2 miles northeast of the Arminius mine and 3 miles northeast of Mineral City, a station on the Chesapeake and Ohio Railway. The mines are connected with the Chesapeake and Ohio Railway at Mineral City by a broad-gauge steam road, built in 1884. The gossan or limonite cap was first mined and furnaced prior to the Civil War in the old Victoria furnace on the present company’s site, which was closed in 1877. Mining of pyrite was begun in 1882. The property is developed by 8 shafts, 3 of which were working at the time of my visit in August, 1906. The greatest depth attained in the working of these shafts is 720 feet. The method of mining the ore is closely similar to that employed at the Arminius mine. Many old cuts are now exposed from which the gossan ore was early mined. Several of these afford opportunity for observing the ore-bodies and their relations to the enclosing rocks as shown in plate XXVIII, figures 1 and 2. Careful measurement of the direction of strike of the lens in one of the largest and longest of the old gossan cuts gave N. 20° KE. and dips 202 MINERAL RESOURCES OF VIRGINIA. ranging from 65° to 75° south 20° east, with an average dip of 66°. Entire conformity with the foliation of the enclosing rocks was noted at every point where observations were made. Here, as at the Arminius mine, slight local changes in the degree of strike and dip are noted while the general direction of each remains constant. The ore-bodies, lenses, average from 40 to 50 feet in thickness and several hundred feet in length. The old gossan cuts, which are now badly caved, confirm these dimensions. The ore-lenses on this property lie ap- parently west of those at the Arminius mine, which gives an average width of the ore-bearing schist zone in Louisa county of from 800 to 1,000 feet. The mineral associations are the same here as at the Arminius mine. Judging from a careful examination of the dumps chalcopyrite, pyrrho- tite, and probably magnetite, are somewhat more abundant than at the Arminius mine, and calcite seems to have considerably greater develop- ment at the Sulphur mine. Both hard and friable ore are produced, the latter existing in largest quantity. At present, only the low grade ore is milled. The milling scheme is closely similar at the two mines except at the Sulphur mines trommels and tables are used. The fine and coarse ore are separated at the tipple and all ore goes to the washer. The concentrates average 42 per cent. of sulphur. Three sizes of ore are shipped, all of which is used in the manu- facture of sulphuric acid. The Sulphur mines surface plant is very large and commodious and is well equipped with all necessary machinery for handling the ore in the mines and at the mill. Preparations were in progress during the summer of 1906 to enlarge and otherwise improve the present mill. Prince William County. THE CABIN BRANCH MINE. Only one producing pyrite mine has been developed in Prince William county. This mine, known as the Cabin Branch mine, is located about 1.5 miles northwest of Dumfries. (Map, figure 36.) Some prospecting for pyrite has been done both to the southwest and to the northeast of the Cabin Branch mine. Two small operations, separated by a distance of several miles from each other, are reported opened about 12 miles southwest of the Cabin Branch mine, in Stafford county. The Cabin Branch mine was first opened in 1889, but it was not con- tinuously operated until several years later. It is developed by 3 shafts, SULPHIDES AND SULPHARSENIDES. 203 the deepest one of which, is 1,000 feet on an incline which varies from 25° to 55°, the dip of the ore-body. The ore-body is worked on all levels from the surface to the depth of the shaft, 1,000 feet. This lens averages from 5 to 10 feet in thickness and is approximately 1,000 feet long. Unlike the pyrite ore-bodies of Louisa county, those developed at .the Cabin Branch mine dip to the northwest with cross- faulting, ordinarily of slight displacement. Variations in dip of the lenses here are much greater than for those of Louisa county. The [FS i Na ce iP 2a KC U Fig. 36.—Map showing location of Cabin branch pyrite mine, Prince William county. Mine indicated by heavy dot. Based on the Mt. Vernon topo- graphic sheet, U. S. Geol. Survey. Scale, § inch 1 mile, approxi- mately. Contour interval, 50 feet. mineral associations are similar to those of the Louisa county mines. Chalcopyrite, a little pyrrhotite, and occasional galena and blende, are intermingled with the pyrite. Galena and blende are present in much smaller quantity than in the Arminius and Sulphur mines of Louisa county. Traces of gold are reported in the pyrite. No attempt is made to save any of these in the mining of pyrite at the Cabin Branch mine. Of the non-metallic minerals, calcite and quartz occur as at the other mines. Hornblende is found, but a careful examination of the dumps showed only an occasional red garnet. 204 MINERAL RESOURCES OF VIRGINIA. The ore is closely similar to that of the Louisa county mines in general character and excellence, and similar grades of ore are marketed. The surface plant is extensive and modern and well equipped for handling the ore. Plate XXVII, figure 2, shows the Cabin Branch pyrite mine. A narrow-gauge road is operated between the mine and Barrow Siding on the Richmond, Fredericksburg and Potomac Railway, distant about 6 miles. The company also controls its own wharf on the Potomac river which is connected with the mine by the above narrow-gauge road and offers magnificent facilities for ore-shipping by water. Cal0s SiQe Fig. 37.—Plan of portion of pyrite lens at Cabin Branch mine, Prince William county, showing interleaved lenses of pyrite, quartz and calcite on hanging- wall, with minor folding. Inclosures of quartz and calcite in pyrite lens. These fill fractures in some cases and are subsequent. METHODS OF MINING. The methods employed in mining the ore at the different mines is, in general, closely similar, differing only in minor details. Since the ore-bodies dip from 25° to 65° the general practice is to develop them by inclined shafts sunk in the direction of dip. Levels are then run out from the shaft on the two sides in the direction of strike of the lenses and at convenient distances above each other. In the Louisa county mines, stopes are opened up by driving levels along the lens at intervals, which are connected by raises, and the ore broken down by overhand stoping. The walls are comparatively strong and but little timbering is necessary. At the Cabin Branch mine, in Prince William county, the conditions are somewhat different from those at the Louisa county mines and the methods employed differ slightly in details. At this mine, the lenses show a greater variation in dip, are cross-faulted, and the wells are apparently softer, which require more timbering. At all the mines the ore is raised by inclined cable and cars. MINERAL RESOURCES OF VIRGINIA. VLATE NNIX. Fig. 2.—View of shaft and dump at the Sulphur mines, near Mineral City Louisa county. 3% PYRITE MINES IN VIRGINIA. SULPHIDES AND SULPHARSENIDES. 205 MILLING. The ore is prepared and marketed in 3 sizes, lump, spall, and fine. The lump represents the first grade ore as broken in the mine and is free from all slate and lean material. Spall is clean lump ore broken to pass a 2.5 inch ring and is freed from finer material by screening. Fine ore is sized to pass a 3¢-inch screen and is usually washed or jigged to bring it up to grade. The ore is sold on a basis of sulphur content at a variable price per unit. The following description of the milling practice at the Virginia pyrite mines has been abstracted from a published paper by Painter, in the Engi- neering and Mining Journal for July, 1905. The larger part of the output from the Louisa county mines consists of the grade “fine” ore. One mine turns all of its ore into “fine.” At this mine, the skip dumps upon a grizzly of railroad iron set 3 inches apart. After picking and forking the slate from the 2 sizes, these go to their respective crushers at the head of the mill. The ore is reduced to jig size by crushing with breakers and rolls and screened by trommels, when it is fed by a distributer to the Hartz jigs. Jigging through a bed of cast-iron balls is employed, and the hutches dis- charge upon a belt-conveyor of ascending grade, which delivers to the stock piles where the ore soon drains. At another mill the skip dumps upon a similar grizzly; the oversize is sorted into No. 1 lump for shipment, No. 2 lump to the mill, slate to the waste; the undersize falls upon a floor, where the slate is eliminated, the remainder going to the mill in a separate car by rope haulage. Usually, the better grade of lump goes to a jaw-breaker set to make spall ore, a fine-bar grizzly cutting out that under 114-inch size, which goes to the mill. After being inspected and the slate thrown out, the spall ore is loaded in box cars. The mill is arranged to crush the ore by successive steps in Blake crushers, roll-jaw crushers and rolls, with repeated screening to jig size. The same practice of jigging through a bed of cast-iron balls is employed ; but the jigs discharge into a de-watering device which feeds a belt-conveyor delivering to the stock pile, bins or hearth drier, depending upon the weather. Tables are being installed to treat the overflow from the de- watering tank. At the Cabin Branch mine, the skip dumps upon a 2.5 inch grizzly. The oversize goes to the lump-ore storage-bin, from which it is drawn off at intervals and sorted. Slate goes to the dump, first-class lump to the spalling floor and the remainder to a roll-jaw crusher at the head of the 266 MINERAL RESOURCES OF VIRGINIA. fine-jigging annex. The No. 1 lump is all spalled by hand to burner size and forked into measuring chutes delivering to the cars. The spalling is done by hand with long-handled hammers of 2-pound weight upon a thin layer of ore on the floor. The resulting “fine” is small in amount and is screened into the fine bin. The undersize from the grizzly goes to a re- volving screen with 1.5-inch round holes, through which the ore is worked into the pebble-ore jig. The oversize goes to a slate-picking chute de- livering upon a spalling floor. The pebble-ore jig is a 3-compartment Hartz jig fitted with No. 2 mesh, No. 8 iron-wire screens. It discharges from the spouts, clean pebble and middling; from the hutch, clean, fine middling and waste. The clean pebble ore is elevated to a screen delivering to a skipping chute; the small ore is returned to the roughing rolls. The clean “fine” ore runs into the fine bin which is heated by exhaust steam. The fine middling is elevated to the roughing rolls. After passing through rough rolls, the crushed ore meets the No. 2 lump which has passed the roll-jaw breaker, and the product from the fine-crushing centrifugal rolls, and is elevated to a 2-unit centripact screen. The upper screen is 2%¢-inches aperture, and the oversize goes to the roughing rolls; the second screen is 14-inch, and the oversize goes to the fine rolls; the through size goes to the 2-compartment fine jigs. Uses. Pyrite is utilized chiefly for the manufacture of sulphuric acid. It is also used in the preparation of the iron salt known as green vitriol or copperas (iron sulphate). Very small amounts of the mineral are util- ized in the preparation of vermillion paints and occasionally for jewelry. The entire output from the Virginia mines is reported to be consumed in acid-making. Production. The total production of pyrite in the United States is distributed among less than 10 states, of which Virginia produces more than one- half. On this basis, the following figures which represent the annual pro- duction of pyrite in the United States will afford some idea of Virginia’s yearly output. The production of pyrite in Virginia for the years 1904 and 1905 was 120,671 and 123,153 long tons respectively, valued at $440,- 753 and $426,008. SULPHIDES AND SULPHARSENIDES. 207 Production of pyrite in the United States from 1882 to 1905 inclusive. (Long tons.) Year Quantity Value Year Quantity Value 1882 12,000 $ 72,000 1894 105,940 $ 363,134 1883 25,000 137,500 1895 99,549 322,845 1884 35,000 175,000 1896 115,483 320,163 1885 49,000 220,500 1897 143,201 391.541 1886 55,000 220,000 1898 193,364 593,801 1887 52,000 210,000 1899 174,734 543,249 1888 54,331 167,658 1900 204,615 749,991 1889 93,705 202,119 1901 241,691 1,257,879 1890 99,854 273,745 1902 a207,874 947,089 1891 106,536 338,880 19038 233,127 1,109,818 1892 109,788 305,191 1904 | = a207,081 814,808 1893 75,777 256,552 1905 253,000 938,492 a Includes production of natural sulphur. References. Adams, W. H. The Pyrites Deposits of Louisa County, Virginia. Transactions American Institute of Mining Nngi- neers, 1883, XII, 527-535; The Virginias, 1884, V, 74, 80-81. Fontaine, W. M. Notes on the Sulphuret Deposits of Virginia. The Virginias, 1882, III, 154-155. Martyn, Wm. Pyrites. Mineral Resources of the United States. United States Geological Survey, 1883-84, 877-905. Merrill, G. P. The Non-metallic Minerals. New York, 1904, 31-37. Nason, F. L. Origin of the Iron Pyrites Deposits in Louisa County, Virginia. Engineering and Mining Journal, 1894, LVII, 414-416. Limestone Associated with Pyrites and Pyrrhotite of the Appalachian System. Engineering and Mining Journal, 1906, LX XXII, 172-173. Painter, R. H. Pyrite Mining in Virginia. Engineering and Min- ing Journal 1905, LXXX, 148-149. Pyrites Mining and Milling in Virginia. Engineer- ing and Mining Journal, 1905, LXXX, 433. Wendt, A. F. The Pyrites Deposits of the Alleghanies. Engineer- ing and Mining Journal, 1886, XLI, 407-411, 426-428, 446-447; Ibid. 1886, XLII, 4-5, 22-24; School of Mines Quarterly, 1886, VII, 154-188, 218-235, 301-322. 208 MINERAL RESOURCES OF VIRGINIA. 2. PYRRHOTITE. Pyrrhotite or magnetic pyrites, known also as mundic, is found in many of the crystalline or Piedmont counties of the State, but the largest concentration of this mineral yet known is that of the “Great Gossan Lead” in Floyd, Carroll, and Grayson counties, in southwest Virginia. (Map, figure 29.) Considerable prominence has been given to this “lead” in past years in the mining of secondary iron and copper ores derived from the alteration of the original sulphides, pyrrhotite, containing some chalco- pyrite, of the surface portion of the vein. The importance of the “lead” as an iron-producer is discussed under Iron on pages 419-421, and as a copper-producer under Copper on pages 511-517. The general geology and character of the vein are given at some length under Copper on pages. 511-518, and need not be repeated here. Where found in Virginia, the pyrrhotite bodies occur as lenses in the crystalline schists and as well-defined veins, the best example of which is. that of the “Great Gossan Lead” in southwest Virginia. This “icad,” a well-. defined vein of pyrrhotite, varying in width up to 100 feet, strikes southwest-. ward from Floyd county, through Carroll into Grayson county, a distance of more than 20 miles. Map, figure 88, shows the position of the “lead,” and plates XXX and LXXYV are views of mines located on the “lead.” Further description and illustrations are given under Copper, pages 491- 519. According to Moxham, an analysis of a sample of the mundic (pyrrho- tite) given as coming from the surface of the “lead” shows: Per cent. Sulphur sa sigsve sc aeeenrsaane 34.06 Copper? scvn ees etnena gone 0.866 TB OT 5 siessoieianutideas wi andreas ES SS 53.15 Phosphorus ... no trace Manganese : 0.306 Silica: svccic. were czasacai secs 2.99 Before the Betty Baker mine, located near Sylvatus, was closed down in 1900, 1,800 tons of the pyrrhotite were shipped to the Southern Chemi- cal Company at Winston-Salem, North Carolina, where it was used for acid-making. The ore contained 33 per cent. of sulphur and after roast- ing carried 58 per cent. of iron. As Moxham states, whether the large amount of sulphur in this de- posit is utilized or not, the main value will not be effectively realized until a process is developed by which the sulphur may be extracted from the ore upon a large scale, at such cost that the residue or “Blue Billy” will be available for the making of pig-iron. MINERAL RESOURCES OF VIRGINIA, PLATE NNN, eral view of pyrrhotite vein, * “Great Gossan Lead,” at “Great Outburst.” near Chestuut Yard, (Photo. by W. H. Weed.) Carroll county, PYRRHAOTITE MINE, “GREAT GOSSAN LEAD,” CARROLL COUNTY, VIRGINIA. SULPHIDES AND SULPHARSENIDES. 209 A considerable amount of sulphur can be driven off by pile-burning of the mundic as is shown in the following tests given by Moxham: Lump ore. : Fine ore. Roasted Per cent. Roasted Per cent. Trot: sass ceases 55.50 Trois. aga eure ie 48.99 Sulphur......... 7.69 Sulphur......... 5.51 The importance of the solution of this problem to the iron manufac- turers need hardly be pointed out, as it would yield an ore containing approximately 60 per cent. of iron, with low silica and manganese, and no -phosphorus—an ideal Bessemer stock. In recent attempts to mine the ore for copper, the percentage of copper in the output of the mines was found to be too small to permit the work- ing of the vein alone for copper. The future value of the “Gossan Lead” apparently lies mainly in the unworked iron ores and the utilization of the pyrrhotite, magnetic pyrite, for both acid- and iron-making. An extensive plant, operated by the Pulaski Mining Company, has re- cently been completed at Pulaski for the purpose of utilizing the pyrrho- tite of the “Gossan Lead” for both acid- and iron-making. For supplying this plant with ore, the pyrrhotite is being mined on the southwest end of the “lead,” near Chestnut Yard, in Carroll county. Plate XXX is a view of the vein opened at this point. References. Boyd, C. R. Utilization of the Sulphur Ores of Virginia in Mak- ing Superphosphates. Engineering and Mining Journal, 1885, XL, 200. The Utilization of the Iron and Copper Sulphides of Virginia, North Carolina, and Tennessee. Transac- tions American Institute of Mining Engineers, 1885-86, XIV, 81-84. Fontaine, W. M. The Sulphuret Deposits of Virginia. The Virginias, 1882, ITI, 154-155. Notes on the Geology and Mineral Resources of the Floyd, Virginia, Plateau. The Virginias, 1883, IV, 167, 178-180, 185-192; 1884, V, 8, 12. Moxham, Edgar C. The “Great Gossan Lead” of Virginia. Transactions American Institute of Mining Engineers, February, 1892, 6 pages. Watson, Thomas L. The Copper Deposits of Virginia. Engineering and Mining Journal, 1906, LXXXII, 824-826. Weed and Watson. The Virginia Copper Deposits. Economic Geology, 1906, I, 309-330. 210 MINERAL RESOURCES OF VIRGINIA. 38. ARSENOPYRITE; MISPICKEL; OR ARSENICAL PYRITES. The mineral arsenopyrite, a double sulphide of arsenic and iron, FeAss, has been noted in quantity at two localities in Virginia, one of which has recently been developed and has produced some arsenic. The localities are in Rockbridge and Floyd counties. In the extreme northeast corner of Rockbridge county, in the Blue Ridge, arsenopyrite is found in association with pyrite and cassiterite in quartz-greisen tin-bearing veins, which penetrate coarse granite and are described at some length on pages 567-577. No attempt has been made to work the arsenopyrite at this locality. Near the summit of the Blue Ridge in Floyd county at Rewald post- office, about 17 miles from Christiansburg, and at an elevation of about 3,200 feet above sea-level, a series of “veins” (lenses) of arsenopyrite in quartz-sericite schist occurs, which outcrop in places on the surface. A second principal rock-type is a biotite gneiss, closely associated with the cuartz-sericite schist, but its relations to the schist and to the ore-bodies are unknown. The principal lens is reported to be 3 feet thick at the sur- face but it widens to a thickness of 14 feet at a depth of 120 feet. Numerous lenses are reported found over a distance of some 7 miles. The location of the mine is shown on the map, figure 99. In 1903, the United States Arsenic Mines Company of Pittsburg, Pennsylvania, capitalized at $500,000, began to exploit the Floyd county arsenopyrite deposits. A 215-foot adit was driven into the mountain side, supplemented with a 55-foot drift extending to an 8-foot “vein” of arsenopyrite, of 25 per cent. arsenic. It is estimated that the arsenic ore can be mined at a cost of 75 cents per ton. The underground workings are shown in plate XX XI, a blue-print copy of which was indly furnished by the company. According to a writer in the Mineral Industry for 1908, the ore as mined is conveyed to a Blake crusher, from which it passes by gravity to rolls, where it is finely pulverized. It is then charged into Howell-White furnaces where the metal is volatilized, the vapors precipitated and further purified by sublimation. The plant comprises a building 300 by 70 feet for the mill and furnaces, besides dwelling-houses, shop, laboratory, office and other structures. Plate XXXII, figure 1, is a view of the milling- plant. The equipment consists of a 125-h. p. Westinghouse engine, 2 75- h. p. boilers, 4 dynamos, a 10- by 20-inch Blake crusher, a 27-foot Howell- White calcining furnace, a set of rolls for pulverizing, etc. PLATE XXXI MINERAL RESOURCES OF VIRGINIA. V \ tie, Fewer Mouse Luu DUVES Mie Plan of the underground workings of the United States Arsenic Mines Company, Floyd county. From blue print furnished by the company. Scale, 1-32 inch = 1 foot, approximate]; MINERAL RESOURCES OF VIRGINIA. PLATD XXXII. Fig. 1—General view of the milling plant and mines of the United States Arsenic Mines Company, Rewald, Floyd county. Fig. 2.—General view of the main opening for nickel ore on Lick Fork, near Hemlock, Floyd county. Owned by the Virginia Nickel Corporation. ARSENIC AND NICKEL MINES, FLOYD COUNTY, VIRGINTA. HALIDES. 211 The above plant for refining the product was started in October 1904, and shipped sample lots until January 1905, when the monthly capacity of the plant was increased to 90 tons of pure white arsenic. Operations at these mines are temporarily suspended at present, December, 1906. Uses.—Arsenic is used in the form of arsenious oxide in dyeing, calico printing, in the manufacture of various pigments, fine-grade glassware and special enamels, in arsenical soaps, in the preparation of other salts of arsenic, and as a preservative. References. Cowan, J. L. The Arsenic Mines at Brinton, Virginia. Engineer- ing and Mining Journal, 1904, LX XVIII, 105-106. Fontaine, W. M. Notes on the Sulphuret Deposits of Virginia. The Virginias, 1882, III, 154-155. Hotchkiss, J. Mispickel. The Virginias, 1883, IV, 168. Struthers, Joseph. Arsenic. Mineral Resources of the United States for 1903, 327-334. Unsigned. Arsenic. The Mineral Industry for 1903, XII, 19-21. Ill. HALIDES. 1. HALITE; SODIUM CHLORIDE; 0R COMMON SALT. Salt brines and rock salt both occur in the Holston valley in association with gypsum. The salt and gypsum deposits are confined to a narrow northeast-southwest valley of the North Fork of the Holston river, ex- tending from Plasterco on the southwest, to within 3 miles of Chatham Hill post-office on the northeast, a distance of about 16 miles. The interbedded salt and gypsum shales with beds of rock salt and gypsum are regarded as of Mississippian (Lower Carboniferous) age. The geology of the valley and its deposits is described under Gypsum on pages 327-335. A general idea of the valley may be gained from: plates XX XIII and XXXIV. In 1871, Jefferson, in his “Notes on Virginia,’ mentioned the occurrence of salt brine in the Holston valley, but it was not until 1840 that rock salt was discovered. In 1840, a shaft was sunk which struck a bed of rock salt at a depth of 210 feet. This shaft was sunk with the idea of securing salt water, but as the operators had no knowledge of rock salt at that time, or at least did not appreciate its value for saturating purposes, and as the shaft was practically a dry one, they considered their efforts and money as having been wasted, because they failed to find what they started 212 MINERAL RESOURCES OF VIRGINIA. after, that is salt water. The shaft was located about 200 feet up the “lick,” that is southwest of the old brick office-building in the upper end of the valley. It is reported that this was the first discovery of a bed of rock salt in the eastern United States. Eckel reports an analysis of the rock salt as follows: Per cent. Sodium chloride............. 99.084 Calcium ehloride............. trace Calcium sulphate ............ 0.446 Iron, alumina, etc............ 0.476 In the early ’70’s, operations were again begun in the bottom of the old shaft sunk in 1840, and the depth was increased about 20 feet in the bed of fine white rock salt. A drift was started from the bottom of the shaft in a due south course and continued for a distance of about 92 feet, when a second shaft was sunk from the surface down to the end of the drift, the idea being to run water down the second shaft and pump brine out of the first one. The foreman’s advice was not followed and the drift was run too near the top of the rock salt, which resulted in the roof being soon dissolved, and the overlying loose rock fell in and completely blocked the drift. The first borings for salt in this valley were in the old swampy lake- covered area near the present site of the town of Saltville, which was drained before the sinking of the wells. Mining of the rock salt has not yet been attempted, the entire salt product coming from the salt brines of the wells. The entire salt industry is, at present, confined to the imme- diate vicinity of Saltville, and is controlled by the Mathieson Alkali Works. As indicated in plate XX XIII, figure 1, a large number of wells have been sunk over the area, the earliest of which were about 200 feet deep and passed through clay, gypsum, and shales. Hayden reports that 6 wells had been put down by 1842, only two of which at the time of his writing were in operation. The more recently bored wells are much deeper than the earlier ones and they show considerable variation in depth, since the beds indicate a strong dip. The average depth of the present wells is not less than 1,000 feet, and some are 1,400 feet. These begin to strike salt at a depth of from 250 to 300 feet, passing through a mixture of salt shale and rock salt. The greatest depth attained in any one of the wells was 2,380 feet. There are 24 producing wells at the present time. Map, plate LII, will show the present salt-producing area. In the early history of operations and, indeed, until within recent years, the product marketed was salt, which for many years amounted to between MINERAL RESOURCES OF VIRGINIA. PLATE XXNIIL. Fig. 1—General view of salt wells at Saltville. Fig. 2.—General view of Saltville, Washington county. SALT WELLS AND SALTVILLE, VIRGINIA. HALIDES. 213. a half million and a million bushels of salt per year. At the present time, no salt is made, the brines being utilized at the Mathieson Alkali Works at Saltville for the manufacture of sodium carbonate and caustic soda. lt is reported that in 1842, two establishments were producing salt, with a total annual production of about 200,000 bushels. Analyses gave: Per cent. Per cent. Sodium chloride.................. 98.540 98.146 Caleium chloride.................. 016 -034 Calcium sulphate.............00005 1.444 1.820 The following analyses of the rock salt and of the salt brines, the latter of which are of a very high degree of purity, show the general char- acter of the Saltville, Virginia, material: I II Per cent. Per cent. Sodium chloride................... 99.084 93.05 Caleium chloride .................. trace — Magnesium chloride ............... — Calcium sulphate..............006- 0.446 2.40 Magnesium sulphate............... — 0.07 Alumina, silica, and iron........... 0.470 3.64 WWIAUOTE ahs oes 8 cuistansijccsuatesibarsventeals Rann ners —— 0.30 I. Quoted from C. B. Hayden. II. Quoted from Thomas Radcliffe. Analyses of brines from Saltville, Virginia. I II Per cent. Per cent. Sodium chloride................... 97.792 98.39 Calcium chloride ................. .033 — Calcium sulphate...............00. 2.17 1.22 Magnesium sulphate............... 39 Alumina, silica, and iron........... trace — Percentage solids in brines......... 24.60 26.40 Specific gravity..............00000. — 1.198 I. Quoted from C. B. Hayden. II. Quoted from G. H. Cook. Analyses of the commercial salt from Saltville, Virginia. I II Ill IV Vv VI VII VIII Per Per Per Per Per Per’ Per Per cent. cent. cent. cent. cent. cent. cent. cent. Sodium chloride......... 98.540 98.146 98.45 99.01 99.18 99.11 98.61 98.89 Caleium chloride........ -016 .034 95 .20 27 68 1.02 — Magnesium chloride..... —_- — .20 .09 05 ll 27° —— Caleium sulphate........ 1.444 1820 ——~ —— —— — — — Water ids jcccceavamnina caus — 40 .70 50 10 10 — I and II. Quoted from C. B, Hayden. III to VIII inclusive. Quoted from G. H. Cook. S 214 MINERAL RESOURCES OF VIRGINIA. The Mathieson Alkali Works—The Mathieson Alkali Works, a cor- poration organized under the laws of the State of Virginia for the manu- facture of salt, alkali, and caustic soda, is located at Saltville, Smyth county, Virginia, on a branch of the Norfolk and Western Railway. The process used is that known as the Ammonia or Solvay, a process first made a practical working success by Ernest Solvey of Liege, Belgium, and is now almost exclusively used by all manufacturers of alkali. The Mathie- son Alkali Works are not manufacturing salt at the present time, having closed down this portion of the operation in October, 1903. The manu- facture of salt, however, will probably be resumed in the near future on an extensive scale. The particular product made by this plant is, and has been. from the beginning, sodium carbonate, commercially known as “Soda Ash.” This product is made in large quantities and in all of the different tests known to the trade. Caustic soda and bi-carbonate of soda are also manu- factured, the former in strengths known as 60, 70, 74, and 76. The first product turned out of the plant was in June, 1895; three years later, June, 1898, the company began the manufacture of bi-carbonate or cooking soda. This product has been of superior merit from the start, and because of this fact, a large and growing trade has been acquired. Plate XXXIV, figure 1, is a general view of the plant. The company operates its own limestone quarry (plate XLVI, figure 2), which is located about 3 miles from the plant, the stone being conveyed from the quarry by means of an aerial tramway. The following are representative analyses of limestone from this quarry: Percent. Percent. Percent. Percent. Percent. Calcium carbonate... 97.03 97.03 97.15 96.95 96.73 Magnesium carbonate 1.24 1.15 0.91 1.12 1.37 Silica Alumina }f........ 1.64 1.57 2.00 2.00 1.80 Iron oxide The Mathieson Alkali Works through their ownership of the Castner Electrolytic Alkali Company of Niagara Falls, New York, are the largest manufacturers of bleaching powder in the United States. They are also the only large manufacturers of chemically pure caustic soda, which is produced in large quantities at the Niagara plant in connection with the manufacture of bleaching powder. All products are handled through the firm of Arnold, Hoffman and Company, Sales Agents, with offices in Providence, New York, Boston, and Philadelphia. MINERAL RESOURCES OF VIRGINIA. PLATE XXXIV. Fig. 1—General view of the Mathieson Alkali Works at Saltville. Fig. 2.—General view of salt wells and valley at Saltville. MATHIESON ALKALI WORKS AND SALTVILLE, VIRGINIA. HALIDES. 215 Representative analyses of the Saltville, Virginia, salt brine made in 1906 show the following results, expressed in grains per liter: Sodium chloride ........ 291.00 286.00 291.00 Calcium sulphate ....... 5.18 4.71 4.21 Caleium chloride........ 0.83 0.97 1.06 Magnesium chloride..... 0.53 0.23 0.19 References. Radcliffe, Thomas. Analysis of Saltville, Virginia, Rock Salt. The Vir- ginias, 1884, V, 138; Chemical News, No. 1038. Taylor, 8. Discovery in Virginia of the Regular Mineral Salt Formation. American Journal of Science, 1840, XLI, 214-215. Rogers, Wm. B. A Reprint of the Geology of the Virginias, New York, 1884. For other references on Virginia salt, see under Gypsum, page 335. 2. FLUORITE; OR FLUORSPAR. The mineral fluorite, known commercially as fluorspar, a fluoride of calcium (CaF,), is sparingly found associated with the ores of lead and zinc in the Cambro-Ordovician limestone of southwest Virginia; in the same limestone in Clarke and other counties of the Valley region in north- ern Virginia; in the mica mines of Amelia county; and as the principal gangue mineral at the zinc and lead mines in Albemarle county, near Faber, a station on the Southern Railway. As yet known, the occurrence in Albemarle county is the only one of fluorite in the State where the mineral is found in quantity. sufficiently large to make it of commercial value. Its occurrence in Albemarle county is described in some detail on pages 542-544. It is obtained in the Albe- marle county mines as a by-product of the lead and zinc. The increasing demand for fluorite should make the Albemarle county deposit of some importance. Uses.—The principal uses made of fluorite are in the glass trade for enameling, in the manufacture of steel and iron, and in the manufacture of chemical compounds of fluorine. References. Watson, Thomas L. Lead and Zinc Deposits of Virginia. Virginia Geo- logical Survey, 1905, I, 156 pages. Lead and Zinc Deposits of the Virginia-Tennessee Re- gion. Transactions American Institute of Mining Engineers, 1905, British Columbia Meeting. 216 MINERAL RESOURCES OF VIRGINIA. IV. OXIDES. 1, SILICA. Quartz—The mineral quartz, corresponding to the formula SiO, when chemically pure and easily recognized by its hardness, glassy luster, lack of cleavage, and insolubility in acids, is one of the most common and widely distributed of minerals. Quartz crystallizes in the hexagonal sys- tem, crystals of which are frequent in occurrence. Its common form is massive-granular occurring as veins in the older crystalline rocks. Quartz has wide distribution in the State. It occurs as an essential constituent of granite, gneiss, and mica schist of the crystalline area; as the dominant constituent in the sandstones, quartzites, and conglomerates of the Piedmont and Valley regions; and in the form of sand in portions of each of the three larger divisions of the State. A principal occurrence of quartz in Virginia is as a chief constituent of the numerous pegmatite dikes and quartz veins penetrating the older metamorphic rocks of the crystalline or Piedmont region. Quartz has been mined in Virginia in association with mica and feld- spar from the large pegmatite dikes near Amelia court-house, in Amelia county; and from a bedded deposit in crystalline schists near Falls Church, in Fairfax county, where the quartz forms a hard and beautifully white, fine granular quartzite. A beautifully white and pure crystalline quartz occurs three-quarters of a mile west of Wirtz post-office, in Franklin coun- ty. Preparations are being made to mine the fine grade of white quartz sand in Catawba valley, Roanoke county, for glass manufacture. Uses.—The purer clear grades of quartz are used to some extent for making lenses, and in cheap jewelry. Its principal uses, however, are as an abrasive, either as quartz sand or as sandpaper, and in the manufacture of pottery. The purer grades of quartz sand are used for glass manu- facture. Chert—Chert, known also as hornstone, a term applied to any impure flinty rock, including the jaspers, is a chalcedonic variety of silica. Chert has wide distribution in certain beds of the Shenandoah or Valley lime stone of the Valley region, in the form of irregular nodular masses of light nearly white, red, brown, and black colors. No special use has yet been made of the Virginia chert. Diatomaceous earth.—When pure, diatomaceous earth is a soft, pul- verulent, siliceous, clay-like material, very fine and porous in texture, OXIDES. 217 somewhat resembling chalk and kaolin in its physical properties, and of white, yellow, or gray color. It is very light in weight. Its predominant siliceous character is shown in’the analyses given below. Origin and occurrence.—Deposits of diatomaceous earth are formed from the shells and tests of certain aquatic microscopic forms of plant life known as diatoms, which have the power of secreting silica in the same manner as mollusks secrete lime-carbonate. These low forms of organ- isms have a wide range of adaptability and are entirely aquatic, living both in salt and in fresh water under different conditions of depth and temperature. On the death of the organisms, the siliceous tests accumu- late on the bottom of the lake, pool, or pond which they inhabited, forming, in the course of time, beds of more or less thickness. Although formed at various geologic periods, the beds of known commercial importance of diatomaceous earth, both in America and in Europe, are of Tertiary age, a period which was apparently particularly adapted to the growth of these organisms. When examined under the microscope, the material from these earths always shows the remains of diatoms or rather similar species, composed, principally of silica with varying amounts of water. The deposits are frequently rendered impure from the admixture of clay and at times are discolored by organic matter. The siliceous nature of diatomaceous earth is shown in the analyses given below quoted by Merrill: I II TIl Per cent. | Per cent. | Per cent. Silica). scwscxwtaws caxiees Rieger se eens 80.53 80.66 81.53 Aldmia). oc.22 cavers. KceeeRies caesar. 5.89 3.84 3.43 DOr O10 6 isscsss canescens nseccssivever aa sevaeiestiss Ses cdcvsne 1.03 —_—— 3.33 TUM Gis haee seas Leisiateq iota eustera sean altheedn waiinie h oiies 0.35 0.58 2.61 Sodas acericiscs wee candela secre cured are viig —- —— 1.43 Potash scoacecc wv eaese we ee toupee aes ——. —- 1.16 Water and organic matter...........-5+ oes. 12.03 14.01 6 04 I. From Lake Umbagogue, New Hampshire. II, From Morris county, New Jersey. III. From Pope’s creek, Maryland. An analysis of diatomaceous earth from Richmond, Virginia, gave Mr. J. M. Cabell: 218 MINERAL RESOURCES OF VIRGINIA. Per cent UIC ais ses o 5 sade ay at wR 75.86 ANUS: . acsicee is atncee ccd 3 elds 9.88 Ferric oxide...............-- 2.92 LAM ess cae mee sees + ares 0.29 MATOS ay iis cietiaun dink ane dice 0.69 BOda: acces 8e a eaiycweeneeas 0.08 Potash. isucactee gexgeadiaigs 0.02 Nitrogenous matter .......... 0.84 Water a cyeveiecs sass cn hea Ph Se 8.37 Tota ly sexe oak ahieew ass was 98.95 The description of the sample of earth yielding this analysis follows: “Sample was procured from the middle of the exposed bed of this earth just below the colored normal school on President Hill in Richmond, Virginia. Without any previous treatment the specimen proved to be almost exclusively of distinguishable infusoria. It is white with a tinge of yellow and feels a little harsh.” Analyses of diatomaceous earth collected from different points in Tide- water (Coastal Plain), Virginia, by Dr. Heinrich Ries, made in the labora- tories of the Virginia Polytechnic Institute, at Blacksburg, and published in the Clay Report, Bulletin No. II of the Virginia Survey for 1906, gave: I II iI Per cent. | Per cent. | Per cent Sili¢ar ge sea deal see os 70.42 78.82 82.85 Aluming .isincciaeues 15.15 9,24 6.76 Ferric oxide........... 5.17 5.42 2.34 VGTIMNE: wade an ceaane 14 .04 .30 Magnesia ............. .79 .12 1.06 Soda: asset aeaesaw ees .39 .81 .99 Potash ........00.00-- 2.24 1.51 1.07 Titanium oxide....... 44 .83 1.09 Ignition 205 ee ccsevet es 5.21 3.66 3.40 Totali.ccwca.cv ented 99.95 99.95 99.91 I. Weathered diatomaceous earth from 7th street, near Richmond Locomotive Works, Richmond, Virginia. II. Diatomaceous earth from along the Rappahannock river, south of Layton. III. Diatomaceous earth from Wilmont, on the Rappahannock river. Distribution—The first bed of diatomaceous earth of any extent dis- covered in this country was in the Richmond, Virginia, area. It is com- monly known as the Richmond bed, the limits of which are from Herring Bay on the Chesapeake, Maryland, to Petersburg, Virginia, and probably beyond. It is not less than 30 feet in thickness, in places, though very OXIDES. 219 impure at times. It is of Miocene age and is exposed along the numerous streams close to their crossings from the crystalline rocks onto the sedi- ments of the Costal Plain. In the Eocene and above it, at a depth of about 558 feet, in the deep artesian well at Fort Monroe a stratum of diatomaceous earth was reached, which on critical examination by Samuel Wells yielded abundant diatoms, nearly all of which were identical with those of the Richmond bed. The following detailed description of the Richmond bed of diatoma- ceous earth is quoted from Professor Wm. B. Rogers, in “A Reprint of Annual Reports and Other Papers on the Geology of the Virgumas.” “The material in question [diatomaceous earth], composing a thick stratum lying between beds of sand and clay, is more or less mingled with them, particularly in the vicinity of its bounding surfaces. But through- out most of its thickness, it presents a very fine texture, admitting of being bruised by the fingers into an almost impalpable powder, and singu- larly free from gritty particles. Its colour in the present specimens is a very light grey or white, but the fragments into which it spontaneously divides at the exposed surface of the stratum often present externally a slightly ochreous tinge. It is decidedly, though sometimes indistinctly, laminated, the planes of the thin flakes or sheets being horizontal. When moistened, it displays considerable tenacity, and hence has hitherto been regarded as a fine clay or fuller’s earth.” “Of all its peculiarities, however, capable of being readily discovered, its great lightness is the most extraordinary and characteristic. When quite free from moisture, a pure specimen has a specific gravity of only 0.334, that is to say, only one-third the weight of water, bulk for bulk.” “In adverting to the curious and astonishing fact of its being com- posed almost entirely of the shells and other appendages of former races of animalcule, it was also mentioned that unlike the microscopic remains composing the chief mass of chalk or the larger fossils of our marl beds, these minute relics consist entirely of siliceous instead of calcareous mat- ter. For this reason it is, that the Leaf Tripoli, or Polir Scheifer of Bohemia, as well as other analogous Infusorial products, have so long been found valuable in giving a polish to metallic surfaces. Our Infu- sorial matter, when properly selected, is capable of being employed for this purpose with no less advantage, and from the trials I have made, I feel assured that when exempt from grit, it may be very usefully substi- tuted for the finer varieties of the Tripoli or rotten stone of the shops.” 220 MINERAL RESOURCES OF VIRGINIA. “Of the minuteness of these objects, some idea may be formed from the following statements :” “The cylindrical bodies of the medium size are from 1-300th to 1-400th of an inch in length, and from 1-1200th to 1-1600th in width, but many fall greatly short of these dimensions.” “The rings, which are found separate in great numbers, are usually from the 1-1500th to the 1-2000th of an inch in diameter.” “The circular discs and convex bodies, reticulated with cells, vary from 1-100th to 1-600th in diameter. In each of these are hundreds, and even thousands, of beautifully wrought cells. The predominance of these flattened forms appears to be the cause of the laminated texture already mentioned as exhibited by the Infusorial earth. It is obvious from these facts, that the number of such fossils comprised in each cubic inch of the material, can only be reckoned in millions or hundreds of millions, and that a bushel measure would contain a number of these skeletons and shells of former races or animalcule, far exceeding the entire population of the globe... .” “The valley of Shockoe creek, lying between Shockoe hill and Church hill, affords numerous favourable opportunities of observing the position of the Infusorial bed, and the strata with which it is associated by explora- tions along the sides of the bounding hills and the deep ravines by which, in many places, they are abruptly trenched.” “The middle of this valley is occupied by coarse gravel, rarely dis- covering any materials in situ. Beside the stream, a little to the left of the crossing of Shockoe hill Main street, as continued over towards Church hill, a patch of primary is displayed, consisting of Gneiss containing some Hornblende, and intersected by several veins of Felspar.” “At the base of Shockoe hill, a short distance up the principal ravines, the felspathic sandstones and conglomerates may be seen, forming the channels of the little rivulets flowing in these hollows, and rising, when best exposed, to a height of about five feet above the bottom of the ravine. Of course, near the outlet of the hollow, the heavy diluvium from the upper part of the hill conceals or replaces everything else, and neither the felspathic sandstone nor overlying beds can be seen, until we enter some depth into the ravine. We may thence trace it upwards, until, in consequence of the slope of the surface, we reach a higher level than the upper limit of this rock, when it disappears from view. This stratum consists of the felspathic sand in irregular layers, loosely cementing MINERAL RESOURCES OF VIRGINIA. PLATE XXXV. Sse Fig. 1.—Diatomaceous earth overlain by Pleistocene clay at Wilmont. Fig. 2.—Bluffs of diatomaceous earth (Miocene age) along Rappahannock river, southeast of Wilmont. DIATOMACEOUS EARTH, WILMONT, VIRGINIA. OXIDES. 221 pebbles of various dimensions from 1 to 4 or 5 inthes, some of which belong to formation I. An analogous material is still more extensively exposed in the mill race at the mill, higher up the creek, and composes the low knoll on which the mill is placed. Here we find the felspathic sandstone in general much stained with ferruginous matter, overlain by a bed of very coarse conglomerate of an ochreous stain and unusual hardness. Similar sandstones and conglomerates are displayed at various points along the margin of the stream, for a thickness of several: feet above its surface.” “Resting upon this sandstone and conglomerate, we meet with beds of sand and sandy clay of a dark greenish and lead colour, and of a light grey, mottled with yellow, containing Sharks’ teeth and Eocene Carditas, Turritellas, Crassatellas, etc., in the form of casts, together with vague vegetable remains in a carbonized condition. The contact of these Eocene strata with the underlying sandstone, is well displayed at numerous points,” The diatomaceous beds of eastern Virginia are capable of supplying an unlimited quantity of excellent material, but as yet they have received only slight attention. During his study of the Virginia Coastal Plain clays for the Virginia Survey in 1905, Professor Heinrich Ries gave some attention to the diatomaceous beds around Richmond. The description of these beds given below is taken from Ries’ clay report. Beds of diatomaceous earth outcrop in great thickness in the embank- ment along the tracks by the Richmond Locomotive Works, as well as along the sides of the valley to the west. The general character of the earth is that of a silty, porous clay, which breaks out in irregular lumps. In places, it is traversed by vertical fissures, which are filled with limonite. Along the Rappahannock river there are long exposures of the diatoma- ceous earth. In places, it forms great bluffs of a yellowish-white color, which stand out prominently in the sunlight and can be seen for a long distance (plate XXXV, figures 1 and 2). This earth appears to be purer and lighter than that around Richmond, but still in places it passes into a clay. . Samples were collected from several localities and examined with some care. Microscopically examined they proved to be somewhat -dis- appointing for the reason that most of them contained very few diatoms, and in some, which to the feel appeared like diatomeceous earth, hardly any diatoms could be found. This is due to the fact that the diatoms 222 MINERAL RESOURCES OF VIRGINIA. are not uniformly distributed through the deposit, but are found chiefly in certain layers. The results of the physical and chemical tests are given in the table opposite page 175. The analyses of the earths given in the table, opposite page 175, collected from different points, show their chemical composition. The location of the samples of the Virginia earths collected by the Pro- fessor Ries and analyzed in the laboratories of the Virginia Polytechnic Institute, is as follows: No. 1322. Weathered diatomaceous earth from 7th street, near Richmond Locomotive Works, Richmond. This, after burning, closely resembles the diatomaceous earth from along the Rappa- hannock river, near Layton. It seems to be vitrified at cone 5 and at cone 8 is viscous. No. 1823. This sample was also collected from the same locality as No. 1322, but farther from the surface. It is quite impure, and shows a high air shrinkage. It burns red and becomes steel-hard at cone 05. It is vitrified at cone 5, and nearly viscous at cone 8. No. 1858. Diatomaceous earth from along the Rappahannock river south of Layton. This burns fairly dense at the higher cones, and gives a clean color, but is quite porous at the lower cones. No. 1363. Diatomaceous earth from Wilmont. This burns to a very porous body as can be seen from the absorption figures. It has a low air and fire shrinkage. It will be seen from an inspection of the chemical analyses (opposite page 175), that these earths show much variation in their chemical composition. All are quite siliceous, and one of them highly so. Nos. 1322 and 1823 represent the fresh and weathered parts respectively of the same bed. The weathered material is more siliceous and contains a lower quantity of fine particles and soluble substances, due probably to the leaching action of water filtering through it from the surface. The higher silica content seems also to affect its porosity and shrinkage in burning. It will also be noticed that the most siliceous one, namely, No. 1363 from Wilmont, is exceedingly porous after being burned. Uses—The chief use of diatomaceous earth is for polishing powders and scouring soaps. Its porous character renders it an excellent absorbent and it has been utilized to mix with nitroglycerine in the manufacture of dynamite. As a non-conductor of heat, it has been used for steam boiler packing, for wrapping steam pipes, and for fire-proof cement. It has also had a limited use in the preparation of the soluble silicate known as water-glass. OXIDES. 223 References. Bailey, J. W. Fossil Infusoria of Virginia and Maryland. ‘he Virginias, 1881, IJ, 56-57; American Journal of Science, 1844, XLVIII. Cabell, J. M. Analysis of Infusorial Farth, Richmond Virginia. The Virginias, 1885, VI, 3. Coryell, Martin. Diatomaceous Sands of Richmond, Virginia. The Virginias, 1881, II, 6-7; Transactions American Institute of Mining Engineers, 1876, IV, 230-232. Hotchkiss, Jed. The Infusorial Deposits of Virginia in the Fort Monroe, Artesian Well. The Virginias, 1882, III, 151-152. Fontaine, W. M. The Artesian Well at Fort Monroe, Virginia. ‘The Virginias, 1882, III, 18-19. Ries, H. A Preliminary Report on a Part of the Clays of Vir- ginia. Geological Survey of Virginia, Bulletin No. II, 1906, 141-144. Rogers, Wm. B. Infusorial Stratum and Associated Tertiary Beds in the vicinity of Richmond, Virginia. The Virgi- nias, 1881, II, 58-59. Virginia Geological Survey Report for 1840. A Reprint of the Geology of the Virginias, 1884, 449-453. On the Infusorial Earth from the Tertiary of Vir- ginia and Maryland, and the Geological Relations of the Strata. Boston Society of Natural History Proceedings, 1861, VII, 59-64. Infusorial Deposits of Virginia in the Fort Monroe Artesian Well. A Reprint of the Geology of the Virginias, 1884, 733-736. The Virginias, 1882, III, 151-152. Stodder, Chas. The Fossils of the Richmond, Virginia, Infusorial Deposit. The Virginias, 1882, III, 159; Boston Society Natural History Proceedings, 1875-6, XVIII, 206-209. 2. CORUNDUM AND EMERY. Corundum.—Corundum, the oxide of aluminum corresponding to the chemical formula Al,O,, has been noted in two counties in the crystal- line area, east of the Blue Ridge. These are Louisa and Patrick. From the first of these, Louisa county, a large deep blue crystal of corundum was found some years ago by Mr. Louis Zimmer, in the soil, but the exact locality is not known. 224 MINERAL RESOURCES OF VIRGINIA. Genth has described the occurrence of corundum in Patrick county, about 2 miles from Stuart, the county-seat, in mica schists on a knob of Bull Mountain. The mica schists are partly garnetiferous, and are inter- sected by granite. The corundum is found associated with andalusite, kyanite, chloritoid, and mica, in rough crystals and nodules up to 1 inch in length and half an inch in diameter. In color, it is grayish-white to white and colorless. It also occurs in finely divided microscopic grains in the mass of associated minerals. According to Pratt, the corundum of this locality is readily cleaned, and tests made for the cleaned product show that it is well adapted for the manufacture of the vitrified wheel. Emery.—Emery, a granular corundum of black or grayish-black color, and containing intimately admixed magnetite or hematite, is found in considerable quantity about 184 miles west of Whittle station on the Southern Railway, in Pittsylvania county. It is found on the land of Keatts, Craddock, Hargrave, Nance and Yeates, but the only place where any attempt has been made to exploit it, is on the Keatts farm. Two openings about 300 feet apart and 20 feet deep have been made on apparently parallel “veins.” Numerous smaller openings are made nearby. The rocks enclosing the emery are probably altered amphibolites or pyroxenites. Miller describes the emery from the Pittsylvania locality as a black crystalline mass, magnetic, polar; with a specific gravity of 4.205, and a hardness of 8. An analysis of the emery gave Miller: Per cent. ANWIMING waa wwe es ee eK pase 8 56.74 Ferric oxide................. 15.50 Ferrous oxide..............-. 20.77 SB IT GA * spicrte'ns teres, hosts we pega agente tee 0.68 Titanié OX1dey wees wecuesaeves 1.86 SOU ay sisinacd ois oth tea wueieied Bie ae 3.95 Uses.—The principal use made of corundum is as an abrasive. The ruby and sapphire corundums ave highly prized as gems. References. CGenth, F. A. Contributions to Mineralogy. On a New Occurrence of Corundum in Patrick County, Virginia. Amer- ican Journal of Science, 1890, XXXIX (3. s), 47-49. Miller, W. W., Jr. Analysis of Emery from Virginia. American Chemi- eal Journal, 1900, XXII, 212-213. Pratt, J. H. Corundum and Its Occurrences and Distribution in the United States. U. 8. Geological Survey, Bulletin No. 269, 1906. OXIDES. 225 3. OCHER. DEFINITION AND PROPERTIES. As ordinarily used, the term ocher is applied to the earthy and pulveru- lent forms of the minerals, hematite and limonite (the anhydrous and hydrous oxides of iron, respectively), which are almost invariably rendered more or less impure through the presence of other metallic oxides and argillaceous or clayey matter. Ocher rarely occurs in nature sufficiently pure for immediate use, and it is usually necessary to prepare it by wash- ing and grinding in order to free it from the common impurities. Natural ochers show a variety of colors which depend in general upon chemical composition. Thus the hematites usually give ochers of red color, while the limonites give yellow or brown; each of. these colors being subject to shade variations according to the amount and kind of impurities. More directly the natural colors of ocher depend on the degree of hydration and oxidation and the kind and amount of impurities. Both the red, yellow, and brown ochers are found in Virginia. According to their natural colors or sources, various varieties of ocher are distinguished. ORIGIN AND OCCURRENCE. The wide variation in the mode of occurrence of ocher in different localities indicates similar variation in its origin. Ocher may result from the leaching action of percolating waters and subsequent deposition; as residual products, formed by the removal on solution of the soluble parts of the original rock leaving the insoluble portions, clay and iron oxide, to form the different ochreous colored clays; from the decomposition of rocks rich in iron-bearing silicate minerals; from the oxidation of pyrite; from the alteration or decomposition of hematite; and from the alteration of the more compact forms of limonite. Lastly, as in the Cartersville district, Georgia, ocher may result from the molecular replacement of the rock in which the deposits are found. DISTRIBUTION AND LOCALITIES. Ocher of more or less purity is found, and to some extent has been mined, in each of the principal geologic divisions of the State, namely, the Coastal Plain, the Piedmont Plateau, and the Valley region. It has been mined at the following localities in Virginia: In the extreme eastern part of Chesterfield county, near Bermuda Hundred, on the Appo- mattox river; in the Little Catoctin Mountain, near Leesburg in Loudoun 226 MINERAL RESOURCES OF VIRGINIA. county; near Bedford City in Bedford county; in the vicinity of Marks- ville, in Page county; near Keezletown, in Rockingham county; from the western base of the Southwest Massanutten Mountain; and in Page and Rockingham counties along Naked creek, about 5 miles southeast of Shenandoah station on the Norfolk and Western Railway. In addition to these, equally as good ocher deposits are found rather widely distributed over parts of the Valley and Piedmont regions, and to some extent the Coastal Plain, which have not been worked. In the Valley and Piedmont regions, the ocher deposits are frequently more or less closely associated with beds of iron ore. Deposits of ocher which vary from red, yellow, and brown in color, and which seem particularly promising but not yet developed, are found in Campbell and Bedford counties; near Bon Air, in Chesterfield county; near Fairfield, in Rock- bridge county; near Waynesboro, in Augusta county; and near Roaring Run, in Craig county. In his “Reprint of the Virginias,” page 49, Professor Rogers states that occasional layers of a beautiful yellow ocher are found with the beds of argillaceous clay of the Miocene in Tidewater, Virginia; and again on page 54, in the Miocene beds exposed along the Pamunkey river rests a thin ochreous clay as brilliant in its tint as the first chrome yellow. This ocher is of the most impalpable texture when dried, and would be found very valuable in coloring. In Buckingham county, on Stonewall creek, near the Ross furnace, yellow ocher is reported by Professor Rogers in association with beds of iron ore, which occur in the micaceous and talcose schists. Also, it is found in similar association and traced for many miles sonthwestward from the furnace near New Canton. DESCRIPTION OF INDIVIDUAL DEPOSITS. Chesterfield County. In the extreme eastern part of Chesterfield county, near Bermuda Hundred on the Appomattox river, an excellent grade of yellow ocher has been extensively mined. This bed of ocher is associated with the Tertiary clays and sands of the Coastal Plain. The property was purchased in 1872 by the Bermuda Ocher Company of New York, which had an investment in the enterprise of $60,000.00 and employed a force of 40 men. The product was offered on the market in 1872 at 214 cents per pound in competition with the Rochelle ocher which was selling at 334 cents per pound. The effect of this competition OXIDES. 227 was to further reduce the price of both ochers, that of the Rochelle ocher to 114 cents per pound in large lots, and that of the Bermuda ocher to 1144 cents per pound. The consumers freely admitted their preference tor Bermuda ocher yet they insisted that it should be sold at a less price than the foreign article. Volume XV of the Tenth Census for 1880, page 844, states that the Bermuda Ocher Company’s mine produced in that year, 1,000 tons of echer valued at $22,000.00; that the total number of hands employed was 20, and the total amount paid in wages was $10,500.00. A writer in the Mineral Resources for 1885 says: “The crude ochre is washed, dried, and then ground into an article which in fineness of quality and in adaptation to all the purposes for which a light-yellow cchre is used, is unexcelled by that from any other deposit known in this country. Three grades are made, all of the same tint but of different degrees of fineness, namely, single washed, double washed, and extra floated. At the shipping point in Virginia these grades have a value, respectively, of $18, $21, and $27 per ton.” Loudoun County. Beginning about 1 mile north of Leesburg, in Loudoun county, and traced for a distance of about 3 miles northward, ocher has been found at numerous points along the eastern base of Catoctin Mountain. Keith mapped and described these deposits in 1894 in the Harper’s Ferry folio of the United States Geologic Atlas. He says: “Ocher has recently been found at several points along the eastern hase of the Catoctin Mountain in connection with the surface wash. The deposits occur beneath the surface of the peneplain at an elevation of about 350 feet. They are usually covered by a bed of gravel and sand from 2 to 8 feet thick, and lie under the bottoms and slopes where the mountain streams deposit their load of sand and gravel. The ocher appears to represent the iron taken in solution from the Catoctin schist and precipitated where it encounters calcareous solutions from the Newark conglomerate. “The ocher thus far prospected is very fine and free from impurities. After the lighter part has been floated off, the small residue consists of grains of magnetite, ferric hydrate, and sand. The particles floated off are ferric hydrate and hydrates of alumina and magnesia. The natural colors of the ocher range from yellow into orange and gray; when mixed with oil, they change materially and give a great variety of reds, yeliows, browns, and greens. 228 MINERAL RESOURCES OF VIRGINIA. “In the same basins with the ocher, beds of reddle are developed, chiefly in the eastern part of the other areas. These are less unctious than the ocher, but very fine and tenacious. They are reddish-brown, and become darker when mixed with oil. “The amount of the ocher deposits is apparently very great, though they have not been prospected over a wide area. Inasmuch as the streams and bottoms along Catoctin Mountain are similar to those already ex- plored, it seems quite likely that most of them will be found to contain ocher. The depth of the ocher in the larger areas exceeds 30 feet.” Page County. About 3 miles south of the village of Marksville, in Page county, and near the western base of the Blue Ridge, where the Shenandoah Valley Railway crosses Stony Run, ocher has been mined for some years. The Oxford Ocher Company of Detroit, Michigan, begun operations here on 30 acres of land, located on Stony Run, where the ocher was exposed in the bluffs along the stream. The company subsequently added 20 more acres. A plant for milling and preparing the ocher for market was built and, in 1876, 200 tons of ground ocher were shipped. In 1877, the production amounted to 350 tons, and since then, about 1,000 tons per year have been produced. During the early years of mining, the product was hauled 18 miles in wagons to New Market and shipped over the Baltimore and Ohio Railway. Since then the ocher has been shipped from a nearer station on the Shenandoah Valley Railway. The ocher is of very light brown color and occurs in the iron-bearing shales of Formation No. I, the Primordial (Cambrian) of Rogers. The deposit is an extensive one, as all the wells sunk between the company’s mine and Marksville have gone through the ocher. It is of good quality and finds a ready sale. Excellent ocher in the same geological horizon is reported further southwest along the western base of the Blue Ridge. According to Volume XV of the Tenth Census for 1880, 875 tons of ocher were produced in 1880, valued at $82,500.00. These mines are producing at present. According to the Mineral Resources of the United States for 1885, an analysis of the ocher mined near Marksville in Page county, Virginia, gave: Per cent. Iron peroxide................ 39.00 AVOMINa, 5c Sateen eae 15.00 U1 CAs G6 5 Brag wruna ie BES ee SF 33.00 Alkaliés: is: 0005405 $3498 03-40% 50 WAtOR so c5 ducetetnaials cies wah 11.50 OXIDES. 229 Rockingham County. Along Naked creek, about 5 miles southwest of Shenandoah Station on the Norfolk and Western Railway, ocher occurs and has been mined, partly in Rockingham, and partly in Page county. The ocher occurs in the Potsdam (Cambrian) in close association with the brown iron ores worked by the Shenandoah Iron Company. The ocher beds are cut across by Naked creek which marks the boundary between the two counties. On the William Merica place in Rockingham county, both yellow- and orange- colored ochers occur. The ocher was first opened by the Virginia Mining and Manufacturing Company of Alexandria, and it was proposed that the crude ocher be shipped to Alexandria to be ground and prepared for market. According to Volume XV of the Tenth Census for 1880, page 44, the production for the year 1880 was 112 tons, valued at $2,240.00. Near Keezletown, in the same county and near the western base of Massanutten Mountain, brown ocher has been mined. The ocher at this locality was first operated by French, Richards and Company of Phila- delphia. The ocher occurs near the contact of the Valley or Shenandoah limestone of Cambro-Ordovician age and the Hudson River slates of Ordo- vician age. It is of very fine texture, of brown color, and good body. An analysis by Professor J: L. Campbell dried at 212° F. gave: Per cent. Ferric oxide...............6- 52.28 Manganese oxide......-....... 1.15 Clay with some sand......... 40.22 Water combined ............. 6.35 Specific gravity.............. 2.82 Augusta County. Professor Fontaine has described in some detail the occurrence of several kinds of different-colored ochers on the Samuel Steele place, 2.5 miles a little northwest from the town of Waynesboro. The ocher occurs in the Shenandoah limestone of Cambro-Ordovician age, which rock is penetrated by a dike of diabase trending northeast-southwest and traceable for a considerable distance. Professor Fontaine says: “A band of yellowish clay runs through Mr. Steele’s land in a N. E. and S. W. direction following the strike of the strata as it seems, and forming apparently one of the more decomposable argillaceous layers interstrati- fied with the limestone. The limestone next to this is, in places, very 230 MINERAL RESOURCES OF VIRGINIA. cherty and seems to have been disturbed. The clay is associated with a peculiar yellowish, to dark brown rock, that graduates from a nearly pure compact silica to an umber or ocher. Near Mr. Stecle’s house and for a short distance to the S. W., the rock is very siliceous and is accompanied by a dark to black wad of impalpably fine texture. This material seems to be composed of very fine manganese powder, clay, and iron, with some graphite. The manganese and graphite give its character to the rock. Sometimes it is purplish in spots, but the most of the mass is nearly black, or a very dark brown. It has a soapy or greasy feel, and clings most tenaciously to any object touched by it. The deposit of wad varies from 10-30 feet in thickness, and in length has been proved for several hundred yards, while in depth, the excavations show that it descends more than 30 feet. There is clearly an immense supply of it. Frequently lumps cf manganese are found in it, sometimes as large as one’s first... ..The wad has been tried as a fireproof paint on boilers, and is reported to act finely. It mixes well with oil, and has so much “body,” that little white lead is needed to mix with it. From all that I could see I consider this to be a valuable material, and I am surprised that it has not been utilized. “A little to the N. E. of the deposit of wad, and apparently in the prolongation of it, we find no longer the wad, but the siliceous rock has become argillaceous, and decayed to a handsome ocher. This varies from a rich yellow to a dark brown. The dark brown ocher makes up much the larger part of the deposit. There are two beds of it lying in clay. The upper one shows a thickness of about 2 feet, and is separated from the lower one which is 3-4 feet thick, by 3 feet of clay. Some of this ocher is firm and looks like a rock, but it may be easily crushed. The yellow ocher occurs replacing a portion of the brown. Both of these appear to be suited for paint. This deposit of ocher appears to continue some distance to the N. E. and 8. W. I was informed by Mr. W. B. Alexander that at Red Bank, about 7 miles N. E. of Waynesboro, and on a line bearing 40° E. of N. from Mr. Steele’s place, similar brown and yellow ochers occur. Fauber’s umber mine occurs some 4 miles to the S. W., in the prolongation of this line of deposits, and is, I think, the same material. There is little doubt that a series of ochers of various colors and excellent quality could be selected along the outcrops of this material. All of the ores and ochers thus far described, lie within a short distance of the Chesapeake and Ohio Railway, and the Shenandoah Valley Rail- way.” OXIDES. 231 Rockbridge County. According to Professor Fontaine, red ocher of good quality is found a half mile from the village of Fairfield in Rockbridge county. He describes it as being very fine-grained, rather firm in texture, decidedly gritty in feel, and most tenacious in its coloring properties. It is found on the land of Major DeVines and is reported in large quantity but has not heen developed. Warren County. In Warren county, about a half mile east of the Shenandoah Railway, umber has been opened up near Major Overall’s house. Tests are reported to have indicated an excellent grade of material. McCreath gives the following chemical analysis of it: Per cent. Siliea, \oeeuit sews nay garcia 31.640 AlUMING: 42 accueseneg seas we 13.510 Ferrie oxide................. 34.000 Manganese sesquioxide........ 6.209 Lime: cedsgcigce veg yerenes ses -720 Ma BIOST A cisshinsie cdc seise Geaeaerantiorns 1.657 Alkalies and undetermined.... 3.390 Water. orga sieie 3 Sh bie ta hades 8.870 McCreath reports about 100 tons of the umber shipped to Pennsyl- vania markets prior to 1884. Uses. The principal use of ocher is in the manufacture of paints for ex- teriors of buildings, the rolling stock of railways, bridges and metal roofing. They are used as a pigment for coloring mortars and in the manufacture of linoleums and oil-cloths. They have been used to produce desirable colors in earthern ware when mixed with a certain proportion of manganese oxide. In addition to these, there are certaim minor very limited uses made of ocher. References. Fontaine, W. M. Notes on the Mineral Deposits of Certain Localities on the Western Part of the Blue Ridge. The Virginias, 1883, IV, 45-46; 58. Hotchkiss, Jed. Hamilton’s Metallic Paint. The Virginias, 1880, 1, 33 The Oxford Ocher Company. The Virginias, 1880, I, 178: The Bermuda Ocher Company. The Virginias, 1882, ITI, 145. 232 MINERAL RESOURCES OF VIRGINIA. Keith, Arthur. Geologic Atlas of the United States. Harper’s Ferry Folio. U. 8S. Geological Survey, 1894. Prime, Frederick, Jr. The Mineral Resources of the Page Valley. The Virginias, 1880, I, 35-36. Rogers, W. B. A Reprint of the Geology of the Virginias, 1884, 49, 54, 311. 4. ILMENITE; MENACCANITE; OR TITANIC IRON. Ilmenite or menaccanite, known as titanic iron ore, is an opaque, iron black mineral, having submetallic luster and differing from mag- netite, which it resembles, by its crystalline form and weak magnetic properties. The mineral occurs in granular form admixed with white apatite in extensive dike-like masses near Roseland and Bryant, in Nelson county, and about 4 miles east of Roanoke, in Roanoke county. The rock occur- ring at the above localities and composed of the two minerals, apatite and ilmenite, is described at more length under Phosphates, on pages 300-302. For location of the Nelson county ilmenite deposit, see map, figure 38. The mineral ilmenite though abundant and cheap has as yet proved of little economic importance. Should the mineral find an extensive use in the future, the Virginia localities noted above will prove to be of con- siderable commercial importance. 5. RUTILE. GENERAL PROPERTIES AND OCCURRENCE. Rutile is a titanium oxide corresponding to the formula TiO, and con- taining theoretically 60 per cent. of titanium. It has a hardness of 6 to 6.5; specific gravity 4.18 to 4.25; metallic adamantine luster, and is generally opaque, rarely transparent. Its usual color is reddish-brown to red and it is insoluble in acids and is infusible. It occurs chiefly in the older crystalline granitic rocks, schists and gneisses, but it is also found in metamorphic limestones and dolomites. DISTRIBUTION. The only locality in Virginia and indeed in the southeast Atlantic states where rutile has been mined is near Roseland, Nelson county, about 7 miles northwest from Arrington, a station on the Southern Railway. (Map, figure 38.) The deposit lies on both sides of Tye river near OXIDES. 233 Roseland post-office, and is owned and operated by the American Rutile Company. The entire limits of the deposit are yet unknown but comprise several hundred acres at least on both sides of the river. The country rock is a pronounced foliated gneiss, penetrated by an occasional diabase dike. { v v Ls ) 20s 7 me, ° Sahn - o ego fe00' JOo0q. 3 s a se 100 Sey? y MY Nelsonite Fig. 38.—Map showing location of rutile and Nelsonite (phosphate rock) in Nelson county. mile. Based on the topographic sheets, U. 8. Geol. Survey. Scale, + inch = 1 Contour interval, 500 feet. aot MINERAL RESOURCES OF VIRGINIA. The rutile occurs in a coarsely crystalline quartz-feldspar rock of probable igneous origin. Both potash and soda-lime feldspars are present, ad- mixed with a bluish opalescent quartz, and in such manner as to suggest at times a doubtful primary crystallization for the quartz. The feldspar is very light gray almost white in color. In places large cleavable masses of a partly altered dark greenish hornblende makes up an essential part of the quartz-feldspar rock. The rutile is of red to reddish-brown color and occurs chiefly in the form of small grains and granules of all sizes up to 4 and 5 millimeters in diameter, disseminated principally through the feldspar, but also segregated in the blue quartz and, to a less.extent, in the hornblende. It is disseminated through the feldspar at times with considerable uni- formity. The rutile occurs in the rock in quantities up to 25 per cent. of the entire mass, with a probable average of 10 per cent. in the run- of-mine ore. In places, the rutile is admixed with ilmenite, which is difficult of separation from the rutile by the present methods of con- centration employed by the company. The ore, of which there is a very large quantity in sight, is mined from open sidehill cuts made in the cliffs bounding the river, as shown in plate XXXVI, figures 1 and 2. Prior to 1902, the ore was shipped to Charlotte for concentration. In 1902, a large and commodious mill was built at Roseland for concentrating the ore. MILLING PROCESS. The run-of-mine ore is hoisted by belt to grizzly, from which it passes to Blake crushers; from crushers the ore passes to stamps, of which there are 10 at present, weighing 750 pounds each, which reduce the ore to 30 mesh. From stamps the ore goes to classifier and from classifier on to Wilfley tables, 3 in number. According to the grade of ore, a concentrate is obtained of 85 to 95 per cent. rutile. The concentrates are treated in a rotary dryer and packed in double sacks of 200 pounds each for shipping. Two grades of the milled product are marketed, designated as “A” grade which averages from 90 to 95 per cent. of rutile, and “B” grade which assays 85 per cent. of rutile. Uses. The Nelson county rutile is of excellent quality, being very pure, but the market for it is yet limited. For the present uses made of rutile the demand is not very great. These include a limited quantity in MINERAL RESOURCES OF VIRGINIA. PLATE XXXVI. Fig. 1—View showing method of side-hill cut mining of rutile along Tye river, near Roseland, Nelson county. Fig. 2.—Same as Fig. 1, but taken from a different place in the area. RUTILE OPENINGS, ROSELAND, NELSON COUNTY, VIRGINIA. OXIDES. 235 alloys and certain grades of steel, for the manufacture of artificial teeth, and of porcelain ware, serving in both as a pigment. Up to the present time, the demand for rutile in the United States has not exceeded 200 to 300 pounds annually. The Nelson county plant is capable of producing from 1,000 to 2,000 pounds per day. References. Merrill, G. P. Rutile Mining in Virginia. Engineering and Mining Journal, 1902, LX XIII, 351; Science, 1902, XV, 389. The Non-Metallic Minerals: Their Occurrence and Uses. New York, 1904, 109-110. Snelling, W. O. Titanium Ores. Mineral Resources, U. S. Geological Survey, 1901, 271-278; Virginia, 277-278. Watson, Thomas L. On the Occurrence of Rutile in Virginia. Economic Geology, 1907, II, 493-504. 6. MANGANESE OXIDES. INTRODUCTION. Elementary manganese is found in nature in the form of oxides, car- bonates, and silicates. Of these, only the oxides are of importance in Vir- ginia. The principal known oxides are, pyrolusite, (MnO.) ; psilomelane, (H,MnO,); hausmannite (MnO.Mn,0,); braunite (3Mn,0,.MnSi0,) ; polianite (MnO,); manganite (Mn,0,.H,O); and wad, probably an impure earthy form of psilomelane. Except when well crystallized, it is often difficult to discriminate between the different oxides, as they are found admixed in nearly all proportions. Usually the well-defined species can be separated from one another by their physical and chemical properties as tabulated below: Species | Hardness ae Color Streak oe ae Pyrolusite....) 2-2.5 |4.73-4.86] Iron black to steel | Black or bluish | Anhydrous gray black Psilomelane..| 5-6 3.7 -4.7 | Iron black to dark | Brownish black Hydrous steel gray Manganite...| 4 4,2 ~-4.4 | Dark steel gray to | Reddish brown to | Hydrous iron black nearly black Polianite....| 6-6.5 |4.99 Light steel gray | Black Anhydrous Braunite... | 6-6.5 |4.75-4.%2! Brownish black to | Same as color Anhydrous steel gray Hausmannite| 5-5.5 [4.856 Brownish black Chestnut brown Anhydrous 236 MINERAL RESOURCES OF VIRGINIA. Of the species of manganese tabulated above, the two first, pyrolusite and psilomelane, make up the principal part of the manganese ores mined in Virginia. The beginning of manganese mining in Virginia and perhaps in the United States was in 1857, when 100 tons of ore were reported taken from the lands of Joshua Robertson, about 5 miles from Waynesboro, Augusta county, in the Shenandoah Valley. In 1868 and 1869, about 5,000 tons of manganese ores were mined near Warminster, Amherst county, which really marked the beginning of systematic mining of manganese ores in Virginia. As shown below, the total production of manganese ores in Virginia, prior to 1869, was 5,684 long tons principally from the Crimora mines, in Augusta county. Virginia has more known deposits of manganese; they extend over a larger territory; more localities have been worked and more manganese has been produced, than in any other state of the United States. Ores of manganese occur in each of the three major geologic provinces of the State, namely, the Coastal Plain, or Tidewater belt; the crystalline area or Piedmont province; and the Paleozoic area or Mountain province. Of these, the Mountain (Valley) province has yielded the principal production, with extensive operations and a large total production from the Piedmont province; and only a slight production from the eastern or Coastal Plain province. The manganese deposits of Virginia are described below under the three sub-divisions here made. GENERAL OCCURRENCE. Manganese ores are usually found embedded in the mantle of residual elays which overlie the rocks, from which the clays have been derived by the usual processes of decay. The underlying rock yielding the ore-bearing clays may be of sedimentary or igneous origin, and may be the usual con- solidated sediment, sandstone, shale, or limestone; or a metamorphic crystalline type. The ore is distributed through the clays in an irregular manner in the form of pockets or lenticular masses, rarely as distinct beds; as veinlets and stringers cutting the clays in all directions; as single nodules or concretionary masses assembled in the clays; and as small disseminated grains scattered through the clays. In places, both in the Piedmont and Valley regions, the ore-distribution in the clays conforms in a general way to the bedding of the enclosing clays; usually, however, this is obscured and the ore-bodies indiscriminately cut the clays in all directions. OXIDES. 237 In the Piedmont region where the residual clays have been derived from the decay of crystalline schists, and the original schistosity of the rocks preserved in the clays, the ore frequently conforms with the folia- tion and is disposed in thin stringers and sheets much after the manner of interleaving. The pockets show much variation in size and number; ranging from small nests to bodies yielding many tons of ore. They are rarely composed of solid ore, free from clay, but the ore forms thickly- studded nodules in the clays. The pockets may be closely spaced or they may occur at wide intervals, usually not connected, although at times stringers or irregular nodules may lead from one pocket to another. Figure 39 is a sketch showing the usual occurrénce of manganese in resi- dual clays. Fig 39,—Section showing ‘the mode of occurrence of manganese ore in resi- dual clay. A, fragments and masses of partially decayed rock; C, residual clay; black areas and dots, manganese ore. The ores are rarely entirely free from inclusions and admixtures of the enclosing clays, and in some of the Virginia mines it becomes neces- sary to jig a certain per cent. of the ore, in order to free it from these. Some of the ore is freer than the others from these mechanical impurities, and in the best grade they are so greatly reduced as to be negligible in pre- paring the ore for market. The proportion of clay to ore varies greatly. KINDS OF ORE. Only the oxides of manganese occur in Virginia. Of these, pyrolusite and psilomelane greatly predominate with, in places, much of the earthy oxide, wad. These different oxides cannot always be 238 MINERAL RESOURCES OF VIRGINIA. separated, but they usually occur admixed in varying proportions. The ore is usually partially or entirely crystalline, of a dark steel-blue color, and the nodular type, which prevails nearly always, displays the complete or partially layered or concentric structure of concretionary masses. THE COASTAL PLAIN REGION. Manganese has been found in small pockets at several localities in the Virginia Coastal Plain area. Near City Point, in Prince George county, a deposit of manganese was worked which produced some hundreds of tons of ore before it was exhausted. Other deposits are reported to have been worked. It is not improbable that other deposits of small extent and similar to those mentioned above will be found in parts of the Coastal Plain area, but deposits of the extent of some of those worked in the Piedmont and Valley provinces of the State, cannot be expected in the Coastal Plain area. THE PIEDMONT REGION. Introduction. The rocks of this area are crystalline schists, gneisses, and granites. They are derived in part from original sedimentary, and in part from original igneous, masses, by metamorphism. Manganese-bearing minerals, principally silicates, frequently enter into the composition of the meta- morphic crystalline rocks of the Piedmont region which, when broken down by atmospheric decay, the manganese is liberated in simpler chemical form, usually the oxide, and is concentrated in the residual clays derived from the rocks through chemical and physical means, sufficient to afford workable deposits of manganese. Because of the widespread occurrence throughout Piedmont Virginia, of rocks composed in part of manganese-bearing minerals, manganese is likely to exist, to some extent, in the residual clays derived from these rocks over much of the area, but not necessarily in sufficient quantity and concentration to be always workable. Workable deposits of manganese ores of good quality are found in the following counties of the Virginia Piedmont province: Albemarle, Amherst, Appomattox, Buckingham, Campbell, Nelson. Pittsylvania, and Spottsylvania. In some of these, mines yielding a laree production of manganese ores have been operated for many years. OXIDES. 239 DESCRIPTION OF INDIVIDUAL AREAS. Amherst County. At Stapleton Mills in the southern part of Amherst county a manga- niferous iron ore is found, which has been mined only to a limited extent. As indicated by the analysis below the quality of this ore is such that the deposit merits more serious consideration than it has apparently had. The quality of the ore is shown in the following analysis quoted by Weeks in the Mineral Resources of the United States for 1885. Per cent. Manganese (metallic)........ 34.56 Tron (metallic) .............. 22.57 Phosphorus ................. .08 Another deposit of manganese is reported from Walker’s Ford Station, in Amherst county, but, so far as known, it has not been developed. Appomattox County. Deposits of good manganese ores are known to occur in Appomattox county, but, so far as the writer is aware, they have received little or no attention. Southeast of Mount Athos in the vicinity of Concord, several recent openings have been made exposing good ore. Froehling and Robertson report the following results on analysis of two samples of ore from these openings: I II Per cent. Per cent. Manganese (metallic) .............. 66.60 52.92 Tron (metallic)................04. .28 2.53 Phosphorus: «.ssv0eceecseevawes we 3 174 002 STITCH). cuecsiievcossavarn dye satin danescuste recast 99 10.58 Buckingham County. Deposits of manganese ores are reported in Buckingham county in the vicinity of Willis Mountain and Spiers Mountain. No developments have been made, but good surface indications are present in these localities. Campbell County. In the northeastern and the middle western portions of Campbell county, near Mount Athos, Evington, and Lynch’s to the east and south of Lynchburg, respectively, large deposits of manganese ores have been worked for many years. The principal mines operated in the county are 240 MINERAL RESOURCES OF VIRGINIA. the Piedmont Manganese Company's mine (formerly known as the Lerner mine) and the Leets mine near Mount Athos, the Saunders mine near Evington, and the Bishop mine near Lynch’s. In 1883, a small pocket of manganese ore was opened at Leesville in the vicinity of Lynch’s, which is reported to have yielded about 30 tons of ore. Prospecting for manganese ore has been in progress during the year near Lynchburg and Evington, with encouraging results at both places, and preparations are now being made to mine the ores. The Leets mine is located about 7 miles east of Lynchburg and about 1.5 miles south of Mount Athos, a station on the James river at the cross- ing of the Norfolk and Western and the Chesapeake and Ohio railroads. Its production of high grade ores has been very large, probably rank- ing next to the Crimora mines, in Augusta county, in quality and quantity of ore produced. The ore is of the nodular or kidney type. The individual nodules show considerable variation in size and shape, and are generally assembled in the form of nests and pockets in a residual clay derived from a dark-colored micaceous schist. The ore is associated with iron. Analyses of the ore from this mine gave the following result: I II III Per cent. Per cent. Per cent. Manganese (metallic)... 48.58 45.87 44.18 Iron (metallic)......... 5.24 5.34 6.64 Phosphorus ............ 316 257 274 Silica. sacav ses teeee we 7.15 7.17 7.73 Ore of much better quality than is indicated in the above analyses was mined; and during the early period of mining the ore was of such superior quality that most of it was shipped to England for use in chemical purposes. Weeks gives the following annual production of ore from this mine, from 1880 to 1885, inclusive: Year Long Tons T88 Oise sre, aiedlatce 104 TSS av cusede es 50 BBR ewe ee mace 130 TSB Be wnceee mors 40 TS84s we pahine 76 1885.66 cvee es 500 The Piedmont Manganese mine is located about -8 miles east of Lynchburg. It was formerly known as the Oxford Furnace Tract and was worked by the Lerner Mining Company, which mined from 2,000 to 8,000 tons of ore. The Piedmont Manganese Company recently ac- quired the property and is actively engaged in mining the ore on a large OXIDES. 241 scale. Mining has reached a depth of about 75 feet with no indications of the ore giving out. The ore is of excellent grade as shown in the analyses given below, and it is suitable for chemical, steel, and brick manufacturing purposes. Analyses of the ore kindly furnished me by the President, Mr. D. W. Meyers, and made by Ricketts and Banks, are: Per cent. Per cent. Manganese (metallic) ............... 54.50 50.18 Jron (metallic) ..............2-26. 2.70 — LTC Bis assoc os thaed4, won sree duerasdcave entececan' othe 4.00 8.58 Phosphorus: ci. cegiewrevericwosces 25 15 Sulphur « seswcssseierda ease es .03 — Water? cc aanientnnicdmaiaen Becca CERN — 6.26 The analysis in column II was made from average samples of a car of lump ore, which was poorly washed, and the sample dried at 212° F. A large mill is operated at the mines, equipped with all necessary machinery for grinding and preparing the different grades of ore for the market. At Lynch’s, a station on the Southern Railway, the Bishop mine pro- duced 13 tons of manganese ore in 1885, which was shipped to England. The ore was of the same general character and quality as that mined at the Leets mine near Mount Athos, and the two mines were operated by the same party. The Saunders mine, located about 1 mile east of Evington, a station on the Southern Railway, may be taken as a typical example of the manga- nese mines in the crystalline area or Piedmont Virginia. This mine was first worked about 20 years ago and it has yielded to date a total pro- duction of between 6,000 and 7,000 tons of ore. The rocks strike N. 30° H. and dip 65°-74° §. 60° E. The main rock is a thinly foilated mica schist composed largely of mica. The underlying rock on the northwest side, locally called “foot-wall,” is a quartzite more or less schistose. The manganese ores occur in the residual clay derived from the decay of the mica schist. This decay is usually yellowish in color, often red, and at times is of lighter hues. The ore occurs in the form of irregular pockets, stringers, and reniform-shaped nodules. Also, it is found as stringers and thin sheets or crusts filtered in and downward along the foliation planes of the schist. Only the oxides occur, pyrolusite and psilomelane. It is partly crystalline and of excellent grade. The property has been extensively developed by shafts, tunnels and open-pits. The greatest depth reached in mining will not exceed 150 feet, and the main tunnel, which produced large quantities of excellent ore, is 242 MINERAL RESOURCES OF VIRGINIA. 900 feet in length. This tunnel was begun a few feet above local stream level and driven from the base of and directly into a prominent north- east-southwest trending ridge. On Wiley’s Mountain, about 134 miles N. 80° E. of Evington, manga- nese ores have been worked by shafts and open-pits to a limited extent. The first work was done about 25 years ago and a shaft 105 feet deep was operated. In the valley adjacent to Wiley’s Mountain on the north- east, a small amount of manganese ore has been mined on the Phillips, Martin, and Mortimer places. Some recent prospecting has been done on Wiley’s Mountain, and the occurrence of the ore is quite similar to that described above at the Saunders mine. It is found in mica schist decay confined between two schistose quartzite bands. Strike of the schists is N. 40° E., dip N. 70° W. Other recent prospecting has been done on some of the adjacent ridges with, in some instances, encouraging results. Nelson County. In past years, several deposits of manganese ores have been somewhat extensively worked in Nelson county, although the ore is not mined to the writer’s knowledge at any point in the county at present. The ore occurs im the southeastern portion of the county, located about 2 miles north of the James river, and in the vicinity of Warminster, and Midway Mills, stations on the Chesapeake and Ohio Railway. The occurrence of the ores is in the form of pockets in the residual clays of the crystalline schists. Four mines have produced considerable ore. These are the Cabell, Bugley, Simpson, and Davis. The Cabell mine, located within two miles of War- minster, has not been worked since 1871. In 1868 and 1869, 5,000 tons of ore were mined and shipped to New Castle-on-Tyne. A reported analysis of this ore shows 82.25 per cent. of manganese peroxide. Two other analyses of ore from this mine are reported by Weeks in the Mineral Resources of the United States for 1885 as follows: Per cent. Per cent. Manganese (metallic).............. 43.30 43.02 Tron (metallic) ................... 3.67 4.24 PHOSPHORUS os iis one cintesnarenee eg e aiarans 243 182 Silica. seed seaideesited esiemeae ems 17.45 18.51 The Bugley mine, located about a half mile southwest of the Cabell, was worked about the same time and is said to have yielded about 2,000 tons of ore. Southwest of Warminster, at Midway Mills, the Simpson mine was worked in 1882, which produced about 12,000 tons of high grade ore, OXIDES. 2438 shipped to Liverpool, England. The mine was developed by a shaft 150 feet deep which had to be abandoned on account of flooding from water. The grade of ore is reported as having improved on depth; that above the water-level yielded 70 per cent. of manganese oxide, and that below the water-level gave 80 to 85 per cent. The Davis mine, operated in the early eighties, is said to have pro- duced 1,000 tons of ore. Weeks quotes the following analysis made of a selected sample of this ore: Per cent. Manganese dioxide........... 90.42 Tron sesquioxide ............. 2.24 Alumina ......... cece cece 1.13 Lime w.isc ved ea seuka pees 1.22 Magnesia ............eeeeeee 2.28 Silla! og seers soma i enwg case osc. dive 1.12 Phosphoric acid.............. 43 Water esseg ses Saks neta an A Seed aeons 0.01983 “ Total mineral matter................. 1.64256 grains Carbon dioxide free................ 12.49 cubic inches An analysis of the water from the Yellow Sulphur Springs, in Mont- gomery county, made by Professor William Gilham, gave: One United States gallon of 231 cubic inches contains: Calcium carbonate.............. cee eee 8.64 grains Magnesium carbonate..................4. 138 = “ Tron carbonate....... 0.0... cece eee eee 62 Calcium sulphate....................005 63.30 “ Magnesium sulphate..................... 21.10 “ Aluminium sulphate..................00. 3.18 “ Potassium sulphate..................000. 10 =“ Sodium sulphate....................000. 75 « Tron, ‘protoxides...:c eee dine owmneteeeesee trace Caleium sulphate....................05. Ol “ Magnesium phosphate................... trace Potassium chloride..............6....00- 10 “ Sodium chloride.................0.00008. 07 “ Organic: matterscc: cs sender vecatcaseanes 3.73 “ 102.98 grains Carbonic: acid)... sguges ae was gee ceawe ee 468 “ 107.66 grains The composition of the Wolf Trap Lithia Spring, at Wolf Trap Station on the Southern Railway, in Halifax county, is indicated by the following analysis, made by Professor M. B. Hardin: One United States gallon of 231 cubic inches contains: Sodium carbonate...................00. 0.24027 grains Lithium carbonate...................0, 0.01726“ OXIDES. 26% Ammonium carbonate.................,. 0.00128 grains Calcium carbonate..................... 7.41222 “ Magnesium carbonate................4. 5.09221 “ Strontium carbonate.................04 0.38489 “ Iron carbonate................... ve... 0.06007 “ Manganese carbonate .................. 0.0134 a Copper carbonate..................004, 0.001234 “ Sodium chloride....................00. 2.62956 “ Sodium bromide....................04. 0.00630 “ Sodium iodide....................00.. 0.00065 =“ Sodium nitrate................ 00.000 ee 2.62548 =“ Potassium sulphate.................0.. 0.06356 “ Sodium sulphate..................04.. 0.06007.“ Aluminium phosphate................. 0.04432 “ DTG,» seeastiertcore sctannt itch Bearabea araransee ect aman 2.01780 “ Barium carbonate..................00, trace Aine carbonates «ies cac.ces eevee. cases trace Magnesium borate..................005 trace Caleium fluoride....................0.. trace Titanic: Oxide. sieiex seven oe eee deen ee ves trace Organic matter (yielding ammonia)..... trace 20.66836 grains Carbon dioxide associated with the above carbonates in the so-called bi-carbonates 6.06682 6c Gases: Carbon dioxide, free................ 12.38 cubic inches NUUTOSEN: 6 opdine bab award citwe 3.60 “ oe ORY BEM sapien stor oem deoacgantaenmaineaee 170“ #6 17.68 cubic inches Production. Of the 43 springs reporting sales, nearly four-fifths of the water is used for medicinal purposes. About half the total number of springs are used as resorts, having accommodations for several thousand people. At a number of the springs the water is used for bathing purposes. Among the most celebrated waters on the continent for bathing purposes, are those of the Warm Springs, in Bath county, a view of which is shown in plate XX XVIII, figure 1. Number of springs Product in Year. vononlng. gallons. Value, 38 1,141,859 $272,868 41 1,562,781 335,869 48 2,442,398 423,412 41 2,561,502 477,410 35 2,117,420 281,998 37 2,340,287 549,102 268 MINERAL RESOURCES OF VIRGINIA. References. The literature relating to the mineral springs of Virginia is very ex- tensive; only several of the more important ones are here noted. Froehling and Robertson. A Hand-Book Prepared for the Virginia Com- mission to the Saint Louis Exposition. Richmond, Virginia, 1904, 97-159. Contains a large number of analyses of Virginia mineral waters. Peale, A. C. Mineral Springs of the United States. Bulletin No. 32, U. S. Geological Survey, 1886. The Natural Mineral Waters of the United States. 14th Annual Report, U. S. Geological Survey, 1894, Part II, 53-88. See also the annual volumes of the Mineral Resources of the United States, published by the U. 8. Geo- logical Survey. Rogers, Wm. B. Mineral Springs of Virginia. A Reprint of the Geology of the Virginias. New York, 1884, 549-566. Artesian Waters.*—The underground or artesian waters are treated only for one province of the State, namely, the Coastal Plain or Tidewater region, for the reason, that, unlike the other two larger provinces, there are no large supplies of portable surface water found within the region. The rivers which traverse the region are either tidal estuaries or are widely bordered by swamps, and the water of their local branches is often of bad quality. Tidewater Virginia extends eastward of a line passing through Alex- andria, Fredericksburg, Richmond, Petersburg, and Emporia, and com- prises an area of about 9,500 square miles. The general structural rela- tions in Tidewater Virginia, so far as they are known, are shown in the sections on plate XXXIX. The Coastal Plain formations which outcrop in the State are as follows: Formation. Characteristics. Age. Columbia.........-. Loams, sands, and gravels in terraces. ............-. Pleistocene. Lafayette....... ..--.| Orange sands, loams, and gravels ....-.6-...e..seeee Pliocene (?) Chesapeake......... Clays, sands, diatomaceous earth, and marl....... Miocene Pamunkey..... .... Glauconitic marls aud sands. ........ s.sseee0es+e+e--| Eocene. Potomac.............| Sands, sandstone, and clayS.......... .cccssceeseeeeeres Early Cretaceous. *Compiled from various papers published by N. H. Darton and M. L. Fuller. The water resources of the Virginia Coastal Plain are being carefully studied by the U. S. Geological Survey and a report formulated. This report, when published, should contain much useful information that is of practical value. PLATD XXXIX. MINHRAL RESOURCES OF VIRGINIA. SECTION 1 feet Ba Chesapeake Ba Chesapeake fd Hepa yaadg 4awhg yaedQ uoynayy ‘ON oonouoy PR “P] 26109935 PH "Id Wd "kd pabbny Wd ‘PH SECTION 2 PH IUIOg yaneg ‘PW “3ul0g jadnyg PR "td Puz bujsog fing SECTION 38 = 3 z = a soupy eenoy SUYM uaand 9 wopseypo a umozy4o, yonog nyu, avauoy 40g qlOg puz emay yaodnay WARWICK COUNTY SECTION 4 Suysog Bangewoiy sony cITY COUNTY CHARLES yoaay Horizoutat acale 20 miles (After N. H. Darton.) Sections, Eastern Virginia. MINERAL RESOURCES OF VIRGINIA. PLATE XL. PROBABLY UNDERLAIN BY CHESAPEAKE cy AND IN PART BY PAMUNKEY WATERS APPROXIMATE AREA UNDERLAIN BY —| PAMUNKEY WATERS APPROXIMATE AREAUNDERLAIN B Y. POTOMAC WATERS WD NEWARK ROCKS NT CRYSTALLINE ROCKS WELLS SCALE OF rat LES Map of eastern Virginia, showing distribution of underground waters. (After N. H. Darton.) OXIDES. 269 WATER HORIZONS IN EASTERN VIRGINIA. According to Darton, the greater part, if not all, of the Coastal Plain region of Virginia is underlain by water-bearing strata, of which, to the eastward, there are several horizons. The failures to obtain the higher water in some of the wells near the bay indicate that in this area at least, there are no good water supplies in the higher horizons, but the waters of the lower horizons have not yet been fully developed. The success of the new well at Fort Monroe definitely proves the existence of one of these. The principal water horizons in eastern Virginia are the Chesapeake, Pamunkey, and Potomac formations, shown on map, plate XL. Potomac——There is more or less water in all of the coarser sand beds of the Potomac formation, but the principal supplies may be expected from the sands and gravels of the basal members, lying on the basement floor of the crystalline rocks. This horizon has been well explored about Wash- ington and Alexandria, in most cases with great success, and was probably reached by the 210-foot well at Quantico. South of Quantico for some distance it does not appear to have been reached by any of the wells except one at Walkerton, on the Mattapony river; but from the general character of the formation as exhibited in its outcrops, and its productiveness of water northward, Darton says there is reason to believe that it is a great water-bearer throughout a wide extent. Its general relations are shown in the sections on plate XX XIX. How far eastward the coarse materials extend in the basal beds of the Potomac formation is not known, for they lie deeper than any of the wells appear to have penetrated. The North Point well is reported to have reached granite and found no water supply in the basal beds, but as elsewhere explained by Darton, the record and conduct of this well do not afford conclusive evidence either of the actual absence of water or of the presence of granite at the bottom of the boring. The well, no doubt, reached the Potomac formation, and it may have penetrated far into it. The water at the Chamberlain Hotel at Fort Monroe is thought to be from upper Potomac but the evidence is not conclusive as to the precise horizon. Water occurs at various horizons in the Potomac formation above the basal beds, in sands intercalated among the clays. This water is an im- portant source of supply in the District of Columbia, and it also affords a large yield at the well at Barrow, near Quantico. Only one of the wells south of Fredericksburg has penetrated to these waters so that their southeastern extension has not been well explored, but there is a fair 270 MINERAL RESOURCES OF VIRGINIA. possibility of finding one or more of them in that region. The 600-foot boring at Gloucester may have reached the Potomac beds, and even pene- trated them for some distance, without finding water, but as this boring missed the higher waters that probably underlie Gloucester, it cannot be regarded as a decisive test for any of the waters. Pamunkey.—The coarse gravel and sand at the base of this formation appears to extend far to the east, and it is a water-bearer throughout its extent. It was reached by the deep well at Naylor’s Wharf at a depth of 386 feet, where sands with rock layers yielded a large flow of water which tose to 45 feet above tide-level. At Chapel Point, Maryland, at 237 feet, in the several deeper wells at Colonial Beach, at Lester Manor, at a depth of 200 feet, and at White House at a depth of from 180 to 230 feet, it fur- nishes a large supply of fine water under considerable pressure. These wells indicate a wide extent of the waters in a region which probably comprises the western half of the area indicated by a distinctive pattern for Chesapeake and Pamunkey waters on the map, plate XL. This horizon is about 250 feet below the Chesapeake water. The meager supply of water in the Clay Bank well and the failure of the deeper borings at Williams- burg and Gloucester probably indicate the limits of the horizon as a water-bearer to the eastward. It may extend under all of the region south of the James river, but none of the wells appear to have been bored suffi- ciently deep to reach it and higher waters are utilized. The experience of the unsuccessful boring to a depth of 386 feet at Dendron is not conclusive, for it probably did not reach the horizon, and if it did, may not have prop- erly tested it; still, it is in line with the experience at Williamsburg and Gloucester. The latter criticism applies also to the North End Point well. It is to be expected that to the eastward the materials of this horizon fi- nally become too fine-grained to carry water, and the eastern limits of conditions favorable for water-bearing appears to be at Clay Bank on York river. Water also occurs in sands in the Pamunkey formation about 90 feet above its base as indicated by the water at 160 feet at Colonial Beach, and at 275 to 325 feet at Naylor’s Wharf; but as it has not been further ex- plored by other wells its extent cannot be discussed. Chesapeake.—Lying between the clays, marls and fine sands of the Chesapeake formation and the top of the Pamunkey formation, there is a series of sands and gravels which may be regarded ag the basal bed of the Chesapeake formation. To the eastward, this series contains thin inter- stratified rock strata which do not appear in the surface outcrops. In this OXIDES. 271 series and in another similar one not far above, there is a large volume of water at a horizon or horizons which appear to be of wide extent in eastern Virginia. These waters have been explored by many wells and been found to underlie a belt of country about 20 miles in width, lying east of a nearly straight line extending from Mathias Point on the Potomac river to Em- poria on the Atlantic Coast Line Railway. This belt has been indicated on the map, plate XL, by a distinctive pattern, and the relations of the waters are shown in the sections on plate XXXIX. The wells which reach these horizons in Virginia are given in the following list: Locality Depth Remarks RICHMOND COUNTY Feet, Naylor's) Wharf..s + ine sence debs sedeene s 1385 Sharps? WATE 0.0.0. 2k disci 65 edd ea sued sees 235 LANCASTER COUNTY Monatico Creek ...........2.--ceeeeeeeee 250 Whealtony 425,60 ax cron wact d een and-ness cuees 230 Monaskon.. «:\ae se ange sds eaera Sean Se eS eae — Wanea’st@n -e.c sg: wees. 4. ace aac pe eae seater lectin 250 Cartérs: Creé@kii ss acs oa na seccnc mac suns 2% ace 330 Weems) @2iciec td antes G25sense cea ceed oenes 260 Windmill Point .................00.00005 450 Well blocked by breaking of tools. WESTMORELAND COUNTY Coles Points 65.405 ou.g aac cis Gud OE au BN SSNS 220 Ragped Point... sic. ca ccd eek ce ee ee 225 Sandy Point: 2.2. esse 24 4002 Peden geceaense 235 NoRBTHUMBERLAND COUNTY Kinsale: av 'ceicg exe aalsie na tie ak gene toes sie 235 Lewisetta: . one ceucnces ok ae aie ee eae PS ay 317 COWATt tise fesse: nels on weeded a ad ne AERP Be0k 238 Water also at 270 feet. Pairports ga: cs ence eens anes aeeb grass os 393 Dymer ‘Creekis.......6% eee 863 ao oa ee cae ee 443 Mattapony RIVER Little Plymouth............--- eee eee 168 Sheppards Warehouse........-..-+.++e+-> 160 YorK RIVER Dudleys Ferry .........-. see eee seer eens 175 West. Point: o:. ssc curds acd sda es aoe ne eee Bei 160 Plum: Points +: sc 8 20 og o a) ba re a Hees n $ I ct 9 = 3 S ake a5 Es SH 3 3B g@ Pe a3 aD ge ‘oS oO sae) wo bP Be o ao a a of mica mines Fig. 42.—Map showing location 282 MINERAL RESOURCES OF VIRGINIA. the soda variety, albite, description and analyses of which are given on pages 276-277. In addition to the three principal minerals, a large number of rarer minerals have been noted in the Amelia county pegmatites. These are microlite, fluorite, columbite, helvite, monazite, allanite, spessaritite (gar- net), apatite, beryl, tourmaline, and zircon. The rocks are everywhere mantled by a considerable depth of residual cecay. Accordingly outcrops are rare, and since the openings, on account of long standing, show much caving from the sides, exact measurements of the dikes could not be made. As nearly as could be determined, the larger pegmatite dikes will measure more than 50 feet across, and they usually cut across the foliation of the enclosing or country rock. These dikes are not schistose but entirely massive and are cut by jointing. The mica occurs as thick highly cleavable blocks and masses of vary- ing size. That found on the dumps is invariably of light, white color, but in some of the openings the mica is very dark in color, nearly black. For a description of the feldspar and quartz contained in these dikes see pages 275-277. MINES. The Jefferson mines——These were the first mines opened in the dis- trict and a large number of openings have been worked, the extreme north- east ones being about 2 miles N. 30° E. from Amelia court-house. Some of these openings are among the largest made in the district, and none of them have been worked for many years. The Rutherford mines—The Rutherford mines are located 1 mile N. 30° E. from Amelia court-house and are reported to have been first opened about 24 years ago. Two openings were worked, aligned in a nearly north-south direction, and are separated by a distance of about 100 yards. The last work done is reported to have been about 12 years ago. Much green feldspar occurs though the bulk of this mineral is white. The largest sheets of mica mined are reported to have cut 22x24 inches. The Berry mine.—This mine comprises one large and deep roughly circular opening, immediately on the southeast side of the Southern Rail- way, about 1 mile northeast of Amelia court-house. No work has been done for many years. The Winston mine—The Winston mine is located on the north side of the Southern Railway about one and three-quarter miles N.70°E. from Amelia court-house. The principal opening is a large one and has not been worked in recent years. MINERAL RESOURCES OF VIRGINIA. PLATE XLI. Fig. 1.—Pinchback mica mine, near Amelia court-house, showing width of pegmatite dike containing the mica. Fig. 2.—View of dump of scrap mica, near Amelia court-house. MICA MINE AND DUMP, AMELIA COUNTY, VIRGINIA. SILICATES. 283 The Pinchback mine——This was the only mine operating in the county in 1906. It is located about 2 miles northeast from Amelia court-house and about one-quarter of a mile southeast of the extreme opening on the Jefferson place. It was first worked about 18 years ago. Some half dozen or more openings have been made, the most recent one of which was made in the spring of 1906, and in July it had been worked to a depth of 28 feet. Plate XLI, figure 1, is a view of this opening. As exposed by this opening, the dike is about 40 feet wide composed of white feldspar and quartz and dark-colored mica and an occasional beryl crystal. Be- tween the middle of the dike and the walling, the feldspar is entirely kaolinized to the depth of working, 28 feet, and much high grade kaolin is being removed and shipped. The feldspar is all partially kaolinized throughout the depth of working, and it rapidly slakes on exposure to the air. It is all saved and shipped to Trenton, New Jersey, where it is util- ized in pottery manufacture. The largest sheets of mica taken out meas- ured 12x14 inches after cut. The average size is probably about 4x6 inches and much of it cuts only 2x2 inches. Both sheet and scrap mica are pro- duced. , The Jetersville District. This area as shown on the accompanying map, figure 42, is 8 miles south of west from Amelia court-house. The Schlegal mine-—Only one mine has been worked in this district, the Schlegal, which is located three-quarters of a mile N. 80° W. from Jeters- ville. It was worked by shaft and open-cut and was first opened about 24 years ago, and was last worked about 5 years ago. The shaft was worked to a depth of 100 feet with several drifts run from it. The country rock comprises a gneiss of granite composition and a sheared, thinly schistose diorite. As measured at the top of the open work, the pegmatite dike containing the mica will not exceed 30 feet in width. The openings are apparently made in a curved or bent portion of the dike the two parts of which strike N.70°W. and S.20°W. The pegmatite cuts across the foliation of the country rock which at the openings strikes nearly north and south. About a half mile N. 10° E. from the shaft, continuous exposures of a large pegmatite dike trending north-south are traced along the valley side of a small stream. No openings are made on this dike and it is re- garded as a separate one from that on which the mine is opened. 284 MINERAL RESOURCES OF VIRGINIA. A mill for grinding and crushing the feldspar which was shipped for use in pottery manufacture was operated at the mine. Blocks or masses of mica yielding cut-sheets of 8x12 inches are reported mined. The mica seen at the time of my visit in July was dark in color. In addition to the three chief minerals, quartz, feldspar, and mica, all of which were marketed, 1umerous small crystals of red garnet occur. Uses. Until within recent years, almost the only use made of mica was as cut sheets of different sizes in the doors or windows of stoves and furnaces, and in other similar places where transparency and resistance to heat were the essential qualities. During this period the small pieces and waste in mining and in cutting the sheets could not be utilized and were thrown away. At the present time, however, the demand for mica for electrical purposes is great and much of the small pieces that were formerly thrown away are now cut into small circular disks and rectangu- lar pieces for insulation purposes in electrical apparatus. The large amount of scrap mica, 75 to 90 per cent. in mining, which was formerly thrown away is now saved and used in the form of ground mica. The mica is usually ground to five sizes to pass through sieves of 80, 100, 140, 160, and 200 meshes to the inch, respectively. This ground mica is now utilized for a great variety of purposes, the principal ones of which are in the manufacture of fire-proof materials, chiefly paint; as a nonconductor for steam and water heating; as a lubricant; for decora- tive purposes; and in the manufacture of paints. Production. Almost the entire production of mica in Virginia has been from the Amelia county area. In some years the production from the mines of this area was quite appreciable but during the present year only one mine was in operation. Mica-mining in Virginia has been so irregular that accurate figures of producton are difficult to obtain. The years given below while not consecutive will probably afford some idea of the annual mica-production in the State: ‘Year. Pounds. 1886 1,500 1887 3,500 1900 16,000 1902 96,000 SILICATES. 285 References. Campbell, J. L. The Steatite, Mica, Fire-Clays, Barytes, Htc., of James River Valley. The Virginias, 1882, III, 160. Fontaine, W. M. Mineral Resources of Blue Ridge Plateau. The Vir- ginias, 1883, IV, 179. Merrill, G. P. The Non-Metallic Minerals. New York 1904, 163- 180. Pratt, J. H. Mica. The Mineral Resources of the United States for 1904, 1175-1184. See also other volumes of the Mineral Resources of the United States. 3. ASBESTOS. Composition and General Character. The name asbestos was originally applied to a fibrous variety of the mineral amphibole, which is a normal metasilicate of cal- cium and magnesium, with frequently varying amounts of iron and manganese and, at times, smaller amounts of the alkalies. As now used, the term properly includes the fibrous varieties of the mineral serpentine, a hydrous magnesium silicate. These two miner- als, the fibrous varieties of amphibole and serpentine or chrysolite, form the present sources of commercial asbestos. They are similar in their physical properties but are distinct chemically. Though equal in their heat-resisting properties, chrysolite is superior in strength and elasticity of fibre to any of the amphibole asbestos. The most marked character of asbestos is its fibrous structure. Chrysolite asbestos is usually greenish- white, yellowish to brownish in color, and has a pronounced silky luster. The amphibole asbestos varies from white to greenish and woody-brown. Its fibres are longer than chrysolite and are flexible and easy to separate. Occurrence. Asbestos occurs in those regions composed of the older eruptive and metamorphic rocks; hence the deposits of Virginia are lim- ited to the Piedmont or crystalline area, east of the Blue Ridge. The amphibole asbestos is usually found in granite or schistose rocks either in pockets or in more or less well-defined veins, a fact which considerably lowers the cost of mining it. The chrysolite or serpentine asbestos is always found in serpentine rocks not in regular veins but as irregular seams which necessitate the mining of a large amount of rock in order to obtain a small amount of the mineral. Amphibole asbestos is less valu- 286 MINERAL RESOURCES OF VIRGINIA. able. It is more easily mined, and where the strength of fibre is not essen- tial it is as satisfactory as the more expensive and rarer chrysolite asbestos. In Albemarle county, Virginia, asbestos is found in thin platy masses along slickensided zones in steatite (soapstone from altered pyroxenite), the fibres of which are parallel to the direction of movement. Distribution. So far as is known the asbestos found in Virginia is of the amphibole variety. It occurs in many of the Piedmont counties of the State and in a few it has been prospected and mined. Bedford is the only producing county at present. In Amelia county about 7 miles north of west from Mattox station, asbestos has been mined near the Appo- mattox river. A very promising grade of the mineral was opened some years ago in this vicinity on the Ligon place. It is found in the vicinity of Whitehall, and Willis Mountain in Buckingham county; and at several points in Powhatan and Goochland counties, although it has not been de- veloped in any of these localities. About 2 miles east of Rocky Mount, in Franklin county, asbestos of excellent grade has been mined to a limited extent. It is associated with soapstone in the form of pockets, is of the amphibole variety, and has a long and white silky fibre. The only producing property at present in the State is that of the American Asbestos Company near Chestnutford post-office, in Bedford county. A number of veins or seams varying from 8 to 50 or more inches wide are worked. The company has recently completed a 40-ton plant erected for the purpose of crushing and separating the asbestos. A con- siderable amount of the crude rock has been mined. Asbestos has also been noted in Floyd, Grayson, and Fauquier counties, but, as yet, it has not been worked in either of these counties. As stated above it is found in Albemarle county in thin platy masses in the soap- stone of the Alberene lead, and is of the amphibole variety. Professor R. L. Packard analyzed a specimen of the amphibole asbestos from Albe- marle county, which gave: Per cent. Silica: (SiO,) csi asa eave eas 56.26 Alumina (AI,O,)............ 1.81 Iron oxide (FeO)........... 6.40 Manganese oxide (MnO)...... trace Lime (CaO)... seasccueeece es 11.98 Magnesia (MgO)............ 20.85 DOTIGION iy acaydoscevycienecos dare ore onl 2.65 SILICATES. 287 Doctor Merrill gives the following analysis, made by Packard, of an amphibole asbestos from Roanoke county, Virginia: Per cent. Silica (SiO,)............006. 55.81 Alumina (AlI,0,)............ 1.66 Iron oxide (FeO)........... 6.81 Time (CaO).............6.- 12.74 Magnesia (MgO)............ 21.09 ERMAGIOM 6 sci aise cienssrsieniendinaie Sent 1.81 Total. . paceseetoasarned Secios 99.92 Uses. The uses of asbestos are many and varied and are constantly increas- ing. Where the chief requirement to be met is non-conductivity of heat, the amphibole asbestos is ordinarily used, but where strength of the fibre is an essential as well as non-conductivity of heat, the chrysolite va- riety is used. Amphibole asbestos is largely used as an ingredient in fire-proof paints for wall plasters, boiler covering, packing in the manu- facture of fire-proof safes, etc. The chrysolite variety is used in the manu- facture of cloth, rope, felt, boards, tubes, washers, etc. References. Campbell, J. L. The Steatite, Mica, Fire-Clays, Barytes, Etc., of James River Valley. The Virginias, 1882, III, 160. Fontaine, W. M. Mineral Resources of the Blue Ridge Plateau. The Virginias, 1883, IV, 178-180. Merrill, George P. The Non-Metallic Minerals. New York, 1904. Day, David T. Mineral Resources of the United States for 1900, 1901, 1902, and 1904. 4. GARNET. Composition and Properties. The garnet group comprises a half dozen mineral species which are essentially silicates of alumina with iron or lime, magnesia, manganese, and chromium. They crystallize in the Regular or Isometic system usually in the form of 12- and 24-faced crystals, known as the dodecahedron and the trapezohedron, with a hardness of from 6.5 to 7.5, and exhibiting a variety of color, the most common among which is some shade of red or brown. The specific gravity varies from 3.55 to 4.30. Probably the two most prominent species of garnet are almandite, the iron-alumina garnet, and grossularite, the lime-alumina garnet. 288 MINERAL RESOURCES OF VIRGINIA. Garnet is a common mineral in many of the crystalline schists and gneisses, including those derived from sediments and from igneous rocks. It is ordinarily a subordinate constituent of these rocks although in some cases it becomes a chief constituent. Distribution. Garnet is a frequent constituent of many of the various types of crystalline rocks composing the Piedmont area, east of the Blue Ridge. Ordinarily it is only a minor constituent of the rocks in which it is found and, therefore, too sparsely disseminated to have commercial value. How- ever, when of large enough size, or uniform color, and without fracture, it is of value as a gem. Very perfect and beautiful specimens of garnet have been collected from the pegmatite dikes in which mica has been mined near Amelia court-house, in Amelia county, and near Hewlett’s station, in Hanover county. The former area has supplied a great many garnets to the trade, the particular species being the manganese-alumina garnet, spessartite. An analysis of the spessartite from the Amelia county area, made by C. M. Bradbury, gave: Per cent. Silica. (Si0.) wcccesescsveses 36.34 Alumina (AI,0,)............ 12.63 Tron oxide (FeO)........... 4.57 Manganese oxide (MnO)...... 44,20 Lime (CaO).............068- 1.49 Magnesia (MgO)............ 0.47 Water (H.O)...........0-2.05- trace Total gaia saiewd ae aeacnedisivere 99.70 Specific gravity.............. 4.20 An analysis by F. W. Clarke of spessartite from the mica mines of the same locality gave: Per cent. Silica (SiO.) ............005 35.35 Alumina (AI,0;)............ 20.41 Iron oxide (Fe,0,).......... 2.75 Iron oxide (FeO)............ 1.75 Manganese oxide (MnO)...... 38.70 Magnesia (MgO)............ none Lime (CaO) .............000. 0.94 POMIHON: i425) sand capmmerennapacie 0.27 Total ve cusses cadnsiseeess 100.17 In Nelson county, about 4 miles south of Arrington, an attempt has recently heen made to mine garnet in the high and steep bluffs along the SILICATES. 289 northeast side of Tye river. Several openings have been made in a garnetiferous sericitic schist. The garnet is of dull red color, in well- defined crystals of small but variable size, and distributed irregularly through the schist. It is very abundant in some places and rather scant in others, a fact which seemingly indicates that the garnet is confined or limited to particular layers of the rock and not disseminated through- out all parts of it. It seems doubtful whether the garnet is sufficiently concentrated in the rock at this locality to be of commercial importance. As a gem mineral, garnet is described on pages 386-387. Uses. Garnet is used chiefly as an abrasive in the form of a sand for sawing and grinding stone and for making sandpaper. Its inferior hardness renders it of less value as an abrasive than corundum or emery. It is also used extensively as a gem, the use to which the Virginia garnet has been put. References. Clarke, F. W. Spessartite from Amelia County, Virginia. U. S. Geological Survey, Bulletin No. 60, 1890, 129. Bradbury, C. M. Garnet (var. spessartite) from Amelia County, Virginia. The Virginias, 1885, VI, 25. 5. TALC AND SOAPSTONE. COMPOSITION. Talc, a hydrous silicate of magnesia, is rather a widely distributed mineral but rarely occurs in large quantities. It is characterized by extreme softness, being readily cut with a knife or scratched with the finger nail, soapy feeling and entire freedom from grit. Ordinarily it is distinctly foliated and of white, gray or greenish color. The name soapstone (steatite an impure form of talc) is ordinarily applied to a dark bluish-gray, greenish rock composed essentially of the mineral tale. Like serpentine and tale it is a hydrous silicate of magne- sia. It is never chemically pure but usually contains varying propor- tions of the minerals mica, chlorite, amphibole (tremolite), pyroxene (enstatite), together with quartz, magnetite, pyrrhotite, and pyrite. The stone is soft enough to be readily cut with a knife and has a pronounced soapy or greasy feel, hence, the name. 290 MINERAL RESOURCES OF VIRGINIA. OCCURRENCE AND ORIGIN. Tale is a secondary mineral representing the alteration product of other magnesia minerals such as tremolite, actinolite, pyroxene, or enstatite, and is frequently associated with talcose or chlorite schists, serpentine, and such basic igneous rocks as peridotite and pyroxenite. Soapstone occurs chiefly associated with the older crystalline rocks. In some cases, it has been derived from an altered eruptive rock; in others, it has probably been derived from magnesian sediments by metamorphism. According to Keith, the soapstone found in Fairfax county, Virginia, was probably derived from the eruptive rocks peridotite and pyroxenite. DISTRIBUTION AND LOCALITIES. Tale. The pure form of tale has only been met with in commercial quantity at one point in the State, namely, near Wiehle, a station on the Blue- mont branch of the Southern Railway, in Fairfax county. The material is reported to be of a good grade of white foliated tale and is operated by a private party with a reasonably good annual production. Soapstone. Soapstone, the impure form of talc, has on the other hand rather wide distribution in the State, being limited to the area of older crystalline rocks, which compose the Piedmont region, east of the Blue Ridge. De- posits of soapstone have been noted in the following counties: Albemarle, Amelia, Amherst, Bedford, Buckingham, Campbell, Carroll, Fairfax, Floyd, Fluvanna, Franklin, Grayson, Henry, Louisa, Nelson, and Patrick. Many parts of the beds found in these various counties are of excellent grade, and the stone has been and is being quarried in at least six of the above named counties. As is noted in the table of production given on page 296, the quarrying of soapstone in Virginia has grown to be one of the important resources in the State, with every promise of greater expan- sion in the future. FLUVANNA AND BUCKINGHAM COUNTIES. In Fluvanna and Buckingham counties soapstone occurs west of the slate belt and is exposed near the mouth of Hardware creek. It was quarried on a small scale at this locality many years ago, strictly for local use as hearths, jambs, and other parts about chimneys. It was SILICATES. 291 also made use of further east in the southern part of Fluvanna county at Bremo. ALBEMARLE, NELSON, CAMPBELL, BEDFORD, AND FRANKLIN COUNTIES. In Albemarle county, a little west of Green Mountain, is a belt of soapstone associated with micaceous schists, which is traced southwest- ward through Nelson into Campbell, Bedford, and Franklin counties. The belt widens in Nelson county and is associated with some serpentine. It passes thence as a narrow belt along the western base of Buffalo Ridge, in Amherst county, crossing the James river above Lynchburg, and is exposed. about 2 miles west of the city on the road leading to Bedford City, and is exposed again 2.5 miles west of New London, in Bedford county. Con- tinuing in the same direction, the stone is seen again at the meadows of Goose creek, where it has been quarried to some extent. Continuing still further westward it is exposed in several nearly parallel belts, of which ‘the most eastern makes its appearance near Pig river in Franklin county. A second belt occurs in the same vicinity near the eastern base of Jack’s Mountain; a third still further west about one mile from Rocky Mount; and a fourth yet more to the west on the eastern slope of Grassy Hill. The stone has been quarried in a small way at several places in Franklin county, near Rocky Mount, and used strictly for local purposes. Exten- sive quarrying operations are in force in the Albemarle-Nelson counties portion of the belt which is described in some detail below. AMELIA COUNTY. In Amelia county south of Chula and 4 miles N. 60° E. from Amelia court-house, occurs a belt of soapstone of good quality which was quarried quite extensively many years ago. A long opening was operated on the outcrop in the direction of the trend of the belt, which is N. 30° W., but is now fallen in and grown up in pine. Excepting huge boulders of the soapstone exposed in the bottom of the old opening, the rocks are entirely concealed beneath a heavy cover of decay. The width of the old opening, which probably represented the thickness of workable stone, will not exceed 50 feet. A second belt of soapstone of good quality is found in Amelia county about 4.5 miles north of Jetersville, a station on the Southern Railway. The soapstone is exposed in numerous places on the north side of Flat creek in several parallel belts having a general northeast-southwest direction. Exposures of the rock along the roadside show a thinly foliated 292 MINERAL RESOURCES OF VIRGINIA. hornblendic schist, probably an altered diorite, and exposures of diabase are found in close association with the soapstone. On the head-waters of Walnut creek, a tributary to and on the north side of Flat creek, the soapstone has been quarried to some extent. Quarrying was begun in 1904, and during the summer of 1906, numerous smaller openings were put down on the belt on top of the hill several hundred yards northeast of the quarry on Walnut creek. The property, including the quarry and other openings, are controlled by a Philadelphia Company and prepara- tions were in progress during the summer of 1906 to begin quarrying on an extensive scale. : LOUISA COUNTY. A deposit of soapstone of very good quality occurs near Oakland in Louisa county. Some stone is reported to have been quarried but no systematic developments have yet been undertaken. FAIRFAX COUNTY. In Fairfax county, there are numerous deposits of soapstone and tal- cose schists, the former of which has been opened and quarried in a num- ber of places. They form small bodies of lenticular shape in close asso- ciation with eruptive rocks, especially the basic ones, and are common around the gabbro areas. According to Keith the soapstone consisting chiefly of impure talc was probably derived from pyroxenite composed of plagioclase and pyroxene. He suggests that rocks of more complex original nature are perhaps represented by the talcose schists. The principal localities where these soapstone masses are found in Fair- fax county are: Two miles east of Annandale, which is the largest area; 1 mile east of Tenley, the next largest body; and in the area east of Falls Church. All of these bodies have been worked to some extent and the stone used chiefly for local purposes. Considerable developments have been made in the large body east of Annandale and much stone has been quarried and sawed. The openings and outcrops show a thickness of 50 feet of soapstone. The rock is of good quality, even-grained, and of uniform light bluish-green color, without seams and schistose plains developed in it. Blocks of desirable size can be readily quarried. GRAYSON COUNTY. In Grayson county, in the vicinity of Mink Ridge south of Grant post-office, soapstone of good quality is reported. It is also found at other 5 At Bi NSA HEN oN interval, 100 feet. 1 mile. Contour circles, Based on the topographic sheet of the U. 8. Geol. Survey. Seale, ¥Y% inch indicated by heavy dots in nties belt. Quarries in the Albemarle-Nelson cou quarries Map showing location of soapstone or BS SI $$ SILICATES. 293 points in the county and preparations are being made to quarry it in one or two places. Professor Fontaine describes a belt. of soapstone found 2.5 miles south- west of the Grayson Sulphur springs near the Carroll-Grayson counties line. It is reported to be of excellent quality, uniform composition, and compact texture. No foreign hard particles are contained in it and it may be planed and sawed with ease. It has a thickness of 8 feet, is traceable for 2 miles or more, and has been used locally about the fire- places in the dwelling-houses. CARROLL, FLOYD, AND PATRICK COUNTIES. Currey mentions a thin seam of soapstone in Carroll county, begin- ning near Greeneville and extending north 54° east within 2 miles of Hills- ville; thence through Floyd within 2 miles of the court-house. It forms large ledges in places, is soft and easily worked. A thin stratum of soapstone is reported by Currey on Colonel M. D. Carter’s place in Patrick county, which, on account of its refractory nature, was used for hearth- stones and other local purposes. HENRY COUNTY. In Henry county, near Spencer’s store, quarries of soapstone were opened some years ago. The material was of excellent quality and blocks of any required dimensions were reported to have been quarried. These were sawn out and then finished by planing. They were used in the foundations of houses and for other purposes. ALBEMARLE-NELSON COUNTIES SOAPSTONE BELT. As described above, the Albemarle-Nelson Counties Soapstone belt lies a short distance west of Green Mountain and to the east, near and ap- proximately parallel to, Hawkins, Findley, Ball, and Appleberry moun- tains. It is distant from this western line of mountains from a quarter to a half mile, and it has a general northeast-southwest direction. It further roughly parallels the main line of the Southern Railway and is distant therefrom 3 to 5 miles. Quarries have been opened on the belt at numerous points with an extreme distance between the two end quarries on the northeast and southwest of nearly 30 miles. At many places where quarries are opened, the belt is apparently separated into several (three) 294 MINERAL RESOURCES OF VIRGINIA. parallel members locally called “veins”. The spacing between the differ- ent members or beds is quite variable with a probable extreme of from 500 to 800 feet. The deposits dip usually to the southeast in conformity with the enclosing rocks and at one point where the beds were favorable for measuring the dip was found to be 60°. . So far as they were measurable at the surface from the more or less altered rock and quarry openings the thickness of the separate parallel de- posits of soapstone varies from 30 feet to 165 feet. A few of the quarries are opened at the point of greatest thickness of stone but the entire thick- ness is not worked. The ratio of worked stone to the total thickness at several localities varies as follows: Total thickness 120 feet, working thick- ness 100 feet; total thickness 150 feet, working thickness 75 feet; total thickness 125 feet, working thickness 65 feet. The above figures do not indicate that of the total thickness, only the width of the present work- ings represents the total workable stone, but that the present conditions do not warrant the working of a greater thickness. The stone varies from light bluish-gray to darker greenish-gray and from very soft to a hardness greater than that of scratching with the thumb nail. It is not penetrated by seams and the jointing is usually sufficiently far spaced to admit of any size blocks being readily quarried. It is compact, of fine texture, and uniform, both in texture and color. A sprinkling of pyrite occurs in places but it is rarely in sufficient amount to be harmful to the stone. The stone is of excellent grade and is admira- bly suited for the various uses made of it. The enclosing or associated country-rock is a variable crystalline schist. In mineral composition variation is from a typical mica-quartz schist of thin and irregular foliation to a micaceous sandstone or quartzite which may be close crinkled, or may be thin, or moderately thick and straight banded. In the Albemarle portion of the belt, a black graphitic schist is associated with the mica-quartz schist on the east side of the soapstone belt, and.at several points further southwestward, the association is with an altered basic eruptive rock. This belt, which is being actively operated at the present time, practi- cally composes the soapstone industry in Virginia. As seen from the table of production given on page 296, the output in stone is large, and Virginia ranks as one of the largest soapstone-producing states. During the summer of 1906, there were 8 quarries producing and beginning to produce stone in this belt. Two of the most extensively worked quarries have reached depths of 120 and 130 feet, respectively. The quarries operating MINERAL RESOURCES OF VIRGINIA. PLATE XLIII. Fig. 2.—View in soapstone quarry in Nelson county. SOAPSTONE QUARRIES IN VIRGINIA. MINERAL RESOURCES OF VIRGINIA. PLATH XLIV. Fig. 1—Partial view of the Schuyler Soapstone Company’s plant, at Schuyler, Nelson county. Fig. 2.—View in the Nationa] Soapstone Company's quarry, Nelson county. SOAPSTONE QUARRIES IN VIRGINIA. SILICATES. 295 in this belt beginning with the most southwesterly one in Nelson county are as follows: Name County The Piedmont Soapstone Company................ Nelson The Phenix Soapstone Company.................. The American Soapstone Company................ The National Soapstone Company................- The Plumbers Soapstone Company of America..... Virginia Soapstone Company...........---+-..--- The Old Dominion Soapstone Corporation......... Albemarle Albemarle Soapstone Company.................5. « Map, plate XLII, shows the location of the above quarries in the Albe- marle-Nelson counties belt. Plates XLIII, XLIV, XLV, and XLVI, show views in the various quarries located on this belt of soapstone. The larger quarries in this belt are well equipped with all necessary modern machinery for getting out the stone. Channelling machines are used in quarrying the rock. At each quarry is located a commodious mill for sawing, dressing, rubbing and polishing the stone and other machines for grooving and drilling holes. The entire product of one or two of the plants goes into the manufacture of laundry tubs, where polishing is un- necessary and hence polishing machinery is not installed. The excellent quality of the stone from this belt is adapted to a wide range of uses. The principal ones include laundry tubs, sanitary purposes, electrical purposes, sinks, and cooking utensils. The mill of the Albemarle Soapstone Company, located 4 miles southeast of North Garden, is the most extensive in the South and it manufactures a much greater variety of products for utilization than any other. It has a very extensive stockyard where a large stock of the manufactured material is kept on hand. The product from this plant is marketed over the entire United States and in many foreign countries including Germany, France, England, South Amer- ica, and Mexico. Uses. Soapstone is one of the most durable of rocks, but on account of its sombre color, greasy or soapy feel and softness, it is undesirable for gen- eral structural purposes. Because of its ready workability due to softness, insolubility and heat-resisting qualities, it is suited for a considerable range of application. Most of the soapstone quarried at the present time is used chiefly in the manufacture of wash or laundry tubs, electric switch- boards and insulators, and laboratory sinks. It was formerly used to some extent for the manufacture ‘of stoves for heating purposes, and to some extent for fire brick, the well-seasoned stone being thoroughly fireproof, 296 MINERAL RESOURCES OF VIRGINIA. but in recent years its use for these purposes has not been so great. The waste material from the quarries or, in some cases, the entire output, is pulverized and used as a lubricant. The principal use made ‘of the Vir- ginia soapstone is given above. Much of it was formerly used in the manufacture of slate pencils but very little, if any, is now used for this purpose. Production. The production of tale and soapstone in Virginia is given for the years 1898 to 1905 inclusive. Quantity Value Year Short tons $ 18985. s:a03 eee ees 10,059 119,480 1899. .........00. 10,886 107,062 VG OO bc seers sn neon xe 9,806 116,930 LOOT os :scie ins aus 38 12,511 232,900 VQ02* 2s sae sc ameec 13,221 372,163 TV9OS* ow css cesses s 13,118 243,552 O04 a sccaycicecesasteaers 17,625 339,928 905 ois ear'g bce oa 21,700 499,780 (*) Includes Maryland. (?) Includes North Carolina. References. Merrill, George P. The Non-Metallic Minerals. New York, 1904, 204- 214. Stones for Building and Decoration. New York, 1897, 45-53. Pratt, J. H. Mineral Resources of the United States for 1900, 1901, 1902, 1903, 1904, and 1905. U. 8. Geolog- ical Survey. Ries, H. Economic Geology of the United States. New York, 1905, 201-203. Rogers, W. B. A Reprint of the Geology of the Virginias. New York, 1884, 27, 79, 297, 314, 459, and 489. 6. FULLERS EARTH. Definition and Properties. Under the term fullers earth is included a variety of clay-like materials which have the property of absorbing greasy substances. The materials are prevailingly greenish-white or gray, olive or olive-green, or brownish in MINERAL RESOURCES OF VIRGINIA. PLATE XLV. Fig. 1—View in one of the Alberene soapstone quarries, Albemarle county, illustrating weathering of soapstone. Fig. 2.—View in one of the Alberene soapstone quarries, Albemarle county. SOAPSTONE QUARRIES IN VIRGINIA. MINERAL RESOURCES OF VIRGINIA. PLATE XLVI. Fig. 2.—Limestone quarry of the Mathieson Alkali Works, near Saltville. SOAPSTONE AND LIMESTONE QUARRIES IN VIRGINIA. SILICATES. 297 color. They resemble clay superficially, but differ from it usually, by having lower plasticity and a higher percentage of combined water in proportion to the alumina content. Chemical analysis is usually of little value, and a practical test is necessary in order to determine its worth. Distribution and Localities, Fullers earth has been reported from a number of localities in eastern or Tidewater Virginia (Coastal Plain) but as yet it has not been investi- gated and very little is known of it in Virginia. Darton has mentioned its occurrence in Westmoreland and Richmond counties, Virginia, and St. Mary’s county in Maryland. He says: “Hastward in the Chesapeake formation the beds of infusorial or diatomaceous remains are often sufficiently pure for commercial use as “fuller’s earth”. The largest deposits are near the base of the formation, and they are best exposed in the bluffs along the Potomac at the mouth of Pope Creek, Maryland, where at one time they were working for ship- ment. The deposits underlie the western part of Westmoreland, Richmond, and St. Mary counties and the southeastern part of Charles County, and they are exposed at many points along streams and in road-cuts. The purity of the material is diminished in some portions of the district by admixture with clay or sand, but over much of the area there are large supplies of relatively pure deposits.” Professor Rogers refers to the beds of infusorial or diatomaceous earth in the Tertiary formations around Richmond as having been regarded as a fine clay or fullers earth. Uses. The material was formerly used chiefly by fullers for removing grease from cloths. It is now principally used in deodorizing and clarifying fats, oils, and greases. References. Darton, N. H. Geologic Atlas of the United States. Nomini Folio No. 23. U.S. Geological Survey, 1896. Merrill, G. P. The Non-Metallic Minerals. New York, 1904, 248- 250. Rogers, W. B. A Reprint of the Geology of the Virginias. New York, 1884, 449. 298 MINERAL RESOURCES OF VIRGINIA. VI. NIOBATES AND TUNGSTATES. 1. COLUMBITE. The mineral columbite, a niobate and tantalate of iron and manganese, occurs in the mica mines of Amelia county with microlite in fine crystals, but so far as is known not in sufficient quantity to be of commercial value. Except as mineralogical specimens and in the preparation of the salts of columbium and tantalium the mineral has but little demand. An analysis of the columbite from Amelia county gave Professor Dun- nington the following results: Per cent. NBO3. «xcaue verdes een en ee ws 31.40 PaO ge: se eds asin vee tee PESTS 53.41 SO 4 heres A tessa 4 RR A a Oa trace OO). obetacw Aine a bee ee Ree RE 5.07 MnO’ s.esecheneds te bes ao 06 om 8.05 CIO hee Sense ea han a Se ee 1.27 MgO) snc. dice ae Seal ena as 0.20 VeO jae so Sirk dees eae nose gune 0.82 Total .c.3 Guedes Ga eee eoreeiee 100.22 Specific gravity.............. 6.48 2. SIPYLITE. The mineral sipylite, the niobate of erbium chiefly with the cerium metals, has been described by Dr. J. W. Mallett as occurring sparingly at the northwest slope of Little Friar Mountain in Amherst county. An analysis of the mineral from this locality by Professor W. G. Brown gave: Per cent. NbjO3. eek temoane Reahand ae kaasd 48.66 W OF swiss erty ox geen Seas wens 16 HOw gests Wars oe goad oewthaue an .08 TBO ge ats 6b a ped tae acteen toy Sebo 2.09 EROS waviia ws acd eae ¥ ow Cees 27.94 WO Oi -isccacerg teat ws ge tees agteocane 1.37 Daa sesso eae tice ha wir cea sebete ok 3.92 on oA aun MEARS Oycew at ener laesteaRs oa pimieedud AR eee reas eee 3.4 HOO © ok sandy stb daseggisbow was othe 4. ged Gees 2.04 BOO! vn aeaccceaare eigen ee ashe .62 MeO: scp ce ti gek ate neg eg ayes 05 CaQ x eats ot nee sete owes ies 2.61 EN ASOD) soos ices 9 due deaaanaeed ieaneed acta 16 KiO caetink ctl syacem ae wexwawies 06 MEO?) cGntag eon ageetse ccsdepeae edie 3.19 NNO" a6 en eeeet sae ee cob es —— BBO) ase bataans Caan he dae trace NIOBATES AND TUNGSTATES. 299 3. WOLFRAMITE. The mineral wolframite, a tungstate of manganese and iron, occurs in the Blue Ridge in the extreme northeastern part of Rockbridge county at Irish creek, in association with the tin ore, cassiterite. It is not known whether the mineral occurs at this point in any quantity. The principal use made of the mineral wolframite, when found in sufficient quantity, is for tungsten, which is utilized chiefly in the manufacture of the so- called self-hardening steel. The material is introduced either as a ferro- tungsten or as the powdered mineral. References. Brown, W. G. Analysis of A New Mineral containing Niobium from Amherst County, Virginia. Chemical News, 1877, XXXVI, 158-159. Occurrence of Wolframite at Irish Creek, Rockbridge County, Virginia. American Chemical Journal, VI, 185. Dunnington, F. P. Analysis of Columbite and Monazite from Amelia County, Virginia. American Naturalist, 1882, XVI, 611. New Analysis of Columbite and Mcnazite from Amelia County, Virginia. American Naturalist, 1882, XVI, 611. Columbite, Orthite, and Monazite from Amelia County, Virginia. American Journal of Science, 1882, XXIV, 153-154; American Chemical Jour- nal, 1882-88, IV, 138-140. Mallett, J. W. On Sipylite, A New Niobate, from Amherst County, Virginia. American Journal of Science, 1877. XIV, 397-400; Ibid. 1881, XXII, 52. Vil. PHOSPHATES. 1. APATITE AND PHOSPHATIC MARL. Like most of the mineral deposits of Virginia the phosphate deposits await investigation. So far as we have knowledge of these, three forms of phosphatic material are found, the first type of which occurs in the Coastal Plain region and includes the phosphatic marls described on pages 397-399; the second in the Blue Ridge region and includes a phosphatic 300 MINERAL RESOURCES OF VIRGINIA. rock composed of apatite and ilmenite; the third in the Paleozoic sediments west of the Blue Ridge and includes a pebble phosphate. The Coastal Plain phosphatic material is discussed, so far as we have knowledge of it, under Marl on pages 397-399. NELSONITE (PHOSPHATE ROCK). A unique and interesting as well as extensive occurrence of phosphatic material is noted at two localities in the Blue Ridge region, namely, in Nelson and Roanoke counties. The rock is closely identical in the two localities; that occurring in Nelson county being known for many years, and has been extensively prospected on many farms, while that in Roanoke county has only recently been noted but actively prospected. For this type of rocks, I have elsewhere proposed the name Welsonite, for the name of the county in which it was first found. Nelson County. The phosphate rock in Nelson county occurs in the foot-hills of the Blue Ridge, near Roseland, about 7 miles northwest of Arrington, a station on the Southern Railway, and again 5 miles northeast of Roseland at Bryant’s post-office. (Map, figure 38.) It is found at a distance of trom a quarter to a half mile west of Roseland on both sides of Tye river, and has been traced for a distance of 2 miles southwest of the river on the Giles place and in a northeastward direction to a point about half a mile east of Bryant, giving a total distance of about 7 miles along a northeast- southwest direction, as shown in figure 38, on page 233. When fresh, the phosphatic material is a hard rock composed of granu- lar white apatite and black ilmenite. It has been extensively prospected near Roseland and Bryant by means of pits, open cuts, and shafts; and near Roseland by numerous additional diamond drillings. The deepest shaft is reported to be about 65 feet and the drillings were put down to a depth of 150 feet and more. Open cuts made near Roseland and Bryant afford some information as to the mode of occurrence of the apatite-ilmenite rock. At both places, the rock exposed in the cuts shows dike-like characters in relation to the en- closing decayed gneisses and schists. As nearly as could be determined it conforms approximately to the structure of the enclosing schistose rocks with sharply defined contacts on the two sides. The greatest exposure in PHOSPHATES. 301 the cuts, which was at Bryant post-office, gave a width of the apatite- ilmenite rock (Nelsonite) from wall to wall of 8 feet. (Figure 43.) Greater widths than this are shown at places on the surface by the weathered. outcrops of the phosphatic rock. The rock is penetrated by several sets of intersecting, closely spaced joints, which break it into small blocks when struck with the hammer. The ratio of apatite to ilmenite is variable, ranging from a rock com- posed of dominant apatite to one composed of dominant ilmenite, with all intermediate gradations. x x x KX * x x x x x x x x x x x x x x x x x x Kw xu KM x x x Fig. 43.—Section showing relations of Nelsonite (phosphate rock) 6 to enclos- ing schists a, in open cut near Bryant, Nelson county. The Virginia Phosphate and Paint Company was organized some years ago for the purpose of working the rock near Roseland for the phosphate which it contains. Should some extended use be found for the mineral ilmenite, these deposits will be of considerable commercial value both for the phosphatic mineral apatite as a source of phosphoric acid and the mineral ilmenite. Roanoke County. About 2 miles east of Vinton and 4 miles east of Roanoke, a similar deposit of the apatite-ilmenite rock (Nelsonite) to that described above in Nelson county, is found occurring on the Valley side and near the base of the Blue Ridge, at an elevation of about 1150 feet above sea-level. Like the Nelson county deposit, the Roanoke county mass shows similar dike-like characters and its traceable on the outcrop in the direction of strike for some distance. It occurs near the contact of the Valley limestone of Cambro-Ordovician age and the crystalline rocks of the Blue Ridge. Although found less than two years ago, the rock has been extensively prospected on a number of adjoining farms by shafts, pits, and open cuts, 302 MINERAL RESOURCES OF VIRGINIA. for the purpose of ascertaining its value as a source of phosphate. Speci- mens of the rock show a considerable preponderance of apatite over ilmen- ite. PEBBLE PHOSPHATE. Doctor R. S. Bassler, of the U. 8. National Museum, noted, during some recent field studies in Virginia, the occurrence of phosphatic nodules at the base of the black shale (Romney) of Devonian age, at Clifton Forge. In a private communication to me, Dr. Bassler states that the noting of the occurrence of these phosphates at Clifton Forge was purely incidental. Thus far only the concretionary or conglomeratic phase of the phosphate has been noted in Virginia. Since no special search has yet been made for these phosphates in Virginia, it is not possible to predict whether commer- cial deposits of them exist or not. An analysis of one of the phosphate pebbles from conglomerate layer at the base of Romney shale, at Clifton Forge, Virginia, gave: Per cent. Insoluble matter............. 25.26 Organic matter.............. 32 Ferric oxide................. 1.21 Alumina .........-..05--058. 1.04 LAME? ae angry ace aie ea awedd Gane 30.86 Maionesay a isin saw eas age ped. ate 27 Phosphoric anhydride........ 27.62 2. DUFRENITE. The mineral dufrenite, an hydrous phosphate of iron, is found in Rockbridge county where it forms radiated coarsely fibrous masses of a dark greenish brown color, forming an irregular bed of about 10 inches in depth, underlying limonite. Analyses of the dufrenite from Rockbridge county, made by Professor J. L. Campbell and Mr. Massie, gave the following results: Massie Campbell Per cent. Per cent. Ferric oxide (Fe,O,)............... 50.89 50.85 Ferrous oxide (FeO).............. 6.30 6.14 Phosphoric oxide (P,0;)........... 31.66 31.76 Water (Hi0)). 2 44 ss bee gle aus paaeye ¢ 8.35 8.53 Alumina (Al,0,).............0..0. 0.25 0.21 Magnesia (MgO)................4. 2.16 0.76 Daimie: (CAO)! ein hata cae eugene Bens — 1.12 Manganese oxide (MnO)........... 0.24 0.40 Silica, (SiOs) 65 sie Liao de ww waned 0.20 0.12 Totals vaccum aceay new eid Sg ee 100.05 99.89 PHOSPHATES. 303 3. STRENGITE. Dr. Koenig has described the mineral strengite, an hydrous ferric phosphate, as occurring in distinct crystals in cavities in dufrenite in Rockbridge county. He gives the following analysis of this mineral from Rockbridge county, Virginia: Per cent. Tron oxide (Fe,0,)........... 42.30 Phosphoric oxide (P,0;)...... 39.30 Water: (HiO) «seuss decus nace 19.87 Potaliecs acecqxrercinane met ancda tuaees 101.47 4, MONAZITE. Monazite, essentially an anhydrous phosphate of the rare earths of the cerium group containing usually a variable amount of thorium, which element gives the mineral its commercial value, has been found only in one locality in the State, namely, Amelia county. The mineral occurs at the mica mines near Amelia court-house in large coarse crystals and masses in association with microlite etc., but not in commercial quantity. Analyses of monazite from Amelia county, Virginia, gave: Per cent. Per cent. Phosphoric acid...............004. 24.04 26.12 Cerium oxide (Ce,03).............. 16.30 29.89 Lanthanum oxide (La,O;).......... 10.30 — Didimium oxide (Di,O;)........... 24.40 26.66 Yttrium and erbium oxides......... 1.10 — Silica: (SiOz): seses-saesicowedeaners terass sis 2.70 2.85 Thorium oxide (ThO,)........-.--. 18.60 14.23 Iron oxide (Fe,O3).........-.0005- 0.90 — Alumina (Al.0;).........-.0000008 0.04 — Jenition. sf my Fossvnoaer\ aquoaa \3 can aN SZ se {i & san upnt © / mee 7 i ; a x “ ia) a, < n fics . oy (@ \ : et 7 vWagdivy oo g K aipaaops0g Gs “ZONvu¥O TAN OL 7 f£ wy f VaHVY ALNNOOD HLAWS ‘8 as \ a SY 3/2 vauy S3ILNNOO T1aMazVL-TIassny ‘9 ‘ vo oN! ay VAYV ALNMO0 WVITIIM SONIUd *P 3 / YX 32 vauv ALNNOO vsINOT *e Lx di 5 fs "ae vauv ALNNOS ayodaaza *% ane \4 Ip wi fe V4YV SILNNOOD VINVATASILId-T1aadWvd “tL L ! SUN aS andar Le ar svauv 3lluva \ 2 ie ; i ) nae . ‘3LINVE JO SV3UV G3NYOM JO NOLLNGIULSIG SAK 4A 3H. ONIMOHS / VINIDYIA JO dVN HOLSNS ™ voy, ‘ § an >» 2anff . “ie es . wf SULPHATES. 307 DISTRIBUTION. Barite is found in a large number of counties in the State but the industry has been confined to only a few of them. (Map, figure 44.) The counties in which barite is found in the State, are (1) those which lie east of the Blue Ridge in the crystalline area or Piedmont province and include Bedford, Campbell, Pittsylvania, Nelson, Buckingham, Amherst, Orange, Louisa, and Prince William; and (2) those counties which lie west of the Blue Ridge and are in the Paleozoic sediments of the Mountain region and comprise Tazewell, Russell, Bland, Wythe, Washington, Scoti, Smyth, Montgomery, Botetourt, Rockbridge, Warren, and Frederick. Of these, Bedford, Campbell, Pittsylvania, and Prince William, of the Pied- mont province; and Smyth, Tazewell, and Russell of the Mountain province have practically yielded the entire production of the State. In 1906, operations were confined to five counties, namely, Bedford, Louisa, Pittsylvania, Russell, and Tazewell. In Bedford and Louisa counties there was no production, the work being in the nature of development preparatory to shipping. Geologically, the barite deposits in Virginia are grouped into three unlike areas: (1) Those deposits in the red shale-sandstone series of Triassic age; (2) those of the crystalline metamorphic area; and (3) those of the Mountain region, associated for the most part with the Shenan- doah limestone or its residual decay. (1) and (2) compose the Piedmont province which stretches eastward from the Blue Ridge. GENERAL OCCURRENCE. Barite is a frequent accompaniment of metallic ores, but as such it has not proved of any value commercially. As a rule, the deposits which have been worked for barite alone are associated with limestone as pockets or lenticular masses, and it follows the structure of the rock with which it is associated. In the Virginia localities which have yielded commercial quantities of barite, the mineral is associated with limestones, largely in the nature of a replacement. In southwest Virginia and elsewhere in the Mountain region, where the barite occurs in the limestone, it is often found as superficially loose lumps and nodules of irregular shapes and sizes em- bedded in residual clays derived from the decay of the limestone. In Bedford, Campbell, and Pittsylvania counties of the crystalline area, a part of the ore has a similar occurrence in a dark manganiferous and ferruginous clay, locally known as umber, which is derived from the decay of the more or less impure calcareous rocks. At other points in Piedmont 308 MINERAL RESOURCES OF VIRGINIA. Virginia, the occurrence of barite is in siliceous crystalline rocks, remote, so far as known, from calcareous masses. One of the best illustrations of such an occurrence is near Thaxton, in Bedford county, where the barite fills an irregular fracture in a coarse-textured granite. The local differ- ences in the mode of occurrence of barite in Virginia are best brought out in the description of the three geologically unlike areas below, in which deposits are found. THE TRIASSIC AREA. As yet only one deposit of barite of commercial importance has been developed in the somewhat extensive areas of Triassic rocks occurring east of the Blue Ridge. About 4 miles south of east from Catlett station, in Prince William county, and within 200 yards of the Fauquier county line, barite has been mined at different times since its opening in 1845. It was last worked in 1903 with a production of 1,500 tens of ore. The opening of this deposit probably marks the first barite mining in Virginia. The property is developed by 3 shafts and a number of open cuts with the greatest depth reached in mining 108 feet. The grinding and preparation of the ore for market were conducted in a mill built for that purpose at the openings. This mill was afterwards burned, and in its place now stands a partly completed crushing-house, located near the main shaft, as shown in plate XLVII, figure 1. The geological position of this deposit is within the eastern margin of the red shale-sandstone series of the Triassic area, which crosses the Potomac river west of Washington and terminates abruptly south of Culpeper, the Virginia portion of the New York-Virginia area as defined by Russell. The rocks of the immediate barite locality consist of ferru- ginous red sandy shales and a light-colored crystalline limestone. The measured dip at numerous places west of the mine gave 10° to 15° west of northwest. Between Catlett station and the mine, the shales are pene- trated by occasional diabase dikes. Much of the material composing the dumps at the mine is a lime- stone breccia, in which red shale fragments are cemented by an impure crystalline limestone. Fractures are frequent and are filled with barite and occasionally with calcite crystals. These facts suggest that the barite deposit occupies a crushed or fractured zone in the Triassic rocks induced, probably, by faulting, although no evidence for such is apparent on the surface. The very gentle northwestward dips of the rock would preclude folding as a possible cause of the crushing. Faulting is a characteristic structure of the Virginia Triassic areas, and indeed of the same areas, MINERAL RESOURCES OF VIRGINIA. PLATE XLVIIL. Fig. 1—Barite mine in Prince William county, near Catlett station on Southern Railway. Fig. 2.—Shaft at barite mine in Prince William county, near Catlett station on Southern Railway. BARITE MINE IN PRINCE WILLIAM COUNTY, VIRGINIA. SULPHATES. 309 further north, and it seems reasonable to ascribe the brecciation in the Prince William county barite locality to faulting. The barite is associated with both the red shales and the impure lime- stone, usually as a deposition product from solution, filling fractures in the red shales. The widest of the barite-filled fractures are reported to be 4 to 8 feet and these form the chief source of the minable mineral. The barite also occurs as thin tabular cleavable masses in the limestone. It is of good white grade, both finely and coarsely crystalline massive, and judging from the ore on the dumps, quite free from most of the common impurities, especially manganese. It is reliably reported that the association of ore with limestone increases in depth. THE PIEDMONT PLATEAU REGION. Barite is reported found in the following counties of the Piedmont region east of the Blue Ridge: Campbell, Bedford, Pittsylvania, Nelson, Buckingham, Amherst, Louisa, and Orange. Also it is found near Mar- shall and Upperville in the crystalline rocks of Fauquier county, west of the Triassic area described above. Practically the total production of barite in the crystalline area has been from 3 counties, namely, Campbell, Bedford, and Pittsylvania. In these counties the ore has been mined for 30 or more years. Prospects in some of the other counties mentioned above in the crystalline area, where the mineral is known to occur, promise well, and, doubtless, further developments in the future will prove the existence of deposits of commercial importance. Exploitation of the mineral in the crystalline area should be especially directed in those localities where lenses or bands of limestone are found and indications of the mineral exist. The Campbell-Pittsylvania Area. Beginning in the middle western portion of Campbell county, a few miles east of Evington, a station on the Southern Railway, and about 15 miles south of Lynchburg, a belt of barite deposits is traced southwestward to 3 or more miles south of Sandy Level in the northwestern part of Pittsyl- vania county, a distance of about 30 miles. Numerous openings have been made at different points on the belt, many of which have been extensively worked and have produced large quantities of excellent ore. Figure 45 is a sketch map of the belt showing the various openings made. It will be observed that the belt is near the Southern Railway for its entire distance, which offers abundant facilities for shipping the ore. At every point opened, the barite is reported to have outcropped on the surface. 310 MINERAL RESOURCES OF VIRGINIA. hain ~Bedford'C} eT Pe 2 Fig. 45.—Map showing location of the principal barite mines in the Bedford- Campbell-Pittsylvania counties area. (After Watson, Trans. A. I. M. E.) SULPHATES. 311 The most extensively worked deposits on the belt are grouped about two centers which occupy the northeast and southwest extremities of the belt, namely, Evington in Campbell county, and Toshes and Sandy Level in Pittsylvania county. Operations were begun in the two counties within a short time of each other, with probably the Hewitt mine in the vicinity of Evington the first to open, which dates back to 1874. The mines in the vicinity of Toshes and Sandy Level in Pittsylvania county were opened not less than 25 years ago, and in both counties, the mines have been operated almost continuously from the beginning to the present time. In Campbell county, the principal mines are the Hewitt, Saunders, Phillips, and Anthony grouped near together and within a few miles east and southeast of Evington. Of these the Hewitt has been the most extensively worked. It is located on the west side of Flat creek, about 2.5 miles from Evington, and about the same distance from the Saunders and Phillips mines. It was worked almost continuously from 1874 until 2 years ago, when it was abandoned on account of water. Ji is developed by numerous shafts and drifts with the greatest depth reached in mining about 160 feet. This is some depth below the local water-level, making it necessary to pump the water from the openings, which was trouble- some and finally led to suspension of work. At the openings the foliation of the rocks strikes N. 55° EH. and dips quite steeply to the southeast. The limestone, with which the ore is associated, has a thickness of about 60 feet and is underlain by a quartzite schist on the northwest side, locally designated the foot-wall, and overlain by a thinly foliated mica-schist om the northeast side, locally called the hanging-wall. As described above, here and elsewhere in this belt, the ore occurs as irregular bodies replacing the limestone, and as irregular rounded nodules and masses in a black manganiferous and ferruginous clay, locally called umber. The Saunders and Phillips mines are located on adjoining properties, opened on the crest of a well-defined northeast-southwest ridge on the east side of Flat creek and about 3 miles east of Evington. The develop- ments comprise shafts, pits, and tunnels, the deepest one of which does. not exceed 100 feet. The first openings were made about 20 years ago. The rock associations are identical with those described at the Hewitt mine. Strike of the schist is N. 30° E. and dip N. 60°-65° W. About 2 miles southwest of the Saunders mine is the Anthony mine, which has produced considerable ore. The barite area in the extreme northwest corner of Pittsylvania county has been more entensively worked than that of any part of the 812 MINERAL RESOURCES OF VIRGINIA. belt. It has been developed by a large number of mines, which are grouped in two nearly parallel belts on either side of Pig river and just south of its entrance into Roanoke river. Beginning at the northeast end of the easternmost belt trending approximately northeast-southwest, it has been > Residual red clay, 10 feet. Umber (black manganiferous and ferruginous clay) containing r barite nodules, 30 feet. Cut by a 5-foot kaolinized pegmatite vein. i Sy talline limestone (marble) containing biotite and tremo- lite, and some pyrite and chalcopyrite, 40 feet. J Umber (black manganiferous and ferruginous clay) containing barite nodules, 10 feet. | Barite, massive granular and white, 10 feet. known. Shaft bottomed 20 feet in it. ee schist, thinly foliated and coarse-grained. Thickness un- Fig. 46.—Generalized columnar section at the Bennett barite mine, Pittsylvania county. (After Watson, Trans. A. I. M. E.) developed by the following mines which are aligned along the strike of the rock, Berger, Ramsey, Bennett, Parker, Thompson, and Dryden Wright. This belt is three-quarters of a mile east of Toshes, a station on the Rocky Mount division of the Southern Railway. The second or westernmost belt SULPHATES. 313 is developed by the Tom Wright mine, 1 mile east of Sandy Level, a station 3 miles west of Toshes on the Southern Railway and by the Hatchet, Mease and Davis mines southwest of Sandy Level. The Davis mine is the most southwesterly one and is 3 miles from Sandy Level. The Thompson mine is reported to have been the first one opened in the area, followed by the Parker, Berger, Bennett, and Ramsay, in the order named. The first four of these were worked more than 25 years ago and the production of barite from each mine was very large and of Fig. 47.—Section at the Bennett barite mine, showing mode of occurrence of the barite and its relations to the rocks. (After Watson, Trans. A. I. M. E.) excellent grade. Except the Bennett, which is operating at present, they have all been idle for some years and very little could be seen at the time of my visit in September 1906. The ore from the Campbell-Pittsylvania area is shipped to the city of Lynchburg, Virginia, nearby, where it is cleaned and ground preparatory to shipping. The mines were developed by numerous shafts and drifts and some open work. The greatest depth yet reached in mining is 120 feet, the depth of the working shaft at the Bennett mine. A description of the Bennett mine, one of the most extensively worked in the district and the only one in operation in 1896, may be taken as typical of the area. 314 MINERAL RESOURCES OF VIRGINIA. The rock succession at the Bennett mine is shown in figure 46, which represents a vertical section made of the 120-foot shaft. As shown in this figure and also in figure 47, the wall rock is a coarse-grained, thinly foliated mica schist intersected by pegmatite dikes, composed of coarse erystallizations of feldspar and quartz. The fresh mica schist is shown in the bottom of the shaft where it is penetrated for a depth of 20 feet, the overlying rock being a black manganiferous and ferruginous clay, thinly foliated, and derived from a calcareous schist in composition. A similar black clay also underlies the limestone occurring between it and the fresh mica schist. The limestone, which is a white coarsely crystalline marble and charged to a small extent with both sulphide and silicate minerals, is 40 feet thick and occurs between the two layers of black clay. The ore, barite, is associated with both the limestone and the black clay, in part as a replacement of limestone and as irregular rounded masses and nodules in the over- and wunder-lying clays. The largest concentration of ore is between the limestone and the schist and has an average thickness of about 10 feet. The contact between the barite layer and the limestone is very irregular, the ore often penetrating far into the limestone, as shown in figure 47. The lower contact be- tween the barite and the mica schist is sharply contrasted with that made with the limestone and is sharply defined and quite regular. The barite is massive granular, moderately coarsely crystalline, and of good white color. Five grades of the ore are made and marketed. Other Prospects—Openings have been made and some ore mined at the following localities between the two developed areas of this belt: One mile northeast of Motley’s station on the Vaughan place; near Hurt station on Major John L. Hurt’s place; about 3 miles south- west of Hurt’s on the Hamner place; one mile west of Lynch’s station. Also 3 miles southwest of the Hewitt mine, the Maddox mine was operated about one mile southwest of Otter River station. Barite of good quality and in large quantity was mined here, but it has not been worked in recent years on account of water, which makes the mining too expensive. MODE OF OCCURRENCE. At the various openings made along the Campbell-Pittsylvania belt the ore was exposed at the surface. Two characteristic occurrences of the barite are observed, always in association and equally as strongly emphasized in one part of the belt as in the other. The first and principal occurrence is in intimate association with the crystalline Jimestone as irregular lenticular bodies or pockets, which measure 100 to 200 feet or MINERAL RESOURCES OF VIRGINIA. PLATED XLVIIL Fig. 2.—Opening from which gypsum was mined, near salt plant, Saltville. BARITE AND GYPSUM MINES IN VIRGINIA. SULPHATES. 315 more, replacing the limestone. At the Hewitt mine, in Campbell county, some of the barite pockets were reported entirely enclosed by limestone. The ore observes the same coarsely crystalline massive structure as char- acterizes the limestone, and in several places gradation of the ore into the limestone has been observed. For the depths attained in mining imme- diately below and above the limestone is a variable thickness of a nearly black clayey mass, usually foliated and colored black from manganese oxide, derived from the decay of limestone schist. Through this black clayey mass is usually distributed in irregular fashion lumps and nodules of barite of large and small size. Occasionally barite stringers of slight thickness are formed along the foliation planes of the clay. Figures 46 and 47 illustrate the different occurrences described above. ASSOCIATED ROCKS. The principal rocks of the barite belt in Campbell and Pittsylvania counties are crystalline schists with intercalated thin beds of coarsely crystalline limestone. Of the former, two distinct types are differentiated, namely, mica and quartz schists. The immediate rocks with which the barite is associated are marked by the essential absence of feldspar. The schists are composed of mica with minimum quartz, and they otherwise bear all the ear-marks of altered sediments, without the slightest suggestion of derivation from original igneous masses. Undoubted igneous rocks of basic composition occur near Toshes depot in the vicinity of the Bennett mine. Again, an irregular biotite gneiss of granitic composition is found within three-quarters of a mile northeast of the same mine; the origin of this gneiss, whether sedimentary or igneous, has not been determined. In the Evington portion of the belt, the underlying rock immediately in contact with the limestone masses on the northwest side is a fine-grained quartzite schist of considerable purity, and containing small brightly re- flecting scales of white mica developed mostly along the planes of schis- tosity. The rock immediately in contact with the limestone lenses on the northeast side is a variable mica schist always of fine texture and thinly foliated. Variation is from a moderately fine-grained muscovite-biotite schist at the Saunders-Phillips mines to a very fine-grained lustrous seri- cite schist at the Hewitt mine. A fine-textured mica schist, heavily charged with minute grains and crystals (octahedra) of black magnetite, forms an additional facies of the schist at the Hewitt mine. The mica schists are composed essentially of mica without feldspar. Those mines developed on the southwest end of the belt in the vicinity 316 MINERAL RESOURCES OF VIRGINIA. of Toshes, Pittsylvania county, indicate an enclosure of the limestone masses by a much coarser textured biotite-muscovite schist on the two sides. Feld- spar is only recognized as a scantily developed constituent of the rock, but thin stringers of quartz are interleaved at times with the schist and small dike-like bodies of a coarse crystallization of pink feldspar and quartz fre- quently cut across the foliation of the mica schist. The kaolinized equiv- alents of these dike-like masses are found in the same position in the residual clays derived from the schist. (Figure 46.) Where exposed in mining this belt, the limestone is a coarsely crystal- line marble of considerable purity in places. In color it is generally white, occasionally pink, and sometimes greenish. It contains ferro- magnesian silicate minerals, especially biotite and tremolite, and is fre- quently charged with chalcopyrite and pyrite. Manganese and iron oxides are noted in places. The limestone widens and narrows alternately, form- ing lenticular masses with an observed maximum thickness of 60 feet, and conforms in dip and strike to the structure of the enclosing schists de- scribed above. In composition the rock is composed essentially of calcium carbonate with small amounts of magnesium carbonate as shown in the analyses below, made by Dr. Walter B. Ellett, of specimens collected by the writer : I II III Per cent. Percent. Per cent. Insoluble matter........ 1.66 0.87 1.10 Alumina eer ‘et LU edarealioss 0.24 0.30 0.96 Calcium oxide.......... 50.04 52.60 51.00 Magnesium oxide....... 3.28 1.40 1.85 Calcium carbonate...... 89.36 93.33 91.07 Magnesium carbonate... 6.61 2.82 3.73 Barium sulphate........ 0.62 0.65 1.62 Copper sulphide......... trace trace 0.36 I. White crystalline limestone from Hewitt mine, Campbell county. II. Same as I III. White and pink crystalline limestone from Ramsay mine, Pittsylvania county. A third important type of rock, intimately associated with the ore and whose fresh equivalent is a limestone schist, is a black manganiferous and ferruginous clay, locally called umber. It is found at every opening made on the belt and its position is next to the limestone, occurring, as a rule, on both sides. Openings made near the outcrop usually penetrate a considerable thickness of the black clay but do not as a rule encounter the limestone. When followed down, however, for a short distance in the direc- tion of the dip, the limestone appears enclosed on either side by the dark SULPHATES. 817 clay which apparently thins on depth and ultimately disappears. Like the associated schists, the black clay always contains the foliation planes of the original limy schist from which it was derived. Leached mica folia and small partially oxidized areas of light green tremolite are found in the black clay of the Pittsylvania county mines. The relations of the clay to the limestone masses and the mica schist, to- gether with its structure and composition, reasonably support the belief that it has been derived by decay from a calcareous schist, which was transi- tional between the well-defined and differentiated limestone on the one hand, and the mica schist on the other. The kaolinized equivalents of the pegmatitic dike-like forms found cutting the schists, are observed in similar position in the black clay, as shown in figure 46. Much good ore is mined trom the black clay, in which it occurs embedded as nodular masses. Figures 46 and 47 make clear the above relations of the clay to the lime- stone and schist. Samples of the black clay collected by me from the Bennett mine in Pittsylvania county, and analyzed by Doctor Walter B. Ellett, gave the fol- lowing results: Per cent. Insoluble residue............. 14,20 PMA oi osasinayt:s. handcerenaiecple eee 4.96 Ferric oxide.............00-- 32.40 Manganous oxide............ 19.49 TANG). xscidcesacacads seve. daonevaue Doeseae oie 2.06 MA BTGSI18) nicsies ease tie es canes trace Barium oxide................ trace COPper ses nxensawoscaeewdmsrs trace ASSOCIATED MINERALS. Calcite in the form of the coarsely crystalline marble, with which the barite occurs, is much the most abundant associate. Pyrite and chalco- pyrite are frequently present as thin stringers and as disseminated small grains and crystals in some of the ore, but more especially in the associated limestone. These are usually intermingled, and in several instances a green staining of malachite has been observed from alteration of the chalcopyrite. Manganese and iron oxides are frequent associates, but, as a rule, they are not noticeable in the best grades of the ore. These are usually more abundant and, therefore, more troublesome in the ore mined from near the surface. A small amount of the ore from the Hewitt mine, in Campbell county, is reported to have been highly charged with manganese oxide. Tremolite has been observed in both the black clay and the marble and in places much biotite accompanies the tremolite in the limestone. 318 MINERAL RESOURCES OF VIRGINIA. STRUCTURE. The rocks are all schistose and preserve a general northeast strike with local variations which, so far as measured, range from N. 30° to 55°E. Greater variations are shown in dip. The pure limestone masses are usually more or less massive, becoming decidedly schistose with de- creasing purity. In the northern end of the belt near Evington, in Camp- bell county, at the Saunders-Phillips mines, the schists dip N. 60°-65° W. At the Hewitt mine, which is about 2 miles S.70°W. from the Saunders, the dip is to the southeast and quite steep, affording a distinct synclinal structure as shown in figure 48. Near the southern end of the belt at Toshes, in Pittsylvania county, the openings at the Bennett mine show a variable dip to the southeast, which is much flatter than in the Campbell «SAUNDERS MANGANESE Fig. 48.—Section from Saunders manganese mine to Saunders barite mine, along a northwest-southeast course, near Evington. Length of section about 2 miles. (1) Crystalline limestone; (2) Crystal- line schists, chiefly micaceous. (After Watson, Trans. A. I. M. E.) SAUNDERS BARYTES MINE HEWITT BARYTES es MINE FLAT CREEK county area, the probable average being about 20°. Other large mines located nearby and on the same strike as the Bennett, had been abandoned for so long a time, that no reliable measurements were possible. However, outcrops of the schist in the vicinity of the mines show dips conformable with that at the Bennett. As indicated in these measurements the folding has not been of uniform intensity throughout, but at the northeastern end of the belt folding is steeper and of a more closed type, while at the south- western end it is flatter and of a more open type. The Louisa County Area. Barite occurrence and mining in Louisa county are limited to the Walker place, 0.75 mile south of Mechanicsville, and 3 miles south of east from Lindsay, the nearest railway point. The openings comprise a number of test-pits and several shafts, the deepest one of which is between 70 and 80 feet. Mining had been temporarily suspended for several months prior SULPHATES. 319 to my visit and the openings were filled with water, which prevented entering them for study of the ore- and rock-relations. The rocks are metamorphic crystalline schists of probable sedimentary origin. They are very thinly foliated micaceous schists, considerably altered, the foliation-planes of which are so regular and closely spaced as to be called, locally, slates. They strike approximately NE-SW, and observe a general southeast dip, with a probable average of about 45°. Exposures of the rock are rare because of the considerable depth of residual decay, chiefly gray and red clays. Quartz-fragments, both large and small, frequently litter the surface, indicating quartz-veins or vein-like masses interleaved with and cutting across the foliation of the schists. Careful search failed to indicate the presence of limestone and close inquiry further confirmed its absence. Examination of the ore was necessarily confined to the dumps. The ore is a moderately white grade of coarsely crystallized barite, remarkably free from impurities other than the usual discoloration from the red iron oxide. Several lumps of the ore showed cavities filled with nearly perfect quartz crystals. Drused surfaces of large tabular barite-crystals are abundant. The ore was traced from the surface downward in the openings, observing a general but variable dip toward the southeast. It is reported to be pockety in mode of occurrence, widening and narrowing sharply and frequently, but having a thickness of about 3 feet where worked in the deep shaft. Evidence is apparently lacking for regarding the ore as a replacement- deposit. It probably represents a filling of an irregular fracture in the crystalline schists, the barium salt of which was probably derived from some mineral or minerals composing the surrounding rocks. The Bedford County Area. Barite occurs and has been mined at a number of different points in Bedford county. Several mines near the Campbell county line yielded large quantities of the mineral. In the western part of the county, between Bedford City and Roanoke, a recent operation shows an interesting occurrence of the mineral. The deposit lies about 3 miles northwest from Thaxton, and is reported to have been first opened in 1866, when a small quantity of barite was shipped to Baltimore. It was re-opened again during the fall of 1906. The barite occurs in a completely schistose coarse-grained granite filling a fracture. Some distance away from the fracture the granite is entirely massive and porphyritic. 320 MINERAL RESOURCES OF VIRGINIA. As nearly as could be determined, the fracture has a N. 10° to 20° E. course, and dips about 60° southeast. An open cut about 20 feet deep has been made along the course of the fracture for a distance of about 450 feet. The granite in the vicinity of the fracture is deeply decayed, although the fracture is distinctly shown at one end of the cut where it carries no barite. The barite is crystalline, and varies in color from white to deep blue- gray. In places, much galenite in small grains and occasional sphalerite are disseminated through the barite. THE APPALACHIAN MOUNTAIN REGION. Introduction. Barite is found in a number of counties in the middle and northern parts of the Greater Valley, but mining of it in this province has been largely confined to Russell, Smyth, and Tazewell counties in southwest Virginia. Within recent years mining operations have been limited to two of these counties, namely, Tazewell and Russell. Where found in the southwest region it is associated with either the Shenandoah limestone or its residual decay. General Occurrence. In southwest Virginia, the barite of the several counties is in associa- tion with the Shenandoah limestone or its residual decay. It observes certain minor variations of occurrence from place to place. It fills in part, at least, fractures in the limestone and, in part, it replaces the limestone. In the southeastern part of Wythe county these occurrences in the limestone are fairly well shown. Here the mineral association of barite is with limonite, sphalerite, galenite, and occasional fluorite in certain openings named below, from which iron and zine ores have been mined. In the Tazewell-Russell area the commoner associates are calcite and limonite, with some siderite, fluorite, and small greenish cherty masses. In addition to its occurrence in the fresh limestone the barite is found as small and large nodules irregularly distributed through the red clay, resulting from the decay of the limestone. (Figure 49.) The variation in local occurrence and in mineral association is brought out in the treat- ment of the individual areas below. Wythe County. In the southern part of the county, near the eastern margin of the Shenandoah limestone, barite is found in association with the metallic SULPHATES. 321 ores in some of the zinc and iron mines. No attention has been given to the mining of barite in this locality, nor is it known whether com- mercially valuable barite occurs. In several of the brown iron-ore pits at Ivanhoe, notably those of the New River Mineral Company and the Painter, barite has been observed in some of the limestone chimneys (pin- nacles) as protruding irregular porous or cellular masses, intimately as- sociated at times with sphalerite and galenite. These latter minerals, sulphides, were noted in several instances as enclosures in the barite, and the barite replaces in part the limestone. Northeast of Ivanhoe at the Bertha zine mines, which have been operated for several years for iron-ore, barite is found in places as loose nodules embedded in the red clay, result- Br Fig. 49.—Section showing mode of occurrence of barite in clays derived from limestone. Tazewell-Russell counties area. (After Watson, Trans. A. I. M. E.) ing from the limestone decay. About a half mile northeast of Bertha at the Barren Springs iron-ore pits, barite is again found similarly occurring. The mode of occurrence and the associations of the barite’ in the above localities suggest the introduction of the barium salt along fracture lines in the limestone and the partial replacement of the limestone by the barite. Smyth County. Barite was extensively mined some years ago near Marion, the county- seat of Smyth. The mining and shipping of barite in this county were begun about 1877 by Mr. Goodell, and the work was continued more or less energetically until about 1885. Some mining on a small scale has since been done from time to time. The mining of barite in Smyth county was largely confined to the west 322 MINERAL RESOURCES OF VIRGINIA. side and at a distance of about 3 miles from Marion, although some ore was mined on the east side of the town. Mining was largely confined to the lumps and nodules of barite embedded in the residual red clays derived from the Valley limestone. In some instances, mining operations extended. into the fresh and hard limestone beneath the clays, but nowhere was a greater depth reached in mining than 100 feet. During the fall of 1906, 2 car-loads of barite were mined and shipped from the W. M. Copenhaver property on the west side of Marion. During the period of active opera- tions in this county the barite was chiefly milled and prepared for market in Marion. A smaller mill was operated both on the east and west sides of Marion. Washington County. About 4.5 miles northwest of Glade Spring and on the north side of and about a half mile from the Saltville branch of the Norfolk and Western Railway, barite occurs in the red clay derived from the Valley limestone on the Buchanan, McNew, and White places. No prospecting nor work for barite has been done in this county. Russell and Tazewell Counties. Russell and Tazewell counties are the largest producers of barite, at present, in the State. Extensive deposits of the mineral are found in both counties. In its geographical distribution the mineral is limited chiefly to the southern slope of Kent Ridge and its prolongation both northeastward and southwestward along the valley of Clinch river, extend- ing from near North Tazewell on the northeast to near Lebanon on the southwest, a distance of more than 30 miles. Map, figure 50, shows the most productive portion of the belt. Barite has been mined at numerous points along this northeast-southwest belt, the principal ones being near North Tazewell; 3 miles south of Richlands; 3 miles from Hon- aker on the Clinch river; and on the southwestern end of the belt in the vicinity of Lebanon. The barite is found throughout this belt in the upper portion of the Knox dolomite and its residual decay. Sections AA and BB, figure 50, show the structural relations of the Knox dolomite and the adjacent rocks on the northwest and southeast, near Sword Creek and Richlands in Taze- well county. The barite occurs as small and large lumps of irregular shapes assembled in the residual clay of the limestone, and in pocket form and vein-like bodies fillmg spaces in the limestone, and in part replacing the limestone. 823 SULPHATES. “aqtaeq st deur jo ofpprar ysno1y} 49 ‘oITTeq 218 suOT}ON8 UT s¥aIe HORT PI]Og * q PeuUl[-ss01g ‘Bare Oq1IBq setTjun0d |[e oz = PTR DSSS . BE RN JE EOE EERON EEG § LA (4aaang ‘Toor ‘g + ‘orfoy T[@49zey, 94} uo paseg ) Thessny oq] Jo suoroes eanjonsys pue dey—og “S1q 324 MINERAL RESOURCES OF VIRGINIA. The ore is crystalline, of good white quality, and in most places is quite free from impurities. The mines of the Clinch Valley Barytes Company, near Honaker and Gardner examined by me, show a coarsely crystalline white barite, in platy more or less radiate masses, a structure which is strongly emphasized on weathered surfaces of the ore. The commonest impurity at these mines is iron oxide, mostly in the form of limonite. Manganese oxide occurs but sparsely, or not at all. In one of the pits, a little violet fluorspar and small fragments of green chert were observed in association with the ore. . All the ore milled at the Clinch Valley Barytes Company’s plant is washed, and the limestone ore is both jigged and washed, before bleaching and grinding. The greatest depth attained in mining is 103 feet at the mines of the Pittsburg Baryta and Milling Corporation on the northeast. end of the belt. Most of the mining done on the belt has been for the lump or nodular ore occurring in the limestone clays, won from shallow open pits and cuts. Some hard-rock mining in the limestone has been done in places. It is probable that in the future much mining of lime- stone ore will be engaged in, since large bodies of excellent grade ore are exposed at a number of places along the belt, especially on the properties of the Pittsburg Baryta and Milling Corporation. At the northeast end of the belt, on the property of the Pittsburg Ba- ryta and Milling Corporation, an ore-body 4 feet wide has been mined to a depth of 22 fect and for a distance of more than 300 feet. The ore has been tested to a depth of more than 100 feet without indications of its exhaustion. Preparations are being made to mine this ore-body to a greater depth. The barite occurs in vein-like bodies in the limestone, is very white, free from impurities, and makes the best “snow flake” grade manufactured by the company. On the extreme southwest end of the belt, near Finney, the properties of the same company show ore-bodies in the limestone of the same white and otherwise excellent grade of ore as that described above on the northeast end. Three miles south of Richlands, this company has mined more than 6,000 tons of barite from the property. Unlike the ore described above on the two ends of the belt, that south of Richlands is lump ore mined from the red limestone clays. Two barite mills are operated on this belt, one owned by the Pittsburg Baryta and Milling Corporation, located at Richlands in Tazewell county, with a capacity of 50 tons per day; the other owned by the Clinch Valley Barytes Company, located 3 miles southeast of Honaker, Russell county, on the Clinch river, with a capacity of 16 tons per day. Both are modern MINERAL RESOURCES OF VIRGINIA. PLATE XULIX. General view of the barite milling plant of John T. Williams and Son, at Bristol. BARITE MILL IN VIRGINIA. SULPHATES. 825 mills and are well equipped. Plate L is a view of the milling plant of the Pittsburg Baryta and Milling Corporation at Richlands. ‘This plant is very commodious, completely equipped with modern machinery, and is one of the best modern barite mills in the country. Methods of Mining. As noted above in the description of the barite mines, now or formerly operated in the different sections of Virginia, the mining is all surface work with no deep mining in any part of the State. The greatest depth yet reached in any of the Virginia mines is a shaft recently operated at the Hewitt mine, in Campbell county, which is 160 feet. In the crystalline area, east of the Blue Ridge, the ore is first located by surface indication and is won by vertical timbered shafts and drifts, which follow the direc- tion of the ore bodies. The machinery employed is simple, light and in- expensive. In the limestone of the southwest Virginia region the mining is shallow and largely by open pit work. In mining the ore in the fresh limestone, blasting becomes necessary for breaking it down. Preparation. For removal of the impurities from the better grades of merchantable ore, washing and bleaching, and occasionally jigging, are the only opera- tions necessary. The common impurities in the best grades of ore include iron and manganese oxides, limestone, clay, and sand. Higyin’s descrip- tion in the Engineering News for 1905 of bleaching barite, in preparing it for market, is here given in full as summarized by Pratt in the Mineral Resources of the United States for 1904: “In bleaching the barytes, the crushed mineral is placed in wooden tanks lined with sheet lead and holding from 5 to 25 tons of mineral. The tanks used are either circular or rectangular, the former being preferable for the reason that the steaming can be more uniformly done. The best size is 4% feet high and 8 feet in diameter. With a tank of this size, one steam inlet is required. The most satisfactory tanks are made of stout, well-seasoned cypress wood, which are well braced on the outside and lined on the inside with heavy sheet lead. A lead coil of pipe one-half to 2 inches in diameter is constructed in such a manner that either steam or water can be supplied through the perforations which are best located at an angle of about 45° to the vertical diameter of the pipe rather than directly on top of the pipe. With the perforations in this position there is less chance of the holes becoming clogged up by fines dropping into them. In charging the tanks the barytes is added to a depth of about 3 feet and then the 326 MINERAL RESOURCES OF VIRGINIA. dilute sulphuric acid solution, which is used as the solvent, is run in. Steam is admitted by means of the coiled lead pipe, which is closed at one end and provided with small perforations from 6 to 8 inches apart. The steam escaping from these perforations agitates and heats the mixture, which requires from six to eighty hours to bleach, depending entirely on the amount of iron contained in the barytes. After drawing off the acid, the cleaned mineral is discharged either by sluicing through a specially constructed spout or else by shovelling over the side of the tank and is transferred to a washer in which the last traces of the acid and clay mate- rial are removed. The cleaned mineral is then dried either on large pans or by means of some one of the patented rotary driers.” “In this bleaching process the manganese dioxide is not removed and the barytes that contains this impurity has to be ground to paste on a 40-mesh screen and then mixed with nitrate of soda, salt, and sulphuric acid in the proper proportions. This mixture is then heated in a specially constructed furnace by which process the iron and manganese are con- verted into chlorides, which, being very soluble in water, can be completely removed by washing, the barytes being allowed to settle in a series of tanks, generally three in number.” “The next step in the preparation of the barytes for market is reducing it first to the size of fine sand by means of rolls and then to an impalpable powder by means of buhrstones, after which it is ready to be packed for shipment.” Uses. The principal use made of barite at present is as a white pigment. It was formerly used as an adulterant of white lead but it is now recognized that barite alone makes a good pigment. At the present time, therefore, barite is put on the market as a pigment in competition with white lead and other white pigments. It has a permanent white color and is not effected by weather and by gases which cause in some cases white lead to blacken. According to Pratt, barite can be used to advantage in combina- tion with either white lead or zinc white. Any pronounced increase in the consumption of white pigments will produce a corresponding increase in barite; and as barite is more and more replacing the other white pigments, there is a noticeable increase in the production of barite from these causes. Pratt states that of the total production of barite, about four-fifths are used in the manufacture of white pigment. A further use made of barite is for giving weight and body to certain kinds of cloth and paper. The use of barite in the manufacture of barium compounds for chemical purposes is increasing. MINERAL RESOURCES OF VIRGINIA. PLATE L. General view of the Pittsburg Baryta and Milling Corporation’s plant, Richlands. BARITE MILL IN VIRGINIA. SULPHATES. 327 Production. The production of crude barite in Virginia from 1901 to 1905 is as follows: Year Quantity Value Short tons $ 1901 nc oameewinas 10,270 31,260 V90 2 iseic.cinisd Generac 12,400 39,700 T9085 :ceaaeenine 5,700 20,400 L904 eo iirare ines 11,214 31,452 T9050 5 wa nen ena x 6,468 27,838 References. Campbell, J. L. The Steatite, Mica, Fire-clays, etc., of James river Valley. The Virginias, 1882, III, 160. Fontaine, W. M. Notes on the Geology and Mineral Resources of the Floyd, Virginia, Plateau. The Virginias, 1883, IV, 167, 178-180, 185-192; 1884, V, 8-12. Higgins, Edwin, Jr. Barytes and Its Preparation for the Market. Engi- neering News, 1905, LIII, 196-198; Engineering and Mining Journal, 1905, LX XIX, 465. Judd, Edward K. The Barytes Industry of the South. Engineering and Mining Journal, 1907, LX XXIII, 751-752. Merrill, G. P. Barite. Non-Metallic Minerals. New York, 1904, 824-326. Pratt, J. H. Barytes. Mineral Resources of the United States, 1901, 915-916. Unsigned Barytes Mining in Virginia. Engineering and Min- ing Journal, 1905, LX XIX, 563. Watson, Thos. L. Geology of the Virginia Barite Deposits. Transac- tions American Institute of Mining Engineers, 1907. See Mineral Resources of the United States from 1883 to date; Mineral Industry from 1892 to date. 2. GYPSUM. General Properties. Chemically, gypsum is a hydrous calcium sulphate corresponding to the formula CaSO,.2H,0. When pure, natural gypsum is usually white when massive, and pearly when crystallized. It is often gray, brown, red, and even black from impurities. Ordinarily the impurities are organic 328 MINERAL RESOURCES OF VIRGINIA. matter, ferruginous and aluminous or clayey matter, and the carbonates of lime and magnesia. The hardness of gypsum varies from 1.5 to 2.0; specific gravity, 2.3. The softness of the mineral, which is such that it can be readily scratched with the finger-nail, serves to distinguish it from the other minerals which it resembles. Three principal varieties of gypsum are usually recognized: (1) The crystallized, foliated and transparent variety, known as selenite; (2) the fine fibrous and pearly or opalescent variety, known as satin spar ; and (3) the common massive, fine-granular variety, known as gypsum. When of white color and sufficiently compact or fine-grained for carving and sculpturing, it is known as alabaster. Origin and Occurrence. In commercial quantities, gypsum is always associated with stratified rocks, when it is usually regarded as a chemical deposit, resulting from the evaporation of inland sea and lake waters. The gypsum beds usually occur interstratified with shales and limestones and in many places beds of rock salt. In southwest Virginia the gypsum deposits are associated with gray and purple clays in shales and shaly limestones of Lower Carboniferous (Mississippian) age. It- may also be formed through the oxidation of sulphides and the action of the liberated sulphuric acid on limestone; or through the action of solutions of metallic sulphates on calcium carbonate (limestone) ; through the hydration of anhydrite; and through the action of sulphurous vapors from volcanoes on lime-bearing rocks. General Geologic Relations of the Southwest Virginia Deposits. The gypsum and salt beds of southwest Virginia are intimately asso- ciated, and are confined to a narrow southwest-northeast valley of the North Fork of the Holston river, extending from Plasterco on the southwest to within 3 miles west of, Chatham Hill post-office on the northeast, a dis- tance of about 16 miles. Plates XXXIII, XXXIV, and LI, views taken at Plasterco and Saltville, give a general idea of the outline and surface character of the southwest end of the valley. The ridges known as Pine and Little Brushy Mountains bound the valley on the northwest sides and are composed of rocks which range in age from Silurian through Devonian to Lower Carboniferous. Near the mid- dle portion of the valley the road follows for some distance close to, on and over, thin-bedded sandstones and siliceous shales of Carboniferous age, which MINERAL RESOURCES OF VIRGINIA. PLATE LI. Fig. 1View of the southwest end of the Saltville valley at Plasterco, showing gypsum masses (white) mined by the Buena Vista Plaster and Mining Company. Fig. 2—The Buena Vista Plaster and Mining Company’s plant, Plasterco, Washington county. GYPSUM MINES AND MILL, WASHINGTON COUNTY, VIRGINIA. SULPHATES. 829 form the basal slope of the ridges. These rocks, dipping at angles varying from 23° to 45° southeast, underlie the Greenbrier limestone. This lime- stone forms a narrow belt extending from and along the basal slope of the ridges to the southeast side of the river where it is cut off by a fault, which has brought up the Cambro-Ordovician limestone. As mapped by Professor Stevenson, this fault, designated the Saltville fault, extends from the south- western end of the area, passing within a short distance to the southeast of Plasterco and Saltville, in a general northeast direction several miles north of Chatham Hill post-office. The rocks on the southeast side of the fault are limestones and blue limy shales which dip to the southeast at angles varying from 21° to 35°, measured along the road extending from Saltville to the limestone quarry of the Mathieson Alkali Works, 3 miles S. 15° E. of the Salt Works plant. A view in this quarry, showing the limestone capped by shales, is given in plate XLVI, figure 2. The accom- panying map, plate LIT. make plain the above geologic relations. New. alroad Holston Fiver J) North Fork P Sea Leve/ Scarce 20090 +OoOoO FT. Fig. 51.—Section across Holston and Saltville valleys on a northwest-southeast line midway between Saltville and Plasterco. (After E. C. Eckel.) Both the gypsum and the salt deposits are limited to the narrow belt on the northwest side of the Saltville fault, included between the fault and the Carboniferous shales and sandstones of the basal slopes of Pine and Little Brushy Mountains. So far as has been made out, this narrow beli is composed of the Greenbrier limestone (Carboniferous) and the beds of gypsum and salt. Figure 51, a section by Eckel across the Holston and Saltville valleys, along a northwest-southeast line between Saltville and Plasterco, shows the relations of the Greenbrier limestone and the gypsum- salt beds. Mining Developments. Commercial deposits of gypsum in Virginia occur only in Washington and Smyth counties, in the narrow valley of the North Fork of Holston river described above. Professor Rogers described the occurrence of 330 MINERAL RESOURCES OF VIRGINIA. gypsum in a number of the Coastal Plain counties of eastern Virginia in association with the greensand deposits, but no developments have been made, nor is it certain that commercial gypsum is found. Within the limits of the Holston and Saltville valley gypsum has been worked at numerous points. The mines and milling plant of the Buena Vista Plaster and Mining Company, situated near the southwest end of the Valley and about 2 miles southwest of Saltville, are the most extensive. The exact date of the discovery and first working of gypsum in this valley is unknown to the writer, but it certainly dates back as far as the early part of the nineteenth century. The location of the principal mines are shown on map, plate LII. Beginning on the northeast end of the belt the principal mines are described in order toward the southwest. On the Buchanan place, about 3 miles west of Chatham Hill post-office, are several openings worked to a depth of less than 50 feet. Several hun- dred tons of gypsum were mined and crushed for use as land plaster. About 8 miles north of west from Saltville a good supply of gypsum has been mined on the Barnes place, situated less than one-half mile south of the base of Little Brushy Mountain. This mine was first opened about 15 years ago and was developed by an incline shaft and drifts which were filled with water at the time of my visit in August, 1906. As judged by the large dump pile at the opening the gypsum mined was of good quality. It is quite similar to that mined at Plasterco and it contains very thin leaves of interlaminated gray crystals of the gypsum. An analysis of the gypsum from the Barnes mine made by Professor M. B. Hardin gave: : Per cent. Calcium sulphate............ 78.60 Water’ sass-cees tiie iets aerncars 20.79 Calcium carbonate........... 0.21 Caleium chloride............. trace Magnesium chloride.......... trace Organic matter.............. 0.12 Silica, alumina, etc.......... 0.23 Lotal s cviutienmresy ven toek 99.95 Gypsum has been worked in the past at a number of places along the North Fork of the Holston river between the Barnes mine and Saltville. The most extensive one of these is that of the Southern Gypsum Com- pany, Incorporated, which began prospecting for gypsum in the valley of the North Fork of the Holston river in the summer of 1906. A drill giv- ing cores 314 inches in diameter was used and a very accurate record of the MINERAL RESOURCES OF VIRGINIA. S Y 7, geen oZ2y, i | S y YN \ as QQ: RAR Wis Y Z D C SQ RA \ \\ Wi VIEL R ANS , IK < x k { q A - A MS) Wi MENG SNvree’ SA HY VQ % a N \ ¢ LN ey G Ne La wy \ RY Si SES SY VIBE ogg 0 SCALE ' 2 3 . ‘l i oS | PLATE LIT. r m G) m Zz Oo CARBONIFEROUS (GREENBRIER LIMESTONE) : . CARBONIFEROUS (GYPSUM AND SALT-BEARING A SILURO-DEVONIAN GYPSUM MINES A GYPSUM MILLS | |] SAtT WELLS AREA == MATHIESON ALKALI WORKS \ FAULT LINE Map of the salt and gypsum deposits in southwestern Virginia. Based on topographic aheat, U. 8. Geol. Survey. Geology partly adopted from Stevenson. SULPHATES. 331 formations passed through was obtained. After nearly a year of drilling, the Pierson Plaster Bank farm, 3.5 miles above Saltville, was purchased. Under this farm, the drilling of the company has already demonstrated a very large amount of gypsum, while a considerable portion of the farm remains to be prospected. The mine of the company is well opened and by July of 1907, the Southern Gypsum Company, will be placing gypsum on the market. The full capacity of the mill will be 400 tons per day. Of this about 44 will be put upon the market in the form of wall plaster, the remaining 14 will be used by Portland cement mills and in the form of land plaster. Gypsum was worked as recently as 1902 at Saltville, where several large openings were developed. The gypsum mined at Saltville was shipped to Glade Spring, where a part of it was used for land plaster, but most of it was used in the manufacture of Keene’s cement. In Volume IV of The Virgimias for 1883, Major Hotchkiss reports an analysis of the gypsum, made by Thomas Jones from the plaster banks of the Salt Works Company, to be: Per cent. LADINO “sp cbevidiaute kets spsneah aasbnesi patales 32.293 Sulphuric acid............... 46.445 Water tismr anaes antin cm ance 20.856 Magnesia. s aasaixccicccsas ses 151 Tron and aluminum oxides.... .149 Siliceous matter............. .070 Lotalycccscaaeenewen se es 99.964 The mines of the Buena Vista Plaster and Mining Company at Plas- terco, about 2 miles southwest of Saltville, are much the most extensive in the valley. Between the years 1815 and 1857 a number of borings were made on this property for the purpose of ascertaining (1) the thickness of the gypsum, and (2) the presence of brine or rock salt. The records of 7 of these borings taken from Bulletin No. 213 of the United States Geological Survey are here given: Feet. Well A. Bored between 1815 and 1820: Red (clays wags tnaed oe sao eRa eee tyEs NAT Md Dame cones O— 14 Clay and plaster icc cccic da coins cts beeen RENEE ee FeO OY ees 14—120 Pure: Pl asterco se: vosisse sad siavinan catatonic oh ales eueupselermars bidieudtnaperai ot 160—200 Well B. Bored in 1847: Red SCY sis dsiec a damtio gee Si ote SNS DUE ORES Mae ae MRT eGns o— 10 Clay and plaster, buhrstone..........--..20 00 see e erence ee 10— 30 Clay and plaster (deep red) ........-. 6. seen eee eee eee 30— 50 Pure plaster’...ns:.i2cnasseecsaneens 50— 965 Impure blue plaster Hard: blue slates: ysso1acewncarinss Uae Ad Whee dau domede eapties MINERAL RESOURCES OF VIRGINIA. Well C. Bored in 1847: Feet. PROC CLAY asaya: en ert ntesncany ausinicn & ee@iaGekvatibbesaidors asGreNk iouieiieasrEs anes Sher 5 o— 10 Clay and plaster, with brown rocks..............+-.0++005- 10— 70 Pure: plasters vsnecnescc1neays vant sees Seba wae eee a 70—100 Slate and plaster 00.006 5s ee ee deen eee eae ETERS 100—200 Hard ble: plastets. cis cscacwcase eran mennennehe mu ioe eaiseno unis > 200—360 Red. slates csiis-wasesien abou Rueiee sac ae He ged aie pees geepenes 360—480 Gray: slate. icd cc cn napaigis seers Nee Y alee aaa aie 480—495 Réd rocks, a. Little salt Yi. ins secs acces we ees aie Tienes 495—505 Well D. Bored in 1847: FRED CLAY a sana idsdoa siecsvees Waap scesarauayeland avoid aie dase etait Bea ce Aiba kie es ae o0— 10 Clay and. PLAS tO ccs sis. cite aves lovn ay ern edevacabantne, $a oy os Sede enlarbie ais. eon 10— 62 Plaster; witha little: clay’. sic cae scn reese sme anna as easwar 62—200 Red clay, with a little plaster............. 0. ec c eee eee eee 200—385 Red: Clay, BIKA], ANG. SAC .e sce aan sain din a wen owes Mel eae mien dane 385—387 PUTe: PlastErisse ss sascersiget sa.laycwl subi iy sa gutnsdeen ghiwlanene ndRerw Wiel erearenaleees yee 387—5Y90 Well E. Bored in 1847: FRED LCL AY eos. saasiaaae's rho sta pee stone as ying cables WEA cae oces Fou aimee Gn minaa deme arate o— lv Clay: sand: plaster se swscciarcsca tn wsnsohass: sib ieuaaualielare apie Sao SIG Tata ni 10— 16 Impure: plaster s.sis v0.0 oucesnannis ee ecrnsewiene dae eee ede 16— 50 Pure: ‘plaster visscavao5 sacar tow £25 we ee ease aawewy ea wee Ne a 50—102 Slate: and: PlAStOES i. .ce-ace dace vunidad s drasecleanicaieanmndaianas eauphaie 102—165 Nearly all plaster ices: sscsscca vacances canta ae wee sini seine ia aterg 165—210 Blue’. slates ips cmdusiecaes peoace gee nswane con nen hate peRes 4 210—320 Blue slate and ‘plasters s0cucc ces ces cede eee oe ed eaees 320—390 ‘VOllOW: SOAPSCONES,.occecsre iuosasicinas wa evertsminn ated aia aiallelbiwiea-anenesiorc mayer 390—445 Pure Plaster cosice- sis cvisis-spessnsav oins seer Gre wera ie a Scar ete eae ape erga 445—490 Red rock, with a little salt........ 0... ccc ec eee eee 490—505 Well F. Bored in 1853: GLY sk oastaeay Saas aeevaciorasioanaearahaltendaonaiternienaia ay Neacg ie Ganig. dd dno easgeuigianadare 0— 17 Clay and: ‘plaster. jiociecgevou sroradaanw cahavinldmompaesadana 17— 50 Pure plasters sss scacsutev eed opiesesiiecawee GareA wwe ae 50— 83 Hard black flint rock...... 6... cece cee cee cece teens 83— 90 Bure: Plaster xaci.ce ccrcns tavsig tes wie.y Ge aes ine aed mud Heemetinies 90— 96 Plaster and sulphur balls.......... 0.0... cece eee eee 96—105 [Record l0stlacaessis san ee areceiwes wees aaa cmseuon saa 105—109 Red and yellow soapstone...... 20... . cece cece cece eee eee 109—120 Hard blue slate and red, blue, and gray rock............... 120—359 Yellow and blue slate.......ccse wee tag ened eet ee te reas dee 359—390 Yellow and blue slate, salty............ cece ee eee eee eee 390—460 Well G. Bored in 1854: Dandand rave is sic cta awe Mindidies dineleosimlis See Raa Rema ae 0— 20 Blue: Clay wsax nek ses deaths aegis ewe eae Saneud waraonsans 20— 30 Hard white sand rock......... 06... cee reece essere eens vee. 380— 40 Clay and, plaster. .c.:20coniis as eulne naiginwsiniee vaminiondawuse 40— 55 Buhrstone: scivdguexaekewsebows ae yer hanes Grainy Fone cee gs 55— 60 The present mines lie near the southeast side of the valley and are developed by drifts and shafts, the deepest one of which is nearly 200 feet. A depth of 280 feet was reached in one of the old shafts. The ma- terial as mined is ground and calcined at the milling plant of the company SULPHATES. 333 en the grounds shown in plate LI, figure 2. The milled product is marketed partly as calcined and wall plasters and partly as land plaster. An underground examination of the gypsum in the several shafts re- veals the fact that it occurs in huge boulder masses in gray and red clays. The two clays are about equally abundant, but the red clay is softer than the gray and is utilized to some extent in the manufacture of plaster. Through the courtesy of Mr. Wyndham B. Robertson, President of the Buena Vista Plaster and Mining Company, I am enabled to give an analy- sis of this clay made by Professor Robert C. Price. Per cent. SUGAy Sect ahs teint Bue Soaseu teers 55.10 AVIA, caesparedospice quitlege aested eesnatione 16.23 Tron OXid6: 2j6:002-ae-nngarcnecas 9.35 LEVIES ‘euensses ena oatecensnnie onoolgaauieniuars 1.78 Magnesia wesc. ccc seine aces 5.80 Soda. cicoa-seleeuaeneeaeigealem ait 3.16 Potash. cv vstegcs dec anesines 3.36 MGIStUTE! 4.4.0.8 shat nthe wees houns 1.39 Loss on ignition............. 3.47 Ota ssi Fiscecdzale Ganasader gar sntvcae 99.64 Ordinarily, the irregular gypsum masses are sharply defined from the clays, although gypsum stringers and nodules penetrate into the clays from the masses and, in addition, the clays are independently penetrated by and impregnated with gypsum, much after the fashion of a breccia mass. This latter condition is particularly true of the gray clay. No order as to dip in the clays and gypsum could be made out by me underground. The gypsum does show a structure resembling stratification, however, from the presence of knife edge leaves of gray crystallized gypsum, but in every place examined these “lamine” dip and are turned at all angles from vertical to horizontal. Since these mines are located very close to the Saltville fault described above, the confused and irregular condition of the clays and gypsum might readily have resulted from the fault disturbance. Much anhydrite is admixed with the gypsum masses. This is, without any degree of regularity, likely to occur as it does, in all parts of the huge masses, and it is usually impossible to say where the gypsum begins and the anhydrite ends, so gradually do they grade into each other. This is recognized by the operators, and the two products are designated by them as “soft” plaster or gypsum and “hard” plaster or anhydrite. 334 MINERAL RESOURCES OF VIRGINIA. Analyses of the gypsum and anhydrite from the Buena Vista Com- pany’s mines are given below: II Ill IV Per cent. | Per cent. | Per cent. | Per cent. TERIA GE Gein estan eetina: sh chines aay lat 33.20 33.20 33.00 31.82 Sulphuric acid............... 46.04 44.74 47.14 40.24 WATER) cc secstcesees issuraavthgs debra 19.40 20.85 19.07 21.30 Magnesia: cs s0d ve varocece ariel’ -—— 0.05 trace 1.75 Baryta eee sisvudenar vase cae —- .19 trace 1.10 Alumina and iron...,........ .70 46 0.55 1.95 SICA: | Gaiiiseaneaushowandormatnné .10 .49 02 1.68 I. Crude gypsum. P. de P. Ricketts, analyst. II. Crude gypsum. Henry Froehling, analyst. III. Ground gypsum or land plaster. P. de P. Ricketts, analyst. IV. Ground gypsum or land plaster. Henry Froehling, analyst. An analysis of the anhydrite (hard plaster) made by Professor Robert C. Price and kindly furnished me by the President of the company, Mr. Wyndham B. Robertson, gave: Per cent. Moisture at 80°C............ .60 Combined water............. 1.20 Insoluble residue............. 26 TAMING: 3 oscar aes gunae muacergwa menace ae 40.75 Sulphuric oxide.............. 56.80 Fron: Oxides s5%¢30 agverven ses ae trace Carbon dioxide, as carbonate... trace Otel cise geataersa ete ia eames 99.61 Uses. The uses of gypsum are varied, and according to whether it is cal- cined or not, these may be classified under (1) uncalcined gypsum, and, (2) calcined gypsum. Uncalcined ground gypsum is used principally as land plaster. When finely ground the crude white gypsum is sold under the name “Terra Alba” (white earth), which is used as an adulterant, largely, in cheap paints. When calcined, gypsum is known as plaster of Paris, the manufacture of which forms one of the principal uses made of the mineral. Its chief use is in different kinds of wall plaster. Production. The annual production of gypsum in Virginia is given below from 1890 to 1906 inclusive. The production given for the years 1902 SULPHATES. 335 toe 1906, inclusive, was kindly furnished me by Mr. Wyndham B. Robertson, President of the Buena Vista Plaster and Mining Company. Year Quantity Value Year Quantity Value short tons $ short tons $ 1890.......... 6,350 20,782 1898 veaesge%us 8,378 23,388 EBON ais cass aieraicers 5,959 22,574 TB OO os tucicssetonuer 11,480 32,043 1892 6 ei acxae ees 6,991 28,207 1900 iin ss scien 11,940 18,11] 1893.......... 7,014 24,359 L901 cea nex pons 15,236 45,144 894 ios ceestivenann 8,106 24,431 W902» 6 28 wid sudecon 10,418 898 es ee cea we 5,800 17,369 LQ B icin danse a 14,741 ES OG ie setiactae esau 5,955 17,264 1904.......... 13,784 1897.......... 6,374 16,899 1905.......... 16,578 1906.......... 20,006 References. Eckel, E. C. Salt and Gypsum Deposits of Southwestern Virginia. Fontaine, W. M. Hotchkiss Jed. Robertson, W. Stevenson, John J. Rogers, Wm. B. U. 8. Geological Survey, Bulletin No. 213, 1902, 406-417. Gypsum Deposits in Virginia. U.S. Geological Sur- vey, Bulletin No. 223, 1904, 36-37. The Saltville Fault. Proceedings American Philo- sophical Society, 1881, XIX, 349. The Geology of Saltville, Virginia. 1881, IT, 92-93. Some Notes on the Holstein, Virginia, Salt and Gyp- sum. The Virginias, 1882, III, 20-21; 42. Notes on the Geological Structure of Tazewell, Rus- sell, Wise, Smyth and Washington Counties, Vir- ginia. Proceedings, American Philosophical So- ciety, 1884, XXII, 114-161. The Salt and Gypsum Deposits of the Holston, Vir- ginia, Valley. The Virginias, 1885, VI, 53-55. New The Virginias, A Reprint of the Geology of the Virginias. York, 1884. a 336 MINERAL RESOURCES OF VIRGINIA. X. HYDROCARBONS. |. COAL AND ITS BY-PRODUCTS. 1. COAL. HISTORICAL. The first coal mined in the United States was in the Richmond basin, where mines were opened and worked on the James river, near Richmond, as early as 1750. For the next 71 years, or from 1750 to 1822, there are no available records of production from the mines near Richmond; the first year for which figures of production are given is 1822, when 54,000 short tons of coal were mined. In 1824 the production was 67,040 short tons; in 1826, 88,720 tons; and in 1828, 100,280 tons. The production from the Richmond basin continued to increase until 1832, when it began to decline. Shortly after the decline began in the Richmond basin, areas in the northwestern part of the State (now West Virginia) began to pro- duce coal, and until West Virginia was made a separate state in 1863, Virginia was numbered as one of the important coal-producing states, which rank has been restored in recent years by the mining of the large reserves of coal in the southwestern part of the State. The construction of the Norfolk and Western Railway through south- west Virginia, in 1882, opened up the famous Pocahontas coal district, which lies partly in Virginia and partly in West Virginia. Likewise, the building of the Clinch Valley division of the Norfolk and Western Railway, nine years later, marked the beginning of the development of the Wise county coal district. The developments in these two fields in southwest Virginia, Tazewell county in 1883, and Wise county in 1891, again restored Virginia to importance as a coal producer. Each year since, the production has shown a large increase over that of the preceding year, and out of 31 coal-producing states in 1905, Virginia ranked as fifteenth. Coal was mined in the Montgomery-Pulaski counties area prior to the Civil War, but not in an extensive way. It is reported that some of the coal used in the bunkers of the Merrimac (Virginia), in her fight with the Momtor in Hampton Roads, came from the Price Mountain mines in Montgomery county. For a period of 30 years after the Civil War, the only mining carried on in this field was to supply a local market. For 337 COAL AND ITS BY-PRODUCTS. ‘sva1e [VO SUIMOYS BIUIBIIA Jo deW—Zs “Sl YNITOUVS HLYON i x e a) re XTAIVAIXOdddY SETI OZ =,J TIVS TIVO) INGSTAdTa SVIAV YOVTIT SVIaV TVO{) JO NOLLOAGRLLSIG ONIMOHS VINIDSIA JO dV $38 MINERAL RESOURCES OF VIRGINIA. a number of years past large developments have been made, more extensive and systematic mining has been carried on in accordance with modern methods, and a steady increase in output over that of the local market has been indicated yearly. The present annual production of coal in Virginia is about 4,500,000 short tons valued at approximately $4,000,000. DISTRIBUTION OF THE COAL. The geographic distribution of coal in Virginia is shown on the accom- panying map, figure 52. As shown on this map, coal is found and has been extensively mined in two of the three larger physiographic provinces of the State, namely, the Mountain province and the Piedmont province. Of these, the deposits of the Mountain province are the only producing ones at present, although recent developments in the Piedmont province will again restore this area to the rank of a producer at an early date. The distribution of the Virginia areas, which have produced or are producing coal, is as follows: I. The Coal Deposits of the Piedmont province. Includes the Rich- mond Coal Basin, which covers parts of the following five counties: Henrico, Chesterfield, Powhatan, Goochland, and Amelia. The Farmville area, which covers parts of Prince Edward, Cumberland, and Buckingham counties. II. The Coal Deposits of the Mountain province, which include a number of separate areas stretching from the northwestern corner of the State southwestward near and beyond the west side of the Great Valley. (1) The Frederick County Area. Includes the Mountain Falls district in the southwestern portion of the county and near the West Virginia line. (2) The Augusta County Area. Includes the North River dis- trict in the northwest corner of Augusta county and the contiguous part of Rockingham county. (3) The Botetourt County Area. Includes the southwest corner of Botetourt county. (4) The Montgomery-Pulaski Counties Area. Includes Price and Brush Mountains in Montgomery county, and Cloyd and Little Walker Mountains in Pulaski county. (5) The Bland-Wythe Counties Area. Includes a small area in the southern part of Bland county and in the northern part of Wythe county. COAL AND ITS BY-PRODUCTS. 339 (6) The Southwest Virginia Area. Forms the southeastern portion of the Kanawha basin, and comprises the Pocahon- tas or Flat-Top and the Big Stone Gap coal fields of the following counties: Tazewell, Russell, Scott, Buchanan, Wise, and Lee. Of these Wise and Tazewell counties are the most important producers at present. Geologically, the distribution of the Virginia coals is not the same for all the areas enumerated above. They are comprised in two of the larger geologic time divisions: (a) The Mesozoic (Jura-Trias or Newark) coals, to which the Richmond basin and the Farmville area coals belong; and (b) the Paleozoic (Carboniferous) coals, to which all the deposits of the Mountain province belong. Of the several coal areas enumerated above in the Mountain province, the deposits of the Mountain Falls district in Frederick county; the North River area of Augusta county; the North Mountain area of Botetourt county; the Montgomery-Pulaski counties area; and the Bland-Wythe counties area, are of Lower Carboniferous (Mississippian) age. The remaining areas of this province and vastly the most important ones in the State are of Upper Carboniferous (Pennsylvanian) age. The coals of Virginia are separately treated below by areas as grouped above. THE PIEDMONT PROVINCE. Numerous areas of Mesozoic rocks, of large and small extent, are distributed over the Piedmont province, east of the Blue Ridge. In a number of the Mesozoic areas, beds of coal occur, but only in one of these areas has the coal proved to be of sufficient thickness and extent to be of much commercial value, namely, the Richmond basin, near the middle eastern margin of the Piedmont region. Some coal has been mined in a smaller, similar area in Prince Edward county, but to a very limited extent; and thin seams of coal, not of workable grade, are known in at least one other of these areas. The Richmond Coal Basin. POSITION AND EXTENT OF THE BASIN. The Richmond coal area, known also as the Richmond coal basin, lies within but near the eastern margin of the Piedmont plateau, on either side of the James river. The total length of the area is 33 miles, and its 840 MINERAL RESOURCES OF VIRGINIA. maximum width is 9.5 miles, comprising a total area of about 190 square miles. It covers parts of five counties, which are Henrico, Chesterfield, Goochland, Powhatan, and Amelia. The position and limits of the basin are shown on the accompanying map, plate LIII. This area is important, economically as well as scientifically, for it contains the only free-burning coal located immediately adjacent to tide- water in the eastern portion of the United States. HISTORICAL. The first coal mined in the United States is said to have been from the Richmond basin in Virginia. In his “Story of American Coals,” Mr. W. J. Nicolls states that coal mines were opened and worked on the James river, near Richmond, in 1750, and for a number of years not only Richmond, but Philadelphia and New York, obtained supplies of coal from these mines. According to Parker, this antedates by 19 years the first reliable record of the use of anthracite coal in Pennsylvania. There is, however, no record of the amount of coal produced prior to 1822, when, according to Taylor in his “Statistics of Coal,” 54,000 short tons were mined. Records of coal production in Virginia that are available date from 1822, and the annual production from 1822 to 1906, inclusive, is given in the table on page 375. GENERAL GEOLOGY OF THE BASIN. The rocks bordering and underlying the Richmond basin are granites and gneisses of the mica type, and are characteristically dominant rocks over many parts of the Virginia Piedmont region. They are older than the rocks filling the basin and a marked difference in attitude and structure is shown in the rocks within and without the basin. The basin rocks are composed principally of sandstones and shales with beds of coal. The rocks are quite fossiliferous in places, both plant and animal remains occurring. The series of sedimentary rocks are penetrated by basic, igneous dikes, the whole, both sedimentary and igneous rocks, being of Newark (Mesozoic) age. Professors Shaler and Woodworth give the following table of formations of the Richmond basin rocks: MINERAL RBSOURCES OF VIRGINIA. oe PLATD LIII. EF PRE UE re hes SAAR SALES OSES S LK >) ae P R rex 7) SERS OOO SOAS LXE OS LZ SKS VIR LAKS Rhee SRE SC RRO PRI SS OE COPA RW * aK . BS SO PPPS ex OK XY HXNES PERE. yY7 zy SOKO RRS x PRA : OR OR EER en > ody SOR XY RON YD XP SPPON eK SL EEN LL RR KANG ae Nee IR FOR ROS SRI BIOS SBOE RR RARER SI LORY e PIRI KAS EIN PESOS AREA EHS OE LS LRA VS SR eee } be ¢ } > oS < ESS Nes AIRC J POR > om RDS BERR OAR E NRE erat SHES FoR OR POPES SIR OOS 3 AK he BYR SORE CORK SIU AHS A : NRO AKC SOK QO ON 5 SOE ZAC S SS SS { DEOL TIP SOXIK ORS PK Re PS SORE Se PERRO RE LO SSS PIRES BAK KOKO j WES ow Ce BLY 2 Se Lau RR f RET eR PORK KS EXPRRS VOR OKS o> X2 OKK LS “ QOPI? PRS eats CRESS EMS PERI OSS 2 SS LOO SESH CP BPI RC ESR OTE POY \Z oe ROR ORES SRR RIOR FOR KO BR XIOO] 5 SAR oe Pe CS rh So SR OS RPO SRR OOK IS OE Od Cy BOYS OK CAA LOE KA Map of the Richmond, Virginia, Coal Basin, showing location of the principal mines. (Based on the map by Shaler and Woodworth, 19th An. Rept. U. S. Geol. Survey.) Scale, 34 inch = 1 mile, approximately. Contour interval, 50 feet. COAL AND ITS BY-PRODUCTS. 341 Divisions Subdivisions General Characters io Coes Samal Svonee often Felasretile, ae snus 3 runks of Arancarioxylon,; well developed north 5 Otterdale sandstones. south, and west of Otterdale. Thickness, 500 -£ ‘eet. x a Black fissile shales, carrying Hstheria ovata, passing 8 Vinita beds. upward and intercalated with gray sandstones; 3 in James River bluff, west of Vinita station, on A Tomahawk Creek. Thickness, 2,000 feet. Interstratified beds of bituminous coal (usually three fs seams), coke, black shales (a) fish-bearing; (b) estheria shales; (c) vegetal shales, sandstones (feldspathic and micaceous), fossil plants; teeth, yup: and tracks of reptiles. Thickness, 500 (?) ‘eet. Productive coal measures. I "i : Sandstones and shales under coal beds, often with ower barren. beds arkose. Thickness variable, from 0 to 300 feet. Tuckahoe Group Local deposits; bowlders of gneiss and granite. Bosen bel Howlder Thickness variable, 0 to 50 feet. ? The same authorities assign a maximum thickness in places to the Tuckahoe Group of as much as 500 feet, and a provisional thickness of 2,000 feet to the Chesterfield Group. The rocks of the basin have been greatly disturbed by faulting and the strata are highly tilted about the margin of the area. Faults, folds and flexures are frequent in the beds of the interior of the basin, but at the surface the evidence for deformation in the interior is less clear than around the margin of the basin. Figure 53 shows the structural relations of the rocks in the Richmond coal basin. Recent work by Professors Shaler Gneiss Fig. 538.—Geologic section of Richmond coal-basin. f, f, faults; ft, fl, folds; d, dike; 6, b, isolated basins. (After J. B. Woodworth.) and Woodworth has shown that the idea of a relatively great central undis- turbed area is erroneous. When compared with other areas of . Newark rocks further north, the Richmond basin shows similar structure in the prevailing westerly dips over broad areas. The supposed synclinal structure 242 MINERAL RESOURCES OF VIRGINIA. attributed to the basin can probably be traced largely to the downward drag of the strata on the west side, perhaps aided by lateral pressure and folding. The Richmond basin rocks, in common with the Newark areas north- ward, are intersected by dikes and sills of diabase. On the eastern border of the basin these rocks have long been known because of the association with them of natural coke in several of the coal mines. The prevailing direction of the dikes is northwest-southeast, with some trending east- west. THE €OAL BEDS OF THE BASIN. From the published accounts of sections in the mines opened in the basin, 3 and sometimes 5 beds of coal occur, separated by beds of sand- stone and shale. The uppermost bed or seam has usually been found to be the thickest. Estimates show considerable variation in the thickness of this bed, varying from 30 and 40 feet in the old workings about Midlo- thian to 5 and 8 feet in other places. According to Professors Shaler and Woodworth, from the vicinity of Midlothian northward to Gayton (Edge Hill or Carbon Hill of the old reports) this uppermost bed is wholly or partly converted into coke, from the proximity of igneous rocks. Sir Charles Lyell states, that at Dover, on the western margin, was an upper bed of coal 16 feet thick, and 2 thick beds below. The true coals of this field are bituminous, the character of which is somewhat variable, as indicated in the analyses below. Ordinarily the quality of the coal is excellent, but occasional thin seams of calcite and pyrite have formed along the joint-plames, cutting the coal in places. In such cases the removal of the calcite and pyrite is desirable and can be easily effected by breaking and washing the coal, when an excellent fuel should be obtained. As proved by nearly a century of constant use, the quality of this coal is entirely satisfactory for many purposes. Extent of the coal beds—Concerning the extent of the coal beds in the Richmond basin, I quote in full from the excellent report of Professors Shaler and Woodworth, based on a detailed geological survey of the area and published in the Nineteenth Annual Report of the United States Geological Survey for 1897-98. “As to the area of the basin underlain by the coal beds, the evidence may be stated as follows: On the eastern margin, where the beds are best placed to be exposed in natural sections, and where they have been most extensively worked in former years, there is a fair presumption that the deposits are substantially continuous. Where, as is shown on COAL AND ITS BY-PRODUCTS. 343 the map, the coal beds have not been found, as is the case in two consid- erable sections of the eastern border, the failure of the slight explorations to disclose them may be fairly explained by the existence of faults which Analyses of coal from the Richmond basin. South of James River. e | oe | s s Name of Pit 2 23 eS g s a (Eastern Outcrop) 3 oS ge a s Analyst a Pa 2 n Clover Hill (Coxe’s Mine).......... 1.339 | 80.984 | 56.831 | 10.132 | 0.514 | Prof. Johnson Clover Hill (Coxe’s Mine)... wae. |b ea0en 65,52 W. B. Rogers Glover Hill (Coxe’s Mine).......... | ..... 55. G. W. Andrews Stone Henge......s.cceseceeeesseeree | seeee 58. W. B. Rogers Creek Company Shaft.............+ " é ; : Prof. Johnson Mills and Reed Yoreek HAL ssciaw | avseve < ‘ ‘ W. B. Rogers Greenhole Shaft........ccseeeeeeeeee | ceeee 31.1% 00 W. B. Rogers Midlothian, average...........eeeee ¢ Prof. Johnson Midlothian, new shaft.............. Prof. Johnson Midlothian, SCTOONEG 6. cis icici on. 4.038 Prof. Johnson Midlothian, 900-foot shaft........... Prof. Johnson Midlothian............cecceceeceecene ; a 3 -...-. | Silliman & Hubbard Midlothian. ...cicssccndemaasciestcauas || janie . ‘ : J. H. Alexander Midlothian, grove shaft, screened... i A.S. McCreath Midlothian, average A. S. McCreath Maidenhead.......... W. B. Rogers English Co., old_shaft.. W. B. Rogers English Co., ’ middle ben W. B. Rogers English, Co. top bench.. WwW. B. Rogers Chesterfield Mining Co Prof. Johnson Willis Pit (Attna shaft)... Clemson Western Outcrop : Powhatan Pits.....62c:cccsccscrssssas | someee 3 = ; ..... | W. B. Rogers Scott’s Pit.... easear ff bata ara 33. 86 . | W. B. Rogers North Q ©, 3 4 = = 3 3 =| o a Name of Pit £ |ee ime | = a Analyst (Eastern Outerop) 8 os | gf a 5 a > z D Carbon Hill, upper seam............ 1.40 | 20.60 | 60.80 | 17.20 O. J. Heinrich Carbon Hill, second seam........... 0.40 | 18.60 | 71.00 | 10.00 O. J. Heinrich Carbon Hill, carbonite.............. 1.57 9.64 | 79.93 8.86 O. J. Heinrich Carbon Hil; BVCTALC. 0... cccesecces 1.785 | 23,959 | 59.976 | 14.28 Prof. Johnson Carbon Hill; natural coke.. wees | 1.116 | 11.977 | 75.081 | 11.826 Prof. Johnson ‘Western Outcrop Anderson’s Pits (Dover)............ | ..... 28.30 | 66.78 4.92 W.B. Rogers Anderson’s Pits (DOver)............. | ..see 26.00 | 64.20 9.80 Clerason T..M,. Randolph iiviiieciecccacecsineses: | cone 30.50 | 66.15 8.35 W. B. Rogers Coalbrookdale..........cceeeeee neces | cece 29.00 | 66.48 4.52 W.B. Rogers Coalbrookdale, Ist seam............ |... 24.00 | 70.80 5.20 W.B. Rogers Coalbrookdale, 2d seam. eek 54,97 | 22.20 W. B. Rogers Coalbrookdale, 3d seam 65,50 9.80 W. B. Rogers Coalbrookdale, 4th sea: 56.07 | 22.60 W.B. Rogers Cranches, upper seam 64,60 5.40 W.B. Rogers Waterloo’.......... 55.20 | 18.00 W. B. Rogers Deep Run Basin ............... 69.86 5.00 W.B. Rogers have thrown the beds down or up, so that the shallow pits which were sunk did not pass through the deep surface rubble. So far as has been learned, there were no indications in the old workings that the coals were 344 MINERAL RESOURCES OF VIRGINIA. fading out in the directions of these portions or the margin where they have not yet been found. In the blank north of the Clover Hill mines the streams run so near the position of the outcrop that exploration has been discouraged by the difficulty which would evidently be encountered from surface water. “On the western margin the coals are practically unknown from a point about 2 miles south of the James River, at the Old Dominion pits, to the southern extremity of the basin, though there are traces of the dark shales which are probably associated with it. In this part of the border the failure to discover the beds may well be due to the abrupt down- faulting which is known to exist along this line. At only one point, viz., in the stream bed of Turkey Branch, has it been possible to obtain a tolerably continuous section of the beds on the western margin of the field. This failed to reveal the coal-bearing beds, but there is reason to believe that they may have been thrown down by an unobserved fault traversing a portion of the line where the strata were not disclosed, or that they are to be found under a slight cover of alluvium. “As to the extension of the coal beds beneath the central parts of the area, the evidence in hand is insufficient to warrant a definite statement. The conditions may be briefly set forth as follows: The tolerably complete if not perfect continuity of the beds on the eastern margin and at either end of the basin appears to afford fair evidence that the coal beds have a continuous habit. It has been suggested that the coals, though continuous along the margin of the basin, may be lacking in the central parts of its area. But it should be noted that the present outcrop line is not to be regarded as the original border of the coal-bearing strata. That line was probably miles east of its present position. The existing face is, in effect, a chance north-and-south section of the deposits. There is no evident reason based on the character of this outcrop why a like exhibition of -eoal beds should not be had if the face were carried 1, 2, or 3 miles west- ward. “The tailure to find the coal beds in the Sinking shaft and in the ‘drill hole in its bottom has been considered as evidence that these beds were lacking at a point about 1 mile from its margin. This failure to attain the coal is to be explained in the light of the information obtained in the Salisbury boring. The depth at the Sinking shaft was altogether insufficient to traverse the barren strata, the drill most likely not penetrat- ing to within 200 feet of the level where the coal beds might be looked for. The Salisbury drill hole, on the other hand, has shown the coal-bearing COAL AND ITS BY-PRODUCTS. 345 rocks at a distance of a mile from the eastern main outcrop, at a depth of about 2,350 feet below the surface. “When all the evidence is weighed, it leads to the conclusion that the central portions of the area most likely contain coal beds in something like the measure that they are exhibited in the margin. The measure of the probability of such occurrence is rather greater as regards that portion of the field which lies to the east of a line drawn from the Clover Hill pits, near the southern end of the basin, to the Old Dominion mines, on the western margin about 2 miles south of the James River, than it is concerning the field west of that line. This is for the reason that out- crops have not been found along the western margin south of the Old Dominion property, though, as before noted, their failure to occur may be accounted for by accidents of faulting. Leaving out of the reckoning the southwestern portion as possibly lacking the coal-bearing beds, there re- mains an area of about 150 square miles where the deposits may reasonably be expected : ito occur. “Although the information obtained from the existing and the old workings show the coal to vary greatly in thickness, and some of the beds much in quality, it is a not unreasonable estimate that the average thick- ness of the workable material is 12 feet. Allowing for occasional strips of coal which have been crushed by faulting and for loss in treatment in the breaker, the yield per acre may be roughly estimated at 1,000 tons per foot in depth, or a total of 12,000 tons. The total area which is reckoned as most probably coal-bearing (150 square miles by 640 acres) equals 96,000 acres, which, on the basis of yield above adopted, would give a total content of 1,152,000,000 tons. This reckoning, it should be said, rests altogether on probabilities. “In none of the mines does it appear that less than two beds of workable thickness [of coal] are encountered. In other instances there is reason to believe that three, four, and at Clover Hill even five beds of economic value were found. Although all these beds thicken here and thin there and probably at points unite or separate, the coal-bearing character of the section in which they lie is probably maintained in a tolerably continuous manner.” Depth of the coal_—tiIn regard to the question as to the depth at which the coal lies, Professors Shaler and Woodworth say: “In the present condition of our knowledge of the basin it will be safe to assume that at the distance of a mile from the eastern outcrop the coal-bearing section lies at a depth of about 2,500 feet below the surface. Farther toward the interior of the 346 MINERAL RESOURCES OF VIRGINIA. field the depth at which it will be found will probably be somewhat greater. It is not impossible that at some points the faulting has carried these deposits more than 4,000 feet below the present surface. From what has been learned of the conditions, it seems unlikely that the section in which the coals belong is at any point as deep as 5,000 feet.” Mines. The Richmond coal basin has been developed by numerous mines, many of which have been extensively worked with a large total production of coal. Considerable depths have been reached in some of these. Hxami- nation of the map, plate LIII, shows the distribution of the mines to be along the eastern border of the basin, and along the west border in the northern part of the area in the vicinity, and north and south, of the James river. No mines have yet been opened in the more central. portions of the basin. The principal mines are further grouped about certain geographic centers along the border portions of the basin. On the eastern border, beginning with the southernmost ones, the princi- pal mines are grouped about Winterpock ; in the vicinity of Coalboro; Midlo- thian, including the mines of the outlying basins Blackheath, Cunliffe, etc. ; to the north of and between Midlothian and the James river, the Salle and Burfoot pits; and Gayton (Edge Hill or Carbon Hill of the old re- ports), including the outlying Deep Run basin. In the northern portion of the basin and along the west border the principal mines are in the vicinity of Manakin on the north and south sides of the James river; and about two miles south of west from Huguenot. In addition to these, many smaller openings have been made along the border portions of the basin and drillings have been put down in places, which, in some cases, reached a depth of more than 2,000 feet. Operations in the Richmond basin during 1905 and 1906 were confined to Winterpock and Midlothian, in Chesterfield county, and were largely in the nature of development work preparatory to shipping. The Gayton mines north of the James river in Henrico county were closed down several years ago. Since closing down, these mines have changed hands and as yet work has not been resumed. At Winterpock a new incline was under way during the summer of 1905. At Midlothian the only mining of coal during the past two years was limited to that for the company’s use. The developments at Midlothian during the past two years comprise a new in- cline 1,020 feet long by 16 feet wide and 7 feet high on a 33° pitch, to COAL AND ITS BY-PRODUCTS. 3847 coal 8 feet thick. The coal has actually been proved in this incline for 1,300 feet and laterally for 700 feet each way. One and a quarter miles of trackage and a tipple will be completed by the close of 1906, when the shipment of coal from this property will begin. The future prospects of this property are very encouraging. The property is under the control of the James River Coal Corporation. THE APPALACHIAN MOUNTAIN PROVINCE. Lower Carboniferous (Mississippian) Coals. The coals of Rogers’ formation No. X (Vespertine) extend, as isolated areas, nearly entirely across the State, in a northeast-southwest direction, west of the Blue Ridge. So far as known the Lower Carboniferous coals in Virginia include the following fields: (1) The Mountain Falls District in Frederick County. (2) The North River Area in Augusta County. (3) The North Mountain Area in Botetourt County. (4) The Montgomery-Pulaski Counties Area. (5) The Bland-Wythe Counties Area. These are separately described below in the order here named. The Mountain Falls District. Prederick county.—Very little is known as yet in a definite way of the geology of this region. In his “Reprint of the Virginias,” page 99, Professor Rogers mentions the occurrence of coal seams in Frederick, Shenandoah, and Rockingham counties along with those of Augusta, Botetourt, and Montgomery counties. In each of these counties, with the exception of the first two, the coal-bearing horizon is known as formation No. X (Vesper- tine) or Mississippian. The inferenee is, therefore, that the coal in Frederick county is of the same age. In the first four counties, Frederick, Shqnandoah, Rockingham, and Augusta, the coal is nearly identical, and according to Professor Rogers the seams vary in thickness from 3 to 7 feet. The dipping west into Little North Mountain, near Coal Run, in Rockingham county, is said to be about 4 feet thick. Two operations have produced some coal during the past few years near Mountain Falls, in the southwestern part of Frederick county, near the West Virginia line. One of these was reported idle during 1905. 348 MINERAL RESOURCES OF VIRGINIA. The North River Coal Field. Augusta county——In the northwest corner of Augusta county and the contiguous part, southwest corner, of Rockingham county is a small area of Lower Carboniferous (Mississippian) rocks which, to a limited extent, are coal-bearing near the top. The formation is mapped by Darton as the Pocono sandstone with thin coal beds and shale in the upper portion. The field is known as the North River coal field and it is west of Narrow (Little North) Mountain. The coal is of the semi-anthracite variety and it has been mined to a limited extent in North River Gap, in Augusta county. The supply has been found sufficient for local use. The beds are thin and the coal is often crushed, but it is reported not difficult to obtain small supplies. Darton states that attempts have been made to find thicker beds by ex- cavations and deep diamond-drill borings, but without success. Hotchkiss gives the following analyses of the coal made by Booth, Garrett and Blair of Philadelphia, from the Augusta county area: , I II III IV Vv VI VII Constituents Per ct. | Per ct. | Per ct. | Per ct. | Perct. | Per ct. | Per ct. CarbOnicncaiai exwiecias 89.47 | 89.02 | 87.65 | 86.35 | 88.09 | 87.40 | 85.85 Volatile matter 6 6.42 7.58 7.27 6.64 6.10 6.20 WERLORS, sscisicecieiesesesBsanecosssyieid 0.40 0.50 0.80 0.80 0.35 0.45 0.60 ASU ais Seracaca’ats pcassiaiann -susseoreree 4.13 4.06 3.97 5.58 4.92 6.05 7.35 I and IV—Opening on Briery Branch about 100 feet above the base of Narrow Mountain. JI—Little Coal Run, from end of a 100-foot drift in an 18-inch bed, and 5.5 miles southwest of ITI. III—Near Briery Branch at foot of Narrow Mountain from a drift 5 or 6 feet in a 4-foot bed. V—Half a mile southwest of II, from a bed 4 to 5 feet thick and 13 feet lower. Vi and VII—From the Scheffer drift in a 6-foot bed, North River Gap, near II and V. The North Mountain Coal Field. Botetourt county—The North Mountain coal field, known by some as the Katawba, Caldwell, or Brushy Mountain field, is located along the Botetourt-Craig counties boundary, in the southwest corner of Botetourt county. The coal is of Lower Carboniferous age and has been used locally for a long time. The coals have had greater or less local value and were considerably mined prior to 1864 for local use. They will probably never furnish a basis for large mining enterprises, as the areas are limited, the beds are crushed and broken, and are cut by faulting. A sample of this coal collected by Mr. O. J. Heinrich on Stone Coal Run, in Botetourt county, gave on analysis: Per cent. Carbon ccmceuials av quisaaadiaiewg) 28 4h Sagem sone Mee Meee ee 78.0 Volatile matter sssus ceeksgstegahecss teccacae alee wee 122 Sulphiris 2s 2<..asewee sees acs aus Adina yo enue ees aoe trace SOB D ore secre sera 2 8 Seasae ast aes 6029 ROM AERA han Soe Sete foe rec 9.8 COAL AND ITS BY-PRODUCTS. 349 The coal is reported to be a semi-bituminous variety, averaging 12 to 14 per cent. volatile matter, 75 to 80 per cent. fixed carbon, and 5 to 9 per cent. ash. It is practically free from sulphur and burns to a white ash. According to Heinrich two principal seams were developed; the lower about 5 feet thick with 2 feet of coal, the upper from 10 to 12 feet thick with 6 to 10 feet of coal. The seams are best developed on Stone Coal Run. The Montgomery-Pulaski Counties Field. Of the numerous Lower Carboniferous coal areas known in Virginia, the Montgomery-Pulaski field is much the most important one, and it is practically the only producing area at present. The area is located 30 to 50 miles west of the city of Roanoke. Map, figure 54, shows the location of the principal mines in this area. In the Montgomery county portion of the area the mines are opened along the south slope of Brush Mountain and on the slopes of a parallel ridge locally known as Price Mountain, distant some 3 to 4 miles south from Brush Mountain. In Pulaski county developments are made on the slopes of Cloyd and Little Walker Mountains, which are a continuation southwestward of Brush Mountain in Montgomery county. The coal area lies near the northern border of the two counties and is crossed by New river, which is the dividing line between the counties. The total estimated acreage of the Montgomery county portion of the field is about 7,000 acres. The extent of the Pulaski part of the field is not certain but it is probably nearly equal to the Montgomery field. It extends from New river to within 6 miles northwest of the town of Pulaski, which includes the developments thus far made. Coal was mined in this field prior to the Civil War but not in an extensive way. It is reported that some of the coal used in the bunkers of the Merrimac (Virginia), in her fight with the Monitor in Hampton Roads, came from the Price Mountain mines. For a period of 30 years after the Civil War the only mining carried on in this field was to supply a local market. For a number of years past large developments have been made, more extensive and systematic mining has been carried on in accordance with modern methods, and a steady increase in output over that of the local market has been indicated yearly. The coal seams occur in strata of Lower Carboniferous (Mississippian) age. The rock series consists of a variable thickness of sandstone, con- glomerate, and shale, dipping at angles varying from 20° to 40°. On “qaay OOG ‘[esAreyUL InoqW0D “Ayeyeuttxoidde ‘orm [ = your % ‘ajeog “Aeaing ‘Joey “§ ‘N ‘syoys o1ydvadodo} uyqnq pu Sinqsuerysliyo au} wo paseg ‘sjop Aavey Aq pazeorpul sou “P[eY [Boo setyuNoe IYsv~ng-AreMoS}uoW ayy UL sour [edroursd Jo uoreooy Surmoys dew—rF¢ ‘Sl STs Mey AUTAS aayding Cr C.. IO OUR ee, “ry, ee, oo 0 oo S eer. 7 D Pty x TF G r Say } Stay N ee Ae ‘5 a Me a 20) ne? 4 TTY at Me = 7 I 4 nh d& ~ 2, Le ps s e3 “ih 0 % “@ { : 20, Lebn,, “4 * 2 veer an Jy Pou, MY o ere, 1 ? 4 esos a ) My ? 9D a gee i 4 on > o oh) one e Soy a8 Agi Me eS 9 dole | T\_@. | Vt 5 , eee sii yA v oat re Se est . re 3 \ a A ot aost . i ae \ " Pr J, NY =F 4 7 ZA : Zam Do DW ete al ‘ ———— WAMVAUE UNV SHNIN T¥OO GLIOVUHINV BItA ‘caywarg puB seUTut [BOO DBULTLLIOIL Snqsuerysiyy watt ‘Kavdurog [eon eploviyyuy viUt VIUTFIL A “APIO SraUOSPUOTL “AIT GLY Td ‘VINIDULA JO SaOUNOSAU TIVUENIWN COAL AND ITS BY-PRODUCTS. 3851 Price Mountain 5 coal seams are indicated, only one of which has yet proved to be workable. An average thickness of 4.5 feet of clean coal is mined from this seam. On Brush Mountain two seams yield workable coal which average in thickness 3 and 4.5 feet of clean coal, respectively ; they are named the “Little? and “Big” seam. Likewise two seams are worked in the Pulaski portion of the field. The coal is the semi-anthracite variety of excellent quality. That from the Price Mountain mines is harder, and consequently not so free-burning as the coal from Brush Mountain. Of the various mines operating in the Montgomery-Pulaski field the Merrimac mines on Price Mountain, Montgomery county, are probably the largest producers. These mines are owned by the Virginia Anthracite Coal Company and are directly on the standard-gauge steam road which connects Blacksburg with the Norfolk and Western Railway at Cambria. A breaker (plate LIV) has recently been completed having a capacity, with the present machinery, of 500 toms per day. By installing duplicate screens and other machinery it is claimed the capacity can be more than doubled. The storage capacity of the breaker is 500 tons. The average tun of the breaker at present is 100 cars of coal per month. The present depth of working at these mines is 1,026 feet on a dip of 22°. During 1905 some half dozen operators were engaged in mining coal in the Brush Mountain area, the principal ones being the Virginia Anthracite Coal Company, the Blacksburg Mining and Manufacturing Company, and a number of private individuals. The principal mines working in the Pulaski field during 1905 were the Altoona, Belle Hampton, and Kimball. The Kimball mines are located on New river, and directly on the Norfolk and Western Railway. This property has recently been acquired by the Pulaski Anthracite Coal Company, which is making extensive improvements with a promising out- look. A breaker has recently been erected at the mines, and a small one is being built at the Belle Hampton mine by the Belle Hampton Coal Company. A spur track connects the Belle Hampton mine with the Norfolk and Western Railway. The Altoona mines, located 6 miles northwest of Pulaski, are owned and operated by the Bertha Mineral Company at Pulaski. All the coal formerly used by the Bertha Company at its zinc furnaces in Pulaski came from the Altoona mines, but only the “firing” coal or reducing material is obtained there at present. A steam road is operated between the mines and Pulaski. 352 MINERAL RESOURCES OF VIRGINIA. The following chemical analyses of coal from the Montgomery- Pulaski field afford a general idea of its composition: , I II III IV Vv VI VII Constituents. Per cent.|Per cent./Per cent./Per cent.|Per cent.|Per cent.|Per cent. 73.012 75.618 70.924 72.737 70.924 74.013 80.16 11,652 11.324 12.870 12.215 12.870 9.675 18.60 1,228 0.816 0.615 0.725 0.615 1.080 0.887 13.560 11,545 15.110 13,990 15.110 14,550 5.76 0.548 0.697 0.481 0.333 0.481 0.682 —_—_— VIII Ix x XI XII XIII Constituents. Per cent.|/Per cent.|Per cent.|/Per cent.|/Per cent./Per cent. Carbon wesscsccacescue| 19/97 74.24 72.737 74,013 69.66 7) 86 Volatile matier.......| 9-82 | 11.00 | 12-218 | 9-971) 14.93 | 18.14 ca gat | 13:68 | 13.000 | 14°35 {| a. Sulphu SM | Be | Torsas | “organ t] 18-41] 15,00 I to V—Brush Mountain mines, Montgomery county, A. S. McCreath, analyst. VI—Price Mountain mines, Montgomery county, A. S. McCreath, analyst. VII—Wilson drift, Price Mountain, Montgomery county, Dr. W. B. Ellett, analyst. VIII—Merrimac mine, Price Mountain, Montgomery county, W. T. Young, analyst. eee mine, Price Mountain, Montgomery county, Dr. W.B. Hillett, analyst. X and XI—William Meyers’ lands, east slope of Price Mountain, Montgomery county, A.S. McCreath, analyst. XII and XIJI—Belle Hampton mine, Pulaski county, H. H. Hill, analyst. The Bland-Wythe Counties Field. A small coal field of Lower Carboniferous (Mississippian) or Pocono age is found in the southern portion of Bland county and in the northern portion of Wythe county. The coal seams appear in the Price sandstone in the vicinity of Bland court-house, Sharon Springs, and near the south- western corner of Bland county; and near and to the south of Little Walker Mountain in Wythe county, on Reed creek. As a rule the seams are small and much broken by partings and the coals are generally high in the percentage of ash. The rocks are usually highly tilted and are more or less crushed. The coals have attracted considerable attention from time to time and attempts have been made to develop them, but thus far without success. The following analyses of the coal from the Wythe county portion of the field made by A. S. McCreath, afford some idea of its character: : I II Constituents. Per cent.|/Per cent. Carb0ne..+ 524 canker escaee) enteicndeae 55.615 | 59.427 Volatile matter............. 00.000 eee 16.264 17.853 Water: sso iitanccan taeda ctatnatagdaae 0.466 0.620 A'S Ih swisriacnich avepnadhelpere tick edgivees desi aeons 26.660 | 20.525 Bul Pwr inc caieves jas ou aiae eee Oe 4 eared a 0.995 1,575 I—Seven miles northwest of Wytheville from a 3-foot bed. Little Walker Mountain, near the level of Stony creek or Reed creek. : ah pre near ie same place as I. Coal from 2-foot bed that had been exposed to the weather ‘or a month. a COAL AND ITS BY-PRODUCTS. 853 The Carboniferous (Pennsylvanian) Coals. LOCATION AND IMPORTANCE. The southwest Virginia coal field is located in the extreme southwestern part of the State, on the west side of the Great Valley, and occupying the eastern and southeastern portions of the Cumberland plateau region in Virginia. It forms the southwestern part of the Kanawha basin, and comprises the following counties: Tazewell, Russell, Scott, Buchanan, Wise, Dickenson, and Lee. Of these, Wise and Tazewell counties are the two most important producers at present. The other counties contain very large coal reserves which, in places, are rapidly undergoing development. The present era of railroad construction in this part of Virginia will witness, in the immediate future, extensive developments and mining of the enormous reserves of excellent coal hitherto undeveloped because of lack of railroad facilities. The southwest Virginia coal field is vastly the largest, most productive, and most important in the State. Indeed, it is due to this field that Virginia is entitled to rank among the principal coal-producing states in the United States. It is estimated that the area of coal-bearing formations in this field comprise 1,850 square miles, with probably 80 per cent. of it productive. The two principal coal fields in the southwest Virginia area thus far developed are (a) The Pocahontas or Flat Top Coal Field, and (b) The Big Stone Gap Coal Field. These are separately described below in the order here named. Geologic Relations. THE AGE OF THE COAL-BEARING ROCKS. The coal-bearing rocks of the southwest Virginia field belong to the Coal Measures division of the Carboniferous. Probably most, if not ali, of the coal-bearing rocks in this field correspond in age to the Pottsville series, the lowest subdivision of the Pennsylvania section. In the Poca- hontas or Flat Top coal field, situated in the northeastern part of the Virginia field, the Pocahontas formation of Campbell is the basal member of the series, and to the southwest in the Big Stone Gap field the Lee formation forms the basal member. The subdivision in southwest Virginia is separated by a probable thickness of coal-bearing rocks of from 2,800 to 8,000 and more feet. 354 MINERAL RESOURCES OF VIRGINIA. Stratigraphy. The Carboniferous formations in southwest Virginia, as mapped in the Pocahontas, Tazewell, Bristol, and Estillville quadrangles by the U. S. Geological Survey, are separately given below in descending order, together with the thickness and character of each formation. In these tables is given the original classification of Professor Rogers of the Virginia Car- ‘poniferous, with the present classification of the U. 8. Geological Survey. The four quadrangles cover parts of the following counties in Virginia, which contain coal-bearing rocks: The Pocahontas quadrangle, includes a part of Tazewell county; the Tazewell quadrangle, includes parts of Tazewell, Buchanan, and Russell counties; the Bristol quadrangle, in- cludes parts of Russell, Wise, Scott, and Dickenson counties; and the Estillville quadrangle, includes parts of Lee, Wise, and Scott counties. Pocahontas Quadrangle. : ' . is Thickness a Rogers | U.S. Geological Survey | in feet Character (| Sewell formation. 100+ Sandy shale . | pees souaeee 80 Spar ue in Lee beds a. i uinnimont shale 300 ale, sandstone, and coa. No. XII Great conglomerate. { Clark formation.. 380 Sandstone at top; shale, sandstone, | and coalat bottom {| Pocahontas formation...| 360 Shale, sandstone, and coal : ( Binestone formation. ms ae sonce tone sara eee sien rinceton conglome: ‘oarse sandstone or conglomera’ [ Greenbrier shale. { Hinton formation 1250-1300 | Shale and sandstone ~ No. XI4- | Bluefield shale ... 1250-1350 | Sandstone and calcareous shale | (Greenbrier limestone. | Greenbrier limestone ....| 1500 Blue limestone No. X Montgomery grits. Price sandstone .............| 200-300 | Shales, sandstones, and coal seams Tazewell Quadrangle. of = ath Tellowa formation..........) 500 Sandstone, shale and coal No. XI Lower coal group. { Sequoyah formation.......] 450 Sandstone, shale and coal (| Dotson sandstone . 180 Coarse sandstone, with shale at base Bearwallow conglom/ate 60 Coarse conglomerate or sandstone Dismal formation... | 490 Sandstone, shale, and coal i eae conglomerat ate . No. XU Great conglomerate. 4 Lentil).. a 0-120 ao neeiate in western part. 1 I Raleigh sandstone ......... 100 Coarse sandstone, sometimes con- glomeratic Welch formation.. «| 700 Sandstone, shale, and coal l) Pocahontas formation... 360 Sandstone, shale; and coal (| Bluestone formation....... 700-800 | Shale, sandstone, impure limestone ( Greenbrier shale } Princeton conglomerate 20- Fine conglomerate | a Hinton formation.. ..{ 1150-1250 | Shale, sandstone, impure limestone No. XI} (| Bluetield shale .| 1150-1250 Shale, impure limestone at the base { t Greenbrier limestone. | Greenbrier limestone...... 900-1000 | Blue limestone No. X Montgomery grits. Price sandstone .,...... 0-200 Sandstone and shale MINERAL RESOURCES OF VIRGINIA. PLATE LV. ——S=N 3500 | | - \ Harlan Sandstone 006 5000|| == Harlan Sandstone \ Wise Formation Wise ( Formation #300 a ae nt ; —— lise Formation Gladevilie Gladeville = Sandstone L sandstone = GiadevilleSandstone'':' ' 1000. 1000 == : = Norton ; Norton =, : eee | > Formation Norton formation 500[ t Middle Section Eastern Section Generalized sections from different portions of the Big Stone Gap coal field, show- ing important coal horizons. (After M. R. Campbell, Bul. 111, U. S. G. 8.) COAL AND ITS BY-PRODUCTS. 355 The Sewell formation of the Pocahontas quadrangle includes the Dot- son, Bearwallow, and Dismal formations of the Tazewell quadrangle. The Quinnimont and Clark formations are included in the Welch. Bristol Quadrangle. Rogers U.S. Geological Survey ae Character Wise formation......... 100+ Shale, sandstone, and coal 2 pe Gladeville sandstone. 100 Coarse sandstone, sometimes con- No. XII Great conglomerate. lomeratic Norton formation. 1200-1300 | Shale, sandstone, and coal (| Lee formation....... 1500+ Sandstone, conglomerate, shale, coal 7 Greenbrier shale. Pennington shale ..........). 1040-1100 | Shale, occasional sandstone, and im- No. XI pure limestone Greenbrier imestone. | Newman limestone........ 1000+ Blue limestone Estillville Quadrangle. (| Harlan sandstone .........) 880 Coarse sandstone, shale, and thin coal seams a | Wise formation...............} 1260 Shale, sandstone, and coal No. XII Great conglomerate. 4 | Gladeville sandstone ..... 120 Cours Us One sometimes con- lomeratic Norton formation............) 1270 Shale, sandstone, and coal || Lee conglomerate ..........) 1240-1530 | Sandstone, conglomerate, shale, coal No. XI { Greenbrier shale. Pennington shale..........| 1040-1100 | Shale and sandstone ree Greenbrier limestone. Newman limestone.......] 700- 930 | Blue limestone As is observed above in the tables of Carboniferous formations, the coal-bearing strata of the southwest Virginia field consist of beds of conglomerate or coarse sandstone, shale, and numerous seams of coal. Beneath this group of coal-bearing strata and to the southeast of the Pocahontas field, in the southern portion of Bland county and the northern part of Wythe county, is a coal-bearing series of rocks, principally the Price sandstone, of Lower Carboniferous or Mississippian age. Areas be- longing to this horizon are found, as described above, at intervals along the western side of the Great Valley in Virginia as far north as Frederick county. ‘These are described above under coals of Mississippian age. On plate LV, are given three generalized sections from the eastern, middle, and western portions of the Big Stone Gap coal field, showing important horizons. These sections, adopted from Campbell, show four well-marked coal horizons. 356 MINERAL RESOURCES OF VIRGINIA. Structure. On plate LVI are given 4 structure sections, adopted from Campbell, from different places in the southwest Virginia field. As may be seen from these and from the position of the area on the accompanying map, figure 52, the strata forming the coal field lie immiediately west of the greatly folded rocks which form the Great Valley, and they show but little disturbance. As would naturally be expected, the beds in general show more disturbance along the eastern margin of the field than toward the west. In general the beds are more or less flat-lying, observing with some exceptions gentle northwesterly dips, as shown in the sections, plate LVI, figures 1, 2, 3, and 4. In the Pocahontas field a fault abruptly terminates the field on the southeastern border. Traces of the coal-bearing rocks, however, are still found in isolated places to the east of the fault, indicating probably a greater eastern extension of the field. The beds show a general tendency to thicken toward the east. The Big Stone Gap coal field, situated upon the eastern margin of the coal basin, is marked by a belt of more or less disturbed strata, which forms the transition from the nearly horizontal rocks of the Cumberland plateau on the west to the highly contorted strata of the Great Valley on the east. The most pronounced structural feature in the region is the Powell valley anticline, which has its northern termination in the Big Stone Gap field. It is an unsymmetrical anticline, the northwestern limb of which is almost vertical, while its southeastern limb dips gently away from the axis and gradually merges into the shallow syncline on the south. The Middlesboro syncline, the most economically important coal basin of the Big Stone Gap field, has suffered considerable minor irregular deformation in the form of folds and flexures. These structural features have an important bearing on the economic development of the field. Character of the Coal. The fuel value of a coal is determined by chemical analysis, by steam boiler tests, and by results obtained in actual practice. Of the large number of analyses made of the coals in the southwest Virginia field, a few of those which seemed most representative of the published ones accessible to the writer are given in the following tabular form: MINBRAL RHSOURCES OF VIRGINIA. PLATBH LVI. Fig. 1.—Structure section along the Virginia-West Virginia line, southwest Virginia coal field. (Adopted from Pocahontas folio, U. S. Geol. Survey.) Fig. 2.—Structure section in Tazewell county east of Richlands, southwest Virginia coal field. (Adopted from the Tazewell folio, U. S. Geol. Survey.) Fig. 3.—Structure section in Scott and Wise counties near Big Stone Gap, southwest Virginia coal field. (Adopted from the Estillville folio, U. 8. Geol. Survey.) Fig. 4.—Structure section in Scott and Wise counties, southwest Virginia coal field, near Dungannon. (Adopted from the Bristol folio, U. S. Geol. Survey.) 3 2 N, 4Sea Levet Fig. 5.—Structure section in the northern Blue Ridge and Valley regions, from Bloomfield to Berryville, Loudoun and Clarke counties. (Adopted from the Harper’s Ferry folio, U. 8. Geol. Survey.) GEOLOGIC STRUCTURE SECTIONS IN THE SOUTHWESTERN VIRGINIA COAL FIELD (Figs. 1, 2, 3, and 4), AND IN THE BLUE RIDGE AND VAL LEY REGIONS OF NORTHERN VIRGINIA (Fig. 5.) Figs. 1, 2, 3, and 4 show differences in structural relations of the rocks on the eastern margin of the coal area (folding and faulting), and the nearly horizontal position of the rocks in the coal area. Fig. 5 shows the relations of the rocks of the Blue Ridge to those of the Valley region. Left half of section represents the Valley region, right half the Blue Ridge. COAL AND ITS BY-PRODUCTS. 357 Analyses of coal from the Tazewell area (Tazewell folio). Moisture Volatile Matter |Fixed Carbon Ash Sulphur Total Per cent. Per cent. Per cent. Per cent. Per cent. Per cent. 0.29 16.00 70.99 12.72 0.62 100.62 0.62 22.36 70,35 6.67 0.91 100.91 0.42 27.19 59.88 12,51 1.30 101.30 0.39 25,29 64.24 10.08 1.17 101.17 0.66 25.91 64,23 9,20 1.19 101.19 8.42 32.86 48 83 9.89 0.51 100.51 6.89 22.55 60.72 10.84 0.55 100.55 0.15 25.61 68.54 5.70 0.94 100.93 0.58 29.68 61.75 7.99 0.79 100.79 2,24 24.65 63.77 9,34 0.65 100.55 0.52 22,88 65.24 11.36 0.73 100.73 2.46 18.45 62.93 16.16 0.54 100.54 0.21 19.32 70.42 10.05 0.72 100.72 0.50 22.09 71,78 5. 0.62 100.62 1,83 18.80 54.54 24,83 0.54 100,54 0.66 30.08 55.90 13.36 0.74 100.74 0.77 33.31 59,22 6.70 0.65 100.65 0.14 24,20 71.63 4.03 0.85 100.85 0.57 30.79 66,52 2,12 0.68 100.68 McCreath reports, as an ‘average of eight samples taken by himself from the Pocahontas, No. III seam, in the Pocahontas field, the results given in column I below. Column II is an analysis of the same coal taken from the West mine of the Pocahontas Collieries Company, at Poca- hontas, made by Professor Hite of the West Virginia Geological Survey. i I II Consubuents Per cent. Per cent. Moisture... 2... . cece e cece ceeeteneeeee .699 21 Volatile matter. ...... 2.0.2.6 18.756 19,62 Fixed carbon. ..........-..00065 73.406 76.61 PBT pecs eceicisracein aistts «vane ene ie vig saia o0000 og 6.388 3.56 SUIPDUE oo ocineics 68.08 samosas emewress 1,752 1.69 PHOSPHOPUS. 5505.0 si6.5 0:2 F9:0HS ecgiereine nace — -006 Analyses of coal from the Big Stone Gap field (Estillville folio). Volatile Fixed Water Sulphur Ash Total : No. Per cent. enh an Per cent. | Per cent. | Per cent. Chemist I 1.716 43.069 48.252 0.738 6.225 100.00 McCreath II 2,284 35.571 58.016 0.749 3.480 100.00 McCreath III 2.260 37.270 57.661 0.539 2.270 100.00 McCreath IV 1.508 38.602 48,393 3.077 8.420 100.00 McCreath Vv 1.206 41.539 48, 3.527 5.460 100.00 McCreatk VI 1.154 846 60.1 0.643 2.750 100.06 Mctcreath VII 0.924 35.971 58.436 0,579 4,090 100.00 McCreath VIII 1.400 33.660 58. 0.705 5.870 100.00 McCreath IX 1.464 36.266 59.741 0.799 1.730 100.00 McCreath x 2.008 31.487 57.704 0.651 8,200 100.00 McCreath XI 1.096 js 58.143 0.662 5,415 100.00 McCreath XII 0.600 35.795 57,428 0.652 5.525 100.00 McCreath XIII 1,480 31.97 62.85 0.68 3.70 100.68 Potter XIV 2.02 32.18 60.66. 0,90 5,14 100.90 Potter xv 2.22 .56 59.66 — 8.56 100.00 Potter XVI 1.090 34.145 59.879 1.081 3.805 100.00 McCreath XVII 0.840 33.720 60. 0.709 4.725 100.00 McCreath XVIII 0.798 34,022 61.411 0.619 3.150 100.00 McCreath 358 MINERAL RESOURCES OF VIRGINIA. The name, stratigraphic position, and location of the seams yielding the analyses given on preceding page are appended below in tabular form. The numbers in the first column on the left of the two tables are the same: No. Name of Seam Stratigraphic Position Location I Cannel 110 feet above Gladeville sandstone | Preacher creek It 80 teet above Gladeville sandstone | Sang Trace creek III On top of the Gladeville sandstone | Clover Fork IV Under Gladeville sandstone (?) Carroll opening, on Jones cree Vv Under Gladeville sandstone (?) Bailey mine on Jones cree. VI Imboden 180 feet below Gladeville sandstone | Little Looney creek Vil Imboden 180 feet below Gladeville sandstone] Little Looney creek VIII Imboden 180 feet below Gladeville sandstone] Little Looney creek IX Imboden (?) 180 feet below Gladeville sandstone | Pigeon creek xX Imboden 180 feet below Gladeville sandstone | Mud Lick creek XI Imboden 180 feet below Gladeville sandstone | Preacher creek XII Upper Banner 800 feet above Lee conglomerate 3 miles E. of Tacoma XII Upper Banner 800 feet above Lee conglomerate Near Tacoma XIV Upper Banner 800 feet above Lee conglomerate Near Tacoma xXxV Lower Banner 690 feet above Lee conglomerate a Greeno-Bodine mine, ‘'acoma, XVI Lower Banner 690 feet above Lee conglomerate Toms creek, 4 miles north- east of Tacoma XVIT Kennedy 425 feet above Lee conglomerate ot Greeno-Bodine mine, ‘acoma XVIII Kennedy 425 feet above Lee conglomerate Banner, 6 miles E. of Tacoma. McCreath and d’Invilliers in their report entitled “Mineral Resources of the Upper Cumberland Valley, Southeastern Kentucky and South- western Virginia,’ give the following analyses of coal collected by them from the Crab Orchard district in Virginia: Analyses of coal from the Crab Orchard district in Virginia (McCreath and @ Invilliers.) Volatile] Fixed r Water Sulphur} Ash Locality. Per cent. ener Poder’ Per cent.|Per cent. Big Crab Orchard creek, McConnell opening 3.122 35.798 52.374 -565 8.146 Big Crab Orchard creek, Wilson opening 2.692 38.723 51.847 2.008 4.730 Sugar Hollow, upper bed, A. C. Morris 2.356 36.314 57.820 1.685 2.825 Sugar Hollow, lower bed, A. C. Morris 2.692 36.933 55.233 947 4,195 Sugar Hollow, R. Mullen’s coal 1.568 38.332 57.865 525 1.710 Wolf Harbor creek, M. Zion’s coal 1.662 38.533 53,329 2.096 4,380 Puckett’s creek, LeRoy Kirk’s coal 2.162 36.573 453 2.632 10.180 Puckett’s creek, Cooper bank 978 «442 47.224 3.771 8.585 Puckett’s creek, J. D. Pennington’s coal 1,734 39.071 57.059 436 1.700 Near Big Branch, E. L. Parson’s coal 3.572 31,913 . 240 -615 15,660 Bailey’s Trace, Newman’s coal 1,586 33,229 51.045 580 13.605 Ely’s creek, N. Woodward’s coal 2.472 37.403 56.389 -586 3,150 Analyses of Coal from Pocahontas or Flat Top Field. FURNISHED BY THE COURTESY OF THE POCAHONTAS COLLIERIES CO. MADE BY CASTNER, CURRAN & BULLITT | CoAL ASH | | | au 3 a NaME | ey | 4 2 | REMARES Ash a § | Ex B |Lime| ¢€ | 3 3 OK 3 s || n n Ko a = |} Hl | Powhatan White Streak... | seo | 20 | 5.94 | 78.14 41 | Lick Branch, 2x No. 21 Room. 5.82 815 60 | 91 2.44 | 1.30 | -78 | Lick Branch, Middle Bench. 6.01 «94 -06 | 46 3.47 | 58 | .27 || Lime visible Norfolk—Top Coal .......... 6.15 s : “41 | 3127 129 | 126 || Lick Branch Top Coal . 6.02 47 3.15 Ol .22 || Rolfe—Lower Bone .... 19.72 nalysis | Buckeye—Black Shale.. “a 35.76 | ee | 8S. W. Va. I. Co., No. 31 on Ten... 7.44 || .261 1.51 1.15 | 3.99 32 06 Lime not visible S. W. Va. 1. Co., No. 4 on Chicago 5.78 || .281 | «71 ‘65 | 2/22 | 135 | 11 | Lime not visible S. W. Va. I. Co., No. 5 on Orleans. | 6.02 || 285 -65 | .60 ; 2.41 | .30 -09 Lime not visible Browning, No. 6 Main E.. 8.01 498 1,24 150 4,28 44 -08 Lime not visible Browning, Ridgeway... | 4.51 450 61) .19 | 2.81 40 10 Lime not visible Mill Creek, No. 53, Pillar. | 4.67 577 66.28 | 2.44 .40 ll Lime not visible Mill Creek, No. 1 4th x | 5.05 2346 69 | .26 2.51 | .43 15 | Lime not visible Mill Creek, No. 5 5th x | 8.85 982 81 | .35 4.31 38 -21 | Lime not visible Caswell Creek, No. 21, 20, En. | 6.28 440 55 0 | B51 | sak | 09 No bone, lime visible Caswell Creek No. 9, 1 x... | 6.59 418 -50 51 | 3.71 225 .09 | No lime visible Caswell Creek, No. 6, San 7.46 455 | .70 51 4.06 a) 17 || No lime visible Booth-Bowen, No. 8, W. E.. 4.99 | .Bd44 41] .15 | 2.73 27 | .13. || No lime visible Booth-Bowen, No.1, 2nd x 5.28 || .362 | 42 25 2.50 23 | 15 | No lime visible Booth-Bowen, No. 2 x... . 7.69 |) 1380 | [65 | 125 | BIb1 | .28 .20 || No lime visible Buckeye, No. 7, Gen. E 6.33 299 86 29 2.80 .47 -23. || No lime visible Buckeye No. 32 Tipton. 7.35 || .321 80 -35 | 3.61 40 .25 || Nolimev Buckeye, Face Main.. 6:72 Bll | 7 Al | 3.15 AT '27 || No lime v Louisville, 2nd, Entry . | .29 | 2,00 04 23 No lime v: Louisville, 5th Entry . | 20 | 1.89 146 | (21 || Nolimev Louisville, 4th Entry..... 22 2.10 06 | 19 || No lime v. Goodwill, No. 11 on Neh. E. | 42? 2.43 41 .13 || No lime vi Goodwill, Jennings E... ...... 1 | 4.01 | .42 | .17 || Nolime vi Goodwill, No. 5, Nicholas E.. Al | 3,020.38 19 No lime vi Coaldale, No. 21, 33 | 63 | 1.04 |) .7 | 219 No trace visih Coaldale, No. 10,1 x.. | .47 | 1,09 .68 | .23 || No trace visible Coaldale, Face 5 x.... 250 | 1.41 70 21 || No trace visible Elkhorn, No. 24 on lst Entry. 57 | 1,58 Bl 09 Slight lime indications Elkhorn, No. 1, 0n 10 x . 1.82 | 1.53 | 2 15 No lime visible Elkhorn, Face of Main .. 39) 1,23 2% | 1 No lime visible Shamokin, No. 9, 8th Entry. | 1.41 | 1.44 31 14 No lime visible Shamokin, Face Main..... e | 1.31 | 1,32 28 12 No lime visible Shamokin, No. 4, 6th Entry : | - 297 1.32 ; .41 -15 | Indications of lime Norfolk, No. 6 on left... ‘ | (12 | 2.96 | [54 .29 || Lime not visible Norfolk, No. 10 of Lukes ; 18 2.17 | .59 .21 || Lime not visible Norfolk, No. 11 of 7th En : 18 3.17 65 389 Lime not visible Angle, No. 1 of 4th Entry.. . } .75 | 1.52 | .29 | .15 || Lime not visible Angle, Face of 2nd Entry.. : 72 1.71 oT .18 || Lime not visible Angle, Fan 2nd Entry. 5. | .70 2.03 «oo | .26 || Lime not visible Lick Branch, Ist x....... 5.5 | .42 | 2.49 67 25 | Lime not visible Lick Branch, Main Entry. ‘ {| 41 | 2.81 61 | 227 Lime not visible Lick Branch, No. 5 Main Entry : 249 .36 | 2.25 68 | .21 || Lime not visible Turkey Gap, No. 11x Entry... -74 | 19.38 | 70 9.59 487 3d 50 | 5.31 1.18 7 Lime visible y Gap, No. 27, 6 x Entry 73 | 19.49 8.75 501 29 .56 | 5.18 | 1.41 73 Lime visible Turkey Gap, No. 51, 2 x Entry . 64 | 19.38 6.26 421 26 438 3.21 36 .70 || Lime visible Crozer, No. 44,0n 4x Entry... 76 | 18.84 6.59 72) 51 .40 3.96 1.29 1.01 || Lime just visible Crozer, No. 11, on 3x Entry .68 | 19.18 8.2: .589 | .50 51 4.67 1.76 1.02 Lime very strong Crozer, No. 12, on 6 x Entry 56 | 19,35 7.37 -608 50 4 4.45 96 1.07 Lime very strong Houston, Face 8 x Entry .. 50 | 17.94 7.37 916 78 ie 3.72 1.50 | 1,44 Lime very strong Houston, No. 34, 4th x k4 | 18.49 4.76 .676 60 | 62 2.90 49 .31 || Lime not visible Houston, No. 11, 4th x. 46 | 18.66 7.68 -610 | 1.09 .87 3.60 1,13 72 Lime strongly marked Upland, Face 5thx.. 46 | 18.76 | 74.: 6.47 .3670 | 260) 57 3.22 | 1.37 79 Lime visible Upland, No. 23, 3rd x .34 | 19.48 | 75.6 4.57 415 20 31 1.60 | 1.85 | .29 || Lime visible strongly Upland, No. 5, Ist x.. .70 | 19.70 | 74.2 5.33 B91 223 51 | 3.08 | 1.01 | .7 || Lime visible faintly Powhatan, No. 4, Ist a 18.72 | 7 | 1 .408 90 46 | 4.21 | 1.09 1.13 | Lime trace light Powhatan, No. 14, lst x .00 | 18.16 | 70. | 10.65 2525) 1.15 57 5.21 | 1.39 1.62 | Lime trace strong Powhatan, No. 9, 2nd x (58 | 19.97 | 71. 7.98 499 | (84 | 149 | 3.53 | 1.99 1.60 | Lime visible Lynchburg, No, 25, 3rd x 56 | 18.52 | 74,E 6.41 .509 49 41 3.61 | 72 5) || Lime not visible Lynchburg, No. 14, 4th x .02 | 18.75 | 72. 8.27 |) .53d .42 48 | 4,42 | 86 | 28 Lime not visible Lynchburg, Face 4th x.. 49 | 19.11 | 74.5 0 |) 537 39 702 | 3.10 | 97 -31l | Lime just visible Elk Ridge, No. 18, 2nd x .73° | 18.54 | 73. 7.64 |, .337 61 | .85 | 3.81 | .86 .22 || Lime not visible Elk Eidge, No. 12, Ist x .87 118.51 | 72.5 8.04 349°) 660 | 66 | 4.11 .59 | .26 || Lime not visible Elk Ridge, No. 9, 2nd 84 | 19.62 | 73 6.14 |) 1361 | 50 JL | 2.93 | 85 | .19 || Lime not visible Algoma, No. 3nd .06 | 17.83 5.89 | 465 39 | (46 | 2.57 | ,86 ‘21 | Lime not visible Algoma, No. 4, 3rd a 18.34 5.52 || .437 43 35) 2.71 | .75 .122 || Lime not visible Algoma, No. 40, Ist x. .48 | 18.56 5.07 | .459 41 | .41 2.78 | 84 19 Lime not visible Gilliam, No. 2, 4th x 71 18.31 7.81 a2) 8S | dG 3.93 | 193 | OF \ Lime visible Gilliam, No. 1) 2nd x. ‘el | 1713: 8.08 || 1352 | 155 | ‘a7 | 4/61 | "71 | [21 | Lime visible Gilliam, No, 24, Fan ry.. .72 | 18,35 4.80 17 | BI 12 | 2.61 dL 21. | Lime not visible Rolfe, No. 3, Main Drift... -46 | 17.57 6.57 303 | .44 54 | 3.47 | 32 .15 || Lime not visible Rolfe, Face Main Entry... .62 | 17,89 5.85 | £825 39 | .52 | 3.21 | .30 17. || Lime not visible Rolfe, No. 15, on Main Entry.. 45 | 18.36 7.15 41) 647 | 53) | 3.62 37 | 23 Lime not visible Roanoke, Face 2nd x... 45 | 19.05 5.29 || .805 | .69 .79 1.19 .59 | 22 Lime not visible Roanoke, No, 14, Ist x.. od | 18.46 5.76 .319 | .71 | .70 | 1,39 (47 | (29 || Lime not visible Roanoke, No. 5 on Ist 3 "36 | 19151 4.47) 285) 84 | 7D | Laz ‘67 | 118 Lime not visible Indian Ridge, Face Main 1 19.69 6.65 |, .289 45 1.32 2.91 | 43 .22 | Lime not visible Indian Ridge, No. 1, Ist x 5) | 18.93 4.56 || 815 52 | 2.61 | 87 | 20 Lime not visible Arlington, Face 2nd 3 | 61 | 18.49 6. 0 | 3.97 41 21 || L Arlington, Face 4th x. | 48 | 19.44 6. 256 | 4.13 “51 126 | Lime not vi Arlington, Face Main .... | 178 | 18.95 6. 53 | 4.97 147 ‘23 || Lime not vi McDowell, No. 5, Fan Entry .44 | 18.44 6.5 50 3.53 | .30 (25 | Lime not vi McDowell, Face Air Course . .62 | 18.96 Ti 52 4.10 237 51 || Lime not visible McDowell, 4th Straight Entry. 135 | 18,65 6. 59 3.12, 132 | [53 | Lime not visible Ashland, No. 2, Ist X.......... .52 | 18.18 : 1) 227 | ae “31 | Lime not visible Ashland, Face Fan Entry. .50 | 19,51 | .50 3.49 | (36 | 299 | Lime not visible Greenbrier, from Ist to 2nd... .60 | 18,30 | 57 | 4.06 30 34 | No lime visible Greenbrier, Face Main Entry. .66 | 18.97 .59 | 3.80 | .22 131 | No lime visible Greenbrier, Face Main Entry. .75 | 19,47 | .82 | 4.72 | .21 | 23 No lime visible Keystone, Face, 2nd Air Course. .70 | 17.90 2.67 | 147 17 No lime visible Keystone, No. 5, lst x Entry 167. | 18.04 273 149 25 | No lime visible Keystone, No. 3, 2nd Entry 70 | 17.75 277 149 125 || No lime visible Pulaski, Main Entry. 76 | 17,51 | 2.91 69 (14 || No lime visible Pulaski, Main Entry 85 | 18.19 | | 4.18 | [73 ‘14 || No lime visible Pulaski, Main Entry. : 94 | 17,62 | 4.2% | (54 26 No lime visible Eureka, Face, 2nd x. -| .685 | 18.76 | | 2.79 | (79 | (35 || No lime visible Eureka, No. 16, 2nd x | .48 | 19.98 | ae | ‘75 | 119 || No lime visible Eureka, No. 9, Ist x... : 5 | 1s | 285 | i711 "99 } No lime visible Shawnee, Face of Mai 2 | 3.89 | (60 | (35 || No lime visible Shawnee, Face 2nd x ‘| | | 3.08 “65 | "54 No lime visible Shawnee, Face 3rd x : | 4.11 (BD | 20 No lime visible Empire, Face 2nd x, : | 242 [61 | (21 | No lime visible Empire, No. 12, 4th x : | 3.71 | .67 31 No lime visible Empire, Face Main... : | 3.51 “60 "19 No lime visible Peerless, Face 4th x. | 1.80 90 ‘91 || Lime visible Peerless, No. 13, 2nd x. ‘| (U3 | im | 119 || Lime not visible Peerless, Face, Ist x...... lh | | 1.70 | (81 125 | Lime not visible Bottom Creek, Main Entry | | | 4,33 558 ‘92 | Lime not visible Bottom Creek, Ist x...... “ | | 2.61 OL 124 Lime not visible Bottom Creek, Ist x... sf | | 2.67 | 61 | 120, Lime not vi Tidewater, No. 2, Ist x | |; 3.69 | .78 | (18 || Lime not Tidewater, No. 4, 3rd x. | | 3.29 | 170 ‘27 =| Lime not Tidewater, No. 4, 3rd x.... | | | 2.71 Lime not visible Analysis of Pocahontas Coal. MADE BY THE WORLD’S COLUMBIAN EXPOSITION FOR THE SOUTHWEST VIRGINIA IMPROVEMENT CO., CHICAGO, ILL., 1893. Sample of Coal No. 865, Record No. 380, furnished by Southwest Virginia Improvement Co., Tazewell co Virginia, from the West Mine: Water, .50 per cent.; Volatile Matter, 22.21 per cent.; Fixed Carbon, 74.36 per cent.; Sulpnur, .78 per cent.; Ash, 2.15 per cent.; Total 100 per cent. (Signed) J. 8S. CARY, Chemist in Charge. Analyses and Boiler Tests of Coal. U.S. Naval Board, Hohenstein Boiler Tests, 190: Babcock & Wilcox Boiler Co. Babcock & Wilcox Boiler Co... Prof. R. H. Thurston, Cornell U sity. Prof. R. C. Carpenter, Cornell University .. Prof. Lord and Prof. Haas, Proc. A. I. M.E., Wm. Kent, Cornell University... csecsenererees = J. W. Hill, Proc. A. 8. C. E., 1899, Ohio State University... 85.94 MADE BY THE COAL TESTING PLANT AT LOUISIANA PURCHASE EXPOSITION, 8ST. LOUIS, MO., 1904. * 7 | staal, * a. 3 og Year. 3 3 Built. (Baila: Coal used. produced. pled = 22s £88 "| ing. | Short tons. | Short tons. ~ [SB | per et. 1883 1 200 0 39,000 25,340 | $ 44,3845 | $1.75 | 65 1884} 1 200 0 99,000 63,600 111,300 | 1.75 | 64.3 1885 1 200 0 81,899 49,139 85,993 1.75 60 1886 2 350 100 200,018 122,352 305,880 2.50 61.2 1887 2 350 300 235,841 166,947 417,368 2.50 70.8 1888 2 550 0 230,529 140,199 - 260,000 1.74 64.7 1889 2 550 250 238,793 146,528 325,861 2.22 61 1890 2 550 250 251,683 165,847 278,724 1.68 66 1891 2 650 250 285,113 167,516 265,107 1.58 58.8 1892 2 594 206 226,517 147,912 822,486 2.18 65.3 1893 2 594 206 194,059 125,092 282,898 2.26 64.5 1894 2 736 100 280,524 180,091 295,747 1.64 64.2 1895 5 832 350 410,737 244,738 322,564 1.32 59.6 1896 7 1,138 101 454,964 268,081 404,573 1.509 | 58.9 1897 6 1,453 110 574,542 354,067 495,864 1.40 61.6 1898 6 *1,564 0 852,972 531,161 699,781 1.317 | 62 1899 6 *1,588 429 994,635 618,707 1,071,284 1.78 62.2 1900 | 7 | *2,331 | 300 | 1,083,827 685,156 | 1,464,556 | 2.137 | 63.2 1901 7 *2,775 0 | 1,400,231 907,130 1,483,670 1.635 | 64.7 1902 | 14 | *2,974 |1,208| 1,716,110 | 1,124,572 | 2,322,998 | 2.065 | 65.5 1903 | 16 *4,251 142 | 1,860,225 1,176,439 2,724,047 2.315 | 63.2 1904 | 16 *4,345 68 | 1,636,905 1,101,716 1,772,717 1.609 | 67.3 1905 | 16 *4,549 0 | 2,184,369 1,499,481 2,869,452 1.913 | 686 *Includes 56 Newton-Chambers by-product ovens. In the following table is given the production of coke in Virginia in by-product ovens in 1902 to 1904: Quantity. Yield per ton of Year. coal. Value per ton. Total value. Short tons. Per cent. 1902 36,748 54.8 $2.76 101,538 1903 33,766 60.6 3.30 111,467 1904 27,337 55.5 3.60 98,387 4. GAS, TAR, AND AMMONIA (BY-PRODUCTS OF COKE WORKS). In the bee-hive form of coke ovens all gases and by-products were allowed to go to waste, a condition which is now being largely remedied by the use of the by-product ovens. This form of oven is coming into greater use, although it is claimed that it does not produce coke with a silvery 384 MINERAL RESOURCES OF VIRGINIA. luster like that from the bee-hive oven, but the structure and quality of the by-product coke is not much inferior to the old bee-hive product. The following tables, compiled from the recent volumes of the Mineral Resources, show the production and value of gas, tar, and ammonia, pro- duced at by-product coke works and in gas-house retorts in Virginia from 1902-1905. Under Coke on page 383, is given a table showing the production and value of coke produced in Virginia in by-product ovens from 1902-1905. Table showing quantity and value of gas produced and sold at by-product coke plants in Virginia from 1902 to 1905. Gas sold for illum- Gas sold for fuel pur- li 8 | 2 3 inating purposes poses Total gas sold BES 8) o8 a ; 5 uan- 8 .3| Quan- eSs| 44 g 2 al @ 3 s3 Quantity | Value 3 2 Qu ty Value 2 8 tity Value Bae qa ge » se] 82 | 8B 28s gg" M5e| 6338 S| Short | Cubic | Cubic BS i EUS i vier a AA Cubic Ay Cubic 47 '5| Cubic A) “tons feet feet $ $ a 8 $ feet $ $ feet 1902] 14 | *66,981 (361,328,023/291,187,286| 352,512 | 1.21 5391,000; 33,966 | 1.082 /322,578,286/ 386,478) 1.198 | 38,749,737 1903} 14 #55,723 399) 92 6, 480) 277, 857, 260 325, 342 | 1.16 a "438, 826) 64,374 | 1.04 339,296,086 389,716) 1.16 60, 630, 394 1904) 13 | 49,247 |447, 7928) 210) 317; 968, 979 348, 962 | 1.10 | 71, 726) 171) 79,797 | 1.11 |889,695,150} 428,750] 1.10 58, 933) 060 1905] 13 | 55,657 513, 801, 470) 329) 709, 181 376, 645 | 1.16 97,711,297 108-728 | 1.11 4207, 420, 478| 485,368] 1.15 93, 380, 992 *Includes 56 Newton-Chambers by-product ovens. The following table gives the coal-tar production in Virginia from 1902 to 1905: Value per | Yield per ton Year. ae na Quantity. Value. gallon of coal. ishments- 1 Gallons. Cents. Gallons. 1902 461,317 $20,493 4.40 6.88 1903 14 606,994 25,293 4.16 10.89 1904 503,460 18,119 3.60 10.22 1905 13 691,530 21,152 3.06 12.40 In the table below is given the production of ammonia liquor in Vir- ginia and West Virginia at the gas and by-product coke works from 1902 to 1905. ‘The returns do not separate Virginia and West Virginia: Ammonia liquor pro- Equivalent to anhy- Year. Coal carbonized. duced. drous ammonia (NH,). Short tons Gallons. Pounds. 1902 258,695 1,052,817 1,311,715 1903 219,481 757,136 1,108,472 1904 238,461 1,183,096 1,336,085 1905 176,398 1,073,102 1,002,058 MISCELLANEOUS. 385 XI. MISCELLANEOUS. 1. GEM MINERALS. Under this heading are grouped those minerals which are distinguished, when cut and polished, for their beauty, durability, or rarity. The essen- tials, beauty and durability, are dependent upon color, brilliancy, and hardness of the mineral, which in turn are dependent upon the chemical and physical properties of that particular mineral. Distribution and Localities. A variety of minerals of gem grade have been found in the crystalline rocks of the Piedmont province of Virginia. Some counties in this area, which seemingly offer good possibilities for the occurrence of gem ma- terials, have not yet been exploited for this purpose. The known counties which have either produced gem minerals, or contain minerals which might be of desirable gem grade, are Amelia, Amherst, Bedford, Buckingham, Fairfax, Hanover, Nelson, and Spottsylvania. Of these, Amelia county is the best known and has produced the largest variety and quantity of gem minerals. These have come from the mica mines opened in the pegmatite dikes, near Amelia court-house. Those minerals known to occur in Virginia which have been used or are capable of being used for gem material are separately described below. Diamond. The largest diamond discovered in the United States up to 1884 was found by a laboring man at Manchester, Virginia, in 1855, in some earth he was digging. So far as known to the writer this marks the only diamond-find in the State. A writer states that this stone was put into a furnace for melting iron at Richmond, where it remained at red heat for 2 hours and 20 minutes, and when taken out it was found to be uninjured. It was valued in Richmond at that time at $4,000.00 and was later cut at an expense of $1,500.00. Its form was that of a slightly rounded trigonal trisoctohedron, and in the rough it weighed 2334 karats; after cutting its weight was 11 11-16 karats. In color it was a faint green- ish white with perfect transparency, but the refraction was somewhat im- paired by a flaw or speck in the interior. 386 MINERAL RESOURCES OF VIRGINIA. It has been suggested that the stone was brought down by the James river during spring floods from the Virginia gold fields. Exact copies of this gem, in glass, as it was found and as cut were deposited in the United States Mint Museum in Philadelphia, and at the Peabody Museum in New Haven, Connecticut. Quartz. Several varieties of quartz are found in Virginia from which a few gems have been cut. These include a greenish colored banded quartz; a milky-white chalcedony; colorless quartz with dark inclusions; and a smoky-brown quartz. These have come from one locality, namely, Fair- fax court-house. Gems cut from each variety of the Fairfax court-house quartzes named above are included in the collection of gems in the United States National Museum. In the cabinet of Tiffany and Company of New York City, is a fine limpid crystal of quartz, one inch long and two-thirds of an inch in diame- ter, yenetrated by fine green crystals of actinolite a half millimeter in di- ameter, from an unknown Virginia locality. Amethyst, a variety of quartz, has long been known to students and collectors as occurring in Virginia. A promising locality has recently been opened and some good gem mineral taken out at a point about 2 miles from Lowesville post-office in Amherst county, and about the same distance from the James river. It occurs in pockets connected with a well-marked vein of white quartz, which extends for some miles along the base of the Blue Ridge. It occupies an area of about 11 acres, and the amethyst oc- curs but a few inches below the surface. The deposit has been only slightly exploited. Garnet. Beautiful transparent spessartite, a manganese-aluminum garnet, used as a gem, is found at the mica mines near Amelia court-house, in Amelia county. Irregular masses of the spessartite variety of garnet with crystalline exterior have been obtained from the Amelia court-house mines, which on cutting finished fine gems very similar in color and luster to the essonite or hyacinth of Ceylon. The cut stones varied from 1 to 100 karats in weight. According to Kunz, George W. Fiss, of Philadelphia, found some of the most beautiful natural gems of microscopic yellow garnets from the mica mines of Amelia county. In his “Descriptive Catalogue of the Collections cf Gems in the United States National Museum,” Tassin lists 9 gems cut from the Amelia county spessartite with the following weights: 39.13, 7.26, 2.38, 2.60, 1.10, 11.51, 8.89, 9.32, and 5.65 karats. MISCELLANEOUS. 387 Analyses of the Amelia county spassartite by Bradbury and Clarke are given on page 288. Andradite. A calcium-iron garnet, usually of black color, has also been reported from the Amelia county mines. Topazolite, a sub-variety of andradite, having the color and transparency of topaz, also occurs in the same mines, near Amelia court-house. Beryl. Beryls of large and small size in more or less perfect crystals are found in the mica mines of Amelia county. Beryl of pure white color has been noted from these mines. An analysis made by Baker of the Amelia county beryl gave: Per cent. Sia snes se Gagne ss rake ehh Bie ee 65.24 Alumina 524 ac. wae os a eee 3 17.05 Ferric oxide...........-...-- 2.20 Beryllium oxide............. 12.64 TAME: sais 5 Gg wher wa aisca sears Arne 0.57 Soda os .c¢s4s secs eced ta ail es 0.68 Water - os cids.e d.nsascnt cage uns 2.70 Total ees 55 ga sss aya w Se! eee a 101.08 Specific gravity.............- 2.702 Apatite. Crystals of apatite are found in association with the mica, beryl, etc., in the Amelia county mica mines. Some of the apatite crystals are of very large size. An analysis made by Rowan of a specimen of apatite from the Amelia county locality gave: Per cent. Tad 6 big siie av cinessb- ager a arash gies 53.94 Phosphoric acid..........040- 41.06 AVUMIING: aces cee ee a he oe Mas 0.19 Ferric oxide..............085 0.81 BluOrine: esicis see ee diese Shes ss 3.30 Chlorine: 44 si66 2 sce s08 Gans dae trace Ignition .......... cece ee eee 0.81 Insoluble residue............. 0.63 Total ...s.cc ds seis eee s 100.74 Specific gravity.............. 3.161 Allanite. Allanite is known in Bedford, Amelia, Amherst, and Nelson counties, Virginia. It occurs in considerable quantity in Amherst county, where 388 MINERAL RESOURCES OF VIRGINIA. it is found in large masses and crystals, very compact and black in color, and would form a black metallic gem stone. It is found in large masses in the Amelia county mica mines. Analyses of allanite from Amelia, Bedford, and Nelson counties, gave: Bedford Amelia Nelson County. County. County. Per cent. Per cent. Per cent. SUBGA. os ayad-eeed core aes 26.70 32.35 30.04 Alumina J5...cees eeaiaes x 6.34 16.42 16.10 Ferric oxide............ 3.21 4.49 5.06 Cerium oxide........... 33.76 11.14 11.61 Didimium oxide........ 16.34 6.91 5.39 Lanthanum oxide....... 1.03 3.47 4.11 Ferrous oxide.......... 4.76 10.48 9.89 Erbium oxide.......... 0.52 — Manganous oxide........ trace 1.12 trace LiIM6-s caw oie na tink ass 2.81 11.47 13.02 Magnesia ............+. 0.54 — 1.11 SOMAy causcsiaucs Wan dd uaa 0.49 0.28 Pohaghi- acces seca vere oa} (0-46 0.02 WIRY os sdee9 24 eben 1.99 2.31 2.56 Tin OX106.. ga205 442 0x9 — — 0.17 Oba iss sxe sun cayg eae 99.04 100.62 99.36 Kyanite. This mineral, a silicate of aluminum, is found at Willis Mountain, in Buckingham county; in the vicinity of the old mica mine near Hewlett’s, in Hanover county; and 2 miles north of Chancellorsville, in Spottsyl- vania county. As yet no really fine gems have been produced from any of the American kyanite. Fluorite (Chlorophane). One of the most remarkable varieties of this mineral, chlorophane, is found at the mica mines in Amelia county. It fluoresces by the heat of the hand, thus affording a fluorescent gem stone, but not hard enough for any kind of wear. Kunz says of the Amelia county chlorophane: “It is a fact of much interest that the variety of fluorspar found at Amelia, Va., has been found extremely sensitive to heat, so that it becomes distinctly luminous by the warmth of the hand, and that it also shows a triboluminescence so marked that the slightest friction will cause it to emit a phosphorescent light. A spectroscopic examination by Humphreys of the Amelia county chloro- phane showed that yttrium was present and ytterbium in some.” For other occurrence of fluorite in Virginia see page 215. MISCELLANEOUS. 389 Feldspar. The numerous pegmatite dikes found penetrating the metamorphic rocks of the crystalline or Piedmont region, east of the Blue Ridge, fre- quently contain feldspar of gem grade. The most noted locality in Vir- ginia where feldspar of gem grade is found, and which has produced moon- stones in some quantity, is that of the mica mines near Amelia court- house, in Amelia county. Three species of feldspar from the Amelia court-house mines have yielded gems. These are the green-colored potash feldspar, microcline, and the soda and soda-lime feldspars, albite and oligoclase. Microcline, variety amazonstone, is found near Amelia court-house of rich green color. An elliptical girdle, a small tray, and two small balls, cut from amazonstone of the Virginia locality, are in the collection of gems in the United States National Museum. Albite and Oligoclase, variety moonstone, occurs near Amelia court- house, varying from colorless to white, opaque, with fine change of color. A goodly number of moonstones from the Amelia county mines, of double and single cabochon cut, elliptical girdle, are in the gem collections of the United States National Museum. The finest examples of moonstone from an American locality, very closely resembling the Ceylon in quality and transparency, are found at Amelia court-house. Analyses of both the amazonstone and the moon- stone from the Amelia county mines are given on page 277. Microlite. The rare mineral, microlite, which is essentially a calcium pyrd- tantalate containing niobium, fluorine, and a number of bases in small amount, is found in Virginia, only at the Amelia county mica mines, in association with beryl, spessartite, fluorite, etc. The microlite occurs in the Virginia locality in fine crystals up to 1 inch in diameter, and in imperfect crystals up to 4 pounds in weight. Where the mineral has been found at other localities it was opaque or at best translucent and not of value as a gem stone. At the Virginia local- ity, however, some of it is of sufficient transparency to be highly prized as a gem, the color varying from an essonite red to that of a rich spinel yellow, and remarkably brilliant. It is remarkable for its density, having a specific gravity higher than that of any known gem, being about 6. 390 MINERAL RESOURCES OF VIRGINIA. An analysis of the Amelia county microlite yielded Professor Dunning- ton the following results: Per cent. ALOg. Bis ihiwihe kin wists vacterae cues 68.43 NBO ge aie ainsre g.arele ques ussica eso 7.74 WO}. feces sagisduw tase adores 0.30 STO ysis Bi cause cicada Wiehe scabs 1.05 CAO! ware dcraiiis saoien secon tages 11.80 MgO! se) 2 da teste sk Pun alee amare 1.01 BeO saessane scnageisd ee naw 0.34 TDs sss aventhoany stants spans nisi abayece 1.59 Vey: ie svi ie aces tains. orslineleicn a ane 0.23 (Ce; Di) sOssis setae seaenseees 0.17 GO, scien oswe taate ne cated 0.29 ALO gra shnecnae wansamend wba eede a 0.13 Na isco wine ae cen and aie ainsia ws 2.86 KO ey ein es sw oo ais we scee's 0.29 TDGO) si saiait ts ieee Sake aves Ebene ec estiege 1.17 solvers, RNS, REA aT ates Sees 2.85 Total .ssai.exec'ess pane vine 6 100.25 Specific gravity.............. 5.656 (Dunnington) Specifie gravity.............. 6.13 (Hidden) Columbite. Columbite, a niobate and tantalate of iron and manganese, occurs in the Amelia county mica mines with microlite in fine splendent crystals. An analysis of the columbite from Amelia county gave Professor Dun- nington: Per cent. NBO p. vcitess ee scsaelaseta ss 31.40 Mas Og: Margie cx teae at daasiie al he 53.41 BNO 3 saiusaview resroee ceens sae ao trace HeO gvceneurs ae side thas ae es 5.07 MnO 522.6 eaceateoeeuaxetticaas 3.05 CaO) 2h clean otiale a Siaece aire’ 1.27 MIO) fe iesncie dawg ic oreuae-enaie we 0.20 ViOs ads enw oo ae ee ee a SS 0.82 AP OUD Liadtcs jus evis gan ep Rack ae 95,22 Specific gravity.............. 6.48 Helvite. This mineral is of yellow color and is found filling cracks in spes- sartite at the mica mines near Amelia court-house. give the following composition of the mineral from the Virginia locality: Sloan and Haines MISCELLANEOUS. 391 Sloan, B. E. Haines, R. Analyst Analyst Per cent. Per cent. 31.42 10.97 40.56 ||| S888 woanw Oowoeo Dotalsc ena scence sees 98.16 99.79 . References. Baker, A. L. Beryl from Amelia County. American Naturalist, 1882, XVI, 340; American Chemical Journal, 1885, VII, 175. Bradbury, C. M. Garnet (variety Spessartite) from Amelia County, Virginia. Chemical News, 1884, L, 120; The Vir- ginias, 1885, VI, 25. Clarke, F. W. Mineralogical Notes. Spessartite from Amelia County, Virginia. U.S. Geological Survey, Bulletin No. 60, 1890, 129. Dunnington, F. P. Columbite, Orthite and Monazite from Amelia Coun- ty, Virginia. American Journal of Science, 1882, XXIV, 153-154; American Chemical Journal, 1882-83, IV, 138-140. Helvite from Amelia County, Virginia. American Chemical Journal, 1882-783, IV, 479. Analysis of Columbite and Monazite from Amelia County, Virginia. American Naturalist, 1882, XVI, 611. New Analysis of Columbite and Monazite from Amelia: County, Virginia. American Naturalist, 1882, XVI, 611. On Microlite from Amelia County, Virginia. Chem- ical News, 1881, XLIV, 44; American Chemical Journal, 1881, III, 130; American Journal of Sci- ence, 1881, XXII, 82. Haines, R. Analysis of Helvite from Virginia. Proceedings. Academy Natural Sciences, Philadelphia, 1882, 101; Chemical News, 1883, XLVII, 6-7. 392 Hidden, W. E. Koenig, G. A. Kunz, G. F. Lewis, H. C. Musgrave, R. N. Page, C. C. Page, W. T. Rowan, G. H. Seamon, W. H. Sloan, B. E. Tassin, Wirt. MINERAL RESOURCES OF VIRGINIA. A Transparent Crystal of Microlite, Amelia Court- House, Virginia. American Journal of Science, 1885, XXX, 82. Notes on Orthite from Amelia Court-House, Virginia. Proceedings Academy of Natural Sciences, Phila- delphia, 1882, XXXIV, 103-104. Chlorophane from Amelia County, Virginia. Amer- ican Journal of Science, 1884, XXVIII, 235-236. Helvite from Virginia, Amelia County. American Journal of Science, 1882, XXIV, 155; American Naturalist, 1882, XVI, 337-338. An American Locality for Helvite, Amelia Court- House, Virginia. Proceedings Academy Naturai Sciences, Philadelphia, 1882, XXXIV, 100-101. Analysis of Albite from Amelia County, Virginia. Chemical News, 1882, XLVI, 204; American Nat- uralist, 1883, XVII, 312-313. Amazonstone from Amelia county, Virginia. The Virginias, 1885, VI, 24-25. Analysis of Allanite from Bedford County, Virginia. American Naturalist, 1883, XVII, 312-313; Chem- ical News, 1882, XLVI, 195. Apatite from Amelia County, Virginia. The Vir- ginias, 1885, VI, 24; Chemical News, 1884, L, 208. Analysis of Garnet from Amelia County, Virginia. American Naturalist, 1883, XVII, 312-313. Analysis of Helvite from Amelia County, Virginia. Chemical News, 1882, XLVI, 195; American Naturalist, 1883, XVII, 312-313. Analysis of the Feldspar Accompanying Microlite in Amelia County, Virginia. Chemical News, 1881, XLIV, 207; The Virginias, 1882, III, 4. Descriptive Catalogue of the Collections of Gems in the United States National Museum. Report of the United States National Museum fo: 1900, 473- 670. 2. SAND. Sand, suitable for the three principal uses made of it, is found in com- mercial quantity in Virginia. This includes sand used for glass manu- facture, molding, and building purposes. The principal production of MISCELLANEOUS. 393 Virginia sand up to the present time is utilized in molding and for building purposes. Although commercial deposits of glass sand occur, there has been no production, as yet, for this purpose, in Virginia. Glass Sand. A purer sand is required in the manufacture of glass taan that used for any other purpose. Sand suitable for glass manufacture is found at a number of localities in the State. Deposits of a fine white sand, derived by disintegration from the hard Potsdam sandstone, are found at several places along the eastern edge of the middle Valley region. An extensive deposit occurs at Balcony Falls in Rockbridge county, along the west base of the Blue Ridge. At Stapleton Mills, in Amherst county, is found a deposit of very pure white sand. In the northern portion of Roanoke county, in Catawba valley, and along Catawba Mountain, about 9 miles north and west of Salem, are deposits of fine white sand, well suited for the manufacture of glass. Preparations are in progress at present by the Catawba Valley Railway and Mining Company looking to the development of the Catawba valley sand deposits. A railroad is being graded between Salem and the Norfolk and Western Railway and Catawba Mountain for the purpose of trans- porting the sand to Salem, where the glass plant will be located. Contract has been let for the building of the glass plant at a cost of $50,000.00. An analysis of the Catawba valley sand, made by Mr. H. H. Hill, in the Laboratories of the Virginia Polytechnic Institute, gave: Per cent. Sili¢ay cea sang gee wey eam aes 96.99 SAVVIS ase espe leads in divans ae one 01 TPOn) OX1dG si cisn beter teacon en 02 Magnesia. o.¢22ces28ecrse vaste 07 MMO gi hlec cre dus dei BE chad ROS 80 Sodan acelin tthe « and See ntincade 1.40 POta Sh pci duisceaiard exces devawe acest 20 Water and organic matter..... 31 Dota lies auscgipeacnens tawnveaae 99.80 An exceptionally pure white sand is described by Professor Fontaine as occurring at the foot of the Potsdam mountains, a short distance southeast of Greenville, in Augusta county. The sand was pierced by a well which, after passing through 6 feet of blue clay, passed through 17 feet of Potsdam bowlders and sand. ‘This sand is described as being of extreme whiteness, in large amount, and valuable for glass-making. A sample of moderately coarse and fine white sand, composed almost exclusively of 394 MINERAL RESOURCES OF VIRGINIA. quartz grains, from the vicinity of Waynesboro, gave on analysis 98.57 per cent. of silica. Glass sand is formed in a number of other counties, but the deposits have not received attention. Molding Sand. Molding sands to be of value must possess certain physical qualities, the principal ones of which are, according to Mason, elasticity, strength, and a certain degree of fineness. According to Ries, molding sand must be sufficiently fine-grained and aluminous to permit molding into the re- quired form; strong enough to hold its shape; resistant to heat, and porous enough to permit the escape of gases, but not admit the melted metal. An excess of clay and iron in the sands will cause the mold to shrink and crack under the intense heat, and too little will cause it to dry and crumble. Sands possessing the qualities enumerated above and of superior quality are found in the vicinity of Richmond, and at other localities in the Coastal Plain or Tidewater region of Virginia. That found on the Cowardin place near Richmond is of excellent quality and is extensively used. During his investigations of the Virginia Coastal Plain clays in the summer of 1905, Dr. Ries studied and collected samples of the molding sand over the same area. The samples were analyzed in the laboratories of the Virginia Polytechnic Institute by J. R. Hoff, Jr., and James H. Gibboney, with the results given below. As indicated below these sands represent localities chiefly in the vicinity of Richmond, Petersburg, and Fredericksburg. I IL Til IV Vv VI Percent. | Per cent. | Per cent. | Per cent. | Per cent. | Per cent. Silica (SiO,).....0 ccc 81.59 82.08 66.12 82.32 70.24 70.40 Alumina (AI,Og).....0.-005 6.46 7.12 16.54 7.80 16.62 3.80 Iron oxide (Fe,O,)...... ... 4.94 4.63 4.46 3.98 3.94 14.94 Lime (CaO).....ce cece 0.14 0.36 0.40 0.54 0.08 0.12 Magnesia (MgO).. 0.22 0 35 0.22 0.41 0.09 0.15 Potash (K,0)... an 219 1.28 2.67 1.64 1.41 1.95 Soda (Na,O)........... | 0.59 0.41 0.35 0.80 0.74 0.41 Titanic oxide (TiO,) 1.90 0.30 0.14 0.22 0.46 0.70 Water (H,0)........... 1.63 1.66 4.90 0.19 4.16 4.08 Water (moisture)........... 1.46 1.52 4.15 0.14 2.42 3.77 Total......sceceeere cree 100.12 99.71 99.95 98.04 | 100.16 | 100.32 MISCELLANEOUS. 395 VII VIII Ix x XI Per cent. | Per cent. | Per cent. |} Per cent. | Per cent. Silica (SiO,)..... sss 84.40 93.92 85.04 86.24 89.39 Alumina (A1,0,)... a 7.56 3.22 5.90 6.32 5.94 Iron oxide (Fe,0,) -. wee 2,52 1.08 3.18 2.44 1.22 Lime (CaQ)....... .... we{ 0.06 0.24 0.06 0.34 0.32 Magnesia (MgO)... es 0.21 0.08 0.14 0.10 0.09 Potash (K,O).......... 1,29 0.45 1.65 1.38 2.10 Soda (Na,O) ....0+.. 0.65 0.23 0.83 1.13 0.53 0.44 0.32 1.99 1.76 Titanic oxide ea) 0.78 0.02 0.18 Water (H,0).. cgevees 0.48 1.57 2.94 0.54 Water (moisture). sadeug tated ; 0.18 1.11 1.29 0.19 Total.. ..0... sesso seseee 100.88 | 100.20 | 100.26 | 102.20 | 100.50 I. Redford sand from foundry, Manchester, Virginia. II. Redford yellow sand collected at pit, Manchester, Wirwinia, III. Coarse sand, Harbaugh pit, Richmond, Virginia. IV. Used molding sand, Redford pit, Manchester, Virginia. V. Sand from near Petersburg, Virginia. VI. Blandford pit, Petersburg, ‘Virginia. VII. Armstrong pit, Petersburg, Virginia. VIII. Sand from near Standard Brick Company, south of Suffolk, Virginia. IX. Griffith’s pit, Fredericksburg, Virginia. X. Curlis pit, southeast of Lanexa, New Kent county, Virginia. XI. One mile south of Layton, Essex county, Virginia. The following physical tests made on the samples of sand from Vir- ginia, shown in the analyses above, by Doctor Heinrich Ries, further serve to show the general character of Virginia Coastal Plain molding sands: LocaLity. 20 40 60 80 100 =100X Clay Redford yellow sand collected at pit in Manchester, Virginia......... 151 126 1.27 0.56 627 71.69 16.52 Coarse sand, Harbaugh pit, Richmond 42.48 12.90 6.16 0.85 1.70 8.58 26.44 Used molding sand, Redford pit, Richmond ..................... 5.34 14.73 10.41 1.28 14.61 59.37 3.52 Sand from near Petersburg ican bach a 0.73 2.34 8.76 2.21 12.25 14.79 30.54 Blandford pit, Petersburg.......... 3.03 1.41 0.97 0.40 2.61 48.32 41.87 Armstrong pit, Petersburg......... 0.09 041 2.21 2.67 17.37 53.20 19.02 Sand from near Standard Brick Com- pany, south of Suffolk.......... 0.12 0.29 13.00 656 38.02 35.18 6.03 Griffith’s pit, Fredericksburg....... 0.19 0.19 0.39 0.19 0.98 81.92 15.97 Curlis pit, southeast of Lanexa..... — 90.01 0.08 0.07 1.11 86.77 19.57 One mile south of Layton.......... 6.68 28.13 51.66 3.18 3.75 2.63 2.16 Building Sand. A much larger amount of sand is consumed for building and construc- tion work than for any other purpose. No special purity is required of a sand for this purpose, loamy sand as well as mixtures of coarse and fine o96 MINERAL RESOURCES OF VIRGINIA. sands as found in the banks being used. Usually when much coarse material is contained in the sand it is screened out before using the sand. Sand of the character described above and in all respects suitable for building purposes has wide distribution over nearly all parts of the State. It is found in considerable quantity along many of the stream courses in each of the larger divisions of the State. . Production. Production of sand in Virginia by years for all purposes, for 1904 and 1905. Molding sand | Engine sand | Building sand |Other purposes Total Value Year Short | Value] Short | Value | Short | Value | Short | Value | Short : tons $ tons $ tons $ tons $ tons 1905 €1,246 | 37.899 | 4,775 | 3,580 |244,572| 96,248) 5,272 | 3,400 |315,865|141,127 1904 | 64,313 | 30,943] 3,600 | 1,800 Hea. 4,357 | 3,482 sas sass 3. MARLS. Definition and Properties. As ordinarily used the term mar] is applied to a variety of soft, earthy materials, composed principally of an amorphous form of carbonate of lime. The greensand marl is an exception, being a hydrous silicate of iron and potash. Marls vary much in color according to the amount and kind of impurities which they contain. When dry the purer forms are invariably of light color, white or cream. The impure forms are usually some shade of an intermediate or dark color. Moisture influences to some extent the color, for the same marl when dry has usually a lighter color than when wet. A marked feature of calcareous marls is their free effervescence in acids, which serves to distinguish them from certain clays and muds which they sometimes resemble. Origin and Occurrence. Based on composition marls may be grouped into (a) calcareous or limy marls, and (b) glauconitic or greensand marls. Both classes have wide distribution over parts of Virginia. The calcareous marls, sometimes known as shell marls, are chiefly formed in bodies of fresh water such as lakes and ponds, and about springs and small streams. They form a considerable part of the filling of many of MISCELLANEOUS. 397 the extinct fresh water-bodies and are now forming on the bottom of many such bodies of fresh water. They are formed principally from the accumulations of the remains of fresh water alge, and from calcareous shells of lime-secreting animals. The stonewort chara is an efiective agent in abstracting the lime from solutions in lake water and forming lacus- trine marl. In some cases, as shown by Blatchley and Ashley from the lakes of northern Indiana, calcareous marls may be formed by chemical pre- cipitation. Glauconitic or greensand mar] derives its name from the presence of the green-colored mineral, glauconite, which is essentially a hydrous silicate of iron and potash, and which imparts a green color to the deposit. Ac- cording to Professor Wm. B. Clark, the mineral glauconite of the green- sand marls, occurs as grains which frequently show themselves to be casts of foraminifera and other calcareous organisms; and as pointed out by Murray and Renard it is always associated with terrigenous minerals, particularly orthoclase (feldspar) and muscovite (mica) and similar pot- ash-bearing minerals. The glauconite grains seldom exceed one millimeter in diameter but occasionally they are agglomerated into nodules of much larger size, the cementing substance of which may be phosphatic. The glauconitic sands have wide distribution through the various geologic formations, and they are forming at present in places on the floors of existing seas, such as along certain parts off the Atlantic ccast. Distribution and Localities. Marls of both calcareous and greensand types are widely distributed over the Coastal Plain or Tidewater region of Virginia. As early as 1838 Professor Rogers reported marls from the following Coastal Plain counties: Gloucester, Isle of Wight, James City, Lancaster, Middlesex, New Kent, Prince George, Surrey, and York. Since that time large deposits of marl have been noted in nearly all the remaining counties of this area. Calcareous marls are also developed in places over parts of the Valley region west of the Blue Ridge. The Coastal Plain Region. Greensand marls.—So far as known this type of mar] is limited to the Coastal Plain region, largely along its inner margin or western portion, where it is exposed along the Potomac, Rappahannock, Pamunkey, and James rivers. It is further found on the interstream areas and has been traced south from the James river almost as far as the State boundary. 398 MINFRAL RESOURCES OF VIRGINIA. According to Professors Rogers and Clark, the Virginia greensands and greensand marls are of Eocene age, and are found in the Pamunkey group, which in Virginia includes the Acquia and Nanjemoy formations. Professors Clark and Miller have described the Acquia formation as con- sisting of greensands and greensand marls, the latter often holding great quantities of molluscan shells that afford enough cement at times to pro- duce, under proper conditions, a hardened limestone. Likewise, the Nan- jemoy formation consists largely of greensands, but contains a larger amount of argillaceous or clayey materials. The combined thickness of these two formations, each measured in different places, is between 200 and 300 feet. In some of the marl beds of this area the mineral particles of glau- conite are so abundant as to impart a pronounced green color to the de- posit. Specimens from James City, York, and other counties in the Co.stal Plain area, contain as much as 35 per cent. of the greensand or glauconite. The greensand marls are valuable for fertilizer from the amount of potash contained in them and at times for its additional phosphoric acid. Potash is very variable in amount in these marls, varying according to the pro- portion of the mineral glauconite present, ranging usually from 1 per cent. in the very impure greensands to 8 and 10 per cent. and more in the purer greensands. The following analyses made by Ellett and Eskridge of the Virginia Experiment Station on samples of marl from Suffolk and Prince George counties, Virginia, serve to show the potash content: Waverly City Point City Point Sussex Prince George Prince George County County County Per cent. Per cent. Per cent. Insoluble residue.. 45.20 61.15 56.03 TAM ag ods states ae 24.38 1.36 1.52 Magnesia ........ 5.22 2.19 0.37 Phosphoric acid... 1.80 0.47 0.05 Potash .......... 4.73 3.85 3.15 Greensands are found further eastward in the Coastal Piain beneath the cover of Miocene and Recent strata, as exposed in the deep well at Fortress Monroe. The Virginia greensand marls have been worked to advantage at a number of places, especially on the James and Pamunkey rivers. : Calcareous marls.—Marls of calcareous composition are extensively de- veloped over all parts of the Coastal Plain, being especially abundant in the Miocene and, in many places, hardly less abundant in the Eocene. These MISCELLANEOUS. 399 have resulted chiefly from the accumulation of the remains of mollusks and other shell-secreting animals. In addition to their agricultural value, many of these marl beds are large enough and of sufficient quality to be used in mixing for the manufacture of Portland cement. In color these marls range from white to blue, and are composed chiefly of calcareous matter, some with as much as 97 per cent., and gener- ally the amount exceeds 80 per cent. Professor Rogers mentions particu- larly extensive beds of pulverulent white marl in Gloucester, New Kent, Prince George, and other counties. In a table given of the Miocene cal- careous marls from 9 localities in Gloucester county, Professor Rogers gives the percentage of calcium carbonate present as ranging from 37.1 to 96.8 per cent.; and 3 from New Kent county as ranging from 76.1 per cent. to 93.6 per cent. In places are beds of hard ferruginous marls consisting of shells more or less broken which are rich in calcareous matter ; and shell-rock approaching limestone in composition, some of which Professor Rogers found to contain 87 per cent. of carbonate of lime. At the Normal cliffs, on the Potomac river, shell marl has been dug for shipment and used in the manufacture of artificial fertilizers. Ellett and Eskridge obtained the following results on analysis of marls from 9 counties in the Coastal Plain: Insoluble Lime Magnesia Phosphoric Potash Locality. residue acid : Per cent. Percent. Percent. Percent. Per cent. Reves, Prince George Co.... 59.00 12.88 0.46 0.07 0.63 City Point, Prince George Co. 67.59 20.41 0.35 0.33 0.41 City Point, Prince George Co. 70.51 12.75 0.09 0.17 0.34 City Point, Prince George Co. 28.07 38.15 0.42 0.29 0.50 City Point, Prince George Co. 41.71 27.40 0.06 0.38 0.26 City Point, Prince George Co. 47.26 24.44 0.48 1.50 0.27 City Point, Prince George Co. 39.05 27.96 0.84 0.13 1.02 Old Church, Hanover Co.... 45.68 21.73 1.10 0.16 0.45 Lumberton, Sussex Co...... 49.09 25.90 0.06 0.18 0.43 Chuckatuck, Nansemond Co.. 13.70 40.97 0.23 5.36 0.26 Fort Lee, Henrico Co....... 15.80 26.79 0.45 0.03 0.25 Fort Lee, Henrico Co....... 29.23 35.74 0.66 0.77 0.65 Claremont, Surry Co....... 8.38 45.83 0.53 0.13 0.35 Yorktown, York Co........ 47.45 24.77 none 0.03 0.71 Roxbury, Charles City Co... 27.61 35.54 trace 1.24 0.20 The Valley Region. Large deposits of marl, usually of good quality, are found in many of the Valley counties on the west side of the Blue Ridge. So far as the writer has information, the marls of this region belong entirely to the caleareous type. Some of these have formerly had a limited use as a flux in iron-making, and, in places, they may offer possibilities for use in the +00 MINERAL RESOURCES OF VIRGINIA. manufacture of Portland cement. See pages 159 and 160, under Cement. and Cement Materials. Elictt and Eskridge give the following analyses of marls from the Valley region: Frederick Frederick Rockbridge Alleghany County County County County Per cent. Percent. Percent. Per cent. Insoluble residue............. 2.61 3.65 4.34 5.91 AGN OS arenes vivanceaer anne aera RA GAEOe 52.62 52.19 47.87 50.58 Magnesia. i. ceaneven ces sa aves 0.43 0.44 3.24 0.86 Phosphoric acid.............. 0.06 0.36 0.80 0.23 GEASS cdiviecd, has ases nse tices aie 4 8 0.58 0.23 0.31 0.28 Uses. The principal use made of marl is as a fertilizer and as an improver of the mechanical or physical condition of certain types of soils. For these purposes its value is proportional, other things being equal, to the amount of phosphoric acid, potash, and lime it contains. The marl beds have been worked at numerous points in the Coastal Plain for local use as fertilizer. Marl is also used in the manufacture of Portland cement, in the manufacture of quicklime, and, in Virginia, it formerly had a limited use as a fluxing material in some of the iron furnaces. References. Clark and Miller. A Brief Summary of the Geology of the Virginia Coastal Plain. Virginia Geological Survey, Bulle- tin No. II, 1906, 12-24. Darton, N. H. Geologic Atlas of the United States. Nomini Folio No. 23. U. 8. Geological Survey, 1896. Ellett and Eskridge. Virginia Marls. Bulletin, Virginia Agricultural Experiment Station, 1897, VI (n. s.), 65-70. Fontaine, W. M. The Artesian Well at Fort Monroe, Virginia. The Virginias, 1882, III, 18-19. Hotchkiss, Jed. The Resources of the Virginias On and Near the Proposed Route of the Richmond and Southern Railway. The Virginias, 1880, I, 91. Rogers, W. B. A Reprint of the Geology of the Virginias. New York, 1884, 28-49, 151, 156, 251, 419. MISCELLANEOUS. 401 4, MILLSTONES (BUHRSTONES), Under this name is included a siliceous conglomerate of quite variable structure, used in the form of flat-circular disks for grinding purposes. About 5 miles west of Blacksburg in the vicinity of Prices Fork, Montgomery county, a sandstone-conglomerate occurs in Brush Mountain, in which quarries have been opened for a distance of 3 miles. The stone is somewhat variable in color but is usually white or gray. Likewise, variation in the size of pebble is shown. The rock is made up of well rounded pebbles of quartz compactly embedded in a fine siliceous sand- stone matrix, the whole forming an exceedingly tough and hard mass. This stone is known on the market as “Brush Mountain” stone. Practically the same variation in the sizes of stone made at the different quarries obtains. The grindstones made from this rock are of excellent quality and they find a ready market. The age of the Brush Mountain stone is Mississippian (Lower Carboniferous) or Vespertine of Rogers. Siliceous conglomerates similar to the above are found in the crys- talline area, east of the Blue Ridge, and are rather abundantly distributed over the Mountain district west of the Blue Ridge, but so far as the writer is aware the Brush Mountain quarries, in Montgomery county, are the only producing ones in the State. Production. The value of millstones (buhrstones) produced in Virginia from 1902 to 1905, inclusive, is as follows: Year Value 1902............ $11,435 1908 io Ged 8 sate 9,812 LOO 4 io os medewhctenrs 4,759 PART IV, METALLIC MINERALS. I. IRON. BY R. J. HOLDEN. Historical. The first iron ore mined in America of which there is any known record was mined in Virginia in 1609 by the Jamestown colonists. This ‘ore was taken to England where it produced 16 tons of superior metal. The success of this experiment led to the erection of the first American iron works between the years 1619 and 1622 on Falling Creek about 7 miles south of the site of the present city of Richmond. These works were destroyed in the Indian massacre of 1622 before they had been operated. For a century there were no further operations in the manufacture of iron. The first successful iron industry in the South was established by Gov- ernor Spotswood in the pyrite area of Virginia. This was in connection with the Germania, or Rappahannock furnace, which was built about 1714, in Spottsylvania county, near the Rappahannock river. This was not only the first furnace in the South but, outside of New England and New Jersey, it was the first iron furnace in America. About 1727 Governor Spotswood erected another furnace at Fredericksville, in the southwestern corner of Spottsylvania county. About the same time the Accokeek furnace was built by the Principio Company, on the land of Augustine Washington, the father of George Washington, in Stafford county. Another pre-Revolutionary furnace was Old’s furnace, near Charlottesville. The limestone limonite ores were early used by Miller’s, or Mossy Creek furnace, built about 1760, and by the Poplar Camp furnace, built in 1778, in Wythe county. The Oriskany ores were probably first used by Zane’s furnace, in Frederick county, in Revolutionary War time. By 1781 there were 3 furnaces in operation south of the James river in the magnetite area. TRON. 403 In the iron industry transportation facilities are a controlling factor. The early furnaces of the pyrite area were within hauling distance of water transportation on the eastern rivers. Some of the early Valley furnaces operated to supply a local demand only. The furnaces of the Shenandoah area, of which the Zane was the forerunner and which, in the period immediately preceding the Civil War, were leading producers of the State, had outlets in the northward flowing branches of the Potomac. To the early furnaces of the magnetite area, the James river was the highway of traffic. By the close of the 18th century the industry had been established on the James west of the Blue Ridge. By the middle of the 19th century the Oriskany district, located on the head waters of the James and dependent on that stream for an outlet for its product, had come to be the most important center of iron manufacture in the State, a position which it has since maintained. The coming of the rail- ways changed the conditions of iron manufacture. The effect was seen chiefly in three ways. These were, the large extension of the charcoal furnace industry in the 70s and 80s in Wythe county, the building of coke furnaces in the central part of the State in the 80s and, finally, in the shipment of iron ore. In the late 80s there was a great boom in the iron business in the State, which resulted in a period of most active furnace building. In the years 1890 to 1892 there were 10 coke furnaces built in the State, which became active just before the panic of 1893. In the 15 years since that time not a furnace has been built. The building of the Cripple Creek extension of the Norfolk and Western Railway in 1885 and, a decade later, of the Craig Valley Branch of the Chesapeake and Ohio Railway, opened two regions to shipment of iron ore which have since been important contributors to the iron ore production of the State. The recent construction of a branch of the Chesapeake and Ohio Railway south- westward from Covington up the valley of Pott’s creek, and the projection of the extension of the Norfolk and Western Railway northeastward from Interior in the same valley, is expected to open up another important area to the shipment of iron ore. Recent discoveries in regard to the size of some of the Oriskany deposits and in regard to new modes of occurrence of this ore have led to larger ideas of the importance of this ore. Iron Minerals and Ores, Iron ores are considered commercially for statistical purposes in four classes. These are red hematite, brown hematite, magnetite, and carbonate. These commercial terms correspond roughly, respectively, to the minerals 404. MINERAL RESOURCES OF VIRGINIA. hematite, limonite, magnetite, and siderite. There are other iron minerals from which iron is obtained as a by-product, the most important of which are franklinite, pyrite, and pyrrhotite. Red hematite corresponds to the mineral hematite (Fe,0O,), which carries 70 per cent. of metallic iron and 30 per cent. oxygen. This mineral is differentiated from the other iron minerals by its red streak or powder. Its specific gravity is 5.2. The mineral rarely takes on crystal form. The characteristics of the ore vary widely, especially in color and texture. There are three principal varieties, namely, red hematite proper, fossil ore, and specular ore. The red hematite is the most common, constituting the larger portion of the Lake Superior ores. In color it varies from red to brownish red, steel gray or even black. In texture, it is commonly fine-grained and varies in solidity from massive to powdery. The fossil ore is dark red to brownish red in color and is characterized by a fossiliferous or an odlitic structure. The specular ore is usually made up of flattened oval-shaped grains and is characterized by a black or steel gray color with a metallic pearly luster. It is the least important of the varieties of hematite. There are some similar metamorphic hematites that are sometimes classed with the specular ore. These are, the slate ore, which has a dark color and a slaty cleavage, and the micaceous hematite, which is even darker than the slate ore and readily cleaves into thin mica- like sheets. These hematites together include about 85 per cent. of the iron ore mined in the United States. Brown hematite corresponds to the mineral limonite (2Fe,0,.3H,O), which carries 59.8 per cent. metallic iron, 25.7 per cent. oxygen, and 14.5 per cent. water. This mineral is distinguished from the other iron minerals by its yellowish brown streak. Its specific gravity is 3.8. It is never crystalline. The characteristics of the ore vary widely, especially in texture. It is usually massive, but may be powdery. As massive it is commonly porous, not infrequently vesicular, sometimes cavernous and stalactitic, rarely solid. In color it is brown, liver-colored to brownish yellow on the fractured surface, but frequently black and shining on the natural surfaces. Gothite (Fe,0;.H,0) and other hydrous oxides carrying less water and more iron than limonite and commonly associated with that mineral are included under the commercial term brown hematite. Brown hematite constitutes about 8 per cent. of the iron ore now mined in the United States and is mined chiefly in Virginia and Alabama. Magnetite corresponds to the mineral magnetite (Fe,0,), which car- ries 72.4 per cent. metallic iron and 27.6 per cent. oxygen. This mineral is differentiated from the other minerals by its black streak and its mag- IRON. 405 netic properties. Its specific gravity is 5.2. The ore is usually crystalline and commonly in small octahedral crystals, but may occur massive. In color it is black. Magnetite constitutes about 5 per cent. of the iron ore now mined in the United States. Carbonate corresponds to the mineral siderite (FeCO,), which carries 48.2 per cent. metallic iron, 37.9 per cent. carbon dioxide, and 13.9 per cent. oxygen. This mineral is differentiated from other iron minerals by its effervescence with hot hydrochloric acid. Its specific gravity is 3.8. The ore rarely occurs in the form of the cleavable mineral siderite but as a fine-grained rock carrying more or less impurities. As such, its color is commonly gray, bluish gray or brown. When exposed to the air and mois- ture, it readily alters to limonite. Nearly all surface carbonate is consider- ably altered to limonite. The commerciai term carbonate includes these altered products and the material so classed is commonly more limonite than carbonate. This is the least important of the ores of iron and con- stitutes less than 1 per cent. of the iron ore now mined in the United States. _ Franklinite contains zinc and is mined for that metal in New Jersey. The iron left after the extraction of the zinc furnishes considerable of the former metal. The mineral has its crystal form, color and magnetic prop- erties similar to those of magnetite. The sulphides of iron are extensively used in the manufacture of sulphu- ric acid. The iron by-product in this manufacture, known as purple ore or “blue billy,” is used in iron furnaces the same as iron ore. The most important of these sulphides are pyrite and pyrrhotite. Both of these occur in Virginia and both are mined. Pyrite, FeS,, disulphide of iron, contains theoretically 46.6 per cent. of iron and 53.4 per cent. of sulphur. It occurs frequently in crystals, which commonly have the form of cubes or pyritohedrons. Usually it occurs massive. In color it is quite uniformly a pale brass yellow. Pyrrhotite, Fe, S41, a sulphide of iron, contains a variable percentage of iron according to its variable composition. With the formula Fe,,S,, it carries 61.6 per cent. of iron and 38.4 per cent. of sulphur. It is rarely in crystals, usually massive with a granular texture. Its color is quite constant and is between a bronze yellow and a copper red. On fresh fracture it speedily tarnishes. It is commonly somewhat magnetic. Impurities of Iron Ore. The chief impurities of iron ore are silica, lime, alumina, phosphorus, sulphur, manganese and titanium. 406 MINERAL RESOURCES OF VIRGINIA. Of these silica, lime and alumina may occur in quantity but in the fur- nace are thrown into the slag. Phosphorus, sulphur, manganese and titanium usually occur in small quantity and in the furnace are eliminated from the iron not at all or only partially and with difficulty. Silica in large quantity is objectionable in an ore, not only because it reduces the percentage of iron in the ore, but also because it reduces the production of the furnace by filling the furnace not only with silica but also with the lime which is necessary to flux out this silica. Ores carrying as high as 40 per cent. silica are used in small quantity. In the limonite ores of the State the silica usually runs from 10 to 20 per cent. Lime in small quantity is not objectionable. In large quantity it is objectionable only when present in amount greater than necessary to flux the silica present. Lime is not an associate of limonite ore but sometimes occurs in undesirably high percentages in the fossil hematite. Alumina is a common associate of iron ores in small percentages. It is usually higher in limonite than in other classes of ores. In many limonite ores much alumina can be removed by washing. Alumina is apt to be particularly high in limonite ores that are associated with a shale residual, and much of this is so intimately mixed with the ore that it cannot be removed by washing. In large quantities alumina causes the furnace to work badly. It is usually present even in washed limonite ores to the amount of 1 or 2 per cent. and may run as high as 6 per cent. Phosphorus is the controlling impurity which determines the use to which the iron made from the ore shall be put. Phosphorus of the ore goes into the pig iron. In minute quantities this element produces marked effects on both iron and steel. It renders iron and steel “cold short,” that is, brittle when cold, but makes molten cast iron more fluid. For foundry iron, phosphorus is desirable in the ore in fractions of 1 per cent. Virginia cres are relatively high in phosphorus and this fact has been largely re- sponsible in determining that the State should produce foundry and basic iron. The limonite ores of the State usually carry from 0.1 to 0.4 per cent. phosphorus. It is an interesting fact that fault deposits are usually high in phosphorus, even to the amount of 2 per cent. or more. Such ores are desirable for mixing with low phosphorus ores to regulate the phosphorus content of foundry iron. Sulphur renders iron products “hot short,” that is, brittle when hot, even where present in small quantity. It is therefore objectionable. How- ever, the furnace coke usually carries so much sulphur that the sulphur in the average ore is negligible. Sulphur is apt to occur in ore as pyrite but IRON. 407 in some limonites it occurs as gypsum or barite. When present in small fractions of 1 per cent. sulphur may be neglected. Manganese usually occurs in iron ores in fractions of 1 per cent. In certain limonite ores it occurs to the amount of several per cent. Limonite ores are now mined in Virginia which carry 6 per cent: manganese. It also occurs in such quantity that the iron is subordinate in amount and the ore is a manganese ore. Manganese is not usually objectionable in fractions of 1 per cent. For the manufacture of foundry iron the Virginia limonites have to be selected that they may not carry too high manganese content. The ores high in manganese are used for basic iron. Titanium is objectionable in that it interferes with the operation of the furnace. According to Virginia blast furnace practice, when titanium dioxide is present in quantities greater than 1 per cent. it makes the ore objectionable for furnace use. Titanium occurs chiefly in magnetites. Origin of Iron Ore. Iron ore originates for the most part by the segregation of iron, leached from rocks relatively lean in that element. The iron.is carried in solution by circulating surface or ground waters and eventually precipitated. The precipitation may occur in some body of standing water and the deposit be a bedded deposit analogous to other bedded deposits, or the precipitation may occur on or near the surface of the land. Deposits beneath the land surface may be in cavities or may be replacements of the rock. In either case limestone is apt to be an associate of the ore deposit. This is true in-the first case because limestone is one of the most soluble of rocks and therefore one of the most cavernous. In the second case it is true because the lime readily acts chemically upon the iron in solution in such way that the iron of the solution and the lime of the limestone exchange places. In Virginia examples of bedded deposits are seen in the fossil ores of the Alleghany mountains and the hematite of the Blue Ridge, and examples of land depos- its are seen in the Oriskany ores. The different kinds of ores and ore minerals may be the result either of original differences in the minerals which arose at the time of the precipitation of the iron from solution, or of subsequent alterations from one form of minerals to another as a result of geological processes. ‘ Classification of Virginia Ores. The iron ores of Virginia-may be grouped according to their character and occurrence into eleven classes. Listed roughly in the order of their im- portance these are as follows: Oriskany limonite, limestone limonite, Blue 408 MINERAL RESOURCES OF VIRGINIA, Ridge limonite, fossil hematite, Blue Ridge hematite, pyrite gossan, pyrrho- tite gossan, Piedmont magnetite and specular hematite, limestone magnetite, pyrrhotite and titaniferous magnetite. Of these the first five include most of the iron ore now mined in the State. The remainder are mined at present either from only one or two mines, or are of historical importance only, or are of possible future importance. Oriskany Ore. The name Oriskany was given to the limonite ore which was formerly supposed to occupy the position of the Oriskany sandstone. The name is here used for those ores to which it was originally applied and also to all other ores which have a similar origin and occur either in the Helderberg, the Oriskany, or the lower part of the Devonian shale. This ore is the most important of the classes designated above. It was much mined for charcoal furnaces before the Civil War, and is now exten- sively mined in the Oriskany area. It is found in the Alleghany mountains from one end of the State to the other. It occurs most abundantly in the Oriskany area, chiefly in the counties of Alleghany, Botetourt and Craig. It has been considerably mined in the Great North Mountain area, chiefly in Shenandoah county. Here the ore occurs chiefly in the Devonian shale. It has been mined to a less extent in Massanutten and Draper mountains and also, in a small way, in a number of other localities. Most of this ore occupies a very definite horizon at the top of the Helder- berg. It occurs in subordinate importance in the lower part of the Devon- ian shale and rarely in the Oriskany. The strata which are associated with the ore, as they usually occur near mines, taken in descending order, may be listed as follows: Devonian 300+ feet. Shale, black at the bottom. Oriskany 0—15 feet. Calcareous sandstones. 10—-60 feet. Pure thick bedded, soft, fossiliferous limestone. Helder | 20—60 feet. Cherty limestone. The ore is found characteristically replacing the upper pure limestone of the Helderberg. In some localities it is found at varying horizons near the base of the Devonian shale. Rarely. the Oriskany sandstone is ore- bearing. Underneath the Helderberg chert there may be several score feet of limestone, shaly limestone and sandstone. These latter present considerable variation in different localities. The lower measures have no significance so far as the iron ore is concerned, as there is not a single instance, known to the writer, in which ore is found below the main body IRON. 409 of the chert. Underneath the Helder- Bee berg’ there is a thickness of about 500 - feet of Clinton and Medina which is mainly quartzite. The quartzite of g these horizons is the ridge maker of the - Alleghany mountains. Where the a mountains are anticlinal, as in the Ng ° Oriskany area, the ore-bearing rocks appear on the lower slopes on both sides of the mountain and in the valleys. The iron of these ores was originally disseminated in the Devonian shale. As this shale was eroded the iron was taken in solution, carried down and deposited in any favorable place. Ordinarily this place was the upper portion of the Helderberg limestone. In some cases there was a direct re- placement of the limestone by the iron and in other cases the iron was de- posited in the space from which the limestone had been removed by solu- tion. The iron rarely occurs in the sandstone in minable quantity. In the shale it has been deposited chiefly parallel to the bedding of steeply in- clined strata. The outcrop of the ore is usually found on the lower slopes of the mountain a few hundred feet above the valley bottom. (See figure 56.) Along the base of the mountain on the strike of the formation the ore may appear with more or less development for miles. Continuous ore-bodies with fairly constant thickness have. been worked for half a mile. The thickness of any ore-body has been largely con- trolled by the original thickness of the i upper layer of the limestone at that a» (a) KLEE LE B . 56.—Cross section of Alleghany Mountain anticlinal showing relations of Oriskany ore. VIII refers to Rogers’ geologic system. . w= oud Tt — Fig. 410 MINERAL RESOURCES OF VIRGINIA. point. Usually this is replaced to its full width, where replaced at all, and it rarely occurs in thicknesses of a few feet. From 8 to 35 feet are usual thicknesses of the ore-body. Smaller thicknesses are not common except on the borders of the ore-body. Greater thicknesses are not unknown. On the slope of the mountain, that is on the dip of the formation, the extent of the ore-bodies varies between wide limits. The outcrop may be a mere pocket or the ore may extend 700 feet on the slope from the outcrop. Where the outcrop of the limestone horizon is not ore-bearing, ore may occur lower down, generally on a sharp fold of the strata. In some instances there are a number of folds which occupy the lower slopes of the mountains on opposite sides of the valley and the valley between. These may be wholly or partly filled with ore on both trough and crest. The ore is commonly a continuous mass filling the space, and not lumps of ore in clay. The ore occupies the position in which it was deposited from solution and has the form which it then assumed. It has not been deformed or fractured since it was deposited. The mass is not solid but porous or cavernous. The cavities vary in size from a fraction of an inch up to a foot or more in diameter. These cavities may be vacant but commonly contain water, clay or sand. Less commonly the clay is more abundant and the ore is distributed in it as nodules, irregular masses and stringers. Rarely the associated material is loose sand and the ore consists of stringers in the sand. Where the ore is associated with the shale it may exist either as a surface pocket or as a concentration at some lower depth above an impervious basement or as stringers dipping at high angles with the bedding of the shale. This last occurrence is the most important of the shale occurrences. In this case the stringers may have widths of from a few inches up to 15 feet or more and extend downward 50 to 100 feet. The ore is washed in log washers to remove the clay and not un- commonly is jigged to remove sand and flint. From 50 to 80 per cent. of the material mined is delivered from the washer as washed ore. The average composition of the Oriskany ores as mined, computed from available analyses, is as follows: Per cent. Metallic iron................ 43.25 SMICA, 0.11 Manganese .........-.0 ec eeee 0.36 Poplar Camp mine.—This mine is located 1.5 miles southeast of Jack- son’s Ferry. This is a fault deposit lying between the limestone and the sandstone. The mine had been operated for lump ore only up to 1906, when it was opened by the Pulaski Iron Company on a larger scale and ore hauled in wagons to the railway at Jackson’s Ferry. A sample taken and analyzed by the writer gave: Per cent. Metallic iron .............00- 40.77 Insoluble ........ ccc eeeeees 13.92 Phosphorus ...........+e.eee 1.19 Manganese .............0005- 6.80 Southwestward from Poplar Camp mine along the north foot of Poplar Camp Mountain in a distance of 3.5 miles there is a series of small mines nearly identical in situation with the Popular Camp mine. This line seems to be a fault line where the sandstone has been thrust on top of the lime- stone and the ores are lying in the mouth of the fault and are character- ized by high phosphorus and high manganese. Indian Camp mines.—These mines are a series of pits along a mile of this line. They were first operated about 1894 and at one time had narrow-gauge railway connection with the Norfolk and Western Railway at Austinville. Average analyses from 4 banks, furnished by the New River Mineral Company, show as follows: Per cent. Metallie iron. ...wccscs cv ceanes 47.91 SIGH, Sanuk cs de racvioavye dames 9.69 Phosphorus .........-..0.00. 1.98 Mariganese: « scwoccsewes vee oes 1.23 William Jackson mine.—Southwest of the Indian Camp mine William Jackson, about 1898, mined some 6,000 tons of ore, which gave the New River Mineral Company the following results on analysis: Per cent. Metallic iron ................ 49.89 STN CAl. acidasis data ica cuneva a aanaera in 11.40 Phosphorus ..............0. 1.22 Manganese .............0006, 0.85 IRON. 457 Gregory mine——Southwest from the William Jackson mine, since 1893, the New River Mineral Company has mined some 20,000 tons, which gave the following results: Natural State. Per cent. Metallic iron................ 35.63 DILICA (cr. fadne duson ienimeeecnbata dine 20.21 Phosphorus ...............-. 0.72 Manganese ..............000- 0.60 In the vicinity of Ivanhoe there has been considerable mining chiefly for the Ivanhoe furnace, which was built as a charcoal furnace in 1882. The ores are all limonite of relatively high grade and occur usually well concentrated in clay through a shallow depth. Ivanhoe mine.—Southwest from Ivanhoe for 1.5 miles the crest and slopes of a ridge have been mined extensively. The most of this is now owned and operated by the Ivanhoe Furnace Company. The following composition of the ores has been furnished by the New River Mineral Company (column I), and by the Ivanhoe Furnace Company (column II). Natural State. I. II. Per cent. Per cent. Metallic iron................. 43.92 42.00—44.00 ITC sctverd bar sgnas rere adr naman 16.83 14.00—18.00 Phosphorus ..............4.5- 0.14 0.15 Manganese ...............04. 0.73 0.40— 1.00 Painter mine.—The north slope of this ridge and a mine north of Painter creek were operated by the Lobdell Carwheel Company. Simmerman mines.—These mines are located a mile east of Ivanhoe. They were operated intermittently between 1890 and 1896. They consist of 5 small pits. : Sisk and Gray mines.—These mines are located 1 mile southeast of Ivanhoe on top of the precipitous bank of New river. Between 1891 and 1895 the New River Mineral Company took some 25,000 tons of ore from these mines. The following composition has been furnished by the operator : Natural State. Per cent. Metallic iron ................ 44.36 BUT CR. ch cdcsccere acini dase Ga eineiagnetes @ 14.79 PhOspROrus, dices vecnaeagiacnns¢ 0.11 Manganese ...............56. 0.39 458 MINERAL RESOURCES OF VIRGINIA. There has been a number of other small operations in the vicinity of Ivanhoe. Wythe Lead and Zinc mines—These mines, located 2 miles east of Ivanhoe, have produced a little iron ore in connection with the lead and zine mining and now produce some ore which is the tailings from the magnetic concentrator. Eight miles west of Ivanhoe in the vicinity of the present town of Cripple Creek there has been considerable charcoal furnace activity. Within a distance of 4 miles of each other there have been 5 charcoal furnaces. Present operations are at the head of Francis Mill creek 2 miles south of Cripple creek. The mines are in the vicinity of the contact of the limestone and the sandstone. In a kettle-shaped depression between Hussey and Iron mountains, which carries limestone in the bottom, are located the Little Wythe and the Norma mines. Intile Wythe mine—This mine occupies the bottom of the depression. A narrow-gauge railway connects with the Norfolk and Western. Railway near Cripple Creek. The composition of this ore, as furnished by the operators, the Virginia Iron, Coal and Coke Company, is as follows: N atural State. Per cent. Metallic iron ................ 42.75 Silica. cc cnc. en siasvnevaees 13.77 Phosphorus ..............4.. 0.25 Matigamese: aoe. sieves avsosc ara simaries 0.32 Norma mine.—This mine is located immediately south of the Little Wythe. It was opened in 1905. The composition of the ore, as furnished by the operators, the Pulaski Iron Company, is as follows: Natural State. Per cent. Metallic iron ..cesice ees ea ed 42.65 Phosphorus) 0... cco eaed aes 0.12 Porter mine —This mine is a contact mine on the north side of Hussey Mountain. There were two charcoal furnaces formerly operated near Speedwell, which used the ‘limonite’ ores. The extension of the Norfolk and Western Railway to that point in 1906 has opened the region to shipment. The Virginia Iron, Coal and Coke Company now operates 3 mines in this vicinity. IRON. 459 Ganaway mine—This mine is located 14 mile southeast of Speedwell. It is equipped with an 8-log washer and is producing 100 tons of ore per day. Percival mine.—This mine is located 1144 miles southwest from Speed- well. It is equipped with an 8-log washer and is producing 100 tons of ore per day. Andis mine—This mine is located 2 miles southwest of Speedwell. It is equipped with a 5-log washer and is producing 75 tons of ore per day. Lick Mountain is a Valley ridge of Cambrian sandstone and shale, situated a few miles north of the New River-Cripple Creek area. This has been prospected for both iron and manganese and some lump ore has been mined and hauled by wagon to Wytheville. It is reported that such mining was done during 1905. On the north side of the Draper Mountain from Clark’s Summit to Hamilton Knob there is a line of outcrop of limestone, presumably the ‘Valley limestone, which has the Carboniferous shales on the north side and in most places on both sides. Clark’s Summit mine.—This mine is located 14 mile south of Summit station and at the east end of the above mentioned limestone. The mine was extensively operated by the Virginia Steel Company about 1893. The ores were then washed at the mine. It was operated in 1905 by J. M. Spriggs for lump ore. Henson mine——This mine is located on the north slope of Hamilton Knob at the west end of the limestone above mentioned. It was operated some years ago and its ores washed in a local washer, but is now abandoned. Locust Hill mine-—This mine is located on the south side of Hamil- ton’s Knob, about 3 miles southeast from Max Meadows. A narrow- gauge railway connects with the furnace at Max Meadows. The ore-bodies are from 6 to 20 feet thick and dip down the mountain with the Devonian shale. The mine was opened about 1899 and has been operated quite continuously since then. A view of this mine is shown on plate LXVIII, figure 1. The composition of the ore, as furnished by the operators, the Virginia Iron, Coal and Coke Company, is as follows: Natural State. Per cent. Metallic iron ................ 37.54 Silica ............-. uae sake 18.79 Phosphorus .............44-. 0.34 Manganese ..............000- 1.55 460 MINERAL RESOURCES OF VIRGINIA. Smyth County. This county has a Jong record in the production of small quantities of iron ore. Barton’s and Nichols’s forges in the Rye Valley and Chatham Hill forge on North Fork of the Holston were built at the beginning of the last century. During the Civil War an attempt was made to operate a furnace, and, since the war a charcoal furnace has been in successful operation. Recently there has been some small shipments of ore. This county extends across the Great Valley. In the southern part of this valley there are anticlinal mountains of Cambrian sandstone which carry “mountain” ores. In that part of the limestone valley which lies south of these mountains “limonite” ore occurs. This is found especially on the head waters of Cripple creek and in Rye Valley. The Oriskany horizon appears in Walker Mountain in the northern part of the county. On the head waters of Cripple creek ore was mined between 1876 and 1904 for the White Rock charcoal furnace. The most important of these mines are the Crigger, Porter, and Home banks. Crigger bank.—This mine is located 44 mile above the junction of the upper branches of Cripple creek. It produced, between 1881 and 1885, some 25,000 tons of “limonite” ore. Porter bank.—This mine is located in the Valley on the divide between the New and Holston rivers waters about 2 miles east of Sugar Grove. It has produced some 35,000 tons of “limonite” ore, which was washed near the mine and hauled 6 miles to the furnace. It is owned by the Lobdell Carwheel Company. This ore is high in manganese and carries some lead. Home bank.—This mine is located near the furnace 5 miles southwest from Rural Retreat. It was mined between 1876 and 1904 and produced “mountain” ore carrying about 38 per cent. metallic iron. In the Cam- brian mountains west of the furnace other “mountain” ores have been mined in a small way, at a number of places. In Rye Valley ores were mined in an early day for forges and in later time a small amount was hauled in wagons to Marion. The completion of the Marion and Rye Valley Railway to Sugar Grove in 1903 opened this region to shipment. Considerable prospecting has shown ore in various places. All of these valley ores are “limonite” which is high in manganese. In the mountains, which lie to the north of the valley, and between it and the main valley, there has been some mining. These. mountains are made up of Cambrian shales and sandstones, which have been thrown into a number of closely compressed folds. Some of the synclinal valleys between the ridges carry traces of the Valley limestone. The ores have IRON. 461 been mined chiefly near this limestone but also high up in the mountains. A furnace was built on the north side of the mountains at the beginning of the Civil War to use these ores. The furnace was destroyed on Stone- man’s raid. The completion of the railway from Marion to the Curran Valley in the north side of the mountains in 1896 furnished an outlet for these ores. Curran Valley mine—For several years considerable ore was mined and washed here in a modern way. The composition of the ore, as furnished by Dr. J. 8. Apperson, is as follows: Per cent. Metallic iron............. 40.00 Sill CAs casaktieidt haan oes 15.00—20.00 Phosphorus ............. 0.25— 0.35 Manganese .........+006. 2.00— 5.00 In 1905 lump ore was mined on Slemp creek on the south side of the mountain and hauled to Sugar Grove. Lump ore was also mined in the mountain and delivered to the railway where it crosses the mountains. Washington County. This county has ores at 3 horizons, the Oriskany in the northern part, the Valley limestone south of Abingdon, and the Cambrian shales on the southern border. This county had early forges and two charcoal furnaces. White’s furnace was located on the North Fork of the Holston 15 miles southwest of Saltville. It probably drew its ores from the Oriskany horizon which outcrops on the south side of Clinch Mountain. It is reported that ore has been mined from this horizon in recent time near Mendota. The Paulina furnace stood near the South Fork of the Holston on Valley creek. Presumably it used the ores which are now being mined. South and southeast of Abingdon iron ore has been mined at several places. The ores are magnetite, hematite, iron carbonate, and limonite. The first three occur together in limestone while the limonite usually caps the lime- stone. The iron has been leached from the overlying shales and deposited in the limestone. Golleher mine.—These ores were mined in a small way at the Golleher mine, 5 miles southeast from Abingdon. An analysis of this ore, as reported by McCreath in 1884, is as follows: Per cent. Metallic iron .............4.. 56.05 Insoluble ............0200 eee 7.76 Phosphorus ...........+s000- 0.036 Sulphur ....240 505 a0rcsee8eoe 0.06 Manganese ............0--00+ none 462 MINERAL RESOURCES OF VIRGINIA. Holston mine.—This mine, located 6 miles southeast of Abingdon and 2 miles southwest of Brown’s Siding, was operated in a small way in 1905. In 1907 the Ivanhoe Furnace Company is reported to be shipping from this mine 1,000 tons of ore per month. Both the magnetite and the iron carbonate limestone are being mined. The limestone is mined where it. Fig. 66.—Section showing the geologic relations of the iron ore in the Holston mine. (a) Athens shale. (b) Shenandoah limestone. (c) Hematite and magnetite. (d) Brecciated Shenandoah limestone, partly altered to iron carbonate and hematite. (e) Limonite derived from the weathering of (d). carries as low as 15 per cent. of iron. A narrow-gauge railway connects with Brown’s Siding. The following compositions have been furnished by the Ivanhoe Furnace Company: Magnetic ore Iron carbonate Per cent. Per cent. Metallic iron................ 62.00 35.00 Insoluble: - severe gairuennearwrrdns 5.50 7.00 Phosphorus css: iseesncnns ce 0.022 0.03 Manganese ............+.45. trace — TSN’: -seenech sitet ar aaceaaraein G ew weap tate 12.00 Mapnesias — aici.cawineuen saaseney ane —— 5.00 Taylor’s Valley mine—In Taylor’s Valley on the State line south- east of Damascus, limonite ore occurs associated with the Cambrian shale. In 1906 the Taylor’s Valley Iron Company shipped from this mine over the Virginia-Carolina Railway about 1,000 tons of ore per month. Bland County. This is a Mountain county and is without a railroad and no ores have been mined. It has the Oriskany and Clinton horizons on the slopes of East river, Buckhorn, Rich, and Walker mountains, which are reported to carry ore. Tazewell County. This county is a Mountain county. Oriskany and Clinton horizons occur in a number of places, but nothing is known by the writer of their IRON. 463 carrying ore. Limonite ore has been mined from the clay of the Valley limestone near Tiptop in two recent operations. Bell Hill mine——This mine is located 144 miles east of Tiptop and Y% mile northwest of Springville. Ore was mined here from 1900 to 1903, washed in a local washer and hauled one mile over a narrow-gauge railway to the Norfolk and Western Railway. May mine——This mine is located a mile or more west of the above mine and was operated about the same time. Lump ore only was mined, which was hauled to Tiptop. Russell County. Iron ore was mined in a small way for early forges, one near Honaker and the other near Dickensonville. In 1906 test shipments were made from the Hall mine, which is located 6 miles southwest from Castlewood. The ore is limonite and occurs in clay above the Valley limestone. The composition, as furnished by the Union Iron and Steel Company, is as follows: Natural State. Per cent. Metallic iron... Bregdangertyits 44.13 DSUNCR. jvc eicuey es aigeer acs e ead ote 20.91 Phosphorus ........0.00000- 0.17 Scott County. This county is a Valley county. The Valley limestone is the surface rock of the greater portion of the county. The Oriskany measures appear in Clinch Mountain and probably produced iron ore in the early part of the last century for the White Forge, which was located 5 miles northeast of Moccasin Gap. Buchanan and Dickenson Counties. These are the two Virginia counties in which the lower measures are covered by the flat-lying Coal Measures rocks. They may have some Coal Measures iron carbonate, but the writer has no knowledge that it occurs in commercial quantity. Wise County. The greater part of this county has for its surface rock the Coal Measures. The southern corner of the county has Silurian measures at the surface and includes a small but important part of the fossil ore area. The anticlinal Wallen ridge carries beds No. 3 and No. 4 of fossil ore, 464 MINERAL RESOURCES OF VIRGINIA. which are mined in the vicinity of Big Stone Gap. There is no record of ore mining in this region till the recent coming to Big Stone Gap of the Louisville and Nashville and the Virginia and Southwestern Railways. The completion of the Union coke furnace in 1902 has made Big Stone Gap the center of the iron industry in this region. Oreton mines.—These mines are located 3 miles south of Big Stone Gap and 44 mile south of Oreton. ‘Kelly and Irvine are operating No. 4 on the south slope of Wallen ridge. The composition of the ore, as fur- nished by the Union Iron and Steel Company, is as follows: Natural State. Per cent. Metallic iron................ 44.90 BUG ae ics aavice srcaunraereneidnealogmaces 15.81 Phosphorus 2: ee% es sxeve nares 0.29 TTS 6dr sin dodt d woeveitua, ao ee OATD 0.22 Keystone mine-—This mine consists of a series of operations north of Oreton on the south slope of Wallen ridge. The Keystone Coal and Iron Company is operating chiefly No. 3, but also No. 4. Irondale mines.—These mines are located 2 miles south of Big Stone Gap. They are the oldest and most extensively operated mines in the district. Kelley and Irvine have operated No. 3 and No. 4 over the crest and south slope of Wallen ridge for half a mile. The composition of the ore, as furnished by the Union Iron and Steel Company, is as follows: Natural State. Per cent. Metallic iron........ si atiiaaa ts 40.14 Silica, cagencdagk. aad ets 27.98 PHOSPhOrus 2.2 sinew anes a 0.32 BIND G15 ial cheanesteastses etgees Goie hie ena es 0.61 Yeary or Bunn mine——This mine is located immediately south of Big Stone Gap on the crest and north slope of Wallen ridge. W. E. Yeary operates No. 3. The composition of the ore, as furnished by the Union Iron and Steel Company, is as follows: Natural State. Per cent Metallic iron ................ 42.34 DiliCa? oceaaieecse RAs ance en 18.36 Phosphorus ................. 0.29 TAME: eid eenena nee arey meine mete 0.11 The Oriskany horizon outcrops at the base of Wallen ridge and scat- tered ore is found in the Helderberg limestone clay. A sample shipment of the ore was made from Oreton. TRON. 465 Lee County. This county has fossil ores in Poor Valley ridge and in Wallen ridge. Between 1825 and the Civil War two forges were operated in this county. These were the Milam forge, situated on Martin’s creek, near Rose Hill, and the Bowling Green, or Bales forge, situated 4 miles southeast of Rose Hill. Pennington forge at Pennington Gap was operated after the war. The only furnace of the county was the Laurel, which operated after the war. Since the building of the Louisville and Nashville Railway there has been much mining for shipment along the Poor Valley ridge. Most of these mines are located close to the Louisville and Nashville Rail- way and their tipples deliver to the railway cars. Fig. 67.—Geologic structure section across Poor Valley ridge showing the relative positions of the three beds of fossil iron ore. Pennington mine.—This mine is located south of Pennington Gap and was operated in a small way for Pennington forge. The composition of the ore, as sampled from the stock pile at the forge and analyzed by McCreath in 1887, is as follows: Per cent. Metallic iron.............-.. 50.50 Silica pseu dat kom a saae sass 18.75 Phosphorus ...............-. 0.158 Lavine mine—This mine is located midway between Pennington and Ben Hur 1 mile from the railway on a spur of Poor Valley ridge. A narrow-gauge railway connects with the Louisville and Nashville Railway. It is operated by Kelly and Irvine. This mine is not located on the Poor Valley monocline, which carries most of the mines of the region, but in closely folded strata situated east of the monocline. The composition of the ore, as furnished by the Union Iron and Steel Company, is as follows: Natural State. Per cent. Metallic iron ................ 43.20 SUC css ore bon ee ae as . 22.31 Phosphorus vee 0.84 DAMC: . sidtesievenvare Begun MPs cus TERN 0.56 466 MINERAL RESOURCES OF VIRGINIA. Ben Hur mine.—This mine is located on the north side of Poor Valley ridge, west of Ben Hur station, where the railway cuts across the Poor Valley ridge. It has been mined 1,500 feet on the strike and 150 feet on the dip. The composition of this ore, as furnished by the operators, the Virginia Iron, Coal and Coke Company, is as follows: Natural State. Per cent. Metallic iron..............-. 34.01 SiGe. sos. ransciberaqenrn pac Grane eegeane 34.50 Phosphorus ..............44- 0.27 Manganese ..........000e sees 0.16 Truro mine-—This mine is located southwest of Ben Hur mine, 14 of a mile northeast from Noes Siding on the north side of Poor Valley ridge. The composition of the ore, as furnished by the operators, the Virginia Tron, Coal and Coke Company, is as follows: Natural State. Per cent. Metallic iron ................ 36.00 PSLTCA: «15 oun aver setevadanivd ice Sorrewetes 33.37 Phosphorus ................. 0.23 Manganese « vs4 ieeacc cess onesie 0.16 Noes Siding mine—This mine is located southwest from Truro and %4 of a mile northeast from Ocoonita on the north side of Poor Valley ridge. It is operated by Kelly and Irvine; has been mined 225 feet on the dip. The composition of this ore, as furnished by the Union Iron and Steel Company, is as follows: Natural State. Per cent. Metallic iron ................ 42.30 Silica. sce asancexvesstaacacmey 27.60 Phosphorus .............006. 0.19 AMG: ss scaicesdnech ahs agen ero varavnace ana 0.10 Between Noes Siding and Hagan no mining has been done. Grabill mine—This mine is located 600 feet northeast of Hagan station and is operated by B. C. Grabill in a small way. The tunnels are at water-level 75 feet below the railway. The ore is hauled in wagons to Hagan. Boones Path mines.——These mines are located 2 miles southwest from Hagan on the north slope of Poor Valley ridge. These mines are operated from 7 tipples along 14 mile of outcrop. It is the largest operation in IRON. 467 the vicinity and is operated by the Boones Path Iron Company. The composition of this ore, as furnished by the Union Iron and Steel Com- pany, is as follows: Per cent. Metallic iron ...............- 40.91 Sii¢a) asian cables hi oe eed eg 16.70 Phosphorus .............005. 0.45 SAI ad. a¢. Sess Guana she Aseael ane onigie-S9 5.18 Magnesia ........eeeeeeeeeee 0.93 Southwest from these mines the railway lies on the south side of the ridge and little mining has been done along the Poor Valley between there and Cumberland Gap. Ewing mine—This mine has its tipple 1 mile east of Ewing. The mine is located 244 miles southeast from the tipple and its ore is brought Ree LC Oe Fig. 68.—Diagram of Ewing mine. (a) Shenandoah limestone. (6) Clinton measures carrying fossil iron ore, represented by black line, faulted up on the limestone and closely folded. to the tipple over a narrow-gauge railway. The mine is located in the end of a faulted segment of Clinton strata which have been thrust over on the Valley limestone. (Figure 68.) The beds are closely folded, contorted and fractured. The ore is thin but of better grade than most of the ore of the region, carrying lime instead of silica. The composition of 26 carloads of this ore, as furnished by the operators, the Union Iron and Steel Company, is as follows: Natural State. Per cent. Metallic iron ................ 34.09 Silica. sacs.c sears, oa aun. w ans «aoe 6.58 Phosphorus ...............5. 0.58 MAING. 6, sein bors sgcoee aye oe 7.72 Magnesia ......... Bree tonsa 2 3.95 468 MINERAL RESOURCES OF VIRGINIA. PIEDMONT COUNTIES. The counties treated below under this head lie east of the western range of the Blue Ridge. Their rocks are chiefly crystalline schists, the most of which are probably metamorphosed sedimentary rocks. These for the most part have been more or less closely folded with the axes of the folds striking northeast and southwest. As the result of this the outcrop of a given formation usually strikes in the same direction. The schistosity usually dips at high angles to the southeast. The ore-bodies usually follow either the bedding or the schistosity and in either case usually dip at high angles. The ores are mostly magnetite, specular hematite, and limonite. The limonite is usually the gossan of a sulphide. In the northeast this sulphide is usually pyrite, with the pyrite sometimes gold- bearing, so that gold mines and iron mines are associated. In the south- west much of the sulphide is pyrrhotite. As the pyrrhotite usually carries some chalcopyrite the iron mines of the southwestern Piedmont counties are usually associated with copper mines. A corner of Bedford county carries some of the Blue Ridge hematite. In general the counties forming the two most northeasterly tiers of the Piedmont carry iron ore while the other Piedmont counties do not. Loudoun County. Iron ore was mined in this county for the Potomac furnace, which was built in 1839. The ore was limonite and was mined near the furnace, a short distance below Point of Rocks. Stafford County. On the property of Augustine Washington, the father of George Washington, iron ore was mined about 1727 for the Accokeek furnace. This furnace was abandoned in 1753. However, this was not for want of ore, as the mine was considered capable of supplying another furnace in Revolutionary War time. There is no known record of any iron ore mining in this county subsequent to 1753. Spottsylvania County. This county carries a strong development of pyrite through the north- western side. The gossan cap of this was early worked for charcoal furnaces. The first furnaces were those of Governor Spotswood. The Germania, located in the northern corner of the county near the Rappa- hannock river, was built about 1714. This was the first furnace in the IRON. 469 South and the first furnace in America to produce pig iron. ‘The other Spotswood furnace, built about 1827, was located in the southwestern part of the county about a half mile from the North Anne river. The Catherine furnace was located about 3 miles west of Chancellorsville. For many years ore was mined at a number of places scattered through the territory between this furnace and the Rappahannock river. Louisa County. Near Mineral City pyrite is now mined. A description of these mines is given under Pyrite on pages 198-202. The gossan from these pyrite deposits was mined for the Victoria and the Rough and Ready charcoal furnaces in the middle of the 19th century. Magnetite was mined for the latter furnace from two mines near the furnace. Albemarle County. This county has pyrite gossan. Old’s furnace, located 12 miles from Charlottesville, was an old furnace in Revolutionary War time. Pre- sumably it used a gossan ore. Stony Point mine—Near Stony Point, some 6 miles northeast of Charlottesville, at the northwest base of Southwest Mountain, gossan has been extensively worked in modern times. It is reported that between 1878 and 1885, 2,500 carloads of iron ore were shipped from here to Pitts- burg furnaces. As stated under Copper, pages 502-503, there is a continuous outcrop of ore for 34 of a mile with widths of from 5 to 6 feet, and it has been mined to a depth of 130 feet. The gossan is underlain by some chalcopyrite and the mine has produced some copper. At North Garden magnetite and limonite have been mined. An analysis of the North Garden ore, as made for the Tenth Census report, gave: Per cent. Metallic iron ............... 46.69 Phosphorus .........--e2000-- 0.055 Nelson County. Greenway mine.—Specular hematite was mined in 1880 in the southern corner of the county at the Greenway mine, located 214 miles west of Greenway. It is said to have been mined to a depth of 200 feet for a length of 500 feet with widths up to 12 feet. An analysis made for the ‘fenth Census gave as follows: Per cent. Metallic iron..........--200- 53.02 Phosphorus ........+--+++005 0.049 470 MINERAL RESOURCES OF VIRGINIA. At Roseland there are extensive deposits of phosphatic titaniferous iron rock. This has been extensively prospected but not mined as an iron proposition. A further account of this is given under Ilmenite and Phosphates, on pages 232 and 300-301. Buckingham County. Limonite ore was mined in this county before 1840 for the Bear Garden furnace near New Canton on the James river. The ore was the gossan of a pyrite lead. Professor Rogers reports, “About a mile east of Whispering Creek, nearly in line with Willis Mountain, a heavy bed of magnetic oxide crosses the road leading from Maysville to Ca Ira, and may be traced for some distance in a northeast-southwest direction. It is from 6 to 8 feet in width.” Mecklenburg County. The magnetic and specular ores, which occur in Granville county, North Carolina, are reported to extend northeastward into Mecklenburg county, Virginia. Amherst County. Elk creek charcoal furnace was operated in the eastern corner of this county in the first half of the 19th century on local magnetic and limonite ores. About 1880 these ores, particularly the magnetite and specular hematite, were zealously exploited. Near Elk creek furnace a 3-foot thick- ness of specular ore was prospected, which, according to the Tenth Census report, carried: Per cent. Metallic iron ................ 38.42 Phosphorus ...........-...6. 0.118 Within a mile of this limonite ore was mined which, according to the Tenth Census report, carried: Per cent. Metallic iron ................ 44.54 Phosphorus ................5 0.85 Riverville mines.—These mines, located within 2 miles of Riverville west and north, consisted of a number of operations in specular and magnetic ore, which lay in beds in widths up to 16 feet, dipping at high angles, and were associated with quartzite and mica shist. Mining was carried to a depth of about 100 feet. No. 1014, sampled across a breast of 16 feet, gave the Tenth Census analyst: Per cent. Metallic iron........ ae ane 8s 40.51 Phosphorus ................. 0.095 IRON. 471 No. 11 of Adams, Scott & Co., with a thickness of 4 feet, gave the Tenth Census analyst: Per cent. Metallic iron ................ 39.75 Phosphorus ........e0.eeeeee 0.126 No. 11 of the Dover Company, with a thickness of 3 feet, gave the ‘Tenth Census analyst: Per cent. Metallic iron ................ 48.47 Tnsoluble> sitacainn susgae gases & 28.53 Phosphorus ...........06.05. 0.10 SHIPRUE we sace ees casas 0.35 Maud vein—Near Stapleton the Maud vein, a mine similar to the tiverville mines, worked for a distance of 900 feet and to a depth of 80 feet with a width of 3 feet, gave the Tenth Census analyst: Per cent. Metallic iron ................ 49.89 Phosphorus ................. 0.139 Appomattox County. Appomattox had a number of ancient charcoal furnaces which were located in the northwestern part of the county near the James river. Of these the Stonewall was one of the more recently operated. These furnaces used chiefly the limonite ores of the region. It is not known that these ores have been operated in recent times. They were prospected at the time of the boom in the James river region in the early 80s. Campbell County. The Ross furnace, located 2 miles south of the present James river bridge, is one of the oldest furnaces in the region. In 1781 Jefferson reports that it was making 1,600 tons of pig iron annually. Under the name of Oxford furnace it was operated in Civil War time. Its chief bank is located a few hundred yards northeast of the furnace site. The mine was a deep open cut located on top of one of the higher elevations of the region. The ore is limonite. At present fine manganese ore is being mined in quantity on the strike of the old iron ore-body and only a couple hundred yards distant. It is reported that ore was shipped from Lawyers in the 80s. Bedford County. While Bedford county is a Piedmont county, a small corner of the county extends into the Blue Ridge and it carries an important develop- ment of the Blue Ridge hematite ore. From the Botetourt county line 472 MINERAL RESOURCES OF VIRGINIA. northeastward for a distance of some 2 or more miles this ore has been worked on the southeast slope of the Blue Ridge. Most of the operations have been small excavations on the outcrop of the bed. Present mining consists of extensive underground operations in which the bed has been entered at the more favorable points where ravines cut it. Ironville mine.—This mine, located 144 mile north from Ironville, was first opened in 1879. It has been operated at various times since. Present workings extend several hundred feet on the strike and through 200 feet on the nearly vertical dip of the bed. The ore is hauled in wagons to Tronville. The composition of the ore, as furnished by the Virginia Iron, Coal and Coke Company, is as follows: Natural State. Per cent. Metallic: 1f00. sa54 soseenedwn ae 34.66 SU ICaly ah. saartectir nsevartetnianoesgccten a8) is 39.06 Phosphorus ................. 0.39 Manganese ...............06. 0.15 Dewey mine—This mine was opened more recently than the Ironville but has been more extensively worked. It is located immediately north- east of the Ironville mine and the underground workings of the two mines are said to connect. The main workings now operated are drifts on the nearly vertical bed for a distance, said to be 1,500 feet, through 6 or 7 levels nearly up to the original outcrop workings. The ore bed is said to vary in thickness from 3 to 12 feet. Recently at two places at this mine operations have been started in sinking on the bed below water level. The ore-body has been somewhat folded and in places is said to be shifted a few feet by faulting. A narrow-gauge railway some 3 miles long con- nects the mine with the tipple near Montvale. The composition of the ore, as furnished by the operators, the Virginia Iron, Coal and Coke Company, is as follows: Natural State. Per cent. Metallic iron ................ 36.90 Silica: ascckrasavsnemeumninweesen 34.85 Phosphorus ................. 0.28 Manganese ............-.04.. 0.23 Pittsylvania County. Pittsville mine-——An important deposit of magnetic iron ore occurs near Pittsville in the northwestern part of the county. This ore was first mined about 1880 by the Pig River Mining Company, which is MINE LAL RESOURCES OF VIRGINIA. PLATE LXX. e Po? er Fig. 1—Shaft house of the Barr magnetite mine, near Pittsville, Pittsyl- vania county. Fig. 2.—Barr limonite mine, near Pittsville, Pittsylvania county. IRON MINES, PITTSYLVANIA COUNTY, VIRGINIA. IRON. 473 reported to have mined 90,000 tons. The ore is fine-grained to massive magnetite. The lead is quite variable in both strike and dip. It has been mined for a half mile of its length. These workings are reported to have an average width of about 3 feet and were mined to a depth of 150 feet. A sample taken across the face of the lead and analyzed for the Tenth Census gave as follows: Natural State. Per cent. Metallic iron .............6.. 59.83 Phosphorus ..............-6. 0.09 Barr Magnetite mine—J. H. C. Barr has mined the extension of the lead of the Pittsville mine since 1896. ‘The lead here lies between walls Fig. 69.—Section in the Barr magnetite mine, showing relation of the ore to the adjacent formations. (a) Mica schist. (6) Magnetite. (c) Umber- bearing clay. (d) Space. (¢) Crystalline lime- stone. of quartz schist and crystalline limestone. (Figure 69.) The lead here has considerably greater widths than is reported for the Pittsville mine and has been worked to a somewhat greater depth. A view of the shaft house at this mine is shown on plate LXX, figure 1. The composition of the ore, as given by the operator, is as follows: Per cent. Metallic iron................ 64.25 TCR. A536 wis mia cana acces oe 4.52 Phosphorus ............5.06, 0.008 Barr Limonite mine——Two miles from the Barr magnetite mine the same operator is mining limonite ore. It is washed in a local washer and 474 MINERAL RESOURCES OF VIRGINIA. delivered over a narrow-gauge railway to Pittsville. Massive outcrops of limonite occur along the crest and slopes of a ridge for half a mile. Where mined the ore is massive or as closely spaced stringers in clay. A view of this mine is shown on plate LXX, figure 2. The composition of the ore, 2s furnished by the operator, is as follows: Per cent. Metallic iron ................ 47.00 Silica: asi: esaccgavesrederiaxs 12.25 Phosphorus .............6... 0.85 Manganese cisicesccnawc cewiee val 2.70 Franklin County. Gossan was mined in this county near the Floyd county line a few miles northeast of the Toncray mine for an early local furnace. Magnetic ores of importance occur in this county. H. B. C. Nitze traced the mag- netic lead from Rocky Mount, Franklin county, southwestward 24 miles to Stewart’s Knob in Patrick county. Rocky Mount mine——The ore at Rocky Mount was mined at an early date for the Saunders’ furnace. In 1880 these ores were mined by the Pig River Mining Company and shipped to Pennsylvania. The ore is a fine-grained pure magnetite with walls of dense hornblende schist dipping 60° southwest. A sample taken at a depth of 20 feet across the 9-foot working face of the mine for the Tenth Census gave as follows: Natural State. Per cent Metallic iron ................ 53.59 DULICA,. Ga Batted janeurd sree tie Roa. 14.67 Phosphorus ............ --. 0.018 Manganese: cess seueres ae ee tien 0.12 Titanie oxide none PUMP BUR 5c nudes Goals thers Bit beens 0.36 Patrick County. A part of the magnetic lead which extends southwest through Franklin county is found in Patrick. Ore was mined at the Hairston mine for the Union furnace. Hairston mine.—This mine is located at Stewart’s Knob in the north- western part of the county. In 1906 a narrow-gauge railway was con- structed from Philpot to the mines a distance of 12 miles for the purpose of furnishing an outlet for these ores. The ore is magnetite, similar to that at Rocky Mount, and occurs in a number of leads which are from 3 to 6 feet wide and associated with hornblende schist. It is operated by IRON. 475 the Virginia Ore and Lumber Company. An average of 10 analyses, made by Mr. W. W. Davis from samples taken by him for a private report, shows as follows: Natural State. Per cent. Metallic iron. .. 59.93 Silica ....... 7.72 Phosphorus .... see. 0.08 Manganese ..... 0.17 Sulphur csseecsancdeareweees 0.19 Henry County. Nitze says that the magnetic ores which occur near Danbury, Stokes county, North Carolina, extend into Henry county, Virginia. Floyd County. Toncray mine——Gossan was mined in the southwestern part of this county on the West Fork of Little river at the Toncray mine for the Shelor’s and West Fork furnaces. In the northeastern part of the county pyrrhotite and pyrite occur which are reported to carry nickel in minable percentages. (See pages 580-582 for a further account of this sulphide.) The county is without a railway and there have been no modern iron ore operations. Carroll County. This county contains the greatest development of the “gossan lead.” Gossan ore was mined for two or more forges on Chestnut creek. At two points: in this county the “lead” has been crossed by a railway and gossan has been extensively mined at both places. Chestnut Yard mines—At Chestnut Yard the gossan has been mined out for several miles along the lead. At the “Great Outburst,” which is a part of the Chestnut Yard operations, the lead from which the gossan has been removed is 175 feet wide. At this point pyrrhotite ore, “mundic,” is now being mined for the acid plant at Pulaski by the Pulaski Mining Company. Plate XXX is an illustration of this mine. An analysis of “mundic” from the “Great Outburst,” furnished by the New River Mineral Company, is as follows: Per cent. Metallic iron ................ 57.26 TriSOUBIE! 2.055 sieieie, dered seed ane oe ove 3.68 Sulphur ..ccsurcs econ nw rcs eos 38.61 Copper: saeas see os ee ea saw oes 0.82 4°%6 MINERAL RESOURCES OF VIRGINIA. After this sample was burned as completely as possible over a blast lamp it gave as follows: Per cent. Metallic iron............+... 60.40 Sulphur acnexvevseegs wheke cas 1.64 Betty Baker mine—At Betty Baker mine the gossan was mined between 1889 and 1902 for a mile along the lead where it had a width of from 10 to 30 feet. The composition of the ore, as given by the operators, the Virginia Iron, Coal and Coke Company, is as follows: Natural State. Per cent. Metallic iron ............0005 36.15 Silica: socks cen fase a ae ned 16.36 Phosphorus ...........20.00- 0.12 Manganese .........-.++.000 1.40 Magnetic ores are reported in this county, but the writer has no knowledge that they have been worked. Grayson County. Gossan ore was mined in this county for the Pine Hope furnace, located 3 miles southeast from Independence. Scattered outcrops of the northern “gossan lead” are said to occur in this county westward from Chestnut Yard. Magnetic ore is known in this county. It is reported that such ore was mined near Independence for the Pine Hope forge. Near Fries magnetic ore has been prospected and it is reported that some was used in the Chestnut forge. Magnetite ore is reported near the Mouth of Wilson on the State line. A sample from the Pugh prospect a half mile south of the State line gave on analysis the following results, re- ported by Nitze: Per cent. Metallic iron................ 45.44 Siliea). tay is crete ewan awed ae 22.74 Phosphorus ..........+00e00- 0.022 PW POUE s cick raencisiaalosmie east 0.049 Near the point where Little Helton creek crosses the State line titan- iferous magnetite has been prospected with a good showing. A sample from the 25-foot Young outcrop a quarter of a mile south of the State line gave an analysis, reported by Nitze, as follows: 2 Per cent. Metallic iron ................ 50.77 SICH seccewuge sea ceesenaeeae 5.12 Phosphorus ........6.-..005. 0.005 Sulphur’ caccnaseearsoemn sna sacnca 0.04 Titanice. ONIdCi 2a sss sea dower ee 4.95 IRON. ard A titaniferous magnetite in a hornblende schist is reported in the south- east corner of the county. This ore was worked about 1886 just south of the State line for the Collins forge. An analysis of this ore, as given by Nitze, is as follows: Per cent. Metallic iron ................ 54.72 SHica), -ccnk eet aesacame peices 6.20 Phosphorus ............-055- 0.047 Sulphur -s.c.6- wee. sega 0.038 Titanic oxide................ 4.86 COASTAL PLAIN COUNTIES. These counties in Virginia have not been producers of commercial iron, ore. In 1609 the colonists mined some ore which was taken to England and there made 16 tons of metal. The iron works at Falling Creek, in the present Chesterfield county, which were built between 1619 and 1622, were to run on local ores. These works were destroyed by the Indians in 1622. Since that time it is not known that there has been any iron mining in these counties. In both North Carolina and Maryland iron ore has been mined from strata similar to those which constitute the Virginia Coastal Plain. In Maryland the ore is carbonate which occurs in lumps scattered through clay in layers, and has been extensively mined. List of Iron Mines in Virginia. In the list appended below are included those mines that are now pro- ducing or have produced in the last two years, or have been recently pros- pected and will probably shortly become producers. Name of mine. County. Kind of ore. Operator. Big Ike Warren Blue Ridge limonite F. G. Grove Happy Creek Warren Blue Ridge limonite H. J. Seibel, Jr. Liberty Shenandoah Oriskany Shenandoah Iron and Coal Co. Rileyville Page Blue Ridge limonite Black Rock Augusta Blue Ridge limonite The Vesuvius Mining Co. Bare Bank Augusta Blue Ridge limonite Crozier Augusta Blue Ridge .limonite Buena Vista Rockbridge Blue Ridge limonite Buena Vista Iron Co. Dixie Rockbridge Blue Ridge limonite Alleghany Ore and Iron Co. Rumsey Alleghany Oriskany Low Moor Iron Co. Dolly Ann Alleghany Oriskany Low Moor Iron Co. Longdale Alleghany Oriskany Longdale Iron Co. Fancy Hill Alleghany Oriskany Longdale Iron Co. Stack Alleghany Oriskany Low Moor Iron Co. Horse Mt. Alleghany Fossil Low Moor Iron Co. Rich Patch Alleghany Oriskany The Goshen Iron Co. Bess Alleghany Oriskany Low Moor Iron Co. Double Ridge Alleghany Oriskany Low Moor Iron Co. Sand Bank Botetourt Oriskany Princess Iron Co. Callie Botetourt Oriskany Princess Furnace Co. Wilton Botetourt Oriskany Princess Furnace Co. 478 MINERAL RESOURCES OF VIRGINIA. Name of mine. County. Circle Botetourt Oriskany Botetourt Grubb Botetourt Grubb Specular Botetourt Edith Botetourt Arcadia Botetourt Wood Botetourt Fenwick Botetourt Rorer Roanoke Porterfield Giles Tasker Pulaski Farris Pulaski Rich Hill Pulaski Reed Island Pulaski Clayton Pulaski Peak Knob Pulaski Barren Springs Wythe Bertha Wythe Cedar Run Wythe Sanders Wythe Morris Wythe Hurst Wythe Patterson Wythe Crawford Wythe Tipton Wythe Foster Falls Wythe Hematite Wythe Posey Wythe Poplar Camp Wythe Ivanhoe Wythe Little Wythe Wythe Norma Wythe Ganaway Wythe Percival Wythe Andis Wythe Clark Summit Wythe Locust Hill Wythe Slemp Creek Smyth Holston Washington Taylor’s Valley Washington Hall Russell Oreton Wise Keystone Wise Irondale Wise Yeary Wise Lavine Lee Ben Hur Lee Truro Lee Noes Lee Grabill Lee Boones Path Lee Ewing Lee Chestnut Yard Carroll Hairston Patrick Barr Pittsylvania Barr Pittsylvania Tronville Bedford Dewey Bedford Kind of ore. Oriskany Oriskany Blue Ridge limonite Blue Ridge hematite Blue Ridge hematite Blue Ridge hematite Blue Ridge hematite Oriskany Blue Ridge limonite Limestone magnetite “Mountain ore” “Mountain ore” Limestone limonite Limestone limonite Oriskany Oriskany Limestone limonite Limestone limonite Limestone limonite Limestone limonite “Mountain ore” “Mountain ore” Limestone limonite Limestone limonite “Mountain ore” “Mountain ore” Limestone limonite Limestone limonite “Mountain ore” Limestone limonite Limestone limonite “Mountain ore” Limestone limonite Limestone limonite Limestone limonite “Mountain ore” Oriskany “Mountain ore” Magnetite “Mountain ore” Limestone limonite Fossil Fossil Fossil Fossil Fossil Fossil Fossil Fossil Fossil Fossil Fossil Pyrrhotite Magnetite Magnetite Limonite Blue Ridge hematite Blue Ridge hematite Operator. Longdale Iron Co. Alleghany Ore and Iron Co. Virginia Iron, Coal & Coke Co. Virginia Iron, Coal & Coke Co. Virginia Iron, Coal & Coke Co. Pulaski Iron Co. G. G. Harvey Low Moor Iron Co. Virginia. Iron, Coal & Coke Co. West End Furnace Co. Pulaski Iron Co. Virginia Iron, Coal & Coke Co. Virginia. Iron, Coal & Coke Co. Pulaski Iron Co. § Hatcher and Shaffer [Hagar and Mahady Virginia Iron, Coal & Coke Co. Pulaski Iron Co. Virginia [ron, Coal & Coke Co. Virginia Iron, Coal & Coke Co. Virginia Iron, Coal & Coke Co. Virginia Iron, Coal & Coke Co. Pulaski Iron Co. Virginia Iron, Coal & Coke Co. Pulaski Iron Co. Virginia Iron, Coal & Coke Co. Virginia Iron, Coal & Coke Co. Virginia Iron, Coal & Coke Co. Pulaski Iron Co. Ivanhoe Furnace Co. Virginia Iron, Coal & Coke Co. Pulaski Iron Co. Virginia Iron, Coal & Coke Co. Virginia Iron, Coal & Coke Co. Virginia Iron, Coal & Coke Co. J. M. Spriggs Virginia Iron, Coal & Coke Co. Ivanhoe Furnace Co. Taylor’s Valley Iron Co. M. A. Hall Kelley and Irvine Keystone Coal and Iron Co. Kelley and Irvine W. E. Yeary Kelley & Irvine Virginia Iron, Coal & Coke Co. Virginia Iron, Coal & Coke Co. Kelley and Irvine B. C. Grabill Boones Path Iron Co. Union Iron and Steel Co. Pulaski Mining Co. Virginia Ore and Lumber Co. J. H. C. Barr J. H. C. Barr Virginia Iron, Coal & Coke Co. Virginia Iron, Coal & Coke Co. IRON. 479 List of Furnaces in Virginia. Annual capy. Name. Place. County. in tons. Operator. Coke Furnaces. Alleghany Iron Gate Alleghany 30,000 Alleghany Ore and Iron Co. Bristol Bristol Washington 50,000 Virginia Iron, Coal & Coke Co. Buena Vista Buena Vista Rockbridge 654.000 Alleghany Ore and Iron Co. Crozier No. 1 Roanoke Roanoke 100.000 Virginia Iron, Coal & Coke Co. Crozier No.2 Roanoke Roanoke ; Virginia Iron, Coal & Coke Co. Dora Pulaski Pulaski 50,000 Virginia Iron, Coal & Coke Co. Gem Shenandoah Page 36,000 Alleghany Ore and Iron Co. Graham Graham Tazewell 40,000 Virginia Iron, Coal & Coke Co. Ivanhoe Ivanhoe Wythe 25,000 Ivanhoe Furnace Co. Longdale No. 1 Longdale Alleghany} 49 999 +The Longdale Iron Co. Longdale No. 2 Longdale Alleghany 2 Low Moor Iron Co. Low Moor A. Low Moor Alleghany Low Moor B. Low Moor Alleghany § 100,000 Low Broce Lron-C6: Low Moor Iron Co. Covington Covington Alleghany Max Meadows Max Meadows Wythe 60,000 Virginia Iron, Coal & Coke Co. Princess Glen Wilton Botetourt 15,000 Princess Furnace Co. Pulaski Pulaski Pulaski 55,000 Pulaski Iron Co. Radford Radford Furnace Pulaski 4,000 Richard Wood Radford-Crane Radford Montgomery 50,000 Virginia Iron, Coal & Coke Co. Union No.1 Big Stone Gap Wise 50,000 Union Iron and Steel Co. Victoria Goshen Rockbridge 50,000 The Goshen Iron Co. West End Roanoke Roanoke 48,000 West End Furnace Co. Charcoal Furnaces. Foster Falls Foster Falls Wythe 3,000 Virginia Iron, Coal & Coke Co. Liberty Liberty Furnace Shenandoah 25,000 Shenandoah Iron and Coal Co. Reed Is. Boom Reed Island Pulaski 3,000 Virginia Iron, Coal & Coke Co. White Rock Rural Retreat Smyth 2,500 Lobdell Carwheel Co. Electric Furnaces. Holeomb Rock Holcomb Rock Bedford 2 furnaces Willson Aluminum Co. Total number of blast furnaces 26, of which 22 are coke and 4 are charcoal. These furnaces produced in 1906, 483,525 long tons of pig iron. Methods of Mining. Iron ore occurs in Virginia in a variety of different ways. These different modes of occurrence demand different methods in mining. The chief methods in open cut mines are steam shovel mining, milling, sluicing, hydraulicing, and pick-and-shovel mining. The steam shovel is extensively used in mining limonite ore in Vir- ginia. It is most used in the New River-Cripple Creek district, but also used on the Blue Ridge and Oriskany ores. In the first mentioned district where it is necessary to move large quantities of lean clay the steam shovel is particularly adapted. This method is not used to advantage where the clay is thin, where there are many limestone horses in the ore, or where the ore-bodies are scattered. In the Oriskany district much ore lies covered by not more than 20 feet of soft rock. This overburden is removed 480 MINERAL RESOURCES OF VIRGINIA. by steam shovel and then the ore itself lifted by the same means. Here the more solid ore requires blasting before the shovel can move it. The shovels are mounted on broad- or narrow-gauge railway trucks and deliver to cars operated on a parallel track. Plate LXIV, figure 1, and plate LXVII, figure 2, illustrate the use of the steam shovel in mining. Milling is shown in plate LXVIII, figures 1 and 2, and in figures 70, 71, and 72 below. The process consists essentially of caving the material of the bank directly to cars. The material of the bank is loosened by hand with the pick and allowed to roll down the steep slope to the cars. The cars are placed in position to receive the material by head- ing them into tunnels. Com- monly the tunnels are short, merely long enough to receive é one or two cars, and the ore WA; is milled down the outer slope. Za The tunnel may be longer and TP Pi pipe? then a shaft is driven from ; ; nis f “ above to meet the end of the mg ee ee of iron tunnel and the ore milled down the shaft. This latter method is not much used, as it involves extra work in handling cars. Milling is a cheap method of mining and is extensively used in the New River-Cripple Creek region. It is serviceable where the minable material is of sufficient thickness and where the overburden is not too great. It can be used in confined situations where a steam shovel cannot. Sluicing is a method of mining in which the material of the bank is loosened usually by hand with a pick and allowed to roll down a slope the same as in milling. The water is pumped through 6-inch or larger iron pipes to the summit of the mine. It is allowed to pour through dirt ditches to the point at which it receives its load and from there conducted in iron troughs to the washer. This method of mining is used in the New River-Cripple Creek region. It is usable in mining ore-bearing clays where there is a slope of one to eight between the mine and the washer and where water is available. It can be used in more confined situations than either the steam shovel or milling and has the advantage over these methods that the material arrives at the washer in excellent condition for washing. IRON. 481 Hydraulicing is the method of mining in which a stream of water from a nozzle is directed against the bank with sufficient force to tear down the bank. The broken down material is carried by the spent water through sluice troughs to the washer. The water is pumped to the mine the same as in sluicing, while at the mine a second pump forces the water through 4 Y, Ly V7. 7 Fig. 71.—Diagram illustrating milling of iron ore (first stage). ei Za (iwi | AO Te Wid Fig. 72.—Diagram illustrating milling of iron ore. Represents a later stage than Fig. 71. the nozzle. This method is used in several mines in the New River- Cripple Creek region. It is usable under conditions similar to those required by sluicing but is not as usable in such confined situations. Plate LXIX, figures 1 and 2, illustrate this method of mining. Pick-and-shovel mining of ore-bearing clay is expensive and is used only as a last resort. It finds its chief application in rich, shallow deposits 482 MINERAL RESOURCES OF VIRGINIA. where other methods are not available. It is also used in confined situa- tions on the richer portions of deposits which have been mined mainly by the cheaper methods. Pick-and-shovel mining in rich lump ore and in solid ore is not so expensive and is much used. For lump ore it is used in prospects where the quantity of wash ore is doubtful, in mines which have been abandoned as not producing sufficient wash ore to maintain a washer, and in deposits which contain both lump and wash ore but contain too little of the latter to maintain a washer. In these cases the lump ore is separated from the clay and fine ore by screening with a wire screen of about one inch mesh. Surface occurrences of solid ore are much mined by pick-and-shovel. This applies to massive limonites, gossan, and to the outcrop of fossil and Blue Ridge hematite. All of these are so solid that drilling and blasting are required. Underground mining has to deal almost entirely with massive ore. Ore-bearing clays such as are mined by open cut methods in the New River-Cripple Creek region will not bear the expense of underground mining. Many of the deep-seated limonites have associated clay, but the limonite usually constitutes more than one-half of the material mined. ‘The methods used in mining these ores vary with the character of the ore, with the shape, size, and attitude of the deposit, and with the character of the enclosing rock. The Valley limonites are rarely mined underground. The limonites of the Blue Ridge are mined underground to some extent. As these deposits are of irregular shape and extent, systematic methods are not readily applied to the mining of them. They are mined in shaft and tunnel in the method best adapted to the individual deposit. The Oriskany ore, in general, has a fairly constant thickness and attitude in any given mine and can be mined systematically. Most of the ore-bodies so far mined dip at high angles. In mining such deposits several parallel horizontal tunnels are usually run one above the other along the strike of the deposit in the ore. The lower tunnel is used: as a main car level and serves for most of the lateral transportation of the ore. The upper tunnel is located near the upper limit of the ore. Most of the ore is mined near the top of the ore-body in robbing rooms which are 10 to 12 feet high. As the ore is removed timbers are set so as to support the debris above. When a room of sufficient size has been created, timbers are laid horizontally on the floor of the room and covered with smaller cross timbers. When the vertical supports are broken by blasting, the debris from above sinks to the floor and the horizontal timbers, previously placed, are in position to serve as caps for the supports in the room which is to IRON. 483 be excavated underneath. The ore as mined is thrown down shoots to a car level. The car levels usually extend horizontally to the surface but in greater depths ore may be lifted in a vertical shaft. Figure 73 illus- trates this method. Most of the limonites are so solid as to require constant drilling and blasting. Several mines are equipped with air drills. In many of the mines the natural circulation of the air in the mine is sufficient for ventilation but in the more extensive and complex mines a forced circulation is produced by means of fans. The outcrop of the hematite of the Blue Ridge has such abrupt and continuous changes of elevation that it is mined to a considerable depth as a surface working. At greater depths methods similar to those used in the Oriskany ores are used. The problem here is however much simpler. The ore-body is usually nearly vertical with good walls of com- pact shale or strong sandstone. Comparatively little timbering is necessary 484 MINERAL RESOURCES OF VIRGINIA. and it is not necessary to support the debris from above. In the fossil hematite the ore-beds may be flat-lying or dipping at angles up to nearly vertical. These beds are mined in thicknesses varying from 16 inches up to 4 feet. The thinness of the beds makes mining a more difficult problem than the mining of the Blue Ridge hematite. The similarity of these beds to coal beds makes the methods of coal mining applicable to the mining of this ore. The room-and-pillar method is generally used. The methods vary considerably with the dip of the strata. With a dip of a few degrees and a relatively light overweight, parallel entries are driven in the ore about 45 feet apart and wide enough for the small entry cars. From these entries 16-foot wide rooms are turned off at right angles to = ty ZL, LMM LLL LLL / SI) Fig. 74.—Diagram illustrating method of mining in steeply dipping beds of fossil iron ore. the entries leaving 40-foot square pillars. When the entries have been extended as far as desired the pillars are robbed beginning at the inner end. Where the size of the pillars is properly adjusted to the overweight, the back edge of the pillar will be crushed by the overweight and render blasting unnecessary. Figure 74 illustrates this method. Where the ore bed is dipping at a high angle, a car level is run in the ore nearly on the horizontal. From this stopes are turned off about 34 feet apart, a few feet wide below but widening above to 30 feet and leaving between adjacent stopes 4-foot pillars. Ore is won chiefly by blasting from the upper end of the stopes. This delivers ore to the car below without further handling. When the stope has reached upwards not more than 100 feet the 4-foot pillars are robbed back. Figure 75 illustrates this method. In these steeply dipping beds the ore is easier mined than in the flat-lying beds IRON. 485 and can be mined in smaller thicknesses. In the flat-lying beds the cheap ore is won from the pillars, while in the steeply dipping beds the cheap ore is won from the stopes. Most fossil hematite contains some portion of the bed which is so soft that it can be bored with some hand-power auger drill. (LL ZZ, VA. Cana Fig. 75.—Diagram illustrating method of mining in flat-lying beds of fossil iron ore. Ore Dressing. Most iron oreg mined in America are sent to the furnace as mined. As most of the Virginia iron ores are limonite, and as most of this occurs associated with clay it requires treatment before it can go to the furnace. In the limestone limonites the limonite constitutes from 3 to 25 per cent. of the total material of the bank. It is, then, obviously necessary to handle from 4 to 30 tons of material to get one ton of ore. In the Oriskany ore the limonite usually constitutes over half of the material mined. In the Blue Ridge limonites the limonite usually constitutes a smaller per cent. of the material mined than in the Oriskany ores. Some 486 MINERAL RESOURCES OF VIRGINIA. limonite ores have associated with them also in addition to the clay, silica in the form of flint, chert, quartz sand, or quartz crystals. To remove the clay, log washers are used. A log washer consists essentially of an axis mounted in a gently sloping trough and having arms spirally arranged about the axis. The logs are usually mounted in pairs and revolve in opposite directions. The material to be washed is delivered to the logs from above well down toward the lower end while a stream of water enters at the upper end. The revolving logs agitate the material and deliver the ore to the upper end while the water carries the clay in suspen- sion out at the lower end. Where the material washed contains sand, gravel, or flint this material is delivered with the ore. Sand is removed from the ore by a revolving screen, mounted so as to receive the heads from the washer. Where there is much coarse flint or mud balls, the sand screens are made to discharge to picking belts, tables, or inclined troughs where this cbjectionable material is removed by hand. Where there is considerable tine flint or gravel which is removed neither by the sand screen nor by hand picking, jigs are used. The separation by the jig depends on the different specific gravities of the ore and the objectionable material. In the process of jigging the sized material is delivered to screens where it is acted on from below by pulsing water which carries off the lighter material at a higher elevation than that at which the heavier ore is discharged. Jigging is a relatively slow and expensive process compared with washing. lt is not used at most of the washers in Virginia. In charcoal furnace days the limonite was usually roasted before it was sent to the furnace. The roasting was commonly done in open heaps which were formed of alternate layers of waste charcoal and ore. Rarely special kilns were used in which to roast the ore. In modern practice the ores are not roasted either for coke or charcoal furnaces. Uses. Iron ore is used chiefly for the manufacture of the metal iron. This use consumes all but a small quantity of the iron ore mined. Used for this purpose, the blast furnace produces pig iron from the ore. Of the pig iron thus produced in the United States in 1904, 84 per cent. was converted into steel. Iron ore is also used for paint, for fix or fettling in puddling furnaces and as flux in smelting the precious metals. 487 IRON. Production. Tron Ore. Pig Iron. Amount. Value. Td 5 22 7 Per ton at Z a 2 7 3 Ss Kinds. the mines. ‘sg 3 |Be gi ie aS ih 3 g Sig = (sl a & ae 3 |Se8 ae g lx ae 2 = mount. Ss Year| 3 a oe Total. 3 S g Total. é ze £ \535 a |Pe 3 He Pa o ogs ~~ a) : a oS mo Saige a [=e | 8 | 4 = | o er wo a Si 4 o qu eaEEE | geal e |e 5 | 2 BE 2% |S8 2 jg5s) 3g | 3 ele Ze 1810 6,931 | ...... 1840 18,810 | $32.75 1850 22,163 | 20.88 1860 9,096 | 22.75 1870 *17,233 | 33.25 1872 *21,445 | 48.88 1873 *26,475 | 42.75 1874 *29,451] 30.25 1875 *29,985 | 25 50 1876 *13,046 | 22.95 1877 *12,484 | 18.85 1878 *16,928 | 17.63 1879 *18,873 | 21.50 1880 *29,934 | 28.50 1881 *83,711| 25.12 1882 *87,731 | 25.75 1883 *152,907,| 22.38 1884 *157,453 | 19.88 1885 *163,782 | 18.00 1886 *156,250 | 18.71 1887 *175,715 | 20.92 1888 *197,396 | 18.88 1889 7 8.4 | 498,154 8,746 483,208 | 6,200| 935,290} 1.93; 2.30] *251,356| 17.75 1890 7 3.4 | 543,583 16,212 522,908 | 4,463/.........]/..... Je... *327,912 | 18.40 1891 6 4.5 | 558,916 3,274 653,342 | 2,300).........|..... |... *330,727 | 17.52 1892 7 4.5 | 741,027 26,120 711,753 | 3,154] 1,428,801] 1.91] 2.04] 342.847) 15.75 1893 5 5.3 | (616,965 | 41,665 568,800 | 6,500) 1,050,977) 1.70} 1.66] 302,856| 14.52 1894 |...... 5.1 | 600,562} 35,843 562,493 | 2,226) 873,305; 1.45} 1.14] 298,086/ 12.66 1895 5 4.5 | 712,241 36,815 674,926 500| 987,077; 1.39} 1.14) 346,589] 13.10 1896 4 5.4 | 859,466 31,271 828,195 |...... 1,220,619) 1.42) 1.42) 386,277] 12.95 1897 5 4.1 | 711,128 13,570 697,558 |...... 974,031} 1.37] 1.08) 307,610} 12.10 1898 6 2.9 | 557,713 2,963 554,750 |...... 1,226,290) 2.20) 1.14) 283,274] 11.66 1899 5 4.0 | $986,476 | 17,178 968,143 | 1,160) 1,766,410} 1.79) 1.42] 365,491] 19.36 1900 4 3.3 | $921,821 3,664 918,157 |...... 1,489,318} 1.62) 2.42) 490,617] 19.98 1901 5 3.2 | $925,394 13,156 910,214 | 2,024) 1,466,423) 1.58) 1.71) 448,662) 15.87 1902 4 2.8 | $987,958 31,677 953,128 | 3,153] 1,667,456) 1.69] 1.84] 537,216| 22.19 1903 5 2.3 | 1801,161 31,609 764,948 | 4,604) 1,432,624) 1.79} 1.89) 544,034] 19.92 1904 5 2.0 | $550,258 17,952 528,853 | 3,448) 951,478) 1.73) 1.56] 310,526| 15.57 1905] ..... 1.8 | 752,045 | 35,357 711,170 | 8,518] 1,276,003} 1.70} 1.77| 510,210] ...... 1906) «serieal| eececa wey aess bovis esareratlly “cou esbyal| cdia.a eceaso lela: gatey | wr gs Boced- Vinieuatoee lke ered 483,525 | ...... *Short tons, all others are long tons. fIncludes a small amount produced by West Virginia. 488 MINERAL RESOURCES OF VIRGINIA. The preceding table of production and value of iron ore and pig iron in Virginia is compiled from the publications of the U. 8. Geological Survey, from the U. 8. Census Report and from the Reports of the American Iron and Steel Association. From this table it can be seen that the ratio of the pig iron production to the iron ore production has not been a constant one. This is due to the fact that there has been both exportation and im- portation of iron ore. Prior to 1880 there was little transportation of iron ores to or from the State or even within the State. For the most part each furnace smelted its own local ore. About 1880 there was considerable shipment of ore to West Virginia and Ohio furnaces, chiefly from the region about Clifton Forge. At this time also there was some shipment to Pennsyl- vania of Piedmont magnetite and of Blue Ridge linomite. In recent years there has been considerable importation of Lake Superior ores. There has been at various times some small importation of ores from adjoining states. At present there is gossan coming into the State from Tennessee and fossil ore being shipped out from Lee county. The large increase in production of iron ore about 1880 was nearly coincident with the first ex- tensive building of coke furnaces. The second rapid increase about 1890 was at the time of the second period of coke furnace building. Since 1900 the iron ore production of the State has added to the wealth of the State $1,500,000 annually, while the annual value of the pig iron pro- duced has been approximately $10,000,000. This State has had a constant and increasing production of iron ore for 180 years. The total value of the ore that has been produced in this time is estimated by the writer to be $36,000,000. References. Adams, W. H. The First Iron Blast Furnace in America. Trans- actions American Institute of Mining Engineers, 1892, XX, 196. The Site of the First Blast Furnace in America. Iron Age, April 13, 1893. Historical Notes Bearing upon the Works of the First Mining Engineering of the Colony. Transactions of the Association of Engineers of Virginia. Bishop, J. L. History of American Manufactures, Philadelphia, 1868, I, 702 pages. Boyd, C. R. Brock, R.A. Byrd, William. Campbell, J. L. Campbell, M. R. Catlett, Charles. Chance, H. M. Curry, Richard O. Darton, N. H. Dewey, F. P. Eckel, E. C. IRON. 489 Resources of Southwest Virginia. New York, 1881, 321 pages. The Ores of Cripple Creek, Virginia. Transactions American Institute of Mining Engineers, 1884, XII, 27. Manufacture of Iron in Virginia 1619-1776. The Vir- ginias, 1885, 133-134. A Progress to the Mines. Writings of Col. William Byrd. Also quoted in part in the Virginias, 1880, I, 59-60. Numerous articles. The Virginias, I-VI. Geologic Atlas of the United States. stillville Folio, No. 12. U. 8. Geological Survey, 1894. Geologic Atlas of the United States. Pocahontas Folio, No. 26. U. S. Geological Survey, 1896. Geologic Atlas of the United States. Tazewell Folio, No. 44. U.S. Geological Survey, 1898. Geologic Atlas of the United States. Bristol Folio, No. 59. U. 8S. Geological Survey, 1899. The Iron Ores of the Potsdam Formation in the Valley of Virginia. Engineering and Mining Journal, 1899, LXVIII, 157-158. The Donald Iron Mine, Virginia. Engineering and Mining Journal, 1900, LXX, 485. The Rich Patch Iron Tract, Virginia. Transactions American Institute of Mining Engineers, 1900. XXIX, 210-223. The Copper and Iron Region of the Floyd—Carroll— Grayson Plateau of the Blue Ridge in Virginia. The Virginias, 1880, I, 62-64, 69-71, 80-81, 95-96. Geologic Atlas of the United States. Staunton Folio, No. 14. U. 8. Geological Survey, 1894. Geologic Atlas of the United States. Monterey Folio, No. 61. U.S. Geological Survey, 1899. The Rich Hill Iron Ores. Transactions American Institute of Mining Engineers, 1882, X, 77-80. The Oriskany and Clinton Iron Ores of Virginia. U. 8. Geological Survey, Bulletin No. 285, 184-189, 1905. 490 Fontaine, Wm. M. Frazer, P., Jr. Holden, R. J. Hotchkiss, Jed. Hungerford, W. 8. Johnson, Guy R. Johnson, J. E., Jr. Lesley, J. Peter. Lyman, B. 8. Lyman, Benjamin. McCreath, A. 8S. McCreath, A. S. and d’Invilliers, E. V. McDonald, M. Moore, P. N. MINERAL RESOURCES OF VIRGINIA. Notes on the Sulphuret Deposits of Virginia. The Virginias, 1882, III, 154, 155. Notes on the Geology and Mineral Resources of the Blue Ridge. The Virginias, 1883 and 1884, IV and V. The Iron Ores of the Middle James River. Trans- actions American Institute of Mining Engineers, 1883, II, 201-216. The Brown Ores of the New River—Cripple Creek Dis- trict, Virginia. U. 8. Geological Survey, Bulletin No. 285, 190-193, 1905. Numerous Articles. The Virginias, I-VI, 1880-1885. Mining in Soft Ore Bodies at Low Moor. Trans- actions American Institute of Mining Engineers, 1889, XVII, 103. Methods of Working and Surveying the Mines of the Longdale Iron Company, Virginia. Transactions American Institute of Mining Engineers, 1892, XX, 96-107. Origin of the Oriskany Limonites. Engineering and Mining Journal, 1903, LX XVI, 231-282. Iron Manufactures Guide, New York, 1859, 772 pages. The Staleys Creek and Nicks Creek Iron Ore Region Near Marion, Smythe County, Va. Transactions American Philosophical Society, 1872, XV, 33-8. Geology of the Low Moor, Virginia, Iron Ores. Transactions American Institute of Mining Engi- neers, 1886, XIV, 801. The Mineral Wealth of Virginia. Harrisburg, Pa., 1884, 157 pages. Iron Ores of the Valley of Virginia. Transactions American Institute of Mining Engineers, 1884, XII, 17. Resources of the Upper Cumberland Valley, South- eastern Kentucky and Southwestern Virginia. Louisville, Ky., 1902, 152 pages. The New River—Cripple Creek Mineral Region. Har- risburg, Pa., 1887, 171 pages. Report of a Geological and Mineral Examination of a Portion of the James River Iron Belt. The Vir- ginias, 1880, I, 10-13. Report on the Iron Ores in the Vicinity of Cumberland Gap. Kentucky Geological Survey, 1878, IV, 241- 254. COPPER. 491 Nitze, H. B. C. Notes on some Magnetites of Southwestern Virginia and the Contiguous Territory of North Carolina. Transactions American Institute of Mining Mngi- neers, 1892, XX, 174-188. Tron Ores of North Carolina, North Carolina Geologi- cal Survey, Bulletin No. I, 18938, 239 pages. Pechin, EH. C. The Iron Ores at Buena Vista, Rockbridge County, Va. Engineering and Mining Journal, 1889, XLVIII, 92-93. The Iron Ores of Virginia and their Development. Transactions American Institute of Mining Engi- neers, 1891, XIX, 1016-1035. Virginia Oriskany Iron Ores. Engineering and Min- ing Journal, 1892, LIV, 150. The Oriskany Ores at Rich Patch Mines, Virginia. Engineering and Mining Journal, 1896, LXI, 113, 134; 159-160. Prime, Fred., Jr. The Magnetic Ores of Page Valley. The Virginias, 1883, LV, 38. Rogers, Wim. B. A Reprint of the Geology of the Virginias. New York, 1884, 832 pages. Ruffner, W. H. Report on the Landed Property of the Buena Vista Company, Philadelphia, Pa., 1889, 104 pages. Swank, J. M. Iron in All Ages. Philadelphia, Pa., 1894, 554 pages. II. COPPER. General Statement. The existence of copper ores in Virginia has been known since the early settlements in the State, and while many attempts have been made to mine the ores, resulting in the opening of many mines in each of the copper dis- tricts, not until recent years have they been, with one or two exceptions, produced in paying quantities. In his “A History of American Manufactures from 1608 to 1860,” Doctor J. Leander Bishop says on page 599 of Volume I: “Thirty hundred weight of copper ore with forty tons of Iron are mentioned by Anderson as having been received, . . . . . . . from Virginia in 1730. In Mecklenburg county, on the Roanoke, not very distant, a mine of copper which promised considerable gold was operated about seventy years ago on the lands of Solomon Draper.” 492 MINERAL RESOURCES OF VIRGINIA. Distribution of the Ores. The ores of copper have wide distribution over the State, although there are at present but few producing mines. Geographical distribution—The distribution of the principal copper deposits in Virginia is given on the accompanying map, figure 76. The known geographic areas of these ores in the State are: I. The Piedmont Region. (a) The Virgilina District, which includes Halifax county, Virginia, and Person and Granville counties, North Carolina. (b) The deposits near Keysville in Charlotte county; those near New Canton, Arvonia, and Dillwyn, in Buckingham county; and those on or near Southwest Mountain in Albemarle county. II. The Blue Ridge Region. Includes those deposits from near Front Royal southward, and embracing parts of Warren, Fauquier, Rappahannock, Madison, Page, and Greene counties. III. The Southwest Virginia Region. Includes the “Gossan Lead” of the Floyd-Carroll-Grayson counties plateau. IV. The Triassic Areas. Includes the deposits near Leesburg and Drakeville, in Loudoun and Culpeper counties. Geological distribution.—The copper ores are confined, geologically, to the crystalline rocks, either the schists or the massive igneous rocks, of the Piedmont and Blue Ridge regions, and to the red shale—sandstone series of the Triassic areas. The ores in the Virgilina district and a part of those to the northeast, near Keysville, in Charlotte county, occur in quartz fissure veins, which intersect masses of altered volcanic rock (meta-andesite) of pre-Cambrian age. Those of the Blue Ridge region of northern Virginia are disseminated through and segregated in, basaltic flows of pre-Cambrian age, designated by Keith as Catoctin schist. The “Gossan Lead” of the Floyd-Carroll-Grayson plateau, in southwest Virginia, is apparently a mineralized faulted zone in crystalline schists of doubtful age, probably pre-Cambrian in part. The rocks are in part altered sediments and in part igneous masses of basic and acid types, principally the former. 493 COPPER. (fe Wa ‘uos “¥8M Joiyy) ‘reddoo yuasorder svare paut[-ssorg ‘svare saddoo jedroursd oy} Jo worynqiysIp Surmoys viursira Jo dep—ogy “Sty Vv N I T oO ua Vv 5 = H i uo N > a, RITs|Nv wa fost ‘ Siyasapis;rg9 I MAERS. Lf “ — of oO oN xvevnong) je co a > SoTTUr O, = yoUuT T ‘opwog 494 MINERAL RESOURCES OF VIRGINIA. The geologic conditions are so unlike in the different copper areas of the State, that the kinds of ore, their association and genesis, must be con- sidered separately by areas, as enumerated above. THE VIRGILINA DISTRICT. Introductory statement.—The Virgilina copper district, which derives its name from the town of Virgilina, located on the Virginia-Carolina boundary, is situated 47 miles east of Danville, on the Atlantic and Dan- ville division of the Southern Railway. The Norfolk and Western and Richmond and Danville roads lie not far to the north and west. The mines thus far developed all lie upon a low ridge, a flat-topped elevation of from 100 to 250 feet above the neighboring stream-valleys, which is from 2 to 3 miles in width. Prospecting and mining are con- fined to an approximate north-south distance of 18 miles along the ridge, and to an average cross distance of from 2 to 3 miles. Although of no conspicuous height, the ridge forms a somewhat prominent feature in the landscape, and is traced northward in Virginia for a continuous distance of 10 miles. A similar area is found as far north as Keysville in Charlotte county. In North Carolina its southward extension is estimated by Hanna to be about 30 miles, reaching nearly to Durham. General geology and petrography.—The country-rock is schist. Natural outcrops are relatively rare and seldom more than 2 or 3 feet high, form- ing sharp and narrow reefs which are persistent for short distances only. The microscope reveals the igneous origin of the rocks, though their true igneous nature is usually not readily recognized in the field. Ordinarily they are schistose, soft, green and purple colored rocks, the schistosity having a strike of N. 10° to 20° E., and an eastward dip of from 70° to 80°. Diabase dikes of later geologic age cut the schists in several places. The minerals composing the altered volcanic rock are: Plagioclase, light green amphibole, chlorite, epidote, zoisite, calcite, iron oxide (partly magne- tite), quartz and apatite. Of these, only the feldspar, a part of the iron oxide (magnetite), and apatite are original. Both chlorite and epidote, intimately associated with more or less hornblende, are abundantly developed in most of the thin sections, sometimes one, sometimes the other, predomi- nating; but the two are at all times intimately associated. Kinds and occurrence of the ores—The workable ores comprise chal- cocite or glance (copper sulphide) and bornite (copper-iron sulphide) in quartz, and to a slight degree impregnations of the country-rock adjacent to the veins. At shallow depths cuprite (copper oxide) and malachite (green copper carbonate) occur as alterations of the original sulphides. A little native copper occurs in places. Chalcopyrite and pyrite are almost entire- MINERAL RESOURCES OF VIRGINIA, PLATE LXNXI. Fig. 1—Specimen of copper ore (chalcocite and bornite in quartz) from the Virgilina copper district—Virginia and North Carolina. Fig. 2.—Specimen of copper ore. Same as Fig. 1. COPPER ORE, VIRGILINA DISTRICT, VIRGINIA. COPPER. 495 ly absent, although the latter is more abundant in the High Hill mine on the Virginia side than in any of the North Carolina mines belonging to this area. The ores are free from arsenic and antimony, but they carry at times very appreciable values in gold and silver, particularly the latter. The ore occurs in quartz veins. In some places it is disseminated as finely divided particles through the more massive portions of the rock, with the workable ore entirely confined to the quartz veins. The gangue is com- posed chiefly of quartz with considerable calcite and epidote admixed lo- cally. Plate LX XI shows the occurrence of the ore, bornite and glance, in the quartz gangue. The veins.—The district has many veins, which in general are more or less parallel, having a course of N. 5° to 10° E., and having overlapping ends. These cross the schistosity of the enclosing rock in part, and in part are parallel to it. Mining developments show that copper occurs in almost all of the veina in greater or less quantity. The veins are lenticular bodies of quartz, and forming in some cases very uniform continuous outcroppings at the surface. They show, in general, a lenticular structure, and like the gold veins of the southern Appalachians, they appear to be a succession of lenses connected by stringers of quartz. Figure 77 shows the bulbous or lenticular form of the quartz veins. The largest veins show outcrops nearly continuous for a half mile to a mile and more, and the underground workings show a con- tinuous body of quartz. Even the largest veins have a bulbous or lentic- ular form, and the veins pinch and widen both horizontally and vertically. ‘This is strongly marked in the smaller veins, and the lenses are frequently connected by a mere film or plate of quartz, which in certain horizontal cross-section may be wanting so that the vein appears to have given out. Fig. 77.—Diagram illustrating the A marked banded structure is some- fie wearin pies nol gettat in times observed in the veins, commonly cluded between fault-fissures or ¥ adjacent to fissures. (After seen near the walls, though it some- Weed and Watson.) ae So Ae vx REID a — Teo Ne NRA TRA LN 7 NF, ae NSS NN ce es — DE I re NI LI et by Ia a BOOS, VN ON NNIAD ON ye aS ee NERO OS “ 3S SACL AES y ee ANON AN 496 MINERAL RESOURCES OF VIRGINIA. times prevails for the entire width of the vein. This banding is due to included plates of the altered schist, which are x / / i NS, . 4 MSR Rais shaft several hundred feet deeper, extending the drifts, and opening new ones on lower levels. Much ore is in evidence both on the dump and in the shaft. It com- prises cupriferous pyrite chiefly, with some chalcopyrite. Good values in gold are indicated by a large number of assays made of the ore. THE ALBEMARLE COUNTY DEPOSITS. The Stony Point copper vein.—Northeast of Charlottesville on the west- ern foot-slopes of Southwest Mountain, in Albemarle county, is a vein cut- ting through micaceous schists which was worked for about a year as an iron deposit. The upper part of the vein, the gossan, is composed of limonite which was shipped to the Pittsburg furnaces. The mines are located in the foot-hill country at the west base of South- west Mountain, on a small branch of the North Fork of Rivanna river. They are located about 2 miles to the east of Stony Point and a quarter of a mile from the main Charlottesville pike. The mines are 2.5 miles from the railroad and 12 miles from Charlottesville. This property was bought by Major Mason in 1878 who worked it in 1885. Numerous openings have been made including shaft, drifts and open cuts, or pits. The shaft which is inclined is reported to have reached a depth of 130 feet. The principal mining has been the gossan for iron ore, of which 2,500 carloads are re- ported to have been shipped, some of which is reported to have averaged very high in iron. Mining was discontinued here about 15 years ago. The country-rock is a bleached and altered, thinly foliated, sericitic schist. The hanging-wall rocks appear to be more altered than those of the foot-wall. The vein is from 5 to 6 feet wide, which width is nearly uniform throughout its extent. In the northern part of the property the MINERAL RESOURCES OF VIRGINIA. PLATE LXXII. Map of the northern Blue Ridge copper district, showing location of mines. Copper mines represented by heavy black dots. Based on the topographic sheets of the U, S. Geol. Survey. Scale, 1 inch = 3 miles, approximately, COPPER. 503 vein strikes north 35° east (magnetic) and dips 55° south. To the south end of the property the vein strikes south 80° east. It consists of a solid mass of gossan which appears when broken more or less cellular, with siliceous portions and occasionally with quartz streaks. The dump is com- posed of siliceous iron ore with occasional blocks of white quartz contain- ing bands and thin layers of chalcopyrite. No pyrite was observed either in the quartz or in the altered schists about the vein. The iron of the gossan has probably resulted from the alteration of chalcopyrite, which alteration extends to a depth of more than 100 feet. It seems not improbable that a thickness of secondary copper glance will be encountered between the gossan and the unaltered primary ore. Samples of the chalcopyrite were assayed with reported yields of $5.00 per ton in gold and 15 per cent. in copper. AMHERST COUNTY DEPOSITS. Amherst county contains green-stained rocks at the Folley, and numer- ous old openings attest the endeavor of earlier explorers to find workable deposits. Professor Rogers again remarks, “that no distinct vein or bed cf copper ore is indicated, but rather an impregnation of the talcose rock of the neighbourhood. more or less strongly with the compounds of the metal. In some of these places the manufacture of copper has been attempted, but without the success that would justify a prosecution of the enterprise.” THE BLUE RIDGE COPPER DEPOSITS. Location and history.—As indicated on map, plate LX XII, the Blue Ridge copper region is located in the northern part of the State, and includes those deposits from near Front Royal southward and embracing parts of Warren, Fauquier, Rappahannock, Madison, Page, and Greene counties. Copper ores have been known to exist in the Blue Ridge mountains since the earliest settlements. The native copper of the region probably furnished the Indians with the metal from which their ornaments and axes were made. A few attempts were made to extract the metal in colonial times but not until 1854-56 were large sums of money expended in this region in attempts to work the ores. Operations were suspended at the beginning of the Civil War and the properties remained practically idle until within the past 10 or 12 years, when attempts were again made to work the ore at many places over the region. During the past 2 years, 6 companies and a few private individuals have been engaged in development work. 504 MINERAL RESOURCES OF VIRGINIA. Geology. In the copper region, the Blue Ridge is made up of a central core of igneous rocks, mostly a dense and black basaltic type flanked by syenite and other igneous types, frequently altered to schistose forms. Resting against these rocks at the base of the mountains and forming the Valley region to the west is the folded sedimentary series, which Keith designates as Cambro-Silurian in age. So far as known the sedimentary rocks are not copper-bearing but the ores of the region are confined to the igneous rocks of the basalt type. @ native copper b quartz © epidote rock Scale ° I é 31nches Fig. 81.—Brecciated epidotized basalt with ore and quartz. Stony Man Peak. (After Weed and Watson ). The basaltic rock is dense, heavy and dark-colored, and parts of it are altered and sometimes schistose. According to Keith the schistose character of the rock is emphasized in the Harper’s Ferry region and the rock is designated by him Catoctin schist. Further south in the copper region the schistose character of the rock is much less well-defined, though in places it is sheeted vertically from close jointing along shear zones. Keith recognizes two varieties of the basalt near Harper’s Ferry, a lower diabase sheet and an upper basalt sheet, both altered and the upper one large- ly epidotized. An amygdaloidal phase of the upper epidotized sheet is COPPER. 505 shown in places. A coarse-grained, usually massive, and dark grayish green syenite has been traced at irregular intervals along the west side of the mountains from Dickey’s Hill south of Front Royal in Warren county, southward to High Top in Greene county. The upper sheet of basaltic rock is generally much altered by secular decay and in part forms a greenish chlorite and epidote schist. According to Keith the igneous rocks including the basalt or Catoctin schist are Algonkian (pre-Cambrian). Character and Mode of Occurrence of the Ores. The ores consist chiefly of cuprite and native copper with small amounts of the sulphides, bornite and chalcopyrite. The native copper often occurs as nucleal masses surrounded by cuprite. Bornite is in excess of chal- copyrite. The ore occurs along crevices and joint-planes, in small, irregular shaped lenses of quartz, and as disseminated grains through the more epidotized portions of the basalt. It occurs mostly where the rocks are fractured and epidotized as shown in figure 81. When ore-bearing the rocks are yellowish-green in color, due largely to the formation of epidote and in part of chlorite. Figure 82 shows a partial basalt shell filled with epidote, and the epidote rimmed by bornite next to the basalt. Figures 83 and 84 show the occurrence of native copper in quartz and in asbestiform serpentine. The ores do not extend more than 50 feet below the surface at many of the localities and at some it is less. From their occurrence in shear zones in the rock; from the confinement of the ore mainly to the secondary epidote and quartz veinlets; and from the character of the ore itself, it is believed that the ores have been formed by a concentration of material leached out of locally copper-rich portions of the igneous rocks. The Fig. 82.—Part of shear a have afforded a place for the gathering of oy a these solutions and the deposition of material. The ores rimmed_ by bor- ‘ é ite “Empire seldom occur in actually continuous masses, but can Vein,” Warren sometimes be traced for miles by the copper-bearing county. — (After . Weed and Wat- debris. son.) 506 MINERAL RESOURCES OF VIRGINIA. Fig. 83.—Quartz with a little calcite Fig. 84.—Asbestiform serpentine with and native copper. Black areas native copper. Black areas cop- copper. Lined area _ schistose per. 7 miles southeast of Luray, basalt. Fletcher, Greene county. Page county. (After Weed and (After Weed and Watson.) Watson.) DESCRIPTION OF THE MINES. Warren County. The copper ores found in the region east and south of Front Royal have attracted attention for many years. In recent years several mining companies have done more or less exploration work and their shafts and tunnels have afforded a favorable opportunity for the study of geologic conditions. The district embraces the main Blue Ridge summit extend- ing from Linden southward. East of Front Royal and south of Linden, on a tract of land reported to have been originally. granted to Lord Fairfax and subsequently trans- ferred to Chief Justice Marshall, good indications of copper appear in the outcrops and as loose masses over the surface. In the early part of the last century a number of shallow pits were sunk at several places, but. no shipments were made until 1861, when 35 tons were collected from the surface and from a 50-foot shaft and shipped abroad. This shipment of ore is reported to have averaged over 10 per cent. in copper. COPPER. 507 The Sealock property.—This property has been very extensively developed by shafts, drifts, and small openings. It is located about 3 miles in a direct line from Linden. The principal shaft on this property, known as the Phillips’ shaft, was sunk to a depth of 80 feet, and a considerable quantity of good ore is reported to have been extracted. A recent tunnel 200 feet long has been driven into the hillside on another part of the property with the object of cutting the so-called copper “vein” on which the Solomon shaft was driven. The ore thus far taken out consists chiefly of native copper and cuprite with malachite, the green carbonate, and a small amount of azurite, the blue carbonate. Some chalcopyrite also occurs. An examination of the dumps at many of the openings on this property by the writer in 1905 showed many beautiful specimens of copper ore. Dickey’s Hill mines——Dickey’s Hill forms a high outlier of the Blue Ridge proper, lying to the west of the main divide. The copper ore is not uniformly distributed over this ridge but occurs in a few localities where more or less work has been done to determine the size and character of the ore-bodies. The Mull’s property (Cove Farm) represents a recent working located about 8 miles from Front Royal. In 1905 a copper-bearing outcrop of epidote rock exposed in a ledge 50 feet long and 20 feet wide and located about 200 feet below the summit of the mountain had been opened. The opening was a cut about 7 feet wide and 35 feet long extending back into the hillside. The copper ores comprised native copper, malachite, and azurite, chrysocolla, and lower down a litte bornite. At the time of my visit in 1905 the property had not been sufficiently developed to warrant a definite statement. Rudacill property—In August, 1905, this property was being worked by the Virginia and Pittsburg Copper Company. The company has made openings at two points on the south end of Dickey’s Hill near the summit, where some shallow openings have been put down and a couple of cabins erected. At that time the workings were located in the cove southeast of the end of the ridge at a point halfway up the slope, comprising a cut about 75 feet long, and about 100 yards distant therefrom, and a shaft sunk to a depth of about 50 feet. The ore comprised native copper, considerable carbonate, malachite, and copper oxide. The Bentonville-Overall District. This district is located 12 to 15 miles south of Front Royal and some of the earliest prospecting for copper in the Blue Ridge region was to the 508° MINERAL RESOURCES OF VIRGINIA. south of Bentonville, a station on the Norfolk and Western Railway. Within the past 12 or 15 years considerable work has been done on a number of properties in this vicinity. In 1905, operations had been suspended except some prospecting work on the Empire “vein”, located on the summit of the ridge known as Mathews Arm, near the Page-Warren county line. Several pits have becn dug on the Empire “vein” showing chiefly malachite with some bornite and cuprite. In 1903-04, a shaft and several openings were put down on the Martin property, located about 2 miles northwest of the Empire “vein” and about 2 miles southeast of Bentonville, about halfway down the ridge slope. The shaft is reported to have reached a depth of 90 feet. An inspection of the material on the dump showed the ore to consist essentially of mala- chite and azurite with some bornite. A second shaft is located lower down on the ridge toward the south- west on the land of F. C. Hartley. This is of long standing and was worked more than 30 years ago. Several other smaller openings, some of which are recent others of long standing, are made in the vicinity. Rappahannock County. The Ambler property.—Several openings have been made on this property comprising an open cut and tunnel, a shaft and several smaller epenings. The shaft is sunk on the north end of the property some distance below the ridge crest and is reported to be 40 feet deep. An examina- tion of the dumps from the shaft showed bornite and native copper with malachite. Similar conditions were noted at the open cut and tunnel. A couple of miles from the Sealock property is a fine exposure of copper ore in a rocky ledge known as Cottam rock on the Ambler place. The Manassas Gap Copper mine—The openings of this company are located on the slope near a small stream, which forms a part of the head- waters of the Rappahannock river, distant from the latter about 600 feet and 6.5 miles south from Front Royal. Openings have been made on the property at five different places, 4 of which are on the east slope of a steeply sloping ridge, the other on top of the ridge, Raven Den Mountain. These comprise shafts, tunnels, and some open work. The greatest depth reached in the shafts is reported to be 60 feet and the most extensive tunnel approximates 200 feet in length. The same kind and character of ore was observed by the writer on the dumps at these openings as from MINERAL RESOURCES OF VIRGINIA. PLATE LXXIII. Fig. 1—View showing shaft house, ore dump, and basalt cliffs, at the Blue Ridge Copper Company’s mine, Madison county. (Unpublished report by Weed and Watson.) Fig. 2.—View of the shaft house at the Virginia Consolidated Copper Com- pany’s mine, near Ida, Page county. (Unpublished report by Weed and Watson.) COPPER MINES IN THE NORTHERN BLUE RIDGE REGION, VIRGINIA. COPPER. 509 the mines described above. In 1905, the company’s equipment comprised a saw-mill, blacksmith shop, and a varied assortment of mining tools. Page County. The copper properties southeast of Stanley, in Page county, lie on the tlank of the Blue Ridge to the east and west of the summit of the ridge, which forms the dividing line between Page and Madison counties. The district has long been known as showing some of the most promising out- crops of copper ores in the Blue Ridge region, and the development near Tda post-office, on the headwaters of Hawk’s Bill creek and in Dark Hollow are more extensive than any other part of the Blue Ridge. The Virginia Consolidated Copper Company’s mine-——One of the most extensive developments in the Blue Ridge district of Virginia is that of the Virginia Consolidated Copper Company, with head offices at McKees- port, Pennsylvania. The property, comprising 160 acres, is located on one of the foothills at the west base of the Blue Ridge, about one mile west of Ida, and about 5 miles southeast of Luray. The company has made extensive developments but operations were temporarily suspended in January, 1905. A manager’s house, a laboratory, shaft-house and other out- buildings have been erected, and the shaft-house equipped with 2 12-H. P. Fairbank-Morse gasoline engines; the one for hoisting, the other for ventilation and working two compressed air drills. In the summer of 1905 an incline shaft had been sunk 308 feet deep, with drifts run on the 80-, 120-, and 280-foot levels. The drift at the 80- foot level extends for 70 feet to the east. The 120-foot level has been driven from 180 feet west in solid rock. The 280-foot level shows 250 feet of work. (The shaft house at this mine is shown in plate LX XIII, figure 2.) The ore comprises the oxidized forms, malachite and azurite, and some red oxide and native copper. No sulphide ores were seen by the writer. Madison County. The Blue Ridgé Copper Company's mine.—The property of the Blue Ridge Mining Company of Chicago comprises about 180 acres of land in Dark Hollow, at the head of Robinson river and about one mile to the south- east of Milam’s Gap (also known as Fisher’s Gap), very near the crest of the Blue Ridge. This is the best developed property in Madison county. The exposures of copper ore found in this vicinity are reported to have been worked before the Civil War, but they have been abandoned for many years. 510 MINERAL RESOURCES OF VIRGINIA. The operations of the present company were begun some 5 years ago. The workings comprise what is known as the old shaft or shaft No. I, located at an elevation of about 250 feet above the confluence of the two main head- water branches of the Robinson river. This shaft and the small opening a short distance to the southwest were made some years ago. Two drifts were run from the shaft, one in a north 12° west direction for 20 feet, and the other in the opposite direction for 9 feet. A few tons of ore are reported to have been shipped from this shaft. (Plate LX XIII, figure 1.) The new shaft, No. 2, is an incline 42 feet in length and located about {00 feet below the mouth of the old shaft. From the bottom of this in- cline a drift has been run for 40 feet in a northeasterly direction for the purpose of intersecting the zone of copper-bearing rock on which the oid shaft was started. In 1904, a third shaft was begun, located northwest of and higher up the hill than the old shaft, No. 1. The ores found in these openings comprise native copper, blue and green carbonates, a little cuprite and some chalcopyrite. The workings of this company are located quite close to the contact of basalt and syenite, shaft No. 2 being not more than a stone’s throw away. The ore is confined to the basalt and as yet has not been observed in the syenite. Stony Man openings—To the northeast of Milam’s Gap and near Stony Man peak some prospecting for copper ores was done many years ago. A shaft filled with water at the time of my visit is reported to have ‘reached a depth of 60 feet, with the usual quantity and mineralogical forms of ore shown as described above. Greene County. The Blue Ridge region of Greene county contains several copper pros- pects, only two of which have been opened by mining operations. These are the Sims mine, 5 miles north of Stanardsville, and the mines of the Hightop Copper Mining Company, % miles east of Elkton. The Sims mine—The Sims mine is located 5 miles north of Stanards- ville, the county-seat of Greene county, and on the eastern slope of the Blue Ridge. A number of shallow openings have been made in places and a shaft 30 feet deep has been sunk. A short cross-cut driven 25 feet north is made at a depth of 30 feet. The ore is native copper, cuprite and chalcopyrite in small amounts. The Hightop Copper Mining Company's mine.—The mine of the High- top Copper Company, the most extensively developed one in Greene county, is located 7 miles east of Elkton on the summit and southern side of the MINERAL RESOURCES OF VIRGINIA. PLATE LXXIV. Fig. 1—General view of the Blue Ridge from the Virginia Consolidated Copper Company’s mine, near Ida, Page county. (Unpublished re- port by Weed and Watson.) Fig. 2.—View of shaft No. 3. High Hill copper mine of the Virginia Cop- per Company, Halifax county. (Unpublished report by Weed and Watson.) BLUE RIDGE AND SHAFT OF COPPER MINE, VIRGINIA. COPPER. . 511 southeast spur of Hightop Mountain, at an elevation of 3,000 feet above sea-level. In the fall of 1905, the workings consisted of extensive strip- ping of the ledges exposed on the mountain side, of a cross-cut tunnel about 150 feet in length below a shaft reported to be 80 feet deep, sunk from the bottom of an open cut driven on the hillside. “The ore observed at the openings of this company consisted of native copper, cuprite, some malachite, and in places a little bornite and chalco- pyrite. A tunnel, entering the hillside at a distance of 400 feet below the summit of the ridge, has been driven for a distance of 111 feet, along a S. 50° E. course. The open cut and shaft mentioned above are 200 feet above the tunnel and the same distance below the top of the ridge. The Mining camp of this company is probably the most extensive one in the district. THE SOUTHWEST VIRGINIA REGION. The “Gossan Lead” of Floyd, Carroll, and Grayson Counties. General statement.—Probably the most noted copper region of Virginia is in the southwestern portion of the State, in a belt of crystalline rocks passing through Floyd, Carroll, and Grayson counties. The region is a part of the eroded Blue Ridge upland, marked by well rounded summits and deeply trenched streams, and is referred to as the Floyd-Carroll- Grayson plateau. (Map, figure 29, page 192.) The region was actively prospected in the early fifties and the rich secondary copper ores found beneath the gossan were boxed and shipped to Baltimore. During 1854-5 there were 8 producing mines on the “Gossan Lead.” The aggregate amount of ore shipped for the 6 months, from January 1855 to July 1855, was 1,545,363 pounds. The ore averaged about 25 per cent. copper, and at that time the metal was worth 26 cents per pound. General geology—The “Gossan Lead” lies in the crystalline schists and its strike conforms very closely to that of the enclosing rocks. A eareful examination shows the vein to be traceable for a distance of 18 miles. From one end to the other there are old pits whose dump heaps show the typical gossan ore (figure 85), and as several of the old mine- workings could be continuously followed underground for miles running at a depth of from 20 to 60 feet below the surface, there seems little doubt that it is one of the greatest veins in the Appalachians. The immediate wall rock of the “lead” is sericite schist. On the 512 MINERAL RESOURCES OF VIRGINIA. southeast or hanging-wall side of the vein the rocks are ordinary mica- schists cut by altered diorite masses. The rocks on the foot-wall side appear to be somewhat different and are similar to the Ocoee rocks of the southern Appalachians. A belt of much altered hornblende syenite extends upward and across the foot-wall series and is found near the “Gossan Lead” in the vicinity of Betty Baker. These facts and the structure of the vein itself prove faulting and, as the dip of the vein is from 45° to 60° the faulting is apparently of the overthrust type, which type predomi- nates in this part of the Appalachian region. General character of the vein.—The vein consists essentially of pyrrhotite with disseminated particles and stringers of chalcopyrite. It ian Gossan iron ore (UT Primary sulphide ore COMPANY STORE BETTY BAKER MINE ANN PHIPPS MINE * OLD COPPER SMELTER & & = S < ke R & 2 8 aos 9 < 8 2a @ =& a 6 x e 3 5 3 so as v 8 3 m3 ‘ 2600 3 Sgt 5 600 2500- Ss 500 f iN 0 2400 2400 2300- 300 2200: Fig. 85.—Profile of “Gossan Lead” from Betty Baker mine to Kirkbride mine, showing gossan (limonite) reserves. Carroll county. (After Weed and Watson, unpublished report.) is not in every place a solid mass of pyrrhotite from wall to wall, but rather a series of layers, partly of pure pyrrhotite admixed with more or less micaceous material, an altered form of the country-rock. The pri- mary ore is exposed at the openings of the Pulaski Mining Company at Chestnut Yard (Great Outburst) at the southwest end of the “lead.” (Plate XXX.) Projecting masses or intercalations of the schists occur in the vein and, in places, where the fresh material is observable, a consid- erable proportion of the vein consists of coarse biotite schist, impregnated with chalcopyrite and interleaved masses of pyrrhotite. Figure 86 shows the interleaving of pyrrohotite with tale at the Pulaski Mining Company’s openings on Chestnut creek at the “Great Outburst.” At the same openings considerable hornblende is associated with the pyrrhotite in places, as shown in figure 87. Quartz lenses occur on the hanging-wall of the. vein. COPPER. 513 Fig. 86.—Pyrrhotite interleaved with tale. Black is pyrrhotite. Lined areas are tale. Chestnut Yard, Carroll county. Two-thirds natural size. (After Weed and Watson.) The vein varies in width from 22 feet to perhaps 100 feet.. A diamond drill hole was put down to a depth of 524 feet on the vein at the Betty Baker mine, proving the deposit to a depth of 734 feet below the outcrop. Other bor- ings proved the width of the vein at Betty Baker to be 35 feet. The strike of the vein varies in accordance with that of the country-rock; at Betty Baker it is N. 35° E., and it a ee ee : ‘ shows various deviations from 1g. -—Lyrrhotite wl columnar orn- . blende and chalcopyrite. White is pyrrho- this when traced southward, tite. Black is chalcopyrite. Parallel lines reaching as much as N. 60° EB. are hornblende. Chestnut Yard, Carroll county. (After Weed and Watson.) in places. It has not only suffered from strike faulting, but shows sharp folding or change of strike southwest of the Cranberry mine; and at the Betty Baker mine a horizontal displacement of 62 feet was measured close to the point where the wagon road crosses the ledge. The dip varies somewhat but averages about 45°. Marked discordance in the dip of the vein and that of the enclosing schists is observed in places. In places, the vein-filling comprises rock fragments of varying character cemented by the sulphides, principally pyrrhotite. These fragments are often well rounded, sometimes subangular and include rock types not seen on the surface either at the vein or nearby. 514 MINERAL RESOURCES OF VIRGINIA. Description of Mines. The mines which were most extensively worked on this “lead” are: the Betty Baker, Cranberry, Kirkbride, Vaughn, Copperas Hill, and Chest- nut Ridge at the “Great Outburst.” The location of these mines and the general trend of the “Gossan Lead” are shown on the accompanying map, figure 88. In addition to these, numerous other smaller mines were opened in different places on the “lead,” the principal ones of which were the Ann Phipps, Wolf Pit, and Wild Cat mines. Carroll County. Vaughn mine.—As indicated on the map, figure 88, the Vaughn mine is southwest of the Kirkbride, and has not been worked for many years. The shafts are numerous and they occur at such frequent intervals that there can be but little doubt of the continuity of the vein. As determined by the old shafts, the direction of the vein was about 65° east with a dip of 45°. The workings of the Vaughn mine and those on the adjacent properties made a continuous drift of 4 miles long. The ore from this mine was pounded up and put in boxes, and hauled to Max Meadows, where it was shipped to Baltimore. Mr. H. E. Vaughn reports that the ore was 75 feet wide in some places. Cranberry mine.—The location of this mine is given on the accom- panying map, figure 88. The mine was closed down in 1859 after working for a period of about 7 years. A copper smelter was once operated at this locality and there was at that time a considerable settle- ment. The old workings for black copper consisted of long tunnels, with drifts along the vein, and frequent air-shafts along the surface, some of which were used for hoisting. The strike of the vein is north 55° east. A shaft 104 feet deep, located in the creek bed, was worked for yellow copper ore. This mine was reopened again about 12 years ago by Edgar C. Moxham, Mining Engineer of New York City. In 1902 some diamond drill holes were put down by the Virginia Iron, Coal and Coke Company. Wild Cat mine——Crossing Cranberry creek to the southwest from the Cranberry mine is the Wild Cat mine, which was developed by a series of shafts. These are still open down to the water level and show the strike of the vein to be north 65° east, and a dip of 45°. The Betty Baker mine —This mine is located about 3 miles southeast of Sylvatus and a short distance west of Big Reed Island creek. It has been 515 COPPER. (qr0da41 paystiqndun ‘uosyea, pue pos Joqy) “spte] giqeqord Joyjo eyeoIpul seul] Usxo1g “jf WO payzeoo] SeUTUT aaddoo [edtourad ay} pue pueq yoetq Aavay Ul ,.pvayT UessoH }EeIH,, EY} JO worytsod sutmoys ‘ears aztyoysridd Ayunod [[orreD ey} Jo dew—'ss ‘Sit 516 MINERAL RESOURCES OF VIRGINIA. extensively operated, as indicated by the numerous cuts, shafts, and drifts, extending over a considerable northeast-southwest distance. Many of the older workings are in poor condition and little could be seen from an examination of the walls. At the time of my visit in 1905 the shafts were filled with water and could not be entered. The narrowest place encountered on the vein was reported at No. 7 shaft, about one mile west of the office of the Betty Baker mine. At this point the vein was squeezed to 5 feet. At the east end of the Betty Baker property the surface shows a width of about 300 feet of limonite. Before closing down the Betty Baker mine in 1900, 1,800 tons of the ‘“mundic” (pyrrhotite) were shipped to the Southern Chemical Company at Winston-Salem, North Carolina, where it was used in acid-making. The ore contained 33 per cent. of sulphur, and after roasting it carried 58 per cent. of iron. Shipments to the Winston-Salem works were stopped when the plant was absorbed in the consolidation of the Southern Fertilizer Manufactures. Plate LX XV shows views of shaft and open cut at this mine. The Gardner and Goad mines——These are separate mines, located close together in the northeastern part of Carroll county, about 10 miles from Betty Baker and not far from the Floyd county line. The openings are made in a dike of altered (schistose) hornblende rock, which cuts across the normal schists of the region. Occasional specks or nuggets of native copper have been found along the weathered outcrop and the dike has for this reason been referred to as a native copper vein. The strike of the country-rock (schists) near the mines varies from north 50° to 65° east, and dips about 60° south. The mines have been opened by shafts and tunnels of moderate depth and length.. The ore is chalcopyrite in more or less rounded nodules ranging in size up to that of a hickory-nut. Post- mineral movement has squeezed these out into pyrite mirrors and streaks. The “Great Outburst.”—The openings on this property are located near the Carroll-Grayson county line, near Chestnut Yard, on the Cripple Creek extension of the Norfolk and Western Railway, between Chestnut creek and New river. The gossan of the vein has been extensively mined from numerous shallow workings for iron. The pyrrhotite vein is very wide here. It is not a continuous mass of pyrrhotite from wall to wall, but the ore is interleaved with micaceous and talcose schist. Plate XXX is a view of the vein as opened in 1905. The pyrrhotite contains stringers and small masses of chalcopyrite through it, usually not in large enough quantity to make it a workable copper proposition alone. The Pulaski Mining Company has been and is mining the pyrrhotite for acid-making, with occasional shipments of the secondary black copper concentrated, below the gossan. MINERAL RESOURCES OF VIRGINIA. PLATE LXXV. Fig. 1—Shaft at Betty Baker mine, west of road, Carroll county. (Un- published report by Weed and Watson.) Fig. 2.—Open cut at Betty Baker mine, Carroll county. (Unpublished re- port by Weed and Watson.) PYRRHOTITE MINES CONTAINING COPPER, “GREAT GOSSAN LEAD,” CARROLL COUNTY, VIRGINIA. COPPER. 517 Grayson County. As indicated on the map, figure 88, the “Gossan Lead” extends from Carroll into Grayson county, and, in the vicinity of Old Town, other probable ones are shown, but, so far as I am aware, the mining of copper along these belts has been largely, if not entirely, limited to Carroll county. In the extreme western and southwestern portions of Grayson county, strong indications of copper exist in places. Less than a mile south of Troutdale, on the Greer place, the quartz-feldspar porphyry on Fox creek contains large granular masses and small grains of chalcopyrite. In the southwestern corner of the county, near the North Carolina line, some prospecting for copper has recently been done on the Douglas Land Com- pany’s property. Good specimens of the sulphides, bornite and chalco- pyrite, and the green carbonate, malachite, were obtained. The openings are made in a green schist not far*removed from the porphyry contact. Floyd County. The Toncray mine—The Toncray mine is located about 8 miles south southeast of Floyd court-house. It was last operated by the New York and Virginia Copper Company. For several years past this company was actively engaged in prospecting the property and large sums of money were expended in buildings and machinery, and the employment of a large force of men. The property has been developed by several tunnels and shafts. Work had just been suspended at the time of my visit in 1905. The vein is, like that described above in Carroll county, pyrrhotite. It was opened in search of the black oxide of copper, a large amount of which was reported found. Intermingled with the unaltered pyrrhotite is con- siderable chalcopyrite, which seems to be present here in amount larger than at other mines in Carroll county. It is reliably reported that in the upper tunnel a band of the yellow copper sulphide, chalcopyrite, was found which measured 6 to 8 inches wide. The rock inclosing the vein is the usual gray-colored mica schist. Franklin County. The Howell mine——This mine, so-called, is near the Rocky Mount- Floyd court-house road, and is located about 1.5 miles from Huff’s store, in the extreme western edge of Franklin county. Very little work has been done. The ore is pyrrhotite, carrying a small amount of intermingled chalcopyrite. The “vein” is found in the altered micaceous schists. Other deposits similar to this one are reported a short distance to the northeast and southwest of the Howell mine. 518 MINERAL RESOURCES OF VIRGINIA. THE COPPER ORES OF THE RED BEDS OF THE TRIASSIC. Several of the Virginia counties covered by the red sandstones and shales of the Triassic formation contain deposits of copper ores of too low grade to permit of profitable working. Numerous attempts have been made to mine these ores at many different points, but as yet without success. During the early part of the last century attempts were made to mine the ore over parts of Loudoun, Culpeper, and Orange counties. Loudoun County. Five miles east of Leesburg and near Sugar Run in Loudoun county, the Triassic series contains greenish or bluish calcareous sandstones and shales intercalated in the lead rocks. The light-colored beds contain films or thin coatings of malachite on joint surfaces, and sometimes carry specks of the phosphate of copper and of copper glance. The area of mineraliza- tion is, according to Keith, extensive, and considerable work has been done; but the ore is too generally diffused to be profitably worked. Culpeper County. Near Stevensburg, 10 miles east of Culpeper, copper-bearing shales were worked. The conditions here are more or less closely similar to those described in Loudoun county. Rich specimens of copper ore are reported to have been frequently obtained during the early history of this region. Professor Rogers’ observations on this region seem to be applicable at the present time. He says: “Unhappily these indications have kept alive the hope of discovering in these shales veins of a workable copper ore and has led to repeated enterprises in mining, from which no really profitable result appears ever to have been derived. Most of the openings, either ancient or modern, have disclosed nothing more than a calcareous shale slightly filmed with the green carbonate, and making in some cases a superficial show of richness where analysis discovers only an insignificant amount of the enticing mineral.” Orange County. Orange county contains areas of copper-stained rocks in the Triassic sandstones. Taylor's copper mine is mentioned by Professor Rogers, who says, “though opened with high expectation of profit, has long been abandoned.” COPPER. 519 References. Boyd, C. R. The Mineral Wealth of Southwestern Virginia. Transactions American Institute of Mining Engi- neers, 1876-77, V, 81-92. The Mineral Resources of Southwestern Virginia. Transactions American Institute of Mining Engi- neers, 1879-80, VIII, 338-348. The Utilization of the Iron and Copper Sulphides of Virginia, North Carolina and Tennessee. Trans- actions American Institute of Mining Engineers, 1885-86, XIV, 81-84. Fontaine, Wm. M. Notes on the Sulphuret Deposits of Virginia. The Virginias, 1882, III, 154-155. Moxham, Edgar C. The “Great Gossan Lead” of Virginia. Transactions American Institute of Mining Engineers, February, 1892, 6 pages. Phalen, W. C. Copper Deposits Near Luray, Virginia. Bulletin No. 285, U. 8. Geological Survey, 1906, 140-145. Watson, Thomas L. Copper-Bearing Rocks of Virgilina Copper District, Virginia and North Carolina. Bulletin Geological Society of America, 1902, XIII, 353-376. The Copper Deposits of Virginia. The Engineer- ing and Mining Journal, 1906, LXXXII, 824-826. Watson, Thomas L. and Weed, Walter H. The Copper Deposits of Vir- ginia. Bulletin No. IV, Virginia Geological Sur- vey. (In press.) Weed, Walter H. Types of Copper Deposits in the Southern United States. Transactions American Institute of Mining Engineers, 1901, XXX, 449-504. Copper Deposits of the Appalachian States. Bulletin No. 213, U. 8. Geological Survey, 1903, 181-186. Weed, Walter H. and Watson, Thomas L. The Virginia Copper Deposits. Economic Geology, 1906, I, 309-330. Rogers, Wm. B. A Reprint of the Geology of the Virginias, 1884, 832 pages. 520 MINERAL RESOURCES OF VIRGINIA. Ill. ZINC AND LEAD. Historical. The first authentic records of lead mining in Virginia date back more than 150 years, and the old lead mines at Austinville on New river, in Wythe county, were the first to be worked. Colonel Chiswell, a native of Wales and one of the earlier adventurers in southwestern Virginia, was one of the first operators of the Austinville mines. Chiswell’s operations at Austinville commenced in the year 1750 and closed shortly after the beginning of the Revolutionary War in the year 1776, covering a period of about 25 years. From that time to the present mining has been carried on almost continuously in the Virginia area. For many years after the Virginia mines were operated, mining was confined exclusively to the lead ores. The zinc ores seem not to have been recognized at the Austinville mines until sometime during the Civil War, when several tons were shipped to the smelting works at Petersburg. Zine ores were first discovered at Bertha near Austinville, in Wythe county, during the year 1886. Mining of zinc ores in Virginia properly dates from the opening of the mine at Bertha in 1879, at which time a small shipment of ore was made to Providence, Rhode Island. The metal obtained from these ores proved to be of such rare purity that attention was directed at once to them and a smelting plant was built at Pulaski, which was later remodeled and enlarged and is owned and operated at present by the Bertha Mineral Company. The “Bertha” spelter is of exceptional purity and has a world-wide reputation. Much if not most of the ores yielding the lead made into bullets, for use by the Confederate soldiers in the Civil War, was produced by the Virginia mines, principally those of Wythe county, with some from the mines near Faber, in Albemarle county. Ore was first discovered on the property near Faber in Albemarle county in the year 1869. Distribution. Excepting the single deposit in the extreme southwestern part of Albemarle county, the known commercial deposits of lead and zinc in Virginia are limited to the Valley province, west of the Blue Ridge. All mining and prospecting for lead and zinc ores in this province have been confined to the western half, extending from and including Roanoke county on the east to and including Scott county on the southwest. Ores, both of lead and zinc, are known to occur either sparingly or in quantity ZINC AND LEAD. 521 in the following southwestern counties of the State: Roanoke, Mont- gomery, Pulaski, Wythe, Smyth, Bland, Tazewell, Russell, and Scott. Of this number only one county, Wythe, has shown as yet producing mines. More or less prospecting has been attempted in a majority of the counties named above and very small amounts of the ore have been mined in a number of them. Geologically the occurrence of lead and zinc ores in southwest Vir- ginia is limited to the magnesian limestone of Cambro-Ordovician age, known as the Shenandoah or Valley limestone. The known commercial et . ra SD one %29 " Fi 2 is Vi ‘ ve Re MM, " - ‘ ‘ MUN oe Se. " J oot 2 : yy Se a -< “vr ~ 3 Vv) fie, x Ps Bo ee mo te NewCastle:/ ar - Me ‘ e Sa LPearinbyhee > ne Ser ptr oie , ter Hl ee a f tors ——— Fig. 89.—Map of southwest Virginia and east Tennessee, showing distribu- tion of lead- and zinc-ores. Lead- and zinc-deposits indicated by heavy dots. Scale, 1 inch = 120 miles. (After Watson, Trans. A. I. M. E.) deposits of these ores occur near the eastern side of the Valley though several promising prospects are opened near the western side. Map, figure 89, shows the location of the principal openings worked for lead and zinc in southwest Virginia and east Tennessee. General Geology. Only those features of the general geology, which are essential to the understanding of the ore-deposition, will be considered here. The rocks included within the limits of the zine and lead region of Virginia-Ten- nessee range from Lower Cambrian to Carboniferous in age. They are. without exception, of sedimentary origin; and include shales, sandstones, 522 MINERAL RESOURCES OF VIRGINIA. conglomerates, and limestones, presenting considerable variety in compo- sition and in appearance. They have been more or less metamorphosed, and in consequence are considerably changed, as a rule, both lithologically and structurally. The ore-bearing formation in Virginia is the Shenandoah limestone, of Cambro-Ordovician age. The formation is a magnesian limestone, dark to light gray or nearly white in color, usually fine-grained and massive, and containing much chert distributed through parts of it in the form of nodules and layers. Wide variation in composition is noted from slight siliceous marble to calcareous sandstone. Folds and faults characterize the entire area of the Great Valley of the Virginia-Tennessee district. The folds have a general trend paralleling approximately the axis of the Valley, which is northeast-southwest in direction. The dips on the western side of the anticlines are frequently vertical, and in places overturned, and many of the folds have been com- pressed until broken. The usual dip on the southeast side of a fold is from 30° to 45° to the southeast. The faults are associated with the anticlinal folds, the breaks occurring usually on or near the northwestern side of the anticlines. The faults are of the overthrust type, with the fault-planes usually dipping from 30° to 50° southeast, with an estimated displacement, by Keith, in some of the faults of the Tennessee area, of nearly 3 miles. The faulted zone is usually characterized by much brecciation, and it is along these zones that localization and concentration of the lead- and zinc-ores have taken place. The Appalachian Valley has been a land-area since early Mesozoic time, during which time the field-evidence indicates several periods of uplift, followed by intervals of quiescence. The periods of quiescence, which followed each uplift, were sufficiently long to enable the streams to establish a system of base-levels over the entire region, and the region was also stationary for a time sufficient to admit of the interstream areas being lowered to an approximately uniform level. The harder and more resistant rocks, such as sandstone and quartzite, were never entirely reduced, but they mark partly umreduced residuals, which stand in relief above the general level of the erosion-plane. Accordingly, evidence favoring several periods of base-leveling and planation is recorded over the area. The oldest and most extensive peneplane was probably formed in Cretaceous time. Subsequent uplifts were followed by shorter periods of quiescence, which record other pene- planes cut during the Eocene and Neocene periods. ZINC AND LEAD. 523 The Ores and Associated Minerals. The ores include (1) the original sulphide forms sphalerite, sulphide of zinc, gelenite, the sulphide of lead, pyrite, the sulphide of iron, and in several places chalcopyrite, the double sulphide of iron and copper; and (2) the secondary or oxidized forms which have been derived from the original sulphides and occur in the residual decay of the limestone. These include calamine, hydrous silicate of zinc, smithsonite, carbonate of zinc, and cerussite, carbonate of lead. The associated non-metallic minerals, named in the order of their importance, are dolomite, calcite, barite, fluorite, and quartz. Of these dolomite and calcite constitute the principal ones and they occur in vastly the largest amount. Barite, fluorite, and quartz are not always present but are confined to several of the mines in southwest Virginia. The Lead Ores. Galenite—The principal occurrence of galenite is in association with the zine ores in the zinc mines. At the principal Virginia zinc mines galenite occurs in fairly large amounts in intimate association with sphalerite. Its usual occurrence is granular and massive-granular less frequently in the form of crystals. Selected specimens from the Austin- ville mines in Wythe county gave the following results on analysis: Per cent. LOA - seiash ces eins Gute e what Somer ge 73.89 TVON) o3s-wow es we 04a eed 4s ees 0.22 AWE 2d 05 cise 1 ana Son Sed Meat 9.31 Sulphur’ scctsina girsway ee oe ys 16.20 Siliea. sveesiavevssaeacaiew se 0.54 FROGS Dis gcs Gove detetene gee irene eek 100.16 equivalents in PHS). singe aa aenaaaes ees 85.29 DOS i siacs ey omar vat dessa 5 13.87 WG Sar. sis wkd Sw aiaes wa iesdes « 0.46 Cerussite—This mineral has been found in more than a trace only at the Austinville mines in Wythe county, where it is not altogether an uncommon ore among the altered forms. It occurs distributed through the residual clays of the limestones as stringers and small irregular masses. The earthy form greatly predominates, the clayey admixture being readily identified by its weight. Crystals grouped in clusters and aggregates of white and light grayish color distributed through the clay are not uncom- mon. It also occurs as white powder-like coating on the crystals and masses of granular galena. 524 MINERAL RESOURCES OF VIRGINIA. The Zinc Ores. Sphalerite—This mineral, forming the most important ore over much of the Virginia area, was the original zinc mineral from which the secondary zine ores concentrated above ground water-level have been derived. It is found usually below the ground water-level, and in some of the mines not yet worked to this depth it has been found but sparingly. It varies in color from yellow, through brown to nearly black, the black color being due to impurities, particularly iron. In some of the larger mines sphalerite is associated with much galenite in places, some pyrite and very occasionally with scant chalcopyrite. The sphalerite occurs in the form of disseminated grains, masses and stringers in the magnesian limestone and similar form, but mostly as stringers in quartz-fluorite lenses intercalated in a talcose schist in Albe- marle county. At Cedar Springs, Wythe county, and Rye Valley, Smyth county, the blende is of exceptional purity, as indicated in the analyses below. It is of yellow color, massive in form, with perfect cleavage, but not preserving outward crystal form. Analyses made of the blende in the laboratories of the Virginia Polytechnic Institute on selected pieces col- lected by the writer from the mines in Albemarle, Wythe, and Smyth counties gave: # Wythe county Wythe county Smyth county Albemarle Austinville Cedar Springs Rye Valley county Per cent. Per cent. Per cent. Per cent. ATIC? said yxte ygrnenos, io hanccteondsanwneeas 65.01 66.76 66.94 62.11 Sulphur’ s.cicmessccesiaac 31.93 33.44 33.26 34.45 IPON: sa sax nwsne ynwa aes 1.94 0.50 0.30 3.44 TEAMING 6 Seccianaringd a cae tncain aaneiseus 0.08 trace trace 0.05 Magnesia ............4.. none trace trace none SUICHF- Acree tania ativsternthaeaned uae 0.33 0.10 0.08 0.26 TOGA sc scasivan’ covutederataleers 99.29 100.80 100.58 100.31 Zine aaron i ee er ee 99.94 99.56 99.86 92.70 Smithsonite—In some of the mines smithsonite forms a fairly im- portant ore of zinc. It occurs in the residual clays derived from the magnesian limestone concentrated, usually, in the bottom portions of the clays and resting immediately on the irregular weathered surface of the limestone, as shown in figures 90 and 92. It is intimately associated with calamine. Smithsonite occurs both in the granular and earthy forms, principally the latter, as crystalline incrustations, and as a porous or spongy material with the cavities frequently filled with the powdery and earthy form of the ore. In color it varies from light gray through yellow to brown according to the impurities present. ZINC AND LEAD. 525 The calculated amounts of smithsonite and calamine, from analyses made by F. P. Dewey, on specimens of the ore of the Falling Cliif zinc mine at Bertha, Wythe county, gave the following results: Per cent. Per cent. Smithsonite .............cceee cues 75.52 79.99 Cea MAINE sos scscsicaingsdnelanaeg wsscnie-aceva teva. 22.22 12.05 Calamine.—This mineral formed originally the principal secondary ore of zinc mined in the district. It is much more abundant than smithsonite. In occurrence it is closely similar to that of smithsonite with which it is intimately associated. It is indeed very difficult and in some cases impossible to separate the two ores, so intimately admixed are they. Calamine occurs in the residual clays, usually in the bottom portions, immediately on and next to the irregular weathered surface of the under- lying limestone, as shown in figures 90 and 92. Beautiful white incrusta- tions of the mineral presenting mammillary and stalactitic surfaces have been observed in places between layers of the more solid massive ore. Granular masses and honey-comb forms of calamine were quite common. Much of the calamine formerly mined at Bertha, in Wythe county, is re- ported to have been in sheet-form, rarely in contact with the limestone but concentrated several inches away from the limestone surface and having the intervening space filled with a mixture of loose powdery calamine and smithsonite. The following chemical analyses of specimens of calamine from the mines of Wythe county, indicate the general character of the ore: I II TIT Per cent. Percent. Per cent. Zine oxide..........-... 67.88 67.42 67.15 Sili¢a. ce.ctdaucecse tee 23.95 25.01 25.33 Water ....... revise rovestenattoe 8.13 8.32 TAT PO balay aidesteaeeiiees euecetys 99.96 100.75 99.95 Specific gravity......... 3.338 3.40 J. MacIrby. Chemical News, 1873, XXVIII, 272. II. Genth, F. H. Proceedings of the American Philosophical Society, 1885, XXXIII, 46. III. Jones, A. Journal of the American Chemical Society, 1892, VI, 620. Calculated amounts of calamine and smithsonite from analyses made by F. P. Dewey on specimens of the ore from the Falling Cliff zinc mine at Bertha, Wythe county, gave the following results: Per cent. Calamine ...........0.ee008- 88.52 Smithsonite ................. 3.26 526 MINERAL RESOURCES OF VIRGINIA, “Buckfat”—“Buckfat” is the name applied by the miners to a mixture of clay with the minerals calamine and smithsonite. It is not a definite mineral but is a lean ore generally too low in zine to be profitably used in the present practice of smelting. The zinc content shows wide varia- tion, however, ranging oftentimes much higher than given in the analysis below. It is both hard and soft and is accordingly called by the miners “hard buckfat” and “soft buckfat.” Its separation from the rich ores is effected by hand-sorting and by subsequent washing and jigging. The treatment practiced at the Bertha mines previous to the conversion of the ore into spelter consisted in violently washing “soft buckfat” in water and crushing and jigging the “hard buckfat.” Heyward gives the following analysis of a zinc-bearing clay from the neighborhood of the Bertha mines: Per cent. Bilicds oicsers eee earns s age 37.38 AMUN: ance 5 ese des 4 ase avevdea aeuns 24.67 Ferric oxide................. 6.34 ANC OX10 Cie. 5 scies ee idiee ya eens > 12.10 Magnesia, oss iaees cnwrsaavas 0.27 POtas he: vse jcse eia dynes esarsvneal Palanan 0.47 SOG a) secivatrimensva nr aina essen See pao 0.27 Water 100° C.—............. 6.69 Water 100° C.+............. 10.35 DL Otall sce suv aie dscns eetads 98.54 Associated Ores. Over the southwest Virginia area iron-ores and manganese-ores, especially the former, are very abundant in some of the larger zinc mines. The iron-ores have been somewhat extensively mined in some places and in several instances mines formerly worked for zine ores are now being worked for iron. Pyrite is rather a frequent associate of galenite and sphalerite in some of the mines. It occurs in the fresh limestone below the belt of oxidation. It is by no means uniformly distributed through the rock, but in places it is sufficiently concentrated to be noticeable, and rarely, if ever, is it present in quantity large enough to be hurtful to the lead and zine ores. Limonite comprises the principal iron ore mined in association with.the zinc ores. Hematite is less common than limonite. Black oxide of manganese is a frequent associate in some of the mines. Associated Minerals. Named in the order of their importance, the associated minerals arc dolomite, calcite, fluorite, quartz, and barite. Of these dolomite and ZINC AND LEAD. 527 calcite comprise the dominant minerals, with some barite and less fluorite. Fluorite and quartz make up the gangue minerals at the zinc and lead mine in Albemarle county. Calcite occurs only sparingly at this mine while fluorite is the dominant mineral. Over the southwest Virginia area dolomite and calcite fill fractures between the magnesian limestone frag- ments in the form of crystalline masses, forming a limestone breccia. The relative proportions of cement (recrystallized calcite and dolomite) to rock fragments vary widely. Numerous analyses of specimens of the calcite and dolomite collected over the southwest Virginia district gave nearly pure calcium carbonate for the former and a ratio of calcium to magnesium of 1:1 for the latter, which is the ratio of normal dolomite. The fluorite found at the Albemarle county mines is usually of white color though the violet shade is fairly common, which latter is sparingly found at several localities in the southwest Virginia zinc mines. Alteration of the Lead and Zine Ores. The important secondary ores comprise calamine, smithsonite, and cerussite, which have been derived from the original sulphides, sphalerite and galenite, by the usual processes of weathering. Until recently only the oxidized or secondary ores have been mined, but preparation is now being made to mine the original sulphide ores in the fresh limestone. Mode of Occurrence. The sulphide ores—The bulk of the sulphide ores belong to the disseminated replacement breccia type. As a rule the process of replace- ment has played an important part in the ore formation, but in some instances very little replacement of the limestone by the ore is indicated. In the latter case the ore would be more properly designated a straight breccia tpye in which practically no replacement has occurred. On the other hand the ore has a, at several places largely through a replacement process. The breccia is usually made up of sharp-angled fragments of the country-rock, magnesian limestone, cemented by a matrix of white crystal- lized calcite and dolomite and blende, with or without replacement of the limestone fragments. The breccia-zones are associated with faulting and folding. Not all parts of the breccia-zones are mineralized, but the ore is distributed at somewhat irregular intervals. Where mineralized and so far as can be judged from developments the ore continues with depth. 528 MINERAL RESOURCES OF VIRGINIA. When occurring in the same mine the blende and galenite are inti- mately admixed. Many parts of the limestone, both small and large, show all blende with only here and there sparing dissemination of galenite through the rock, closely intermingled with the blende. Other parts of the limestone usually much smaller in area show a preponderance of galenite with little or no disseminated blende. The same relation holds true for the very small amount of pyrite present in the rock which may be intermingled with the galenite or blende or both. The oxidized ores.—-Where sufficient developments have been made, as in the mines of Wythe county, the oxidized ores usually show much richness and they are often concentrated in massive form as large irregular masses and layers. This is especially true of the calamine which forms the dominant oxidized ore. So massive was the calamine in places in the old Bertha mines that blasting is reported to have been necessary at the time for its removal. Concentration of the oxidized ores has taken place principally at and uear the bottom of the residual clays, closely hugging the irregular weathered surface of the limestone, as shown in figures 90 and 92. Frequently several inches separate the massive form of the ores, calamine and smithsonite, from the limestone. This space is filled oftentimes with a loose, powdery mixture of the two ores. At times the partly decayed limestone in pul- verulent granular form partly or entirely fills the space. Much galenite is intermingled in places with the concentrated calamine and smithsonite in the lower portions of the clays. Usually when associated with the oxidized ores in the way mentioned the galenite is observed to diminish in quantity upward more rapidly than the calamine and smithsonite. Smithsonite, which is present in much smaller quantity than calamine, is ordinarily admixed with the calamine and the two concentrated in the basal portion of the clays next to the limestone surface. Cerussite occurs largely in stringer form penetrating the clays and as a coating on the nodules and masses of galenite. These stringers vary much in thickness and extent but in the larger ones a nearly vertical position in the clays is often assumed. As a rule the residual clays are highly ferruginous. Limonite com- poses the principal part of the clays in some of the mines and it was derived in part at least from the oxidation of the original pyrite dissem- inated through the limestone in association with galenite and sphalerite. It is usually of good grade and several of the mines formerly worked for zine ores are now being worked for iron ore. The relations between the ores, the limestone and the clays, as described above, are shown in figures 90 and 92. MINERAL RESOURCES OF VIRGINIA. PLATE LXXVI. Fig. 2.—View in open cut, showing limestone “chimneys” at Bertha zinc mines, Bertha, Wythe county. : LIMESTONE WEATHERING, ZINC MINES, WYTHE COUNTY, VIRGINIA. ZINC AND LEAD. 529 Relation of the Ores to Geologic Structure. The lead and zine district of the Great Valley region of Virginia- Tennessee is one of intense deformation—folding, faulting, and brecciation. Moreover, the localization and concentration of the ores follow closely these structural lines. Mineralization has not taken place through all parts of the breccia-zones which follow the anticlines, but only along some of the zones in places and at irregular intervals have the ores accumulated. Wherever the ores have been found they have been noted in some part of an anticlinal fold in or near a faulted breccia-zone. The ores are accord- ingly of the breccia type, as shown in figures 94, 95, and 96. At Austin- ville, Wythe county, the ores appear in well-defined ore-bodies which have resulted largely from a replacement process, mostly where the joint and bedding planes of the limestone intersect and on the limb of a faulted anticline. Origin of the Ores. The statements here made concerning the genesis of the zinc and lead ores apply only to the Great Valley region of Virginia and Tennessee. So far as known there are no igneous intrusions found within the limits of this region with which to connect the ores. There appears no good reason for regarding the ores as having been derived from profound depths as indeed the evidence is against this source of the material. The field evidence favors the original deposition of the ores in the Cambro-Ordovician limestone in disseminated form, but so very sparsely disseminated as to render subsequent localization and concentration of them by underground waters along certain structural lines, previously indi- cated, in their present workable form. In some of the Virginia deposits the ores are intimately associated with the more carbonaceous layers of the limestone, which indicates that the ores were probably introduced as sulphates and were reduced by the organic matter in the limestone and deposited as sulphides. In addition to the sulphide cycle, it seems probable that there was a second or sulphate cycle, in which the metals were transported as soluble sulphides and were deposited as such. This was probably the process of deposition at Austinville and in some other of the Virginia deposits. Many of the deposits show little or no replacement of the limestone substance by the ores. The mingling of the ore-bearing solutions with other solutions in the faulted breccia-zones, and the reaction of the ore-bearing solutions 530 MINERAL RESOURCES OF VIRGINIA. on the wall-rock, limestone, largely resulted in the precipitation of the ores, where not connected with reduction and precipitation by organic matter. Description of the Mines. The production of lead and zinc ores in the State has been almost exclusively from the Valley region of southwest Virginia. The ores have been worked in the following counties of the Valley region: Botetourt, Roanoke, Montgomery, Pulaski, Wythe, Smyth, and Russell. Of these Wythe has been the important producing county. Work in the other counties has been largely in the nature of prospecting. THE GREAT VALLEY REGION. Roanoke and Botetourt Counties. Ores of zinc and lead have been opened at two places in the vicinity of Roanoke City, namely, on the Martin property 234 miles southwest of Roanoke City, in Roanoke county, and just across the county-line in Botetourt, a half mile northeast of Bonsack station. The openings on both places are of long standing and will not exceed 50 feet in depth. The developments here comprise some half dozen small openings in the lime- stone. The Martin prospect—An examination of the dumps at the openings showed the occurrence of the sulphides of lead, zinc, and iron in close association. No ore was seen in place. The Bonsack prospect—The development consists of a single shaft less than 50 feet deep. At the Bonsack prospect the dump showed some pyrite, a little chalcopyrite and sphalerite, the former predominating. No galenite was noted. Neither of these properties has passed beyond the prospecting stage. , Montgomery County. More or less prospecting for zinc and lead ores has been done in a number of places in this county, but as yet no productive areas of the ores have been found. The localities at which prospecting has been done are as follows: In the extreme southwestern part of the county on Bony’s creek; several miles southeast of Shawsville on the Langhorn estate; on the Walker and Vaughn properties south of the Norfolk and Western Railway between Shawsville and Big Tunnel; about 2 miles south of Christiansburg; and on the Cloyd property on New river, about 8 miles south of Blacksburg. ZINC AND LEAD. 531 Pulaski County. The known occurrence of zinc ores in Pulaski county is limited to the extreme southwestern part of the county, near the Wythe county line and in the vicinity of Allisonia and Delton along New river. The ore com- prises zinc blende occurring in the unaltered limestone and the oxidized ores, calamine and smithsonite, concentrated in the residual clay derived from the limestone. Openings have been made at 3 places only, one of which has produced ore in sufficient quantity to be workable. The Delton mines.—The Delton mines are located about one mile south of Delton and about the same distance west of New river, where crossed by the Cripple Creek branch of the Norfolk and Western Railway. These mines were opened by the Bertha Mineral Company in May, 1902, and were continuously worked until December, 1903, when it is claimed that the ore pinched out, about 8,000 tons of ore having been mined. The entire output from these mines was of the oxidized ores, comprising zinc silicate, calamine, and zinc carbonate, smithsonite. After concentration the product contained 40 per cent. metallic zine, 0.5 per cent. lead, and 5 per cent. iron. The Forney openings.—Two openings were made in the limestone, several years ago by Mr. B. 8. Forney, on the opposite side of New river from each other and about one mile northeast of Allisonia. The opening on the south side was a shaft sunk to an unknown depth, and that on the north side of the river comprised a tunnel driven into the limestone slope at an elevation of about 300 feet above the river level. Beautiful specimens of light yellow zinc blende were noted on the dump at the tunnel. Zinc blende was observed in the limestone in the bed of New river, during the construction of a coffer dam across the river, at a position nearly opposite the shaft and tunnel on the two sides. Wythe County. Wythe county has been and is at present the main producing county of lead and zine ores in Virginia. At least nine-tenths of the lead and zine ores produced in the State has been from the Wythe county mines. The mines at Bertha and Austinville in the extreme southeastern corner of Wythe county have produced practically the entire output in these ores. It was here that the first mining of lead and zinc ores in the State was done, dating back more than 150 years. Until about 2 years ago the ores mined included the oxidized forms concentrated at only slight depths 532 MINERAL RESOURCES OF VIRGINIA. below the surface. Recent exploitation below this level has developed the presence of original sulphide ores in the fresh rock, which, at Austinville, appear to be sufficiently concentrated in places to be workable. At Cedar Springs, 22 miles west of Austinville, and in the southwest corner of Wythe county, zinc blende is being mined and milled. The ores mined include calamine, smithsonite, sphalerite, galenite, and cerussite. Pyrite occurs sparingly in some of the mines in association with sphalerite and galenite. The Bertha Zinc mines.—The old Bertha zine mines, located about one mile south of Bertha, a station on the North Carolina extension of the Norfolk and Western railroad and 20 miles southwest of Pulaski, have produced a larger quantity of zinc ores than any other mines in the State. These mines were regularly opened in 1879 and were systematically mined for zine ores until 1898, since which time the property has been worked for iron ores by the Pulaski Iron Company. The annual output in zinc ores from these mines was large and comprised only the oxidized forms, silicate and carbonate of zinc. Mining was confined entirely to the residual clays between and around the limestone chimneys, with a depth in some places of nearly 100 feet. (Figure 90.) Plate LXXVI, figures 1 and 2, are views of the limestone chimneys in the Bertha mines after the stripping of the residual clays. Figure 91 shows the relations of the soft ore to the limestone chimneys and the residual clay, and the method of mining the ore. The Austinville Lead and Zinc mines.—The Austinville Lead and Zine mines, owned by the Bertha Mineral Company, are located in the south- eastern corner of Wythe county, 29 miles southwest of Pulaski by rail and 10 miles west of the Bertha mines described above. They are further located about a quarter of a mile south of New river on the limestone plateau, at an elevation of 290 feet above the river. These mines were first worked more than 150 years ago when lead ores were mined by Colonel Chiswell, in 1750. The ores occur in a metamorphosed zone along the southeast limb of an anticline, which trends northeast-southwest and is cut through by New river at this point. The limestone along this zone has been crushed and broken and cemented, and, in many places, recrystallized. So extensive has been this metamorphism in places that the original lime- stone bedding is obscured. In many places, however, the bedding planes are sharply defined, dipping on an average of 45° southeast. J ointing is rather strongly emphasized in the limestone at the mine openings. MINERAL RESOURCES OF VIRGINIA. PLATE LXXVII. Fig. 1.—View showing weathered limestone surface in open cut at Bertha zine mines, Bertha, Wythe county. Fig. 2.—Weathered limestone surface; bedding obliterated by recrystalliza- tion of limestone. Austinville lead and zine mines. LIMESTONE WEATHERING, ZINC MINES, WYTHE COUNTY, VIRGINIA. 533 ZINC AND LEAD. ay} pus Siw aver TT ene res W3HSVM ‘oumiaaal isi a wise Nep, '0, wen ny Ning is se sht — pelea, Hoses | Tere a, CCRIPPLE CREEK EXTension) VE Oo a : wil a4) BS\ 2 » S3I\ \e & 338 4 \s ? SSI UN os o Rail aS » Spit ~ A t& a8 z% vA ° gall Al wos ; Xo = all a \ 3 % Ae % | . ao Mp 4 - Ae > oven \7 4 hee 7 ‘D a} NN 8 cr \ ID S » & WY tas 10S 7 2\ oO SZ) S$) D---® /€ yk ee Pes Ra ‘eo 4 . s 0 =, \ o ; Song “e ba Js ! \ {| SUNK Ep is is \ F Ps is f Bevey if | wf ee Vad - ° ynesTone yw oe Y BUNKER HILL ws hn or” \ Y aX - \ i gor ss z Lae BD, “7 g on /y if Ss ~3_ sop” “7 » y / y z=, a t f , © é/ 7» ° sD x % %D e 2 AZ ’ je ° / z& gs 7 o t, / 2 Sf eo” ° zm LW / £f 2 Lt Py ee 2 “& Y JS %& a a # Xp € SA 7 7 oO & c GZ at & ny 4, we x sa = pee oP = y S 0? LP o Ny XS ; YF & eset ee \\ Fig. 93.—Sketch map of the Austinville lead and zinc mines, showing posi- tion and general character of workings, and line of contact between sand- stone and limestone. 538 MINERAL RESOURCES OF VIRGINIA. The New River Mineral Company’s mines——The mines of the New River Mineral Company, located near Ivanhoe, have been extensively worked for limonite or brown iron ore. Much zinc ore, comprising cala- mine and smithsonite, is reported to have been mined from these openings, from time to time, in winning the iron ore. Similar conditions are re- \ ¢ \ = 17 TA, ' a a™. an \-xX SAY rey) ie ¥\L be Yt Vie 1 oe \ “ - \ \ 7 S; ae Nae a: 7“ at N Le \ Ny / = \ VV _ \ > -\ \- \\ -- |\ me 4 No \ [- Tie -\% . ee \7\7Ne% AN7 NNN ADS alee {-\7 i S7ANTIN PE sraceare RFS LIMESTONE, oe EN ANTS AND DOLOMITE Fig. 94.—Limestone breccia from Cedar Springs, Wythe county, showing relations of sphaler- ite to calcite-dolomite filling and to the limestone. S i i ee g ome replacement of the limestone is ported to have obtained in the Simmerman iron ore pits nearby. The zine ores mined are reported to have been shipped to Trenton, New Jersey. The Cedar Springs Zinc mines——The mines of the Cedar Springs Zine Mining and Development Company are located in the extreme southwest corner of Wythe county, about 5.5 miles south of Rural Retreat on the main ZINC AND LEAD. 539 line of the Norfolk and Western Railway. The property comprises 387 acres of land, located along the headwaters of Cripple creek, on which numerous openings are made, extending from Cedar Springs eastward for a distance of one or more miles. The openings comprise open cuts, shafts and tunnels, and in addition to these some drilling has been done, the deepest of which reached a depth of 250 feet. The ore is of the breccia type composed of zine sulphide, practically, without galenite and pyrite. (Figures 94 and 95.) The blende is in massive form, of light yellow color, and is of exceptional purity, as shown in the analysis made by Mr. J. R. Koff, Jr., on pieces collected by the writer: Per cent. ZINC: sciences eee euwcisrawss 66.76 PSC PUT ese ce cards ccs sas iatt Rinses sae RSs 00 33.44 LEO: - ca Sjavesacerolaceseletananerare: er axitiers 50 Insoluble matter ) _Caleium carbonate fae Magnesium carbonate f e Water 110° C. Lead Cadmium $ Sees ER SE none NININ/N CALCIT. PSNI LIMESTONE CN BALK Fig. 95.—Limestone breccia from the Cedar Springs Zine Mining and Develop- ment Company’s openings, showing the relations of fluorspar to sphalerite, and to the calcite-dolomite filling. Natural size. Cedar Springs, Wythe county, Virginia. . 540 MINERAL RESOURCES OF VIRGINIA. A commodious concentrating plant has recently been built at the mines by the company for concentrating and milling the ore. Smyth County. Much prospecting for zine ores has recently been carried on in Rye Valley in the south central portion of Smyth county. Operations have been almost exclusively confined along the South Fork of the Holston river in Rye Valley, extending in a general east-west direction. The Rye Valley Mining Company’s mines.—The largest operation in the county is that of the Rye Valley Mining Company, the mines of which Fig. 96—Sketch showing relations of sphalerite and galena to fluorspar and calcite-dolomite. Rye Valley Mineral Com- pany, Sugar Grove, Smyth county, Virginia. are located a quarter of a mile north of Sugar Grove post-office, and about 200 yards from and on the north side of the South Fork of the Holston river. The openings comprise 2 main shafts and a number of small test- pits. The depths reached by the shafts are 100 and 200 feet respectively, on the dip of the rock, 60° southeast. The shafts are connected under- ground by a drift at the 100-foot level. The ore is chiefly galenite, lead sulphide, with zinc blende in close association at the bottom of the 200-foot shaft. (Figure 96.) The total production from this mine is reported at about 25 carloads of ore, which was hand picked, there being no concentrating mill on the property. Other properties in Smyth county, which have been considerably pros- pected but which have not yet produced ore, are: The Calhoun, located ZINC AND LEAD. 541 about 2 miles west of Sugar Grove post-office; the Virginia Lead and Zinc Company on the Scott place, located about one mile south 80° west from the Calhoun openings ; the Livesay, situated about 2.5 miles south 70° west from the Scott openings; the McCarter place, located about three-quarters of a mile southwest of the Livesay place; the Martin prospect, located about 4 miles north 80° west of the McCarter openings; and the Van Hoy prospect, located about one and three-quarter miles south 80° east of the Martin place. The openings on the above places comprise in part shafts, open cuts, and pits, some of which have been dug to a depth of 50 feet and more. An examination of these during the spring of 1905 showed, at that time, fairly encouraging indications of workable zinc ore on several of the properties. On the Scott place the blend closely resembles that described above at Cedar Springs, in Wythe county. An analysis of selected pieces of the ore from this place, collected by the writer, gave Mr. J. H. Gibboney the fol- lowing results: Per cent. ZINC sisrieis canine saaimen ee eae ae 66.94 DROW. sacais tenn waseancgosasindiss wlelainaacata nu 30 SUIPHUP exe caccaneiene d semurers 33.26 Silica. eaieu nad wee Soe mare ee ee 08 DIM? 5.5 eke netsh wae ares trace MASNESIA si seca wesarcd ans trace DG ye eatasors res aca sessed sue dveeacevs 100.58 Zine sulphide................ 99.86 Russell County. Zinc ores have been mined at only one locality in Russell county, namely, cn Copper creek, about 7 miles south of Castlewood, a station on the Clinch Valley division of the Norfolk and Western Railway. Developments have thus far been entirely limited to the Osborn place, although ore is re- ported on several of the adjoining properties. The developments include one large main pit and numerous small test-pits, with an average elevation above Copper creek of about 350 feet. The property has been worked at several different times by different parties, and much money has been spent in developing it. The ore comprises calamine, sphalerite, and some admixed galena. The chief difficulty in mining this ore is the distance from the railroad and the rough mountainous area over which the ore must be hauled for shipping. MINERAL RESOURCES OF VIRGINIA. 542 THE PIEDMONT OR CRYSTALLINE REGION. Albemarle County. it of lead and zinc ores in Albemarle county marks the The single depos only type of its kind yet known in The mine is owned by the and is located 2 miles slightly north of the south. Albemarle Zinc and Lead Company, Zee AVA S VTLS AIX eSEO SN Kae 8A a NleV Vb yA syle, eee Syeary IN MNT SE San 2 INS M15 S08 at Sera avae “ Ne yo Fon FX Rs MEN NN es IN me ANN Ty NS ARIS rp AN t “xy a NWT \ NOLES “a aNn"try NT. CUE AREA AN LANE ee a te Albemarle Zine and Lead About one-third natural size. ite and galenite. Company’s mine, near Faber. Fig. 97.—Specimen from fluorspar lens, showing distribution of the sul- phide minerals, sphaler: east of Faber, a station on the Southern Railway, in the eastern Blue Ridge foot-hills. The main developments comprise 3 shafts, sunk respectively to depths of 25, 50, and 120 feet, and separated by a distance of about 1,000 feet between the two extreme shafts. In addition to the 3 shafts, an adit ZINC AND LEAD. 543 level has been run into the ridge from the valley bottom, and a cross-cut run from the adit on and along the vein for a distance of 140 feet. The rocks in which the lead and zine ores occur are metamorphosed crystalline schists, cut by a series of basic igneous rocks of the diorite and diabase types. The metalliferous vein is traced for a distance of several miles. It is of variable width, with an average of 4 feet; the strike is north 45° east, exactly paralleling the diorite dike 25 feet distant, on the northwest side; and it dips 80° to 85° northwest. Where opened the vein is of the lenticular type, composed of bulbous bodies of fluorspar mixed with some quartz, through which the ore, blende and galena, is distributed. The ore, consisting of blende and galena, occurs chiefly in the fluorspar lenses, although the schists next to the lenses is often more or less min- eralized. Figure 97, a drawing of a large mass of the ore-bearing fluorspar- quartz broken from one of the lenses, illustrates the typical occurrence of the ore. Some chalcopyrite and smithsonite occur in addition to the principal minerals, blende and galena. Cerussite and azurite were reported some years ago from the dumps. The galena is argentiferous, and arsenic and antimony are reported in very small quantities. Fluorspar is the principal gangue mineral. Specimens of the mineral collected by the writer gave Mr. J. H. Gib- boney the following results on analysis: Per cent. 62.11 3.44 34.45 0.05 0.26 The following analysis was made by Professor W. H. Seamon on a sample of the ore collected by him and believed to represent an average of the vein at that time: Per cent. FANCY isieacindesioencuiea panel eeie 32.00 Lead) axcsdawes sawed oon wees 4.02 PEON: «5. haiduainesaigh aires adonetacdiaa areas 1.88 Calcium 9.09 Insoluble residue 2 to 3 oz. Copper trace Arsenic trace Through the kindness of Mr. Wilkens U. Greene, Mining Engineer in 544 MINERAL RESOURCES OF VIRGINIA. charge of the plant, several bags of the lead and zine concentrates were sent to me and were separately analyzed with the following results: Lead Zine concentrates concentrates Per cent. Per cent. Lead) «sccus sexe are ensawlnwve 63.05 6.02 ZAG! s3sita: a edesteracchentverd, cleat vate Ss 12.12 47.88 TOM! fervsrosshads siiciucsriaisneds we eas ane 3.16 7.26 Copper’ asexsexcaeenaseneeuee trace 0.94 Sulphur ............-2 ee eee 19.32 29.52 Calcium fluoride.............. 1.31 4.74 Insoluble residue............. 1.08 2.90 TOtallecrecioe aeeiaieaenartyese 100.04 99.26 Equipment and treatment.—The equipment includes a concentrating mill of 80 tons copacity per 24 hours, recently completed; 8 sets of dry jigs; crusher, dryer, rolls, and screens; and steam power of sufficient horse- power for operating the entire plant, including hoist, tram-cars, and cable for conveying the ore from the shaft to the mill. Compressed air drills are used in the underground mining. The dry process for separating the ore is employed in milling, which differs essentially from the wet process in the form of jig used. The Krom jig is used, made of screens of different size meshes, substituting air for water. These can be set to 700 puffs of air per minute. At the Albemarle plant the ore is crushed and sized to pass a 16-mesh screen. All ore above this size is passed back to the rolls and crushed until properly sized. The ore goes thence to 4 rough jigs, and from here to 4 finishing jigs. It is claimed that the tailings are practically freed from all ore by this process. If not the jigs can be so regulated as to make a nearly complete separation. The trials so far made at the mill required the jigging process to be re- peated several times on the same ore before a clean concentrate was obtained. Methods of Mining the Ore. Until very recently the mining of lead and zinc ores in Virginia was limited entirely to the surface belt of weathering—the residual clays. The mode of occurrence and the character of the ores to be mined demanded the employment of methods used in mining secondary concentrated ores. Accordingly, a system similar to that practiced in mining brown iron ores was employed, modifications being made to meet the changed conditions. Practically all the ores mined are oxidized forms, concentrated chiefly in the lower portion of the clays and are won within a depth of 100 feet. The mining has largely been by open cuts, tunnels and shafts. The ZINC AND LEAD. 545 open cut method differs from that of mining the iron ores in that the former is one essentially of stripping, while in the latter the ores and en- closing clays are mined together and sent to the washer for separation. The open cut method was later changed to that of shaft and drift as shown in figure 91, page 534. The mining of sulphide ores in the fresh limestone has only recently begun at Austinville, in Wythe county. Preparation and Smelting of the Ores. The preparation and treatment of the ore can best be explained by outlining the method used at Austinville. The run-of-mine ore at Austin- ville averages in composition from 28 to 30 per cent. of metallic zinc, from 8 to 10 per cent. metallic lead, and from 8 to 10 per cent. metallic iron. The method of treating the Austinville ore from the time the ore is mined until it is ready for the furnace at Pulaski is, briefly, as follows: The ore as mined, is carried by trolley to tipples, from whence it is carried by tram-cars to the mill, and dumped on a 4-inch grizzly; thence to a log washer, through a 9x24-inch Blake breaker set at 1.5-inch; and thence to a 14x24-inch corrugated rolls, set at 6 millimeters. From the corrugated rolls the ore is carried to a second log washer, thence to elevator and sizing screens of 6-mm., 2-mm., and 1-mm. mesh, respectively. The oversize from the 6-mm. screen goes to smooth rolls, 12x18-inch in size, and is returned to the system or second log washer. The undersize from the 6-mm. on 2-mm. screen goes to the 4-compartment Cooley jigs; 1st hutch and side draw making clean lead; 2d hutch and side draw, mid- dling, recrushed and returned to the system or second log washer; 3d and 4th hutches, clean zinc. Tails are passed to settling boxes; head of boxes reworked. Lighter material goes to the oxide furnace. Undersize from 2-mm. on 1-mm. screen goes to the 5-compartment jigs; 1st and 2d hutches and side-draw making clean lead; 3d hutch and side- draw, middling; 4th and 5th hutches and side draw, clean zinc. Tails go to boxes. Undersize from 1-mm. screen goes to 3-compartment classifier; 1st and 2d draw to 6-compartment jigs; Ist and 2d hutches and side draw, mid- dling ; 5th and 6th hutches and side draw, clean zinc. Tails go to boxes. Third draw from classifier and overflow goes to the 3-compartment double jigs; 1st and 2d hutches clean lead; 3d hutch, middling, reworked. Tails go to boxes. The middlings and tails from all jigs are treated in 4-compartment jigs 546 MINERAL RESOURCES OF VIRGINIA. as described above. The overflow from 1st and 2d log washer, except the lower end or lighter material, goes to settling boxes, 25 feet long and 8 feet wide; thence to the oxide furnace. The lead concentrates, averaging lead, 57 per cent.; zinc, 4.8 per cent. ; and iron, 3.29 per cent., go to the Scotch hearth furnace, which makes metallic lead and gray slag, the latter averaging lead, 31 per cent.; zinc, 25 per cent.; and iron, 13.3 per cent. This slag goes to the slag furnace, which makes metallic lead and slag, averaging 3.5 per cent. lead. The zinc concentrates are carried by tram cars from the mill to the separators, where they are put through a revolving dryer to expel moisture and combined water to the amount of 7 per cent. Thence to a water-cooled scraper-conveyor to the top of the building by elevator to sizing screens of 9.5-mm., I-mm., 2-mm., and 0.25-mm. holes. Oversize from 0.25-inch screen is returned to 12x14-inch rolls set close. Undersize re-enters the system. From screen to bins, four sizes. The four sizes, which pass through screens, go to Wetherill magnetic separators, one 4- and one 6-magnet machine; the smallest sizes going to the smaller machine. Heads from separators, containing iron, 47 per cent., and zinc, from 5 to 7 per cent., are shipped to the iron furnace. The capacity of the mill is about 90 tons of raw ore per day of 10 hours. Zinc oxide plant.—This plant, consisting of 12 furnaces, has only re- cently been added for the purpose of utilizing the low-grade ore and tail- ings, which were formerly discarded. The grade of ore, including tailings, used for making the oxide will average from 15 to 20 per cent. metallic zinc. ‘The zinc oxide made is sent to the Pulaski furnaces where it is used for making spelter. The oxide made is white, and contains about 4 per cent. of lead, and averages from 70 to 80 per cent. of metallic zinc. The suc- cessful operation of this plant at Austinville is of great importance, since it furnishes a ready method for utilizing low-grade zine ores, which have elsewhere been claimed not to be profitable for making spelter. The Bertha Zinc Smelting Plant. The only zinc smelting plant in the south, located at Pulaski, Virginia, is owned and operated by the Bertha Mineral Company. This plant was built shortly after the beginning of zine mining at Bertha, Wythe county, Virginia, in 1879. It was remodeled and enlarged in 1886, and, at present, it consists of 10 large smelting furnaces, ore-sheds or bins, refiners, coal-pit, engine room, pottery, metal storage houses, and a roasting furnace. Suf- MINERAL RESOURCES OF VIRGINIA. PLATE LXXIX. Fig. 1—General view of zinc smelting plant of the Bertha Mineral Com- pany, Pulaski. Fig. 2.—View of dismantled zinc furnace, Bertha Mineral Company, Pulaski. ZINC SMELTING PLANT AND FURNACE, PULASKI, VIRGINIA. ZINC AND LEAD. BAY ficient railroad trackage is in operation around the plant for shifting the cars; and a narrow-gauge road is operated between the plant and the com- pany’s coal mine at Altoona. Plate LX XIX, figure 1, is a view of the smelting plant. Spelter. The high grade spelter made by the Bertha Mineral Company, at Pulaski, has a world-wide reputation. Three grades of spelter are made, branded according to purity: “Bertha Pure Spelter,” “Old Dominion,” and “Southern.” The “Bertha Pure Spelter’ is sold under a guarantee of 99.98 per cent. of metallic zinc. The following analysis gives an idea of the composition of this grade of spelter : Per cent. ZANG) ois lacedein ies ieRiaratn ganna 99.981 TOM sésicareceansdar cen dbase alton isons 0.019 Lead .... trace Sulphur .. trace Silicon none Carbon none Arsenic none The “Old Dominion” brand of spelter contains from 0.2 to 0.4 per cent., and the “Southern” brand from 0.8 to 1 per cent of lead. References. Boyd, Chas. R. The Wythe Lead and Zinc Mines, Virginia. Engi- neering and Mining Journal, 1893, IV, 561-562, 566. The Mineral Wealth of Southwestern Virginia. Trans- actions American Institute of Mining Engineers, VIII, 338-348; also V, 81. _ The Ores of Cripple Creek, Virginia. Transactions American Institute of Mining Engineers, XII, 27- 40. The Mineral and other Resources of Southwestern Vir- _ginia. The Virginias, 1880, I, 39. Case, William H. The Bertha Zinc Mines at Bertha, Virginia. Engi- neering and Mining Journal, 1893, LVI, 292-294; Transactions American Institute of Mining Engi- neers, XXII, 511-536. Clere, F. L. The Mining and Metallurgy of Zinc in the United States. Mineral Resources of the United States, 1883, 358-386. Dewey, F. P. Note on the Falling Cliff Zinc Mine. Transactions American Institute of Mining Engineers, X, 111- 112. 548 MINERAL RESOURCES OF VIRGINIA. Dunnington, F. P. Analysis of Aragonite Containing Lead from the Aus- tinville Mine, Wythe County, Virginia. Proceed- ings American Chemical Society, II, 14. Bertha, Virginia, Zine Ore and Spelter. The Vir- ginias, 1881, II, 147. Fontaine, Wm. M. Notes on the Geology and Mineral Resources of the Floyd, Virginia, Plateau. The Virginias, 1883, IV, 185-193. Genth, F. H. Contributions to Mineralogy. Proceedings American Philisophical Society, 1886, XXIII, 30-47. Heyward, B. H. Ona Zinc-Bearing Clay from the Neighborhood of the Bertha Zinc Mines, Pulaski County, Virginia. Chemical News, 1881, XLIV, 207; The Virginias, 1883, IV, 4. Higgins, Edward, Jr. Zinc Mining and Smelting in Southwestern Vir- ginia. Engineering and Mining Journal 1905, LXXTX, 608-610; 658-659. McCreath and The New River—Cripple Creek Mineral Region of d’Invilliers. Virginia. Harrisburg, Pa., 1887, 18, 24, 40, 51, 54- 58, 70-76, 82, 89. McDowell, E. H. Stripping Ore Deposits. Transactions American In- stitute of Mining Engineers, XVIII, 627-633. Moxham, E. C. Zine Smelting at the Bertha Works, Virginia. Engi- neering and Mining Journal, 1893, LVI, 544. Payne, C. Q. The Zinc Ores of Virginia. Engineering and Mining Journal, 1904, LX XVII, 544. Seamon, W. H. The Faber Lead and Zinc Mines. The Virginias, 1885. VI, 47. Stevenson, J. J. A Geological Reconnaissance of Bland, Giles, Wythe and Portions of Pulaski and Montgomery Counties, Virginia. Proceedings American Philosophical So- ciety, 1887, XXXIV, 61-108. Watson, Thomas L. Lead and Zinc Deposits of Virginia. Geological Sur- vey of Virginia, Bulletin No. 1, 1905, 156 pages. Lead and Zinc Deposits of the Virginia-Tennessee Region. Transactions American Institute of Min- ing Engineers, 1906, XXXVI, 681-737. The Mining, Preparation and Smelting of Virginia Zinc-Ores. Transactions American Institution of Mining Engineers, 1907, XX XVII, 304-318. GOLD AND SILVER. 549 IV. GOLD AND SILVER. Historical. The earliest reference to gold in Virginia, so far met by the author, is by Thomas Jefferson, in 1782, in which he describes a lump of ore weigh- ing about 4 pounds, taken from the north side of the Rappahannock river, about 4 miles below the falls. The lump is reported to have yielded 17 pennyweight of gold. Jefferson heard of no other indications of gold in the neighborhood. The first discovery of gold in Virginia, after the date of Jefferson’s note referred to above, is reported in 1831. The Virginia Mining Company of New York, operating between the years 1831 and 1834, the Grasty tract of land in Orange county, was the first gold mining company incorporated in Virginia. The date of the incorporation was March 10, 1832. The Orange county, Virginia, deed books show that a one-half interest in a 20-year lease on the 5-acre mining tract, dated 1829, was purchased in 1831 for $30,000 in cash. In 1836 there was considerable activity in gold mining in the State, and the production was reasonably steady from the rediscovery in 1831 to 1850, the annual value being given between $50,000 and $100,000. Increased activity in gold mining in the State was manifested in the early fifties, but the Civil War almost completely stopped mining opera- tions both in Virginia and in the South generally. The first mint returns from Virginia date from 1829. Considerable activity was again manifested in the Virginia gold fields after the close of the Civil War, and milling and reduction plants were erected at various points. Many of these attempts met with only small success and in most cases they were abandoned, not because of the lack of ore but because, largely, of bad management and inexperienced mining, together with the refractoriness of the Virginia ores. Distribution. Map, figure 98, shows the location of principal areas in Virginia from which gold has been mined. The principal gold deposits of Virginia are found east of the Blue Ridge and occur in the crystalline rocks of the Piedmont plateau. ‘These are arranged in a belt which begins in Mont- gomery county, Maryland, and extends across Virginia in a southwesterly direction to the North Carolina line. The belt varies in width from 15 to 25 miles and is 200 miles long, covering an area of some 4,000 square miles, with its best developed portion in Fauquier, Stafford, Culpeper, MINERAL RESOURCES OF VIRGINIA. 550 ‘seare 010 ploS [edrourid oy} Surmoys vrursstA yo dep[—s6 ‘SLT YNITOUVS HIMON 7 AL ) A ; ie @MIONALVOIGN] Svaudy MOV 1g uv 1noduyy] XTSALIVWIXOdddy SAT OZ=HON] FIVIS SViadV du0 dIOo TvdIONINd AHL SNIMOHS VINDOUIAYo dvi GOLD AND SILVER. 551 Orange, Spottsylvania, Louisa, Fluvanna, Goochland, and Buckingham counties. Gold is also found in Appomattox, Prince Edward, Charlotte and Halifax counties, which mark the southwest extension of the principal belt. Excepting Halifax no developments have yet been made in these last named counties. Gold is found in Franklin county between Pig river and Rocky Mount in quartz veins enclosed in micaceous schists. Some alluvial gold has also been noted. A smaller belt is situated on the west side of the Blue Ridge in Montgomery, Floyd, and Grayson counties, but as yet it is undeveloped and has proved of little economic importance. The work in Montgomery county has been mostly in the nature of sluicing and panning. Many of the mines in the principal belt have produced large quantities of gold, as shown in the United States mint returns tabulated below, and have been rather extensively worked. So far as is known at present very few of the mines are actively producing, although considerable prospecting is in progress and at some, extensive preparations for mining are being inade. The mines in Fauquier, Stafford, Culpeper, Orange, and Spottsylvania counties are grouped about and near the junction of the Rappahannock and Rapidan rivers in a belt about 15 miles wide. This principal belt is crossed by innumerable streams bordered by placers. General Geology. The country-rocks.—The principal rocks of the Virginia gold belt are micaceous schists and gneisses, often garnetiferous and chloritic, and in places hornblendic. They include both altered sediments and igneous imasses. The prevailing strike is north 20°-30° east and the dip is toward the east and southeast at varying angles, frequently steep, and in many cases nearly vertical. Granite masses and dikes of basic igneous rocks eccur in the region, sometimes sheared from dynamic causes. The veins.—The gold-bearing veins are quartz, which vary in texture from large crystalline masses to very fine saccharoidal grains. In structure they vary from massive to thin platy or schistose bodies, both usually penetrated by closely spaced irregular fractures. The principal metallic content is auriferous pyrite which, at times, is copper-bearing and contains more or less admixed chalcopyrite. Within the weathered zone, which extends from the surface down to local water level and accordingly is variable in depth, the quartz is rendered more or less porous or cellular and discolored or stained with iron-oxide from the oxidation of the 552 MINERAL RESOURCES OF VIRGINIA. sulphide minerals, and the liberation of free or elementary gold. The degree of porosity and staining is proportional to the amount of the sulphide minerals present and the stage of oxidation. Below the local water level the veins are fresh, the sulphides are unaltered, and elementary gold is less frequent in occurrence. From the general descriptions of the mines given below, it will be cbserved that the principal and early operations were confined largely to the oxidized portions of the veins, which yielded a free milling ore that was easy of treatment. Since then operations include the mining of sulphurets or the sulphide bodies, which require a different metallurgical treatment of the ores, in order to extract and recover the gold. The gold occurs both as free milling ore within the weathered zone and as sul- phurets below the local ground water-level. The auriferous quartz veins conform in the main to the structure, strike and dip, of the enclosing rocks; a fact which has caused various explanations to be advanced by different observers. They were regarded by some as contemporaneous with the formations in which they occur; hy cthers as true veins of injection, and formed subsequent to the schisfosity of the enclosing rocks; by still others as beds; and lastly by some as veins of segregation. As pointed out by Professor W. B. Rogers, in 1836, that although in the main the dip and strike of the veins conform with those of the enclosing rocks, the correspondence is far from being exact, for they frequently cut the schists at small angles both in dip and strike. This evidence is sufficient to establish the fact that the formation of the veins post-dates the schistose structure of the enclosing rocks. The vein structure is irregular lenticular, varying in width frem a few inches to as many feet. Often the lenticular stringers are discontir:vous. One stringer may dwindle to a thread or disappear and is replaced by another or by others. Some of the veins are remarkable for their per- sistence and continuity, conditions best illustrated perhaps by the Fisher lode in Louisa county, which has been opened along the strike for a distance of some 5 miles and to a maximum depth of 250 feet, by at least 5 mines. The gangue minerals—Excepting quartz and pyrite, the gangue minerals in the gold veins of Virginia comprise the following species: Chalcopyrite, native copper, galena, mispickel (arsenopyrite), pyromorphite, tetrahedrite, tourmaline, vanadinite, sphalerite, pyrrhotite, and siderite. According to 8. F. Emmons the telluride of bismuth, tetradymite, is found in several of the Virginia gold mines. So far as the gangue minerals are MINERAL RESOURCES OF VIRGINIA. PLATH LXXX. Map of the principal gold belt in Virginia, showing distribution of mines. Gold mines represented by the heavy black dots. Based on the topographic sheets of the U. S. Geol. Survey. Scale, 44 inch = 1 mile. GOLD AND SILVER. 553 concerned the Virginia gold ores are entirely typical in character. The ores are quartzose deposits in which pyrite is usually present, chalcopyrity common, galena, mispickel, and sphalerite are not rare. DESCRIPTION OF MINES. Fauquier County. Map, plate LXXX, shows the location of the known mines in the principal gold belt of Virginia. The mine description which follows below by counties amounts, in most cases, to hardly more than the naming and location of the known gold mines in the State. This is made necessary because of the fact that a majority of the openings are of very long stand- ing, and are at present in such condition that the geological relations are practically obscured. The gold mines are located in the southern part of Fauquier county. near Morrisville, about 8 miles southeast of Bealeton, a station on the main line of the Southern Railway. The principal mines are the Wykoff, Kelly, Bancroft, Franklin, and Kirk. Of these, the Franklin mine was the most extensively worked and comprised a 20-stamp mill. An average of 10 assays of samples of ore taken from this mine gave a reported gold value of $24.24 per ton. In 1901 and 1902 about 1,000 tons of tailings were reported cyanided from this mine, but a satisfactory extraction was difficult, presumably, because of the presence of selenium. According to Lindgren, the deposit is a strong fissure in, diorite, accompanied by an intrusion of diabase, and was worked to a depth of 80 feet for a continuous length of 700 feet. The Kelly and the Kirk mines both operated 10-stamp mills. Stowe described 3 veins at the Wykoff mine, one of which, known as the “Mill-House,” is given as 20 feet thick. The assay values of the 3 veins are given as follows: “Mill-House,” $41.28 per ton; “Tunnel” vein, same value as the “Mill-House”; “Slate” vein, $89.19 per ton. An assay of a sample of ore taken from still another outcrop gave $30.00 per ton. None of the Fauquier county mines were operating in the summer of 1906. The Kelly mine is reported to have been the one most recently worked. The Virginia Mining and Development Company is working the Liepold mine. Preparatory to opening the mine, a 10-stamp amalgamation mill was worked on the property. Stafford County. The principal mines are located in the western part of the county near the Rappahannock river. The Hagle mine, located 12 miles north- west of Fredericksburg, was extensively worked until 1894 by the Rappa- 554 MINERAL RESOURCES OF VIRGINIA. hannock Gold Mining Company. Its length of workings is 600 feet and its greatest depth is 250 feet. The Monroe, Lee, and Rattlesnake mines are in the same vicinity; the Monroe and Rattlesnake mines adjoin the Eagle on the northwest. The Rattlesnake mine was worked as a placer and large quantities of nuggets are reported to have been taken from it, which weighed from one-half to 5 dwts., and some ranging as high as 125 dwts. The Rappahannock mine, 14 miles northwest of Fredericksburg, is situated in the Hartford district, near the Rappahannock river, and was operated both before and after the Civil War. This mine was worked to a depth of more than 200 feet. Culpeper County. The Culpeper mine is located on the Rapidan river, 18 miles west of Fredericksburg. In a report made by Professor Silliman in 1836 it is stated that the average value of this ore was $25.00 per ton. Other mines in the district are the Richardville and Ellis. The Powhatan Land and Mining Company operated a mine in Culpeper county in 1894, treating the ore in Crawford mills and a 10-stamp mill in connection with Frue vanners. Spottsylvania County. The oldest mines worked in this county were those operated by the United States Mining Company, located near the Rappahannock river, in the extreme northwest corner of the county. A 2-foot vein was operated by adits and shafts, the deepest of which was 80 feet. The value of the ore mined was reported to have been $25.00 per ton and the cost of milling 80 cents per ton. The following description of some of the earlier milling methods, as practised at the mine near the Rappahannock river, is taken from a report of the Supervising Committee of the United States Mining Company in 1835, as quoted by Nitze and Wilkens in Bulletin No. X of the North Carolina Geological Survey: “The plant consists of a crushing (rolls) and a vertical mill (stamping-mill) in a building 26x36 feet. Both mills are located on the ground floor and are propelled by a water-wheel 11 feet in diameter, with a 11-foot face. The crushing-mill has 3 sets of cylinders 2 feet in length and 15 inches in diameter, the first or upper set fluted, the other smooth. The ore is thrown into a hopper on the upper floor, from which it is conducted over an inclined shaking-table to the fluted cylinders by which it is crushed to a size from 4 to 1 inch in diameter. The crushed material is equally divided and goes to the two rrr EXPLANATION OF PLATE LXXN{I. a (uoyesrodiog peoSnyeysyi pue Sarmrpy yioutpetd ey) -erursItA ‘Ajunoo e8uviQ ‘eutt} yey} 4B popele SBA |[[IU uOONpal 9} YOIYA Uo azIs oy} St AOUTAIYD aq} JO Je] Oy} OF, ‘s9}8Ig PezTUQ ay} UL zyaenb Zurrvay-pjos wory pjos Suryovsjxo ye ydutey3e worjowad ATeoyTyUEIOs 4619 OY} 0} JUOUINUOUL v sI 4, = “payetduIOD qsig way 8B Aaa Se JSOU[S St pus ‘gegy ul Aueduog Zura viuwarA 943 Aq yJINq sem AouMIYD oT, ,,e8paT esnoy eXoUL,, aq} jo Uorjs0d &@ sopnpoUr pues ‘T ‘ON espe Suoye yooy OPP Jo ySus,T @ syueserdey ‘sutea zyTenb Surlreaq-plos Jo MetA—'Z OINSLT (aorze1odiop [eolsini[eyy pue Sump, yUomMpatq ey) -erurZata ‘€quno0o aSueiQ “2z4Lenb uaa Jo syoo[q are eoBjne oy} WO Uses Siop[nog ese] ays, “Wyeys ,teddn,, sAuedmop virus -IIA-OBBOIYO IOWIO} 94} JO YNos souvjzsrp Hoys B ..“QOVA], YAV]O,, AoULIOJ oy} wo dosoyno urea zazenb asny B Jo UorTAog—T einai MINERAL RESOURCES OF VIRGINIA. PLATE LXXXI. GOLD-BEARING QUARTZ VEINS, ORANGE COUNTY, VIRGINIA. GOLD AND SILVER. 555 sets of smooth cylinders. By them it is further greatly reduced, ranging from impalpable powder to grains as large as coarse hominy. From these cylinders it falls into a sifter having the fineness and motion of the common meal-sifter, from whence the material which passes through is con- ducted to 12 amalgamators, constructed upon the principle of the Tyrolese bowls, making from 90 to 100 revolutions per minute. They perform the office of washing and amalgamating. The sand discarded by them, after being washed, is conducted through troughs to the vertical mill, where, keing reduced to an impalpable powder, it passes in the shape of turbid or muddy water to another set of amalgamators similar to those above- mentioned, and thence to the river. The portion of the ore reduced by the cylinders which pass over the sifters is conducted to the vertical mill, and is treated in the same manner.” West of the central portion of the county is a group of mines among which the Whitehall is the most prominent. Gold was first found at the Whitehall mine in 1806, and it was worked from 1848 until just before the Civil War and subsequently as late as 1884. Returns from the Philadel- phia mint show that this mine produced $1,800,000 in gold from the be- ginning of operations down to 1881. Ata depth of 28 feet a pocket 3 feet square is reported to have yielded $160,000 of gold. Some of the ore from the shaft of the Chicago-Virginia mine assayed $30.00 per ton in gold. An average assay value of 12 samples was $14.00 per ton. Prior to 1880 considerable placer work was done. Other properties in this group are the Higgins, Johnston, Pulliam, and Grindstone Htll mines. Farther south on Pigeon Run are located the Mitchell and the Good- wyn mines. In the earlier days considerable placer work was done along Pigeon Run. The placer workings of the Pocahontas Gold Mining Com- pany at Andrews in the south central part of the county comprised 150 acres in the eighties. Orange County. The gold mines of Orange county are located in the northeast corner of the county, near the Rapidan river, and along and north of the narrow- gauge railroad, operated between Fredericksburg and Orange. The first gold mining company incorporated in Virginia was the Virginia Mining Company of New York, operating between the years 1831 and 1834 on the Grasty tract, near St. Just post-office in Orange county. The Vaucluse mine, discovered and opened in 1832, is the most promi- nent one among the mines of Orange county. In 1843 its plant was valued at $70,000. A description of the milling practice at this mine in 556 MINERAL RESOURCES OF VIRGINIA. 1847 is quoted from Bulletin No. X of the North Carolina Geological survey: “The machinery consists of a condensing Cornish mining engine of 120 horse-power; the mill-house contains 6 large Chilean mills; the cast-iron bed-plate of each is 5 feet 6 inches in diameter, and on it are iwo cast-iron runners of the same diameter, the total weight of the mill being 6200 pounds. The ores, on arriving at the surface, are divided into two classes: 1. The coarse and hard ore for the stamps; 2. Slate and fine ore for the Chilean mills. This is done by means of a large screen. The very large pieces are first broken by a hammer before they are fed to the stamps. All of the ores are ground with water, each mill being supplied with hot and cold water at pleasure. Twelve inches from the top of the bed-plate there is a wide, open mouth, from which the turbid water escapes to tanks. On the south side of the steam engine is the stamp house and amalgamation mill, containing 6 batteries of 3 stamps each; these stamps, with the iron head of 125 pounds, weigh 350 to 380 pounds each. Each battery is supplied with water, and at each blow of the stamp a portion of the fine ore passes out of the boxes through the grates to the amalgamation room. Here are stationed 18 small amalgamation bowls of cast iron, 30 inches in diameter. The bowls are supplied with runners which move horizontally; in the center of these runners is an eye or opening like that in the runner of a corn-mill. The ground or finely- stamped ore, gold and water pass into this eye, and by the rotary motion of the same are brought into contact with the quick-silver deposited in the center, forming amalgam. From the amalgamators the pulp passes through 3 dolly-tubs or catch-alls, acting as mercury and gold tubs. After this the whole mass passes to the strakes or inclined planes, where the sulphurets are deposited and the earthy matter washed away. These sulphurets were formerly treated in two heavy Mexican drags or arrastras; but not answering so good a purpose, they have been altered into three heavy Chilean mills.” A 14-foot vein at the 60-foot level was reported in 1880 at the Chicago- Virginia mine at Mine Run. Other mines in the vicinity are the Randolph, Orange Grove, Greenwood, Melville, and the Grasty. The Piedmont Mining and Metallurgical Corporation of Philadelphia, Pennsylvania, incorporated under the laws of Virginia, recently obtained 930 acres of the desirable gold-bearing lands, stretching northward from St. Just post-office, near Clark’s Mountain and about 8 or 10 miles west of the Vaucluse mine, in Orange county. Several of the tracts included in this property were extensively worked and were large producers in the carly days of gold-mining in Virginia. One of these, the Grasty tract, was MINERAL RESOURCES OF VIRGINIA. PLATE LXXXII. Fig. 1—Exposure of large gold- and copper-bearing veins near the northern part of the “American Tract,” on Ledge No. 1, about 14 mile south of the “North-East” shaft. Chimney of the old Virginia Mining Com- pany’s mill, built in 1832, shown in the background. Orange county. (The Piedmont Mining and Metallurgical Corporation.) Fig. 2.—Specimens of gold- and copper-bearing quartz ore (sulphides), from Orange county. (The Piedmont Mining and Metallurgical Cor- poration.) ; GOLD- AND COPPER-BEARING VEINS AND ORE, ORANGE COUNTY, VIRGINIA. GOLD AND SILVER. 557 the first gold mine incorporated in Virginia. Five different mining com- panies formerly operated on 3 of the tracts now owned by the above corporation. These were: The Virginia Mining Company of New York, operating between the years 1831 and 1843; the Chancellorsville-Freehold Gold Mining Company of London, England, operating between the years 1853 and 1857; the Chicago-Virginia Gold Mining Company, operating between the years 1879 and 1881; the American Gold Mining Company, operating between the years 1881 and 1883; and the Gold Run Mining Company of New York, which sank the shaft north of the branch on Minc Run. The mining work done by these companies comprised a total of 578 feet of shaft-sinking, 11 shafts of which were on the Grasty tract, 3 on the Chicago-Virginia tract, and 1 on the Dickey tract; more than 1,000 feet of drifting on the veins; and about 400 feet of underground cross-cutting, tunnelling and surface open-cut work, the largest part of which was on the Grasty tract. This work proved all the veins to be gold-bearing, of good width, and carried good ore values. It is reported that the above mining companies mined several thousand tons of ore during the time of their operations, which embraced several periods of workings between 25 to 75 years ago. The reported gold values of the ore mined varied from $6.00 to $32.00 per ton. Recent develop- ment work on these properties, to a depth of 40 feet, by the Piedmont Mining and Metallurgical Corporation, show gold values made on many tons shipped to reduction works ranging from $4.13 to $201.67. Sorted ores gave assay values as high as $41.34, while concentrated ores ran as high as $103.00. The estimated probable cost of mining and milling these ores will not exceed $2.25 per ton, in a 100-ton per day plant. Louisa County. The gold-bearing rocks of Louisa traverse the central portion of the county, in a southwesterly direction, in the form of a narrow but well- defined belt. Near the center of the county and in the gold belt, 2 to 5 miles northeast of Mineral, are the famous Louisa county pyrite mines described on pages 198-202 of this volume. These large bodies of pyrite are probably contemporaneous in origin with the gold veins. The ore lenses of pyrite and the quartz veins carrying gold observe similar strike, dip and pitch. Traces of gold are found in the pyrite and small gold- bearing quartz veins which, according to W. H. Adams, formerly manager of the Arminius mines, are gold-bearing to the extent of from $4.00 to $15.00 per ton, are reported encountered in the mines on the hanging- and foot-wall rocks. 558 MINERAL RESOURCES OF VIRGINIA. The Tinder Flat placer deposits, located along and on both sides of North Contrary creek, at the north end of the pyrite mines, were perhaps the best known and most productive source of placer gold in the early days cf Virginia gold-mining. These placer bottoms were tested again in 1895 with a view to putting in the necessary modern machinery for working them on a large scale. The silver content of the Allah Cooper mine, 2 miles northeast of the Tinder Flats, is reported to have been un- usually large. A half-mile southwest of the Arminius pyrite mine and on the same line of strike is the Walton gold mine. According to Nitze and Wilkens this mine produced some very rich ore from a shoot or chimney developed to a depth of 150 feet. No recent mining has been done as the mine has been tied up for many years in litigation. The Walton mine is located south 10° west about half a mile from the Arminius pyrite mine. Considerable pit prospecting has been done on the property and one shaft has been worked to a depth of 150 feet. The country rock is mica schist of the same character as that enclosing the pyrite lenses at the Arminius pyrite mines. This mine has not been operated for some years, but during the period of its operation, its is reliably reported to have been one of the best producers in the area. A most creditable exhibit of the ores from this mine was made at the Philadelphia Centennial. The Cooper mine, located about a quarter of a mile south 10° west of the Arminius pyrite mines, is developed by a principal shaft about 100 feet deep sunk on an incline of 56° south 80° east. The property has been further prespected quite extensively by numerous open pits. The country- rock is the same as that at the Arminius pyrite mines. It contains thin quartz stringers which in turn contain some admixed calcite with pyrite, and a little chalcopyrite. Work was suspended here in 1903. The Luce gold mine is located about one mile south 25° east of Mineral and about a quarter of a mile south of the Chesapeake and Ohio Railway. The country-rock is a crinkled mica schist containing some garnets. The property has been developed by 2 shafts about 300 feet apart and aligned along a north 30° east direction. These shafts dip 60° and 70° nearly southeast. Numerous smaller openings are made over all parts of the property. A 20-stamp mill was operated at this mine, but from neglect it is rapidly going to wreck and ruin. Indications point to a period of considerable activity at this mine some years back. Much ore was mined and milled. It was probably the most extensive gold operation in the cistrict. GOLD AND’ SILVER. 559 The Chick mine, situated about 1.5 miles east of Mineral, is a recent development in the district. At the time of my visit in July, 1906, opera- tions had been suspended and the development work comprised an open cut. and tunnel about 50 feet long and 10 to 15 feet wide. This opening is made in a garnetiferous mica schist, the schistosity of which strikes north 15° east and dips nearly vertical. The vein where exposed consisted of thin stringers of quartz interleaved with the schist, the thickest one of which did not exceed 4 feet. A 2-stamp mill had been built and the total pro- duction was $65.00. Two miles east of and parallel to the pyrite ore-bodies, and about one mile east of Mineral, the veins known as the Fisher lode have been opened and developed by the Harris, Luce, Slate Hill, Louisa, and Warren Hill mines. The Luce and Slate Hill mines were operated as late as 1895. The Luce mine was developed to a depth of 200 feet with the total length of drifting on the vein more than 1,000 feet. Width of the vein is from 3 to 8 feet. A 20-stamp hand-feed mill was operated at the mines. The Slate Hill mine was first opened in 1850 and was extensively worked for a while. It joins the Luce mine on the southwest, of which it formed a part. Two veins were developed to a depth of 150 feet. According to a report made in 1853 the average value of the ore is given at $4.00 per ton and the cost of mining and milling at $1.40 per ton. In 1895, a Huntington mill had been erected and the mine was being developed in the lower levels. Fluvanna and Goochland Couiuties. The gold belt traverses the boundary of Fluvanna and Goochland counties, crossing the James river at Bremo Bluffs into Buckingham county. Some of the mines in this belt are located partly in both counties, and for this reason the two counties are treated together. Among the principal properties are the Tellurium, Bowles, Payne, Page, Hughes, Moss, Fisher, Busby, Taugus, Gilmore, Collins, Snead, Marks, Hades, Bertha and Edith, Walters, Manning, Big Bird, and the Belzora. From 1830 to 1860 this belt was extensively operated but at present the district is comparatively quiet and but little work is in progress. The Tellurium mine, located 6 miles from Columbia, lies partly in Fluvanna and partly in Goochland counties. It was discovered in 1832 and was continuously worked until 1857. It was operated again as late as 1886 and during its several periods of activity is reported to have yielded $1,000,000.00 Three gold-bearing veins, the “Big Sandstone,” “Middle,” and “Little,” trending northeast-southwest and dipping 20° to 30° east have 560 MINERAL RESOURCES OF VIRGINIA. been traced for a distance of more than a half mile. It is reported that the average value of the ores mined from the “Little” and “Middle” veins during the 14 years was $100.00 per ton, the minimum being $5.00 and the maximum $300.00 per ton. The value of the ore mined from the “Big Sandstone” vein during the 9 years of operating is estimated at $20 per ton. This vein was developed by numerous shafts, the deepest one of which is reported to have been 120 feet. A 10-stamp mill was operated at the mine. The Bowles mine adjoins the Tellurium. Lying partly in Fluvanna and partly in Goochland county, within a half mile of the Tellurium and Bowles inines are the Fisher, Moss, and Busby mines, all on the same lode. In 1882, the Bertha and Edith mine was worked chiefly as a placer deposit. The Snead mine, located 2 miles north of Fork Union, Fluvanna county, has not been worked for 20 years. The Fisher mine was opened in 1860 and in 1895 had been developed by a 40-foot shaft and 175 feet of levels. The vein varies from 3 to 15 inches in width but carries reported values of from $25 to $300.00 per ton. One mile northeast of the Fisher is the Moss mine, which was dis- covered in 1835. It was worked to a depth of 65 feet and the vein, which according to Nitze and Wilkens is 2 feet in places, carries values from $15.00 to $65.00 per ton. This mine is located 2 miles west of Caledonia, Goochland county, and is leased by the Telluric Gold Mining Company. Recent developments at this mine have been very encouraging. Two veins traverse the Moss property for a distance of about 2,500 feet along the strike. One of the veins is described as composed of lentic- ular masses of highly laminated quartz enclosed by micaceous schists and dipping about 45° southeast. The ore is practically free-milling down to a depth of 130 feet on the dip, when the sulphides appear. Recent sampling of the workings is reported to have given an average value of $16:00 per ton. Recent developments comprise 2 shafts, one of which is 118 feet. deep on a 55° dip, with a total of 285 feet of drifts in ore milling $15.00 per ton. A small shoot was cut in the west level which averaged about $150.00 per ton of gold and 40 ounces of silver. The second shaft is down 130 feet with 60 feet of drifts in ore yielding $14.40 per ton. A milling plant is in operation. Work at the Busby mine a half mile northeast of the Moss has been of a superficial nature. According to an early report by Professor Silliman this ore gave values of $160.00 per ton. The Page mine is located a half mile west of Wilmington on Long Island creek in Fluvanna county. La EXPLANATION OF PLATE LXXXIII. OO Figure 1—General view of the Hughes Gold Mining and Milling Company’s plant, near Fork Union, Fluvanna county, Virginia. Figure 2.— pes cut a few feet south of the old Virginia Mining Company’s main shaft. e gold-bearing quartz ledge No. 1 is shown at the rear end of the — open cut. The Piedmont Mining and Metallurgical Corporation, Orange county, irginia. PLATE LXXXIII. MINERAL RESOURCES OF VIRGINIA. GOLD MILLING PLANT AND OPEN CUT, VIRGINIA. GOLD AND SILVER. 561 Mining of the quartz vein was begun in 1856 and an 8-stamp mill was built. Considerable prospecting work was reported in progress prior to 1895. The Hughes mine, owned and operated by the Hughes Gold Mining and Milling Company, comprises a tract of 275 acres, located 5 miles north of Bremo, a station on the Chesapeake and Ohio Railway. This mine was first opened in 1836. Operations conducted by the Hughes Gold Mining and Milling Company for the past several years have been very encouraging. The developments comprise shafts, drifts and open-pit work. Shaft No. 1 is sunk to a depth of 40 feet on the large ore-body. A level is driven southwest for a distance of 140 feet from the bottom of the shaft and more than 50 feet of ore have been stoped and milled above this level. Test-pits sunk to the northeast of the shaft have proved the vein for 4 distance of 1,500 feet, with a thickness of from 1 to 5 feet. According to the general manager, Mr. William Bugbee, a mill run on 585 tons of ore stoped from this vein gave a gross value of $9.00 per ton of gold. Shaft No. 2 is sunk on a second vein 800 feet southwest of the former one to a depth of 110 feet. Two levels at depths of 60 and 110 feet, respectively, are driven from this shaft. The ore-body stoped out from the surface to the first level, 60 feet, varied from 1 to 3 feet in width and showed an average value of $20.00 per ton. Some favored spots are reported to have averaged as high as $711.00 per ton. This ore-body has been opened for a distance of about 230 feet and shows an average thick- ness of 2 feet, varying between 1 and 4 feet. The average value of the ore is given at $13.00 per ton of gold, based on most careful sampling and assaying. In addition to these, pits have been sunk on 4 other gold-bearing leads, 3 of which are from 2 to 3 feet thick and assay at or near the surface about $5.00 in gold per ton. The fourth is a 15-inch vein which assays $23.00 per ton of gold at a depth of 18 feet. The milling plant, comprising stamp mill, concentrating, cyaniding, and furnace departments, is commodious and modern in all respects. The 3 following facts have been demonstrated by Mr. Bugbee: (1) That more than 90 per cent. of the gold in the ore can be saved. (2) That the ore will average nearly $11.00 per ton of gold. (3) That the total cost of mining and treating the ore is a fraction over $4.00 per ton based on the present capacity of the plant. The Belzora mine, discovered in 1832, is located 7 miles from Columbia, in Goochland county. It was worked by surface washings until 1849, after 562 MINERAL RESOURCES OF VIRGINIA. which time the veins were opened. Adjoining the Belzora are the Marks, Collins, Hades and Big Bird mines. Buckingham County. Buckingham is the most southwesterly county of the Virginia gold belt in which mines have been actively worked. As stated above, the occurrence of gold is known still farther to the southwest in Appomattox, Prince Edward, Charlotte, and Halifax counties but, as yet, no developments have been made, except in the last named county, Halifax. The principal mines operated in Buckingham county were the Booker, sometimes called the Morrow; London and Virginia, Buckingham, Garnet ond Mosely, Morton, Ford, Philadelphia, Willis Creek, Puedmont, Apper- son, Duncan, Anaconda, and the Lightfoot. All of these were actively worked at one time. The largest ones were operated extensively before the Civil War and are reported to have produced large amounts of gold. Some of these have been worked since the War and a few within recent years. The Booker mine is located 4 miles southwest of Dillwyn and was extensively worked prior to the Civil War by an English Company. The mine is developed by numerous shafts and drifts, the deepest of which is 106 feet. The work is of such long standing and the dumps so entirely cleaned up that very little could be seen at the time of my visit in August. It is reported that the ore was treated in a Howland mill and yielded $13.00 per ton. The London and Virginia, and the Buckingham mines join each other and the openings extend from one on to the other, along a north 40° east direction. These mines are located one mile northwest of Dillwyn. They were developed by shafts and open-cuts, the deepest of which will not exceed 160 feet. The principal opening is a cut which extends nearly entirely across both properties. It is variable in both width and depth, with a probable average of about 12 feet wide and from 20 to 80 feet deep. It follows the dip and strike of the vein which closely conforms with the structure of the enclosing mica-schists. The schists vary from biotite-muscovite to sericite and finely laminated quartzose rocks. These properties were large producers before the Civil War, but at the beginning of the War they were closed down and practically no work has been done since. Some placer gold was mined in the early days in the vicinity on Turpin’s creek. At the Anaconda mine, three-quarters of a mile southwest of Johnston, GOLD AND SILVER. 563 development work on a small scale was in progress in August, 1906, by the Anaconda Gold Mining Company. This property was worked as a placer deposit some years ago. The Lightfoot mine, situated 2 miles northwest of Arvonia, on the east side of the Slate river, was worked in 1861 and again developed by an 85- foot shaft and drifts some 5 or more years ago for copper. Preparations are now in progress for the further development of this mine. The Apperson mine, 12 miles southwest of New Canton and 10 miles northeast of Buckingham court-house, comprises 3 veins, one of which measured 10 to 15 feet wide of gold-bearing rock. Halifax County. In the Virgilina copper belt of Halifax county, gold-mining is engaged in and 2 mines have been opened up, situated close together, about 6 miles directly north of the town of Virgilina. One of these, the Goldbank mine, incorporated under the name of the Virgilina Gold Mining Company, is an active producer of gold at the present time. The vein is parallel and similar to the numerous other veins in the district worked for copper, except that besides a little copper its chief value is in gold. The vein material is quartz enclosed by highly altered andesite, resembling somewhat a sedimentary slate. It is nearly vertical, and has a nearly due north-south strike. The elementary gold is very finely divided and is contained in both the quartz-filling and the enclosing country-rock. Sulphides of copper occur in subordinate amount but no attempt is made to save them. The value of the vein is said to average $8.00 per ton of gold across its width of 6 feet. A vertical shaft has been sunk to a depth of 160 feet and drifts have been run along the vein at this level for a distance of 100 feet to the north and 300 feet to the south, taking out the entire width of the vein. A mill containing 2 batteries of 5 stamps each is operated at the mine. Two more batteries are contemplated. The stamps weigh 750 pounds each. No attempt is made to save or treat the tailings which are known to be rich in gold. During 1906 about 10 tons of ore per day were being milled. The Howard gold mine, located only several hundred yards from the Goldbank mine of the Virgilina Mining Company, has temporarily sus- pended operations. A milling plant has been built at the mine carrying a battery of 5 stamps. The underground developments comprise some shaft and drift work. 564 MINERAL RESOURCES OF VIRGINIA. Montgomery and Floyd Counties. On the west side of the Blue Ridge and at the southeast base of Pilot Mountain, placer deposits were opened in 1879 along Brush and Laurel creeks, in Montgomery and Floyd counties. Most of the tributaries to Brush and Laurel creeks show some gold and prospecting has extended over an area 20 miles wide by 4 miles long, a total of 80 square miles. The area is further traversed by numerous white and mottled gold-bearing quartz veins. According to Professor Fontaine, the average yield for the best of the earth in 1882 was about 5.5 grains of gold per pan of 25 pounds of earth. The gold contains about 32 per cent. of silver. The quartz veins and stringers charged with pyrite are in gneiss and specimens of the vein and of the gneiss were sampled by Professor Fontaine and separately assayed with the following results: Veins....... 64.6 grains per ton of. which 27.1 grains were silver. Gneiss...... 5.7 grains per ton of gold and silver. Gneiss...... 6.4 grains per ton of gold and silver. In 1880, $2,500 worth of gold is reported panned out in 2.5 months. One assay is stated to have yielded $94.00 per ton of gold and $3.00 of silver. Nuggets were taken from the loose deposits that sold for $2.00 and more a piece. An analysis made by Mr. Porcher of a specimen of native gold from the workings in Montgomery county gave: Per cent. Gold (by cupellation and parting)............. 65.31 Silver (by cupellation and difference)......... 34.01 COPPEl? serena coeia stetens Sugteiseraeomte dine be acraclate 0.14 ALTON | csaisseuesissasnlenas wiaseiarayaeeiieiei guar aeatanea ales tulaal regal cael 0.20 QUAIEZ! aeiere esas aressicetyuars avochanc wore ceneay ated seve 0.34 LOU cca /suesnatarai sewn dears ne in deatania alka vas 100.00 Specie, eravitynisucine venamneeaaiadion womens dau 15.46 Gold occurs in Patrick, Carroll, and Grayson counties in small quan- tity in association mostly with copper ores. Production. Records of actual production from mining operations in Virginia date from 1829. The U. S. Mint returns from 1829 to 1854 show that nearly one and a half millions of gold were deposited during that period from Virginia mines. The following tables are compiled from the produc- tion reports of the U. 8. Mint. The figures represent not only the amounts GOLD AND SILVER. 565 deposited at the U. S. Mint and Assay Offices but such other amounts as were produced and not turned into the Mint of which records could be obtained: Production of gold and silver in Virginia by years. Year Value 1799-1879. . .$3,091,700 US 80s wen iigewae 11,500 I88ls.sccess 10,000 TBB2 iver 15,000 S83 .is6s:doeans 7,000 1884........ 2,500 1885........ 3,500 1886........ 4,000 1887........ 14,600 1888........ 7,500 1889........ 4,113 1890........ 6,496 1891........ 6,699 1898 es ee as 5,002 Year Value 1808 i saans awe $ 6,190 TBO Ss ecinccerecenave 7,643 VB OB ivi sereonaiaser 6,325 W896 venesw ness 4,466 1897........ not given 1898.......... 4,500 V8 99 is6 sirens oes 7,160 1900.......... 3,200 TOOT iscanwcrkwtaars 5,720 1902). cre earnaiees 6,227 1903 6.0 sacie sees 18,630 L904 eaistaeen 7,686 N90 Siri sca ntvre ae 5,122 The following results show the U. 8. Mint returns for the first 5 years of production of gold in Virginia, from 1829 to 1833, inclusive: Year Value The following table shows the distribution of gold and silver in Vir- ginia, annually, as to sources of production, from 1900 to 1905, inclusive: Gold Silver XY Quartz Placer Quartz Copper ores ear Fine ounces Fine ounces Fine ounces Fine ounces 1900 78. 94 96 1901 185 128 617 427 1902 181 27 — 1,344 1903 216 _- —_ 17,073 1904 —- _—- —_— —— 1905 202 39 173 os Ses In 1904, the production of gold and silver in Virginia was contributed to by eleven counties. From the U. 8. Mint returns for 1905, Lindgren estimates thaf for Virginia, gold increased in value over 1904, $1,182; and silver decreased $3,779. In 1905, 7 mines were reported producing, 3 of which were placer mines. According to Lindgren the 4 deep mines yielded an estimated tonnage of 800, giving an average of $5.35 per ton in gold and silver. 566 Becker, G. F. Campbell, J. L. Credner, H. Delrio, A. Emmons, 8. F. Hotchkiss, Jed. Johnson, W. R. Judd, Edward K. Locke, A. G. Maury, M. F. Morton, J. H. Nitze, H. B. C. MINERAL RESOURCES OF VIRGINIA. References. A Reconnaissance of the Gold Fields of the Southern Appalachians. 16th Annual Report, U. S. Geologi- cal Survey, 1894-5, Part ITI, 251-331. The Montgomery County, Virginia, Gold Fields. The Virginias 1880, I, 12%. The Virginia Gold Belt, near the Richmond and Alleghany Railway. The Virginias, 1882, III, 120-121. On the Gold Mines of Virginia. American Journal of Mining, 1867-69, VI. Transactions Geological Society of Pennsylvania, 1834, I, 59-166. Notes on the Gold Deposits of Montgomery County, Maryland. Transactions American Institute of Mining Engineers, 1890, XVIII, 391-412. The Gold Regions of the Atlantic States. The Vir- ginias 1880, I, 136. Tellurium Gold Mine, and Virginia Gold Mining. The Virginias, 1881, II, 85. Some Observations on the Gold Formations of Mary- land, Virginia and North Carolina. Proceedings American Association for Advancement of Science, 1850, IV, 20-21. A Virginia Gold Mine. Engineering and Mining Journal, 1907, LXX XIII, 342. Gold, Its Occurrence and Extraction, 1882, 182. Notice of the Gold Veins of the United States Mine, near Fredericksburg, Virginia. American Journal of Science, 1837, XXXII, 183-185, 325-330. The Gold Mines of Fauquier County, Virginia. Engi- neering and Mining Journal, 1877, XXIV, 345. Gold Mines in Virginia. Engineering and Mining Journal, 1878, XXV. The Present Condition of Gold Mining in the Southern Appalachian States. Transactions American Insti- tute of Mining Engineers, 1896, XXV, 661-797, 1021-1025. GOLD AND SILVER. 567 Nitze, H. B. C. and Hanna, G. B. Gold Deposits of North Carolina. North Carolina Geological Survey, Bulletin No. III, 1896, 16, 17, Nitze, H. B. C. and Wilkens, H. A. J. Gold Mining in North Carolina, and Adjacent South Appalachian Regions. North Carolina Geological Survey, Bulletin No. X, 1897, 13-14, 26, 40-42, 71-76, 32 et seq. Porcher, 8. On an Intere:ting Specimen of Native Gold from Montgomery County, Virginia. The Virginias, 1882, IIT, 3. © Spilsbury, E. G. Notes on the General Treatment of the Southern Gold Ores, and Experiments in Matting Iron Sulphides. Transactions American Institute of Mining Engi- neers, XV, 767. Taylor, J. W. The Gold and Silver Mines East of the Rocky Mount- ains. American Journal of Mining, 1867, II, 390; Mineral Resources of the United States, 1867, 323- 850. Silliman, B. Remarks on Some Gold Mines, and on Parts of the Gold Region of Virginia, Founded on Personal Observations Made. in the Months.of August and September, 1836. American Journal of Science, 1837, XXXII, 98-130. Culpeper Gold Mine, Virginia. American Journal of Science, 1837, XXXII, 185. Whitney, J. D. - Metallic Wealth of the United States, 1854.. See also reports on Precious Metals issued by the Director of the Mint; Tenth Census, Precious Metals, XIII; the Mineral Resources of the United States; the Mineral Industry; and Census Report on Mines and Quarries in 1902. Vv. TIN. Mineralogical and Chemical Character. The tin-bearing mineral, cassiterite, is an oxide corresponding to the formula SnO, and contains theoretically 78.6 per cent. of metallic tin. When pure, cassiterite is nearly white, but it usually contains more or less ferric oxide which imparts a reddish to brown or black color, pro- portionate to the percentage of iron present. The mineral sometimes occurs in prismatic crystals of Tetragonal form, though when found in commercial quantity it is more often granular and in rough masses. Three varieties of the mineral are recognized: (1) ordinary or tin-stone 568 MINERAL RESOURCES OF VIRGINIA. -obtained directly from the vein; (2) wood-tin having the color and ap- ‘pearance of dried wood and of botryoidal and reniform shapes; and (3) stream-tin found along stream courses in the loose sand and gravel deposits. Historical. ‘The ‘existence of tin ore on Irish creek, in Rockbridge county, was known for a long time prior to the. first prospecting in 1883, when active operations were begun. The tin ore from this locality was first tested by Professor Armstrong of Washington College, Lexington, in 1846; he ‘claimed that the specimen contained both tin and silver. Only two openings had been made prior to 1883. Since that time prospecting for tin ore thas been reported along the eastern edge of Rockbridge county, extending ‘parallel to the Blue Ridge, from a few miles north of the James river into ‘Nelson county. Thus far the most favorable portion of the region in ‘which tin has been found is that known as the Irish ereek area, located in ‘the northeastern corner of Rockbridge county, in the crystalline rocks of ‘the Blue Ridge, about 7 miles distant from Vesuvius, a station on the ‘Shenandoah division of the Norfolk and Western Railway, and at an average -elevation of about 2,800 feet. A company known as the Virginia Tin “Mining and Manufacturing Company was organized in 1883 for the pur- ‘pose of working the tin deposits along the headwaters of Irish creek. The wwork of sinking a shaft commenced in November, 1884. Occurrence. ‘The Irish creek area is about 4 miles long in a northeast-southwest direction and is 3 miles wide, embracing a total area of 12 square miles. The immediate rocks of the area are crystallines, of granitic composition, ‘composed principally of a coarse aggregate of quartz and feldspar (ortho- ‘clase and acid-plagioclase, albite), with hornblende. The rock is porphyritic ‘ta places, the large feldspar crystals measuring as much as an inch and more in length. ‘The coarse granite enclosing the tin veins is reported to be ‘often rich in tourmaline. The granitic rock is generally much decayed at ‘the surface to a mottled clayey mass which is as much as 50 feet thick. A finer textured facies of the granitic rock is quite common. Further ‘variation is shown in lenticular masses of a flesh-colored granitoid facies of the rock, consisting of orthoclase, quartz and epidote, which closely resembles unakite and has been so designated by some. Dikes of fine-grained altered diabase traverse the granitic rock in all directions and apparently they are frequently associated with the veins of TIN. 569 tin ore. Sedimentary rocks are commonly developed along the western flank of the ridge and lower down the slope they pass beneath the Valley limestone. The tin ore occurs principally in well-defined quartz veins which traverse the granite in all directions and have steep though varying dips. The veins are banded and contain pyrite and arsenopyrite in addition to cassiterite. The walls of the enclosing granite are changed to greisen (quartz and fine scaly muscovite) containing a small amount of cassiterite. The veins are usually narrow not exceeding a foot and less though a greater thickness is frequent and some of the veins measure several feet across. In the veins proper, the gangue is quartz in which the cassiterite occurs as crystals, nodules, and stringers. According to Winslow, the general char- acter of the gangue is a dark earthy rock, composed largely of quartz with pyrite, mica and various earthy minerals, among which cassiterite is disseminated in small crystals and in fine grains indistinguishable to the naked eye. Near the surface, the vein rock is much altered and softened from weathering and is of a reddish to yellow-brown color from the oxidation cf the iron-bearing minerals. In its undecomposed or fresh condition it is readily distinguished from the enclosing country-rock. The location and character of the veins have been proved by numerous openings usually cf shallow depth. Analyses have proved nearly every vein to contain tin but in many cases the quantity is reported to be very small. On the cther hand many of the veins show rich returns. Through some of these, veinlets of solid cassiterite an inch or more thick and pockets composed of nodules of tin-stone are reported. Winslow describes numerous nodules of cassiterite the size of a hen’s egg; and in one of the veins at a depth of 6 feet below the surface, he describes a block about a foot in diameter cf nearly pure cassiterite. The associated minerals so far discovered comprise wolframite, mis- pickel (arsenopyrite), pyrite, and beryl. In addition to these, siderite, limonite, chlorite, muscovite, damourite, and fluorspar have been reported: found. The mispickel is reported by McCreath to contain both gold and silver. Opening No. 1 on the Cash lands of Irish creek showed the crystalline rocks to dip nearly vertical, consisting mostly of an aggregate of quartz, feldspar and hornblende and, in places, mica-schist. The vein was com- posed of white quartz with tin ore, the largest piece of which did not exceed 2 inches in thickness and much of it was not over 1 inch. The samples assayed, showed an average of 31.60 per cent. 570 MINERAL RESOURCES OF VIRGINIA. According to the prospectus of the Virginia Tin Mining and Manu- facturing Company, there is a continuous and well-defined vertical vein of crystalline cassiterite, averaging 1 inch in thickness, in one of the two trenches at opening No. 1 on the Cash lands. About a ton of ore was reported removed which yielded on assay about 75 per cent. metallic tin. According to Professor Henry D. Campbell, who visited the Martha Cash mines in 1883, secured a specimen from one of the veins, which he analyzed with the following results: Per cent. Tin (metallic) ............... 63.583 Tron (metallic) .............. 1.680 STIG! «aa ccoe hier we aaeee eases TS -415 SUI pPHUT cocciaascacewteaenns 0.066 APSONIC \wWagocdemanrde sed pareiots 0.301 Titan 20 i008 eae es distinct trace In 1885, Massie described the character of the ore on the Cash lands as occurring in the form of cassiterite or black tin in sheets, strings and nodular masses, in the gangue of veins. The color of the cassiterite is from light yellowish-brown to dark brown and the ore is free from injurious minerals. Operations stopped in the Irish creek area as early as 1886, owing to the tin lands becoming involved in litigation. In 1889, a party of Boston capitalists obtained control of the Cash mines and, in 1890, they began operations by erecting a small concentrating plant, Sturtevant mill, a set of jigs and a vanner. At the close of 1891, the mill, located near Vesuvius, on the Norfolk and Western railroad, which cost $50,000.00, was ready. At the same time the development work put about 290 tons of rock, averaging about 3.3 per cent. of metallic tin, on the dumps. About 240 pounds of the black tin concentrates were shipped to Boston to be smelted. These are reported to have averaged only 48 per cent. of metallic tin be- cause of the arsenopyrite and ilmenite. The property again became in- volved in litigation and operations were again suspended. The vein from which the ore was obtained by the Boston parties for the above tests was 6 to 8 feet wide. The tin ore impregnates the granite on the two sides of the vein but in such small quantities as not to be workable. The late Major Hotchkiss examined the Irish creek tin area for the Lexington Tin Company in 1885. A part of his report follows which is quoted from the Mineral Resources of the United States for 1885: “The tin ore of this region is found in the form of crystals, threads, or stringers, and in masses of varying size, disseminated in fissure veins traversing, in all directions, the granitic and other Archaean rocks that TIN. 571 here constitute the crest and the immediate westerly slope of the Blue Ridge, and that disappear beneath the Potsdam rocks 1 or 2 miles to the northwest of the tin-bearing field. “The tests to prove the existence of these ores were made by sinking, Criving, or cutting pits, trenches, shafts or tunnels, at the points indicated, as hereinafter described in detail, mainly in a territory about 114 miles long and 114 miles wide. At other points, outside of this territory, the existence of tin ore has been proved. The character of these test works and of the ore found at each, and therefore the present condition of information about these tin ores, based on what has been actually ascer- tained about them, can best be learned by a brief statement about each of these trial works. “No. 1. This is known as the “Cash No. 1 mine,” as it is at the point on the Cash land where tin ore was first found in this region. This is an open cut about 60 feet long and from 3 to 10 feet deep, driven into the base of the spur of Cash Mountain a few feet above the level of Painter branch. The tin-bearing vein here has an average thickness of about 84 inches; this consists of tin-stone disseminated in small grains ard small pockety masses throughout a gangue of quartzose and micaceous rock that can be easily mined and crushed, and next to the wall, a per- sistent vein of solid tin-stone, or cassiterite, that averages one inch in thickness, and is sometimes 6 inches thick. Several branchings of veins from the main one, penetrating the crevices of the adjacent rocks, have also been discovered here. Portions of this large vein are occupied by massses of quartz rock. “Professor Campbell sampled 72 inches of the thickness of this vein, including the wall rock involved with the ore, and found it to contain 66 pounds of metallic tin to the ton. Mr. McCreath analyzed a sample of this ore selected by Mr. Rittenhouse ‘representing all grades, from pure tin crystals to quartz and rock containing little or no tin, and found in it an average of 3.160 per cent. of metallic tin. The cassiterite will yield, by itself, from 65 to 70 per cent. of metallic tin. “No. 2 embraces four openings; the second opening is a shaft 40 feet deep, said to include a vein of tin ore that is 36 inches thick at the surface and 120 inches thick in the bottom of the shaft where sinking was sus- pended. Mr. Cabell Whitehead found in an average sample of the ore of this vein, representing its whole thickness, after repeated assays, an average of 5 per cent. of metallic tin, or from 125 to 130 pounds of tin te the ton of ore. Professor Campbell made the percentage larger. 572 MINERAL RESOURCES OF VIRGINIA. “About 3,000 pounds of the ore from this shaft were sent to England as a trial lot; the purchaser reported a considerable yield of metallic tin. I requested Mr. Massie, who selected the ore for that shipment, to sample the ore lying scattered around this shaft for me, so as to give me what would fairly represent the ore that was shipped to England. I wit- nessed the sampling, and am satisfied that it was fairly done. This sample of several pieces I submitted to Dr. Frank W. Traphagen, analytical and consulting chemist of the Staunton Male Academy, and he found in it, after repeating his analysis, 17.54 per cent. of binoxide of tin, or 13.79 per cent. of metallic tin. Nodules of cassiterite, from small sizes up to some 12 inches in diameter, have been found in this vein; there is no question about its richness. This shaft is on the slope of Painter mountain, and more than 400 feet above the level of Irish creek at the foot of the mountain to the north. No. 2a is a pit uncovering a large bowlder of quartz that is veined with crystals of tin-stone; that will probably yield as well as the vein at the shaft, or No. 2, which is 70 feet above this in altitude, the intermediate ground being strewn with tin ore. No. 2b is an open drift, at a level 90 feet below No. 2, cut for 60 feet into the slope of the mountain, ending there about 15 feet deep, where a vein of tin ore, apparently averaging with that at No. 2, had been cut and found 108 inches thick. No. 2c is a trench on a tin-ore vein of about the same character as the preceding. “No. 3 is some 500 feet above the level of the creek opposite, is a long trench, about 6 feet deep, exposing some 10 feet of a vein of tin- stone that is 48 inches thick. An average sample of this ore, assayed by Prof. H. D. Campbell, yielded 0.292 per cent. of metallic tin; a sample acsayed by Prof. M. B. Hardin, at Virginia Military Institute, yielded 0.41 per cent. A quartz vein is exposed near this, resembling the one near No. 2. Traces of ore extend from this to No. 2. “No. 4 is a shallow cut, about 1 foot deep, exposing a tin vein 12 inches thick that yielded 0.19 per cent. when assayed by Prof. M. B. Hardin. “No. 5 consists of three pits connected by a trench. The tin vein in the middle pit is 18 inches thick; samples from this yielded 5 per cent. metallic tin in an analysis by Professor Hardin. A sample from the upper cut, or pit, an average of the ore from 6 feet of length of vein, gave 0.799 per cent. of binoxide of tin on analysis by Prof. H. D. Campbell. In the upper cut the vein is one-half inch thick at the depth of 10 feet; it be- comes thicker as it goes down, and will average ¥ inches. A good many erystals of tin-stone are found here. TIN. 573 “No. 6 is a pit exposing a vein 12 inches thick; it widens in going down. An average sample yielded 0.28 per cent. of metallic tin as analyzed by Professor Hardin. “No. 7 is a pit showing a vein 18 inches thick; it is much like No. 6 but poorer. “No. 8 is a pit showing a vein 36 inches thick of lean ore. “No. 9 is a pit showing a vein 4 inches thick; ore not assayed. “No. 10 is a shaft 40 feet deep, sunk on a vein 36 inches thick. A sample taken at the depth of 3 feet, before the shaft was sunk, representing an average of the exposed vein, yielded 1.12 per cent. of metallic tin to an assay by Dr. Dabney, of North Carolina; at a depth of 10 feet, 2 per cent. of cassiterite was found in an assay of the vein by Mr. A. D. Robert- son. This vein is in trap rock. Three or four threads of ore come together in the bottom of the shaft. “No. 11 is a pit exposing a vein 43 inches thick containing a trace of tin. “No. 12 exposes a vein 12 inches thick containing a trace of tin. “No. 13 exposes a vein 8 inches thick containing a trace of tin. “No. 14 is a vein 48 inches thick of lean ore between trap and granite. “No. 15 is a trench exposing a 6-inch vein in quartz in which crystals of tin-stone are found. “No. 16 is a tunnel in rotten granite 30 feet long, cutting a vein of lean ore from 3 to 12 inches thick. “Nos. 17, 18, 19, and 20 are pits exposing a 6-inch vein of lean ore. “No. 21 is a tunnel driven in rotten granite some 60 feet along an 18- inch vein. Professor Hardin assayed picked samples from this vein and obtained 314 per cent. of metallic tin. Professor Campbell assayed a sample, averaging 25 feet of the length of the vein, and obtained 0.582 per cent. of metallic tin. In a pit sunk above this tunnel this vein is also 18 inches thick. “No. 22 is a vein exposed by the roadside that is from 3 to 4 inches thick in solid rock; it is regarded as an offshoot thread from No. 21. “No. 23 is a pit and a short tunnel on a lean 10-inch vein. “No. 24 consists of two parallel veins about 10 feet apart, from 3 to 6 inches thick, which meet No. 25; this ore assays next to that of No. 21. “No. 25 is a vein about 12 inches thick, which crosses and dips towards No. 24; it assays about 0.25 per cent. “No. 26 is a tunnel about 30 feet long in a vein 24 inches thick in places; this assays 0.10 per cent. 574 MINERAL RESOURCES OF VIRGINIA. “No. 27 is a pit exposing two parallel veins about 6 feet apart, one 4 to 6 inches and the other 12 inches thick of lean ore. “No. 28 is a pit exposing a 24-inch vein of lean ore. “No. 29 is a drift cut some 30 feet long and over 30 feet deep at the end, exposing a vein of lean ore averaging 24 inches thick. Assays 0.10 per cent. This vein has been exposed for 400 yards, to the top of the mountain, where it is 120 inches thick; in places in the drift below it is 240 inches thick. The tin-stone here is associated with quartz and iron pyrites. It is believed that this and Nos. 30, 31, and 32 will finally come together. “No. 30 is a vein 12 inches thick in very hard rock; an assay of a sample gave 1 per cent., but the average will be less. “No. 31 is a vein averaging 24 inches in thickness (36 in places). Professor Hardin obtained 0.17 per cent. of tin from an average of the whole vein. It also carries $1.86 of gold to the ton. “No. 82 is a vein 48 inches thick, averaging in richness between Nos. 30 and 31. “Nos. 33 and 34 are cuts on a quartz and pyrites vein containing traces cf tin. “No. 35 ig an outcrop of veins from which an 8-inch cubic block of crystals of tin-stone was obtained. Not opened as yet. “No. 36 is a quartz vein 60 inches thick that yielded an average of 0.12 per cent. of metallic tin to assay of Mr. A. D. Robertson. “No. 87 is a vein 36 inches thick, on Mount Nettle, some 1,200 feet above Irish creek, in micaceous granite. , “No. 88 is a 10-inch quartz vein containing iron pyrites and a trace of tin. “Tn the above notes the measurements of Messrs. Winslow and Robertson have been accepted and used, and the assays of Messrs. McCreath, Camp- bell, etc., as reported in published articles and as furnished to Mr. Robertson. “The forty odd testing pits, trenches, shafts, tunnels, etc., above men- tioned, are distributed over a territory nearly 10 miles wide and 4 miles long in the north and middle spurs, Mount Maria, Cash mountain, Painter mountain, Mount Elizabeth, Little Hill and Big Hill, and Mount Nettle, all spurs of the Blue Ridge projecting between the northeasterly and the easterly head branches of Irish creek. In all of these more or less metallic tin has been found, ranging from “traces” up to 70 per cent. Those that have been assayed may be recapitulated as follows: “No. 1, 0.292 to 65 or 70 per cent., 66 pounds to the ton average. “No. 2, 5 to 13.79 per cent., 125 to 130 pounds to the ton. TIN. 575 “No. 3, 0.292 to 0.41 per cent. “No. 4, 0.19 per cent. “No. 5, 0.799; 17.58 pounds of “black” tin to the ton. “No. 6, 0.28 per cent. “No. 10, 1.12 to 2. per cent., 85 pounds of “black” tin to the ton. “No. 21, 0.582 to 3.25 per cent., 18 pounds of “black” tin to the ton. “No. 25, 0.25 per cent. “No. 26, 0.1 per cent. “No. 29, 0.1 per cent. “No. 31, 0.17 per cent. of tin and $1.86 of gold to the ton. “No. 36, 0.12 per cent. “The localities of the above and the per cents. of tin are: “No. 1, on Cash mountain, 31.60 to 70 per cent. “Nos. 2 and 8, on Painter mountain, 0.292, 0.41, 13.70 per cent. “Nos. 4 and 5, on Mount Elizabeth, 0.19, 0.799 per cent. “No. 6, on Little mountain or hill, 0.28 per cent. “No. 10, on Big Hill, 1.12, 2 per cent. “Nos. 21, 25, 26, 29, and 31, on Mount Maria, 0.17, 0.25, 0.582, 0.1, and 3.25. “No. 36, on North Spur, 0.12 per cent. “Omitting from the above the deposit on Cash and Painter mountains assays Nos. 1, 2, and 3, the averages of yields from the other localities do not vary greatly among themselves, showing that these ores range in rich- ness from 0.1 to 3.25 per cent.; the eleven assays of these localities averaging 0.805 per cent., or nearly 18 pounds of “black” tin to the ton. 1 see no reason why an abundance of ore should not be had from these, Mount Elizabeth, Little mountain, Big Hill, Mount Maria, and North Spur veins, that will yield this average result. “The assays of the Cash and the Painter mountain ores range in rich- ress from 0.292 to about 70 per cent., making an average for the five given of 23.218 per cent. This is probably too high an average for all the well-picked tin stone that could be obtained from these localities; and yet it would not, in my opinion, be very difficult to obtain from them a large quantity of ore that would run such an average. The prospecting that has been done, the condition of the veins as exposed, and their rich- ness in metallic tin, I think, warrant the conclusion that an abundance of high-grade ore can readily be obtained from these localities. “While the developments that have been made here are by no means extensive, and are not such as one would like to see, still they cover a very , 576 MINERAL RESOURCES OF VIRGINIA. considerable area and fairly well expose the tin veins at moderate depths from the surface, and so that their character can be seen very well. More than this, the openings that have been made are so located as actually to expose to inspection fully 600 feet of the vertical depth of the tin veins of this region, some of them having been made near the level of Irish creek and others near the top of the spurs more than 600 feet above that level; horizontally these openings are many of them but a short distance apart; consequently, it is fair to say that we have here, in this deeply and steeply eroded or naturally trenched region, the equivalent of shafts uf varying depths, up to over 600 feet in a level country. For example, numbers 1 and 2 are but 1,600 feet apart horizontally, and yet they are over 300 feet apart vertically. It is considered that from these two and their surroundings there are nearly the same data for conclusion as would be obtained if the shaft at No. 2 were sunk to a depth of 320 feet. The same may be said of the other localities where the tin ore has been ex- posed. This knowledge has led me to the favorable conclusion above ex- pressed in reference to the quantity and the quality of these ores. “The geological and mineralogical conditions of the Irish creek tin- bearing region are similar to, if not even identical with, those of the Cornwall (England) and other noted tin-producing districts. There are the same crystalline and metamorphic rocks, broken, fissured, and faulted by dikes of trap, basalt, and other igneous rocks, thus furnishing similar conditions for the formation of true, profitable, metalliferous, fissure veins, such as are caused by profound movements of the earth’s crust—just such veins as those in which stanniferous ores of the Irish Creek district are found. “The exposure of the Irish Creek tin veins, both natural and artificial, unmistakably leads to the conclusion that these veins compare in general character, extent, thickness, and richness in metallic tin, most favorably with those of the famous Cornwall district of England, while the mining conditions are better. I may add that no region can offer superior ad- vantages for extensive mining and metallurgical operations; the climate is all the year round salubrious and favorable for work; the Blue Ridge proper of Virginia, unlike most mountain chains, is a very garden of fertilitv and varied productiveness, and the same may be said of Piedmont, Virginia, that flanks it on the east, and of the famous limestone Valley that flanks it on the west. The forests of this region can be depended on for charcoal; and it is not far by direct railway to the best metal working and coking coals in the United States. TIN. Bu “In conclusion, this report is emphasized by the opinion that this Irish Creek tin-bearing district, as above described, will prove abundantly productive in tin.” Other Localities. The occurrence of tin is reported from Nelly’s Ford, near Rockfish river, in the northern portion of Nelson county. No prospecting has yet been attempted. Bruce in his book entitled, Southwest Virginia and Shenandoah Valley, published in 1891, makes the following statement concerning tin in Clarke county (pages 234-5): “Along the foothills of the Blue Ridge, in this county, fine specimens of copper and lead have been discovered east of the Shenandoah river, and tin has been reported to have been found on the Capon Springs property by Mr. Bale, who shipped a cargo of the ore to Wales.” References. Blake, W. P. Ores of Tin. Mineral Resources of the United States. 1883-84, 592-640. ‘ Brown, W. G. On Cassiterite from Irish Creek, Rockbridge County, Virginia. American Chemical Journal, 1884, VI, 185-187. Occurrence of Wolframite at Irish Creek, Rockbridge County, Virginia. American Chemical Journal, 1884, VI, 185. Campbell, H. D. Tin Ore (Cassiterite) in the Blue Ridge in Virginia. American Journal of Science, 1884, XXVII, 411; The Virginias, 1883, IV, 151. Campbell, J. L. On Dufrenite from Rockbridge County, Virginia. American Journal of Science, 1881, XXII, 65-67. Hotchkiss, Jed. The Tin Ore of Virginia. The Virginias, 1884, V. 38; Mineral Resources of the United States, 1885, 371-376. McCreath, A. S. and Platt. Description of Locality of Tin Ore, Rock- bridge County, Virginia. Bulletin Iron and Steel Association, 1883, 207. Robertson, Dr. W. On Virginia Tin. Mining Journal, 1884, Oct. 18. Rolker, Chas. M. The Production of Tin in the Various Parts of the World. 16th Annual Report, U. 8. Geological Survey, 1894-5, Part III, 458-538. 5%8 MINERAL RESOURCES OF VIRGINIA. Ulke, T. The Occurrence of Tin Ore at Kings Mountain, North Carolina, and Cash Mine Near Vesuvius, Virginia. Mineral Resources of the United States, 1893, 178- 183. Whitehead, Edgar. Report on the Martha Cash Tin Mines. Prospectus of the Virginia Tin Mining and Manufacturing Company, 1885. Williams, A., Jr. The Virginia Tin Mines. The Virginias, 1885, VI, 169-170. Winslow, A. Tin Ore in Virginia. Engineering and Mining Journal, 1885, XL, 320. The Virginia Tin Mines. The Virginias, 1885, VI, 168. VI. NICKEL AND COBALT. General Statement. Nickel and cobalt can best be treated together, for most of the ores containing one are apt to carry some of the other. Virginia has not, as yet, produced any appreciable quantity of either of these metals, but there are occurrences. in certain localities of the State which afford promise of commercial quantities of the metals, especially nickel. The existence of nickel in Virginia has been reported from a number cf localities in the Piedmont region or crystalline area, especially in asso- ciation with many of the extensive pyrrhotite bodies of the Floyd-Carrol'- Grayson plateau in southwest Virginia (map, figure 29), and in Amherst county near and to the east of Lynchburg. In Amherst county the pyrrho- tite is somewhat sparingly developed as small grains and moderate size granular masses, in crystalline schists, partly hornblendic, of doubtful origin. More recently, nickel, in association with peridotite masses, has been reported from near Broadrun station, in Fauquier county, northern Vir- ginia; but this locality has not yet been investigated. Reliable analyses of the southwest Virginia pyrrhotite bodies, giving the exact percentage of nickel and cobalt, are unfortunately not available. Recent developments in northern Floyd county, near the boundaries of Montgomery and Roanoke counties, give very encouraging results of the existence of nickel in commercial quantities. This area is described below in some detail. In addition to the above occurrences and associations, cobalt is found in association with some of the impure earthy manganese (wad) deposits NICKEL AND COBALT. 5Y9 of the Valley region, especially on the east side of the Valley along the western base of the Blue Ridge. The following analysis of manganese ore trom the Church Mountain mine in Rockingham county, made by Professor air Pointe | = t , & $ cod + 2 ch iL =f 8 \ Botto™® Ruy \ $ wt E R Lao Cabes Hill y Rut J Ko F ID MZKET BETWEEN \, I SV ACLEY FORMATION: ee ran BLUE, AIDGE: fi NG Se 500) A CRYSTALLINES ZAR CROCKETT SPRINGS 4 bs a Fishers Vie PYROXENITE DIKES) if* 1 ai p= q ‘ - ) “ i Saw Tooth Coles Knob 290. SCALE OF NILES v 1 2 3 4 ro co - Fig. 99.—Map showing location of nickel and arsenic mines in ‘Floyd coun- ty, Virginia. 580 MINERAL RESOURCES OF VIRGINIA. F. W. Clarke of the U. 8. Geological Survey, shows a noteworthy percentage of cobalt: Per cent. Metallic manganese........... 39.20 Cobalt. acc seesanvenase seg she 2.48 Iron and aluminum oxides.... 5.14 Insoluble matter............. 22.11 TenibiOn a5 tie gc itainin RRA ROS 11.30 The Floyd County Area. The property, controlled by the Virginia Nickel Corporation, as indi- cated on the accompanying map, figure 99, is located in the extreme Shop and Engine House Fig. 100.—Ground plan showing location of openings at nickel mine on Lick Fork, near Hemlock, Floyd county, Virginia. northern part of Floyd county, along the boundaries of Montgomery and Roanoke counties. The openings thus far made are wholly in Floyd county, the principal ones being directly on Lick Fork, within a few hundred feet of its confluence with Flat Run (figure 100), suutheast head- waters of the South Fork of the Roanoke river. The Lick Fork openings are further located in a direct line from Shawsville, the nearest railway station, 7 miles nearly south-southeast. From 1904 until recently, the Virginia Nickel Corporation exploited the area under the name of Fidelity Exploration Company. Openings have been made at four different places, aligned along a nearly northeast- southwest direction, for a distance of about 4.5 miles. Some of these are in schists and contain pyrite instead of pyrrhotite as the ore. NICKEL AND COBALT. 581 At the Lick Fork openings, the principal ones in the area, the ore is chiefly pyrrhotite with some intermingled chalcopyrite. This occurrence of pyrrhotite has been known for many years. The ore was dug and copperas ruade from it in a very crude way before the Civil War. The Lick Fork openings, shown in figure 100 and comprising shafts and drifts, were begun in the hard rock out-crops at the base of a high and steep ridge, a few feet above the stream level. At the time of my visit, in May, 1907, a large amount of ore on the dumps was reported to average by actual assays not less than 1.75 per cent. of nickel, and a fraction of 1 per cent. of copper. As much as 0.4 per cent. of cobalt was reported, but the average is SX ROX PRS SSRN > © \ zi’ N ! . € o ze ON oot ‘ Nuys “ =- o Se EHH SYENITE NORITE DIKE, DIABASE DIKE, WITH PYRRHOTITE AND NICKEL. Fig. 101.—Section showing structural relations of the rocks at nickel mine, near Hemlock, Floyd county, Virginia. considerably less. Assays of the pyrite from other openings in the area are reported to yield from 3 to 4 per cent. of nickel. Arsenopyrite (mispickel), pages 210-211, is mined less than 4 miles southwest of the Lick Fork openings, but numerous analyses made of the ore do not show the presence of either nickel or cobalt. The area is composed exclusively of crystalline metamorphic rocks derived in part from original sediments and in part from igneous masses. The country-rock is chiefly made up of a complex of micaceous quartz- schists and gneisses of variable composition, and usually of a pronounced thinly foliated type. The rocks immediately associated with the ore are without exception of igneous origin, and range in composition from a pyroxene syenite to a very basic gabbro. These comprise pyroxene syenite, diabase, and gabbro. They are intruded into the schists and gneisses. The 582 MINERAL RESOURCES OF VIRGINIA. gabbro and diabase penetrate the pyroxene syenite in dike-like forms and are accordingly younger in age. The structural relations of the syenite, diabase, and gabbro, as indicated in the larger opening on Lick Fork, are shown in figure 101. The diabase is in direct contact, as a hanging-wall, with the gabbro, has an average thickness, so far as the openings extend in depth, of from 8 to 10 feet, and an outer contact with the syenite, as its own hanging-wall. The mica gabbro is the ore-bearing rock, has an average width in the present main opening on Lick Fork of from 18 to 22.feet, and like the diabase dips from 45° to 60° east-southeast. The ore, comprising pyr- rhotite chiefly and some chalcopyrite, is quite freely distributed, but with- out striking regularity or uniformity, through the gabbro. In some parts of the gabbro, the proportion of sulphides is very small; in others, they make up 50 per cent. and more of. the total rock-mass, with all gradations between. Thin sections of the ore studied under the microscope strongly suggest that the ore is chiefly of secondary origin. Microscopic sections. show that from the relations of the sulphides to the rock minerals the sulphides followed, principally, the lines of weakness in the silicate minerals with considerable replacement of them. Uses.—The principal use.made of cobalt is as a pigment or coloring constituent in glass and earthen wares. Cobalt steel, while possessing high elastic limit and breaking strength, cannot compete with nickel steel on account of its high cost. Probably the principal use made of nickel is in the manufacture of nickel and nickel-chromium steel. Some of the other important uses are tor large forgings, marine engines, wire cables, electrical apparatus, and in alloys. Reference. Watson, Thomas L. The Occurrence of Nickel in Virginia. Transactions American Institute of Mining Engineers, 1907, 15 pages. INDEX Albemarle county, copper, 502-503. Stony Point copper vein, 502-503. Albemarle county, iron, 469-470. Stony Point mine, 469. Albemarle county slate belt, 46-47. Albemarle county, soapstone, 291. Albemarle county, zine and lead, 542-544. Albemarle-Nelson counties soapstone belt, 293-295. Alexandria area and vicinity, clay, 174. Allanite, 387-388. Analyses of, 388. Alleghany county, iron mines, 438-442. Bess mine, 441. Dolly Ann mine, 439. Double Ridge mine, 441. Fancy Hill mine, 440. Given mine, 441. Horse Mountain mine, 441-442. Iron Mountain mine, 439. Iron Gate fossil ore mine, 441. Low Moor mine, 440. Potts Valley mine, 441. Rich Patch mine, 440. Rumsey mine, 439. Stack mine, 440. Alteration, lead and zine ores, 527. Amazonstone, 389. Ambler property, copper, 508. Amelia county area, mica, 279-284. Amelia court-house district, 280-283. General geology, 280-282. Mines, 282-283. Berry mine, 282. Jefferson mines, 282. Pinchback mine, 283. Rutherford mines, 282. Winston mine, 282. Jetersville district, 283-284. Schlegal mine, 283-284. Amelia county, soapstone, 291-292. Amelia court-house district, mica, 280- 283. General geology, 280-282. Mines, 282-283. Berry mine, 282. Jefferson mines, 282. Pinchback mine, 283. Rutherford mines, 282. Winston mine, 282. Amethyst, 386. Amherst county deposits, copper, 503. Amherst county, iron mines, 470-471. Maud vein, 471. Riverville mines, 470-471. Amherst county, manganese, 239. Analysis of, 239. Amherst county slate belt, 47-48. Ammonia, gas, tar and, 383-384. Anaconda mine, copper, 498. Analyses, allanite, 388. Athens shale, 135. barite, 316-317. ecalamine, 525. calcareous marls, 399-400. carbonite (natural coke), 379. cement material near Harrisonburg, 113. Chambersburg formation, 98, 99. coal, 348-352. coal, Richmond coal basin, 343. coke, 381-382. diabase, 37, 38, 39. diatomaceous earth, 217-218. dufrenite, 302. feldspars, 277. greensand marls, 398. gypsum, 334. helvite, 391. Holston formation, 136-137. iron ores, 414, 453, 457, 462. Knox dolomite, 132-133. Lenoir limestone, 134. Lewistown limestone, 154, 155, 156. Liberty Hall limestone, 122. 586 INDEX. limestone, 71, 72, 75, 80, 81, 96, 98, 99, 101, 104, 105, 109, 110, 118, 117, 119, 122, 123, 128, 130, 132, 134, 1386, 137, 188, 139, 140, 141, 151, 154, 155, 156, 157, 158, 161, 162, 214. limestone and marble, 75, 77, 80, 81. limestone from Covington, 156. limestones from Lexington, 122. limestone, Warm Springs, 154. limestone and shale near Craigsville, 155. limestones and shales, Staunton, 117, 118, 119. limestones and shales, vicinity Lu- rich, 157-158. limestones and shales, vicinity Stras- burg, 109. limestone at Woodstock, 110. manganese, 239, 240, 241, 242, 243, 248, 249, 250, 251, 252, 253, 254, 255. Marysville limestone, 130. mineral waters, 261-267. Moccasin limestone, 140. molding sands, 394-395. monazite, 303. Murat limestone, 104. natural cement rock, Balcony Falls, 161. natural cements, Maryland, 161. Newman limestone, 158. older crystalline limestones, 68, 70, 11; 72. Ordovician limestones at Ben Hur, 151. Ordovician limestone near Stokes- ville, 120. Pearisburg limestone, 138-139. pyrite, 196. pyrrhotite, 208-209. residual clays, 170-172. Rogersville shale, 130. Russell shales, 129. Rutledge limestone, 129. salt brines, 213, 215. Sevier shales, 140-141. West Virginia— Shenandoah limestone, 162. sphalerite, 524. Stones River formation, 96. Trenton limestones, 100-101. Trenton shales, 100. Analysis, apatite, 387. anhydrite, 334. asbestos, 286, 287. Bays sandstone, 141. bertha spelter, 547. beryl, 387. “buckfat,”’ 526. clay, gypsum-bearing, 333. coal, 348. columbite, 298, 390. diabase, 38. emery, 224. galenite, 523. glass sand, 393. gypsum, 330, 331. halite (salt), 212, 213. iron ores, 410, 416, 418, 419,430, 431, 432, 433, 434, 435, 436, 439, 440, 441, 442, 443, 444, 445, 446, 447, 448, 449, 450, 451, 452, 453, 454, 455, 456, 457, 458, 459, 461, 463, 464, 465, 466, 467, 469, 470, 471, 472, 473, 474, 475, 476, 477. lead concentrates, 544. Lewistown limestone, 153. limestone, 68, 70, 77, 94, 107, 115, 118, 120, 153, 160. limestone east of Winchester, 107. limestone, Seven Fountains, 153. limestone, Weyers Cave, 115. manganese, 239, 244, 245, 253, 254, 580. microlite, 390. Natural Bridge limestone, 94. Nolichucky shale, 131. ocher, 228, 229, 231. pebble phosphate, 302. sandstone, 142, sipylite, 298. smithsonite, 525. sphalerite, 536, 539, 541, 548. strengite, 303. syenite, 33. INDEX. tin ore, 570. travertine, Staunton, 160. unakite, 31. Utica shale, 102. zine concentrates, 544. Andis mine, iron, 459. Andradite, 387. Annandale, granite, area, 29. Ann Phipps mine, copper, 514. Anthony barite mine, 311. Apatite, 387. Analysis of, 387. Apatite and phosphatic marl, 299-302. Nelsonite (phosphate rock), 300-302. Nelson county, 300-301. Roanoke county, 301-302. Pebble phosphate, 302. Analysis, 302, Appalachian Mountain province, coal, 347-374. Appalachian Mountain province, 7-12. Appalachian Mountain region, barite, 320-325. Introduction, 320. Occurrence, 320. Russell and Tazewell counties, 322- 325. Smyth county, 321-322. Washington county, 322. Wythe county, 320-321. Appalachian Mountain region, manga- nese of, 244-255. Augusta county, 246-250. Analyses of, 248, 249, 250. Botetourt county, 251-252. Analyses of, 252. Description of individual areas, 244- 255. Frederick county, 252. Introduction, 244. Other Valley deposits, 254-255. Analyses of, 154, 255. Page county, 244-245. Analysis of, 244, 245. Rockbridge county, 253-254. Analysis of, 253, 254. Rockingham county, 250-251. Analyses of, 251. 587 Shenandoah county, 252-253. Analyses of, 253. Appalachian Mountain region, sandstones of, 59-63. Appomattox county, iron, 471. Appomattox county, manganese, 239. Analyses of, 239. Arcadia mine, iron, 445. Area, Alexandria and vicinity, clay, 174. granite, Annandale, 29. Bedford county barite, 319-320. Belfield, clay, 185. Bermuda Hundred, clay, 182-183. Broadway, clay, 183. Chester, clay, 182. City Point, clay, 184. Curle’s Neck, clay, 181-182. Fairfax county, granite, 28-29. Floyd county, nickel and cobalt, 580- 582. Fort Lee, clay, 180-181. Fredericksburg, clay, 175. Fredericksburg, granite, 26-28. gneiss, Lynchburg, 33-34. granite, Falls Church, 29. Layton, clay, 177. Louisa county barite, 318-319. Milford, clay, 177. Norfolk and vicinity, clay, 185-186. Nottoway-Prince William counties granite, 29-30. Oldfield, clay, 185. Petersburg, clay, 183. Petersburg granite, The, 19-21. Richmond, clay, 177-180. Richmond granite, The, 21-26. Sturgeon Point, clay, 184. Suffolk, clay, 186-187. Triassic, barite, 308-309. Wilmont, clay, 176. Areas, clay, description of, 174-187. granite, description of, 19-33. manganese, description of, 239-243, 244-255, other gneiss, 34-35, slate, description of, 42-51. Arminius pyrite mine, 199-201. 588 Arsenopyrite (imispickel), 210-211. References, 211. Uses of, 211. Artesian waters, 268-275. List of Coastal Plain formations, 268. References, 275. Water horizons in eastern Virginia, 269-272. Chesapeake, 270-272. Pamunkey, 270. Potomac, 269-272. Wells in eastern Virginia, 272-274. Arvonia, slate, 44-45. Asbestos, 285-287. Analysis, 286-287. Composition and character, 285. Distribution, 286-287. Oceurrence, 285-286. References, 287. Uses, 287. Associated minerals, 526-527. barite, 317. ores and, zine and lead region, 523- 527. pyrite areas, 196-197. Associated ores, 526. Associated rocks, barite, 315-317. Analyses of, 316-317. Athens shale, 134-135. Analyses of, 135. Augusta county, coal field of, 348. iron mines, 434-436. Bare bank mine, 435. Black Rock mine, 435. Blue bank mine, 435. Buffalo Gap mine, 434. Crozier mine, 435. Ferrol mines, 434. Fisherville mine, 435. Lofton mine, 435. Mine bank mine, 435-436. Augusta county, manganese, 246-250. Analyses of, 248, 249, 250. Augusta county, ocher, 229-230. Austinville lead and zine mines, 532-537. Baleony Falls, analyses of natural ce- ment rock from, 161. INDEX. Bank, Razor, manganese, 254. Bare bank mine, iron, 435. Barite (heavy spar), 305-327. Appalachian Mountain region, 320- 325. Introduction, 320. Occurrence, 320. Russell and Tazewell 322-325. Smyth county, 321-322. Washington county, 322. Wythe county, 320-321. Composition and properties, 305. Distribution, 307. Historical, 305. Methods of mining, 325. Occurrence, 307-308. Piedmont Plateau region, 309-320. Bedford county area, 319-320. Campbell-Pittsylvania area, 309- 318. Analyses, 316-317. Associated minerals, 317. Associated rocks, 315-317. Mines, 311-314. Mode of occurrence, 314-315. Structure, 318. Louisa county area, 318-319. Preparation, 325-326. Production, 327. References, 327. Triassic area, 308-309. Uses, 326-327. Barnes place, gypsum, 330. analysis of, 330. counties, Barr limonite mine, 473-474. Barr magnetite mine, iron, 473. Barren Springs mines, iron, 452. Basalt, Diabase and, 36-39. analyses of, 37, 38, 39. Bassler, R. S., contribution of paper by, 86. acknowledgments to, xxx. Bath county, iron, 438. Bays sandstone, 141-142. analysis of, 141. Bedford county barite area, 319-320. INDEX. 589 Bedford county, iron mines, 471-472. Kelley seam, 372. Dewey-mine, 472. Seam just beneath Gladeville Ironville mine, 472. sandstone, 372. Bedford county, soapstone, 291. Eastern portion of the field, 367- Belfield area, clay, 185. 370. Bell Hill mine, iron, 463. Edwards seam, 368. Belt, slate, Albemarle county, 46-47. Imboden seam (?), 369. Amherst county, 47-48. Introduction, 367-368. Buckingham-Fluvanna, 42-46. Jawbone seam, 369-370. Fauquier county, 49-50. Kennedy seam, 369. Prince William-Stafford counties, Lower Banner seam, 368-369. 51. Upper Banner seam, 368. Ben Hur, geologic sections in vicinity of, Geologic sections, 366. 150. Operations, 367. analyses of Ordovician limestones at, | Bishop manganese mine, 241. 151. Black Rock mine, iron, 435. Ben Hur mine, iron, 466. Bennett barite mine, 312, 313, 314. Bentonville-Overall district, copper, 507- 508. Berger barite mine, 312-313. Bermuda Hundred area, clay, 182-183. Berry mine, mica, 282. Berryville mine, iron, 430. Bertha mines, iron, 452-453. Bertha zinc mines, 532. Bertha zine smelting plant, 546-547. Beryl, 387. analysis of, 387. Bess mine, iron, 441. Betty Baker mine, copper, 514-516. Betty Baker mine, iron, 476. Beverley, Kimball, and Shenandoah Iron Works mines, 432. Beyer mine, iron, 432. Big Hill mine, iron, 443. Big Ike mine, iron, 430. Big Stone Gap and western portion of coal field, 370-373. Big Stone Gap coal field, 364-373. Location and importance, 364-365. The coal, 365-373. Big Stone Gap and western por- tion of field, 370-373. Coals of Wise formation, 372- 373. Imboden seam, 371-372. Introduction, 370-371. Bland county, iron, 462. Bland-Wythe counties coal field, 352. analyses of coal from, 352. Blue bank mine, iron, 435. Blue mine, manganese, 250. Blue Ridge area, granite, 30-31. Blue Ridge copper deposits, 503-511. Character and occurrence of the ores, 505-506. Description of mines, 506-511. Greene county, 510-511. Madison county, 509-510. Page county, 509. Rappahannock county, 508-509. Warren county, 506-508. Geology, 504-505. Location and history, 503. Blue Ride Copper Co’s mine, 509-510. Blue Ridge, granite, area, 30-31. Blue Ridge hematite ore, 418-419. Blue Ridge limonite ore, 414-416. Bonsack prospect, zinc, ete., 530. Boones Path mines, iron, 466-467. Botetourt county, coal fields of, 348-349. Botetourt county, iron mines, 442-445. Arcadia mine, 445. Big Hill mine, 443. Callie mine, 442. Circle mine, 443. Crozier mine, 444. Edith mine, 444. Grace mine, 443. 590 Grubb or Lynchburg mine, 443-444. Grubb specular mine, 445. Houston mine, 444. Lemon mine, 445. Oriskany mine, 443. Ried mine, 443. Roaring Run mine, 443. Sand bank mines, 442. Wilton mine, 442. Wood mine, 445. Botetourt county, manganese, 251-252. analyses of, 252. Bremo, slate, 46. Brines, salt, analyses of, 213-215. Broadway area, clay, 183. Buchanan and Dickenson counties, 463. Buchanan place, gypsum, 330. “Buckfat,” 526. Buck Hill mine, iron, 437. Buckingham county deposits, 500-502. Lightfoot mine, 501-502. New Canton mines, 501. United States Mineral Co’s mine, 501. Buckingham county, gold mines, 562-563. Anaconda mine, 562-563. Apperson mine, 562-563. Booker (Morrow) mine, 562. Buckingham mine, 562. Duncan mine, 562. Ford mine, 562. Garnet mine, 562. Lightfoot mine, 562-563. London and Virginia mine, 562. Morton mine, 562. Mosely mine, 562. Philadelphia mine, 562. Piedmont mine, 562. Willis Creek mine, 562. Buckingham county, iron, 470. Buckingham county, manganese, 239. Buckingham, Fluvanna and, counties, soapstone, 290-291. Buckingham-Fluvanna slate belt, 42-46. Buena Vista mines, iron, 436. Buena Vista Plaster and Mining Co’s mines, 331-334. copper, INDEX. analyses of gypsum and anhydrite from, 334. analysis of anhydrite from, 334. clay from, 333. records of well borings, 331-332. Buena Vista shales, 94. Buffalo Gap mine, iron, 434. Bugley mine, manganese, 242. Buhrstones, see millstones, 401. Building and ornamental stones, 16-85. General statement, 16. Building sand, 395-396. Cabell mine, manganese, 242. Cabin Branch pyrite mine, 202-204. Calamine, 525. Caleareous marls, 398-400. analyses of, 399-400. Callie mine, iron, 442. Cambrian and Ordovician formation of northwestern Virginia, 91. Lower Cambrian quartzites, shales, and sandstones, 93. Martinsburg shale group, 99-102. Eden shales and sandstones, 102. Trenton limestone, 100-101. analyses of, 101. Trenton shales, 100. analyses of, 100. Utica shale, 101-102. analysis of, 102. Massanutten sandstone group, 102- 103. Shenandoah limestone group, 93-99. Buena Vista shales, 94. Chambersburg formation, 96-99. analyses of, 98-99. Generalized section of, 97. Geologic section, vicinity of Stras- burg, 95. Natural Bridge limestone, 94. Sherwood limestone, 94. analysis of, 94. Stones River formation, 95-96. analysis of, 96. Table of, 92. Cambrian and Ordovician formations, southwestern Virginia, 128. INDEX. Cambrian and Ordovician strata south- western Virginia, distribution of, 124-128. Cambrian formations, southwestern Vir- ginia, 128-131. Cambrian (Lower) quartzites, and sandstones, 93. shales Cambrian sandstone, 60. Cambro-Ordovician, southwestern Vir- ginia, 131. Campbell county, iron, 471. Campbell county, manganese, 239-242. analyses of, 240-241. Campbell county, soapstone, 291. Campbell, H. D., acknowledgments to, 87. Campbell-Pittsylvania barite area, 309- 318. Associated minerals, 317. Associated rocks, 315-317. analyses, 316-317. Mines, 311-314. Mode of occurrence, 314-315. Structure, 318. (Pennsylvanian) coals, Carboniferous 353-374. Age of the coal-bearing rocks, 353. Analyses, coal, 357-358. Big Stone Gap coal field, 364-373. Character of the coal, 356-358. analyses of, 357-358. Coal, Carboniferous, 356-358. Geologic relations of, 353. Geologic relations, Carboniferous coals, 353. Importance, location and, Carbon- iferous coals, 353. Location and importance of, 353. Location and importance, Carbon- iferous coals, 353. Pocahontas or Flat Top coal field, 359-364. Introductory statement, 359. Operators, 359-360. The coal, 360-364. Coals of Dismal formation, 364. character of, 591 Coals of Pocahontas formation, 362-363. Coals of Sequoyah and Tellowa formations, 364. Coals of Welch formation, 363- 364, Geologic sections, 360-361. Introduction, 360. Stratigraphy, 354-355. Stratigraphy, Carboniferous 354-355. Carboniferous sandstones, 62-63. Mississippian group, 62. Pennsylvanian group, 62-63. Carbonite (natural coke), 378-380. analyses of, 379. References, 379-380. Carroll county, copper mines, 514-516. Betty Baker mine, 514-516. Cranberry mine, 514. Gardner and Goad mines, 516. Great Outburst, 516. Vaughn mine, 514. Wildcat mine, 514. Carroll county, iron mines, 475-476. Betty Baker mine, 476. Chestnut Yard mines, 475-476. Carroll county, soapstone, 293. Carter bank, iron, 453. Cartwright and Davis, granite, quarries, 28. Castle Rock mine, iron, 446. Catlett, Charles, acknowledgments to, 87. Cedar Run mine, iron, 453. Cedar Springs zine mines, 538-540. Cement and cement materials, 86-167. Cement industry in Virginia, 162-165. Cement, kinds of, 87-88. Cement materials, 88-89. Cement materials, cement and, 86-167. Cement materials, distribution of, 89. Cement materials near Harrisonburg, an- alyses of, 113. Cement materials, post-Ordovician, 151. Cement, natural, 160-162. Central western Virginia, analyses lime- stones and shale of, 123. Cerussite, 523. coals, 592 Chambersburg formation, 96-99. Analyses of, 98-99. Generalized section of, 97. Chappel mine, copper, 498. Character and composition, mica, 278. Character, composition and, asbestos, 285. Character, composition and, feldspars, 275-276. Character and occurrence, Blue Ridge copper ores, 505-506. Character and occurrence, pyrite ore, 193-197. Character and structure of rocks, Louisa and Prince William counties areas, 191-193. Character of vein, gossan lead, 512-513. Charlotte county, Keysville Copper area in, 500. Chemical analyses, mineral waters, 261- 267. Chert, 216. Chesapeake (formation), 270-272. Chester area, clay, 182. Chesterfield county, ocher, 226-227. Chestnut Yard mines, iron, 475-476. Chickamauga limestone, 76-77, 133-134. analysis of, 77. Chlorophane (fluorite), 388. Cirele mine, iron, 443. City Point area, clay, 184. Clarke county, iron mines, 430. Berryville mine, 430. Clarks bank, iron, 448-449. Clarks Summit mine, iron, 459. Classification of clays, 168-169. Classification of Virginia iron ores, 407, 408. Clay areas, description of, 174-187. Clay, definition and properties of, 167- 168. Clay, origin of, 168. Clays, 167-187. Clays, classification of, 168-169. Clays, Coastal Plain, The, 173-187. Clays, residual, 169-172. analyses of, 170-172. Clays, sedimentary, 172. INDEX. Clayton mine, iron, 451. Clinch sandstone, 142. Coal, 336-378. Appalachian Mountain province, 347- 374, Lower Carboniferous coals, 347- 352. Augusta county, 348. Bland-Wythe counties field, 352. Botetourt, 348-349. Frederick county, 347. Montgomery - Pulaski field, 349-352. Mountain Falls district, 347. North Mountain coal field, 348- counties 349. North River coal field, 348. Carboniferous (Pennsylvanian) coals, 353-374. Age of the coal-bearing rocks, 353. Big Stone Gap coal field, 364- 373. Location and importance, 364- 365. The coal, 365-373. Big Stone Gap and western portion of field, 370- 373. Coals of Wise formation, 372-373. Imboden seam, 371-372. Introduction, 370-371. Kelly seam, 372. Seam just beneath Glade- ville sandstone, 372. Eastern portion of the field, 367-370. Edwards seam, 368. Introduction, 367-368. Imboden seam (?), 369. Jawbone seam, 369-370. Kennedy seam, 369. Lower Banner seam, 368- 369. Upper Banner seam, 368. Geologic sections, 366. Operations, 367. INDEX. Character of the coal, 356-358. analyses of, 357-358. Geologic relations, 353. Location and importance, 353. Pocahontas or Flat-Top coal field, 359-364. Introductory statement. 359. Operators, 359-360. The coal, 360-364. Coals of Dismal formation, 364. Coals of Pocahontas forma- tion, 362-363. Coals of Sequoyah and Tel- lowa formations, 364. Coals of Welch formation, 363-304. Geologic sections, 360-361. Introduction, 360. Stratigraphy, 354-355. Structure, 356. Distribution, 338-339. Historical, 336-338. Methods of mining, 373-374. Piedmont province, 339-347. Coal beds of the basin, 342-346. Analyses of coal from, 343. Depth of the coal, 345-346. Extent of the coal beds, 342-345. General geology of the basin, 340- 342. Historical, 340. Mines, 346-347. Position and extent of basin, 339- 340. Richmond coal basin, 331-347. Production, 375-376. References, 376-378. Coal and its by-products, 336-387. Coal beds, Richmond coal basin, 342-346. Coal, Big Stone Gap coal field, 365-373. Coal, depth of, Richmond coal basin, 345- 346. Coal, methods of mining, 373-374. Coal, Pocahontas or Flat Top coal field, . 360-364. Coals of Dismal formation, 364. 593 Coals of Pocahontas formation, 362-363. Coals of Sequoyah and Tellowa forma- tions, 364. Coals of Welch formation, 363-364. Coals of Wise formation, 372-373. Coastal Plain clays, 173-187. Coastal Plain counties, iron, 477. Coastal Plain formations, list of, 268. Coastal Plain limestones, 66. Coastal Plain province, The, 3-5. Formations of, 4. Coastal Plain region, manganese of, 238. Coastal Plain region, marls, 397-399. Caleareous, 398-399. Greensand, 397-398. Coastal Plain region, sandstone of, 54-55. Cobalt (see under Nickel). Coke, 380-383. Analyses of, 381-382. Statistics on, 382-383. Coke, natural (see under carbonite). Columbite, 298, 390. analysis of, 298, 390. Composition and character, asbestos, 285. Composition and character, feldspars, 275-276. Composition and properties, barite, 305. Composition and properties, garnet, 287- 288. Composition and properties of pyrite, 190. Composition, character and, mica, 278. Composition, mineral, granites, 18. Composition of pyrite ore, 196. Composition, tale and soapstone, 289. Cook, granite, quarry, 20. Copper, 491-519. Albemarle county deposits, 502-503. Amherst county deposits, 503. Blue Ridge copper deposits, 503-511. Character and occurrence of ores, 505-506. Description of mines, 506-511. Geology, 504-505. Location and history, 503. Buckingham county deposits, 500- Copper ores of the Triassic, 518. Distribution of the ores, 492-494. 594 Geographical, 492. Geological, 492-494. General statement, 491. Gossan lead, 511-517. Description of mines, 514-517. Keysville area, Charlotte county, 500. The Southwest Virginia region, 511- 517. References, 519. Virgilina district, 494-499. Description of the mines, 496-499. Geology and petrography, 494. Introductory statement, 494. Kinds and occurrence of ore, 494- 495. The veins, 495-496. Copper ores of the Triassic, 518. Copperas Hill mine, copper, 514. Corundum, 223-224. Corundum and emery, 223-224. Ccrundum, 223-224. Emery, 224. analysis of, 224. References, 224. Uses of, 224. Counties west of the Blue Ridge, 429- 467. Alleghany county, 438-442. Augusta county, 434-436. Bath county, 438. Bland county, 462. Botetourt county, 442-445. Buchanan county, 463. Clarke county, 430. Craig county, 445-446. Dickenson county, 463. Frederick county, 429. Giles county, 447-448. Highland county, 438. Lee county, 465-467. Montgomery county, 447. Page county, 431-433. Pulaski county, 448-451. Rockbridge county, 436-437. Rockingham county, 433-434. Roanoke county, 446-447. Russell county, 463. INDEX. Scott county, 463. Shenandoah county, 430-431. Smyth county, 460-461. Tazewell county, 462-463. Warren county, 430. Washington county, 461-462. Wise county, 463-464. Wythe county, 451-459. Covington, 156. analyses of limestone from, 156. Craig county iron mines, 445-446. Fenwick mine, 446. Oriskany mine, 446. Craigsvilie, 154-155. analyses limestone and shale near, 155. Section near, 155. Craigsville, Portland cement plant at, 163-165. Cranberry mine, copper, 514. Crawford mine, iron, 454. Crigger bank, iron, 460. Crimora manganese mine, 246-249. Crozier mine, iron, 435-444. Culpeper county, copper, 518. Culpeper county, gold mines, 554. Culpeper mine, 554. Ellis mine, 554. Richardville mine, 554. Curle’s Neck area, clay, 181-182. Curran Valley mine, iron, 461. Davis barite mine, 313. Davis mine, manganese, 243. Definition and properties, fullers earth, 296-297. Definition and properties, marls, 396. Definition and properties, ocher, 225. Definition and properties of clay, 167- 168. Definition, granite, 17. Delton mines, zine, ete., 531. Deposits, copper, Albemarle county, 502- 503. Deposits, copper, Amherst county, 503. Deposits, copper, Blue Ridge, 503-511. Deposits, individual, ocher, description of, 226-231. Depth of coal, Richmond basin, 345-346. INDEX. Description of clay areas, 174-187. Description of individual areas, manga- nese, 244-255. Description of areas of granite, 19-33. Description of individual deposits, ocher, 226-231. Description of individual areas, 239-243. Description of mines, Blue Ridge copper district, 506-511. Description of mines, copper, southwest Virginia, 514-517. Description of mines, gold, 553-564. Description of mines, Virgilina district, 496-499. Description of mines, zine and lead, 530- 544. Description of slate areas, 42-51. Details of localities, 154-156. Details of localities, northwestern and central western Virginia, 105-120. Geologie section, Wadesville, 114. Harrisonburg and vicinity, 110-1138. analyses cement material near Harrisonburg, 113. Structure sections, 112. Middletown, 107. Section of Ordovician rocks near Middletown, 107. Mount Sidney and vicinity, 115. analyses limestone, Weyers Cave, 115. Geologic section, Mount Sidney, 115. Riverton and vicinity, 114. Staunton, 115-119. analyses, shales and limestones, Staunton, 117, 118, 119. Strasburg, 107-109. analyses, limestone and vicinity of, 109. Wadesville, 113-114. Western edge of Valley, north of Staunton, 119-120. Geologie section, Staunton, 117. Winchester, 105-107. analysis limestone east of Win- chester, 107. manganese shales, 595 Structure section Virginia, 106. Woodstock and vicinity, 109-110. analyses of limestone, Woodstock, 110. Details of localities, southwestern Vir- ginia, 142. Developments, mining, gypsum, 329-334. Devonian sandstones, 61. Dewey mine, iron, 472. Diabase and basalt, 36-39. analyses of, 37, 38, 39. Diamond, 385-386. Diatomaceous earth, 216-223. Analyses of, 217-218. Distribution, 218-222. Origin and occurrence, 217-218. References, 223. Uses of, 222. Dickenson, Buchanan and, counties, 463. Dickey’s Hill mines, copper, 507. Diorite, 39-40. Dismal formation, coals of, 364. Distribution and description, 279. Distribution and localities, fullers earth, 297. Distribution and localities, gem minerals, 385. Distribution and localities, graphite, 188- 190. Distribution and localities, marls, 397- 400. Distribution and localities, ocher, 225- 226. Distribution and localities, pyrite, 191. Distribution and localities, tale and soap- stone, 290-295. Distribution, asbestos, 286-287. barite, 307. Cambrian and Ordovician strata southwestern Virginia, 124-128. coal, 338-339. diatomaceous earth, 218-222. ete., older crystalline limestones, 67- 72. ; feldspars, 276-277. garnet, 288-289. geographical, iron ores, 425-428. northwestern 596 geological, iron ores, 423-425. gold, 549-551. granites, 17-18. niter, 304-305. of cement materials, 89. of limestones and marbles in Vir- ginia, 65-66. of the copper ores, 492-494, Geographical, 492. Geological, 492-494. rutile, 232-234. zine and lead ores, 520-521. District, copper, Bentonville-Overall, 507- 508. Diversity of resources, 15. Dixie mine, iron, 436-437. Dolly Ann mine, iron, 439. Dolomite, knox, 131-133. Dorothy mine, copper, 498. Double Ridge mine, iron, 441. Dressing, ore, iron, 485-486. Dufrenite, 302. analyses of, 302. Eastern portion of the Big Stone Gap coal field, 367-370. Eden shales and sandstones, 102. Edith mine, iron, 444. Edwards coal seam, 368. Effects of weathering and erosion, 12-14. Elements, 188-190. Emery, 224. analysis of, 224. Erosion and weathering, effects of, 12-14. Ewing mine, iron, 467. Fairfax county area, granite, 28-29. Annandale area, 29. Hoffman and Miller quarry, 29. Falls Church area, 29. Trip quarry, 29. Fairfax county, granite, area, 28-29. Fairfax county, soapstone, 292. Falls Church, granite, area, 29. Fancy Hill mine, iron, 440. Farris mine, iron, 449. Fauber mine, manganese, 250. Fauquier county, gold mines, 553. Bancroft mine, 553. Franklin mine, 553. INDEX. Kelly mine, 553. Kirk mine, 553. Liepold mine, 553. Wykoff mine, 553. Fauquier county slate belt, 49-50. Features, surface, 1-12. Feldspar, 389. ' Feldspars, 275-277. Analyses, 277. Composition and character, 275-276 Distribution, 276-277. Occurrence, 276. References, 277. Uses, 277. Fenwick mine, iron, 446. Ferrol mines, iron, 434. Fisherville mine, iron, 435. Floyd county area, nickel and cobalt, 580-582. Floyd county, copper mines, 517. Toneray mine, 517. Floyd county, gold (see under Mont- gomery county). Floyd county, iron, 475. Toneray mine, 475. Floyd county, soapstone, 293. Fluorite (fluorspar), 215. References, 215. Uses, 215. Fluorite (chlorophane), 388. Fluvanna and Goochland counties, 559- 562. Belzora mine, 559, 561, 562. Bertha and Edith mine, 559-560. Big Bird mine, 559-562. Bowles mine, 559-560. Busby mine, 559-560. Collins mine, 559-562. Eades mine, 559-562. Fisher mine, 559-560. Gilmore mine, 559. Hughes mine, 559-561. Manning mine, 559. Marks mine, 559-562. Moss mine, 559-560. Page mine, 559, 560, 561. Payne mine, 559. Snead mine, 559-560. INDEX. Tellurium mine, 559-560. Walters mine, 559. Fluvanna and Buckingham soapstone, 290-291. Formation, Dismal, coals of, 364. Formation, Holston, 135-137. Formation, Pocahontas, coals of, 362-363. Formation, Welch, coals of, 363-364. Formation, Wise, coals of, 372-373. Formations, Cambrian, southwestern Virginia, 128-131. Formations, Coastal Plain, list of, 268. Formations, Sequoyah and Tellowa, coals of, 364. Forney openings, zine, ete., 531. Fort Lee area, clay, 180-181. Fossil hematite ore, 416-418. Foster Falls mines, iron, 455. Fox Mountain mine, iron, 434. Frederick county, coal field of, 347. Franklin county, copper mines, 517. Howell mine, 517. Franklin county, iron mines, 474. Rocky Mount mine, 474. Franklin county, soapstone, 291. Frederick county, iron, 429. Frederick county, manganese, 252. Fredericksburg area, granite, 26-28. Cartwright and Davis quarries, 28. Hazel Run granite, 27-28. Fredericksburg area, clay, 175. Fredericksburg granite area, 26-28. Fullers earth, 296-297. Definition and properties, 296-297. Distribution and localities, 297. References, 297. Uses, 297. Furnaces in Virginia, list of, 479. Gabbro, 40. Gale mine, iron, 446. Galenite, 523. Ganaway mine, iron, 459. Gangue minerals, gold deposits, 552-553. Gardner and Goad mines, copper, 516. Garnet, 287-289, 386-387. Composition and properties, 287-288. Distribution, 288-289. " counties, 597 References, 289. Uses, 289. Gas, tar, and ammonia, 383-384. Gem minerals, 385-391. Distribution and localities, 385. Mineral species, 385-391. References, 391-392. General character, graphite, 188. General geology and stratigraphy of cen- central western Virginia, 103-105. analyses of Murat limestone, 104. analyses of Liberty Hall limestone, 105. General geology of Virginia, 1-15. geographic position of, 1. Generalized section, Chambersburg for- mation, 97. Geographical distrioution, iron ores, 425- 428. Geographical position of Virginia, 1. Geological distribution, iron ores, 423- 425. Geologic relations southwestern Virginia deposits, gypsum, 328-329. Geologic section at Mount Sidney, 115. Geologic section in Scott and Russell counties, 148-149. Geologic section in Smyth county, 146. Geologic section, Lexington and vicinity, 121. Geologic section near Craigsville, 155. Geologic section, north Thompson Val- ley, 144. Geologic section, Pearisburg, 137-138. Geologic section, Speers Ferry, 136. Geologic section, vicinity Ben Hur, 150. Geologie section, vicinity Lurich, 157. Geologie section, vicinity Seven Foun- tains, 153. Geologic section, vicinity of Strasburg, 95. Geologic section, Wadesville, 114. Geologic section, Warm Springs to Mt. Grove, 154. Geologic sections Big Stone Gap coal field, 366. Geologic sections, Pocahontas coal field, 360-361. 598 Geology and petrography, Virgilina cop- per district, 494. Geology and stratigraphy, general, cen- tral western Virginia, 103-105. Geology, Amelia court-house mica dis- trict, 280-283. Geology, Blue Ridge copper deposits, 504- 505. , Geology, general, gold, 551-553. Country rocks, 551. Gangue minerals, 552-553. Veins, 551-552. Geology, general, Richmond coal basin, 340-342. Geology, general, Virginia, 1-15. Geology, general, zinc and lead region, 521-523. Geology, gossan lead, 511-512. Geology of Louisa and Prince William counties pyrite area, 191-193. Character and structure of the rocks, 191-193. Geology of southwestern Virginia, 123. Cambrian and Ordovician forma- tions of, 128. General distribution, Cambrian and Ordovician strata, 124-128. Major faults, 123-124. Stratigraphy, 128. Structure sections in, 125. Giles county, cement materials, 142. Giles county, iron mines, 447-448. Interior mines, 448. Jchnson mine, 447. Porterfield mine, 448. Given mine, iron, 441. Gladeville sandstone, coal seam just be- neath, 372. Glass sand, 393-394. analysis of, 393. Gneisses, 33-35. Gold and silver, 549-567. Description of mines, 553-564. Buckingham county, 562-563. Culpeper county, 554. Fauquier county, 553. Fluvanna and Goochland counties, 559-562. INDEX. Halifax county, 563. Louisa county, 557-509. Montgomery and Floyd counties, 564, Orange county, 555-557. Spottsylvania county, 554-555. Stafford county, 553-554. Distribution, 549-551. General geology, 551-553. Historical, 549. Production, 564-565. References, 566-567. Golleher mine, iron, 461. Goochland county, gold mines (see under Fluvanna county). Gossan lead, geology of, 511-512. Gossan lead, southwest Virginia, 511-517. Gossan, pyrite, 419. Gossan, pyrrhotite, 419-421. Grabill mine, iron, 466. Grace mine, iron, 443. Granites, 17-33. Definition, 17. Description of areas of, 19-33. Blue Ridge area, 30-31. Fairfax county area, 28-29. Fredericksburg area, 26-28. Nottoway-Prince Edward counties area, 29-30. Petersburg area, 19-21. Richmond area, 20-26. Distribution of, 17-18. Kinds of, 18. Mineral composition, 18. Granite, Hazel Run, 27-28. Granite production in Virginia, 35. Granite quarries, list of, in Richmond area, 23. Graphite, 188-190. distribution and localities, 188-190. general character, 188. Occurrence, 188. References, 190. Uses, 190. Grayson county, copper, 517. iron, 476-477. soapstone, 292-293. ‘Great Outburst, 516. INDEX. Great Valley region, zinc and lead, 530- 541. Montgomery county, 530. Pulaski county, 531. Roanoke and Botetourt counties, 530. Russell county, 541. Smyth county, 540-541. Wythe county, 531-540. Greenbrier limestone, 80-81, 157-158. analyses of, 81, 157, 158. geologic section of, near Lurich, 157. Greene county, copper mines, 510-511. High Top Copper Mining Co’s mine, 510-511. Sims mine, 510. Greensand marls, 397-398. analyses of, 398. Greenway mine, iron, 469-470. Gregory mine, iron, 457. Griffin mine, iron, 446. Griffin specular mine, iron, 447. Grubb or Lynchburg mine, iron, 443-444. Grubb specular mine, iron, 445. Gypsum, 327-335. General properties, 327-328. Geologic relations southwestern Vir- ginia deposits, 328-329. Mining developments, 329-334. Analysis, anhydrite, 334. Analysis, clay, 333. Analysis, gypsum, 330-331. Analyses, gypsum and anhydrite, 334. Records of well borings, 331-332. Origin and occurrence, 328. Production, 334-335. References, 335. Uses, 334. Hairston mine, iron, 474-475. Halides, 211-216. Halifax Copper Co’s mine, 498. Halifax county, gold mines, 563. Goldbank mine, 563. Howard mine, 563. Halite (salt), 211-215. Analysis of, 212-213. Analysis of limestone, 214. 599 Analyses of brines, 213-215. Mathieson Alkali Works, 214-215. References, 215. Hall mine, iron, 463. Happy creek mine, iron, 430. Harrisonburg and vicinity, 110-113. Analyses, cement material near, 113. Structure sections in vicinity of, 112. Hatchet barite mine, 313. Hazel Run granite, 27-28. Heiston mine, iron, 433. Helvite, 390-391. analyses of, 391. Hematite mine, iron, 455. Henry county, iron, 475. Henry county, soapstone, 293. Henson mine, iron, 459. Hewitt barite mine, 311. High Hill mine, copper, 496-498. Highland county, iron, 438. Hightop Copper Mining Co’s mine, 510- 511. Historical, barite, 305. Historical, coal, 336-338. Historical, gold, 549. Historical, iron, 402-404. Historical, Louisa county pyrite de- posits, 198. Historical, Richmond coal basin, 340. Historical, tin, 568. Hoffman and Miller, granite, quarry, 29. Holden, R. J., contribution of paper by, 402-491. Acknowledgments to, xxx. Holston formation, 135-137. analyses of, 136-137. Geologic section, Speer Ferry, 136. Holston mine, iron, 462. 7 Home bank, iron, 460-461. Honaker limestone, 131. Horse Mountain mine, iron, 441-442. Houston mine, iron, 444. Houston mine, manganese, 251-252. Howell mine, copper, 517. Hurst mine, iron, 454. Hydrocarbons, 336-384. Ilmenite (menaccanite), 232. Imboden coal seam, 369, 371, 372. 600 Importance, location and, Big Stone Gap coal field, 364-365. Impurities of iron ore, 405-407. Indian Camp mines, iron, 456. Individual mines, iron, 428-477. Intericr mines, iron, 448. Tron, 402-491. Blue Ridge hematite, 418-419. Blue Ridge limonite ore, 414-416. Classification of Virginia ores, 407- 408. Coastal Plain counties, 477. Counties west of the Blue Ridge, 429- 467. Fessil hematite, 416-418. Geographical distribution, 425-428. Geological distribution, 423-425. Historical, - 402-40+4. Impurities of iron ore, 405-407. Individual mines, 428-477. Limestone limonite ores, 410-414. Limestone magnetite, 422. List of furnaces in Virginia, 479. List of iron mines in Virginia, 477- 478. Methods of mining, 479-485. Minerals and ores, 403-405. Ore dressing, 485-486. Origin of iron ore, 407. ‘Oriskany ore, 408-410. Piedmont counties, 468-477. Piedmont magnetites, 421-422. Production, 487-488. Pyrite gossan, 419. Pyrrhotite gossan and pyrrhotite, > 419-421. References, 488-491. Titaniferous magnetite, 422-423. Uses, 486. Irondale mines, iron, 464. Iron Gate fossil ore mine, 441. Iron minerals and ores, 403-405. Iron mines in Virginia, list of, 477-478. Iron Mountain mine, iron, 439. Tron cres. analyses, 414, 453, 457, 462. INDEX. Iron ores, analysis, 410, 416, 418, 419, 430, 432, 433, 434, 435, 436, 439, 440, 441, 442, 443, 444, 445, 446, 447, 448, 449, 450, 451, 452, 453, 454, 455, 456, 457, 458, 459, 461, 463, 464, 465, 466, 467, 469, 470, 471, 472, 473, 474, 475, 476, 477. Ironville mine, iron, 472. Ivanhoe mine, iron, 457. Jawbone coal seam, 369-370. Jefferson mines, mica, 282. Jetersville district, mica, 283-284. Schlegal mine, 283-284. Johnson mine, iron, 447. Johnson shaft, copper, 501. Jura-Cretaceous sandstone, 54-55. Kelly coal seam, 372. Kelly mine, manganese, 250. Kendall and Flick mine, manganese, 250- 251. Kennedy coal seam, 369. Keystone mine, iron, 464. Keysville area, copper, Charlotte county, 500. Kimball mine, manganese, 245. Kinds and occurrence of ores, Virgilina district, 494-495. Kinds of cement, 87-88. Kinds of granite, 18. Kinds of ore, manganese, 237-238. Kirkbride mine, copper, 514. Knox dolomite, 131-133. analyses of, 132-133. Kyanite, 388. Lassiter, granite, quarries, 20. Lavine mine, iron, 465. Layton area, clay, 177. Lead (see under Zinc). Lead and zine ores, alteration of, 527. Lead ores, 523. Cerussite, 523. Galenite, 523. Lee county, cement materials, 149-151. analyses of Ordovician limestones in, 151. Geologie section in, 150. INDEX. Lee county, iron mines, 465-467. Ben Hur mine, 466. Boones Path mines, 466-467. Ewing mine, 467. Grabill mine, 466. Lavine mine, 465. Noes Siding mine, 466. Pennington mine, 465. Truro mine, 466. Leets mine, manganese, 240-241. Lemon mine, iron, 445. Lenoir limestone, 134. analyses of, 134. Lewistown limestone, 77-80, 151-156. analyses of, 80, 153, 154, 155, 156. Geologic sections of, 153, 154, 155. Lexington, 120-123. analyses of limestones from and near, 122-123. Geologic section, Lexington and vi- cinity, 121. Liberty mines, iron, sul. Lightfoot mine, copper, 501-502. Limestone, analyses of, 214. Limestone, Chickamauga, 133-134. Covington, analyses of, 156. east of Winchester, analysis of, 107. Greenbrier, 157-158. Honaker, 131. Lenoir, 134. Lewistown, 151-156. Lexington, analyses of, 122-123. limonite ores, 410-414. magnetite, 422. Marysville, 130. Moccasin, 139-140. Newman, 158. Newman, analyses of, 158. Ordovician, near Stokesville, analy- ses of, 120. Pearisburg, 137-139. Rutledge, 129. Shenandoah, analyses of, 162. Weyers Cave, analyses of, 115. Woodstock at, analyses, 110. Limestones and marbles, 65-85. Coastal Plain region, 66. Distribution of, 65-66. 601 Mountain province limestones, 73-83. Chickamauga limestone, 76-77. analysis of, 77. Greenbrier limestone, 80-81. analyses of, 81. Lewistown limestone, 77-80. analyses of, 80. Marble, 82-83. Cave (onyx) marbles, 83. Shenandoah (Valley) limestone, 74-76, analyses of, 75. Piedmont Plateau region, 66-73. Newark (Jura-Trias) limestones, 73. Older crystalline limestones, 67- 72. analyses of, 68, 70, 71, 72. Distribution, occurrence, ete., 67-72. General properties, 67. Marble, 69-70. Verd antique, 70. Production, 84. Properties, composition, etc., 65. References, 85. Uses, 83-84. Limestone and shale near Craigsville, analyses of, 155. Limestones and shales, central western Virginia, analyses of, 123. Limestones and shales, Staunton, analy- ses of, 117, 118, 119. Limestones and shales, vicinity Lurich, analyses of, 157-158. Limestone and shales, vicinity Strasburg, analyses of, 109. Limestones, Mississippian, 156-159. List of Coastal Plain formations, 268. List of furnaces in Virginia, 479. List of iron mines in Virginia, 477-478. List of producing mineral springs, 260- 261. List of soapstone quarries, 295. Little Wythe mine, iron, 458. Localities, details of, 154-156. Localities, distribution and, fullers earth, 297. 602 Localities, distribution and, gem min- erals, 385. Localities, distribution and, marls, 397- 400. Localities, distribution and, ocher, 225- 226. Localities, distribution and, of pyrite, 191. Localities, distribution and, tale and soapstone, 290-295. Localities, southwestern Virginia, details of, 142. Localities, tin, other, 577. Location and history, Blue Ridge copper deposits, 503. Location and importance Big Stone Gap coal field, 364-365. Location Louisa county pyrite deposits, 198. Locust Hill mine, iron, 459. Lofton mine, iron, 435. Loudoun county, copper, 518. Loudoun county, iron, 468. Loudoun county, ocher, 227-228. Louisa county, gold mines, 557-559. Allah Cooper mine, 558. Chick mine, 559. Cooper, 558. Harris mine, 559. Louisa mine, 559. Luce mine, 558-559. Slate Hill mine, 559. Tinder flats mine, 558. Walton mine, 558. Warren Hill mine, 559. Louisa county pyrite deposits, 198-202. Arminius mine, 199-201. Historical, 198. Location, 198. Smith mine, 201. Sulphur mines, 201-202. Louisa and Prince William counties py- rite areas, geology of, 191-193. Louisa and Prince William counties py- rite deposits, 198-204. Louisa county, 198-202. Arminius mine, 199-201. Historical, 198. INDEX. Location, 198. Smith mine, 201. Sulphur mines, 201-202. Prince William county, 202-204. Cabin Branch mine, 202-204. Louisa county barite area, 318-319. Louisa county, iron, 469. Louisa county, soapstone, 292. Low Moor mine, iron, 440. Lower Banner coal seam, 368-369. Lower Cambrian quartzites, shales anc sandstones, 93. Carboniferous coals, 347-352. Bland-Wythe counties field, 352. analyses of coal from, 352. Montgomery-Pulaski counties field 349-352. analyses of coal from, 352. Mountain Falls district, 347. Frederick county, 347. North Mountain coal field, 348-349. Botetourt county, 348-349. analysis of coal from, 348. North River coal field, 348. Augusta county, 348. analyses of coal from, 348. Lurich, geologic section near, 157. analyses of limestones and _ shales, 157-158. Lynchburg, gneiss, area, 33-34. Maddox barite mine, 314. Madison county, copper mines, 509-510. Blue Ridge Copper Co’s mine, 509- 510. Stony Man openings, 510. Magnetite limestone, 422. Magnetite, titaniferous, 422-423. Magnetites, Piedmont, 421-422. Major faults, 123-124. Manassas Gap copper mine, 508-509. Manganese Corporation of Virginia mines, 250. Manganese oxides, 235-259. Appalachian Mountains region, 244- 255. Description of individual areas, 244-255, Lower (Mississippian ) INDEX. Augusta county, 246-250. analyses of, 248, 249, 250. Botetourt county, 251-252. analyses of, 252. Frederick county, 252. Other Valley deposits, 254-255. analyses of, 254-255. Page county, 244-245. analysis of, 244-245. Rockbridge county, 253-254. analyses of, 253-254. Rockingham county, 250-251. analyses of, 251. Shenandoah county, 252-253. analyses of, 253. Introduction, 244. Coastal Plain region, 238. Introduction, 235-236. Kinds of ore, 237-238. Methods of mining, 255-256. Occurrence, 236-237. Piedmont region, 238-243, Description of individual areas, 239-243. Amherst county, 239. analysis of, 239. Appomattox county, 239. analyses of, 239. Buckingham county, 239. Campbell county, 239-242. analyses of, 240-241. Nelson county, 242-243. analyses of, 242-243. Pittsylvania county, 243. analyses of, 243. Introduction, 238. Preparation of the ore, 256. Production, 257-258. References, 258-259. Uses, 256-257. Marble, 69-70, 82-83. Cave (onyx) marbles, 83. Verd antique, 70. Marbles, limestone and, 65-85. Marls, 396-401. Definition and properties, 396. 603 Distribution and localities, 397-400. Coastal Plain region, 397-399. Caleareous, 398-399. Greensand, 397-398. Valley region, 399-400. Origin and occurrence, 396-397. References, 400. Uses, 400. Martin prospect, zinc, etc., 530. Martinsburg shale group, 99-102. Trenton shales, 100. analyses of, 100. Mary creek mine, iron, 437. Marysville limestone, 130. analyses of, 130. Massanutten sandstone group, 102-103. Materials, cement, 88-89. Mathieson Alkali Works, 214-215. Maud vein, iron, 471. May mine, iron, 463. McCloy, granite, quarry, 24. McGowan, granite, quarry, 24. McIntosh, granite, quarry, 24-25. McKenna shaft, copper, 501. Mease barite mine, 313. Mecklenburg county, iron, 470. Menaccanite (ilmenite), 232. Metallic minerals, 402-582. Methods of mining barite, 325. Methods of mining coal, 373-374. Methods of mining iron, 479-485. Methods of mining manganese, 255-256. Methods of mining pyrite, 204. Methods of mining the ore, zinc, 544-545. Mica, 278-285. Amelia county area, 279-284. Character and composition, 278. Distribution and description, 279. Occurrence, 278-279. Amelia court-house district, 280- 283. General geology, 280-282. Mines, 282-283. Berry mine, 282. Jefferson mines, 282. Pinchback mine, 283. Rutherford mines, 282. Winston mine, 282. 604 INDEX. Jetersville district, 283-284. Schlegal mine, 283-284. Production, 284. References, 285. Uses, 284. Mica mines, 282-283. Mica schist, 35. Microlite, 389-390. analysis of, 390. Middendorf, granite, quarry, 25. Middletown, 107. Section of Ordovician rocks near, 107. Midvale mine, iron, 437. Milford area, clay, 177. Milling process, rutile, 234. Milling, pyrite, 205-206. Millstones (buhrstones), 401. Production, 401. Mine, bank mine, 435-436. barite, Anthony, 311. barite, Bennett, 312, 313, 314. barite, Berger, 312, 313. barite, Davis, 313. barite, Hatchet, 313. barite, Hewitt, 311. barite, Maddox, 314. barite, Mease, 313. barite, Parker, 312, 313. barite, Phillips, 311. barite, Ramsay, 312, 313. barite, Saunders, 311. barite, Thompson, 312, 313. barite, Wright, Dryden, 312. barite, Wright, Tom, 313. copper, Anaconda, 498. copper, Ann Phipps, 514. copper, Betty Baker, 514-516. copper, Blue Ridge Co’s, 509-510. copper, Chappel, 498. copper, Copperas Hill, 514. copper, Cranberry, 514. copper, Dorothy, 499. copper, Halifax Copper Co’s, 498. copper, High Hill, 496-498. copper, Hightop Mining Co’s, 510- 511. copper, Howell, 517. copper, Kirkbride, 514. copper, Lightfoot, 501-502. copper, Manassas Gap, 508-509. copper, Sims, 510. copper, Staples, 501. copper, Taylor’s, 518. copper, Toncray, 517. copper, United States Mineral Co’s 501. copper, Vaughn, 514. copper, Va. Consolidated Co’s, 509. copper Wild Cat, 514. copper, Wolf Pit, 514. iron, Andis, 459. iron, Arcadia, 445. iron, Bare bank, 435. iron, Barr limonite, 473-474. iron, Barr magnetite, 473. iron, Bell Hill, 463. iron, Ben Hur, 466. iron, Berryville, 430. iron, Bess, 441. iron, Betty Baker, 476. iron, Beyer, 432. iron, Big Hill, 443. iron, Big Ike, 430. iron, Black Rock, 435. iron, Blue bank, 435. iron, Buck Hill, 437. iron, Buffalo Gap, 434. iron, Callie, 442. iron, Castle Rock, 446. iron, Cedar Run, 453. iron, Circle, 443. iron, Clayton, 451. iron, Crawford, 454. iron, Crozier, 435-444. iron, Curran Valley, 461. iron, Dewey, 472. iron, Dixie, 436-437. iron, Dolly Ann, 439. iron, Double Ridge, 441. iron, Edith, 444. iron, Ewing, 467. iron, Fancy Hill, 440. iron, Farris, 449, iron, Fenwick, 446. iron, Fisherville, 435. INDEX. 605 iron, Fox Mountain, 434. iron, Pittsville, 472-473. iron, Gale, 446. iron, Poplar Camp, 456. iron, Ganaway, 459. iron, Porter, 458. iron, Given, 441. iron, Porterfield, 448. iron, Golleher, 461. iron, Posey, 456. iron, Grabill, 466. iron, Potts Valley, 441. iron, Grace, 443. iron, Radford furnace, 449. iron, Greenway, 469-470. iron, Rich Hill, 449-450. iron, Gregory, 457. iron, Rich Patch, 440. iron, Griffin, 446. iron, Ried, 443. iron, Griffin specular, 447. iron, Rileyville, 432-433. iron, Grubb or Lynchburg, 443-444. iron, Roaring Run, 443. iron, Grubb specular, 445. iron, Rocky Mount, 474. iron, Hairston, 474-475. iron, Rorer, 446. iron, Hall, 463. iron, Rumsey, 439. iron, Happy creek, 430. iron, Sanders, 453. iron, Heiston, 433. iron, Stack, 440. iron, hematite, 455. iron, Starkey, 447. iron, Henson, 459. iron, Stony Point, 469. iron, Holston, 462. iron, Tasker, 449. iron, Horse Mountain, 441-442. iron, Taylor’s Valley, 462. iron, Houston, 444. iron, Tipton, 454-455. iron, Hurst, 454. iron, Toncray, 475. iron, Iron Gate fossil ore, 441. iron, Truro, 466. iron, Iron Mountain, 439. iron, Under Rock, 450-451. iron, Ironville, 472. iron, Vaughn, 433. iron, Ivanhoe, 457. iron, Walton, 453. iron, Johnson, 447. iron, West, 431. iron, Keystone, 464. iron, William Jackson, 456. iron, Lavine, 465. iron, Wilton, 442. iron, Lemon, 445. iron, Wood, 445. iron, Little Wythe, 458. iron, Yeary, or Bunn, 464. iron, Locust Hill, 459. manganese, Bishop, 241. iron, Lofton, 435. manganese, Blue, 250. iron, Low Moor, 440. manganese, Bugley, 242. iron, Mary creek, 437. manganese, Cabell, 242. iron, May, 463. manganese, Crimora, 246-249. iron, Midvale, 437. manganese, Davis, 243. iron, Mine bank, 435-436. manganese, Fauber, 250. iron, Morris, 453. manganese, Houston, 251-252. iron, Noes Siding, 466. manganese, Kelly, 250. iron, Norma, 458. manganese, Kendall and Flick, 250- iron, Oriskany, 443-446. 251. iron, Painter, 457. manganese, Kimball, 245. iron, Patterson, 454. manganese, Leets, 240-241. iron, Pennington, 465. manganese, Newton, 250. iron, Percival, 459. manganese, Old Dominion Co’s, 249. iron, Pit Spring, 433. manganese, Paddy Mills, 252. 606 manganese, INDEX. Piedmont Manganese Co’s, 240-241. manganese, Saunders, 241-242. manganese, Simpson, 242-243, mica, Berry, 282. mica, Pinchback, 283. mica, Schlegal, 283-284. mica, Winston, 282. pyrite, Arminius, 199-201. pyrite, Cabin Branch, 202-204. pyrite, Smith, 201. Mines, barite, 311-314. Beverley, Kimball, and Shenandoah Iron Works, 432. copper, description of, southwest Virginia, 514-517. copper, Dickey’s Hill, 507. copper, Gardner and Goad, 516. copper, New Canton, 501. description of, Blue Ridge copper district, 506-511. description of, zine and lead, 530- 544. gold, iron, iron, iron, iron, iron, iron, iron, iron, iron, iron, iron, iron, iron, iron, iron, iron, iron, iron, iron, iron, description of, 553-564. Barren Springs, 452. Bertha, 452-453. Boones Path, 466-467. Buena Vista, 436. Chestnut Yard, 475-476. Ferrol, 434. Foster Falls, 455. Indian Camp, 456. Interior, 448. Irondale, 464. Liberty, 431. Oreton, 464. Peak Knob, 451. Reed Island, 450. Riverville, 470-471. Sand bank, 442. Simmerman, 457. Sisk and Gray, 457-458. Victoria, 436. in Virginia, list of, 477-478. lead and zinc, Austinville, 532-537. manganese, Manganese Corporation of Virginia, 250. nica, Jefferson, 282. mica, Rutherford, 282. Richmond coal basin, 346-347. Sulphur, 201-202. Virgilina district, 496-499. zine, Bertha, 532. zine, Cedar Springs, 538-540. zine, Dalton, 531. zinc, New River Mineral Co’s, 538. zine, Rye Valley Mining Co’s, 540. zinc, Wythe lead and zinc, 458. Mineral and Artesian waters, 259-275. Mineral waters, 259-268. Chemical analyses, 261-267. List of mineral springs producing, 260-261. Production, 267. References, 268. Artesian waters, 268-275. List of Coastal Plain formations, 268. Water horizons in eastern Vir- ginia, 269-272. Chesapeake, 270-272. Pamunkey, 270. Potomac, 269-270. References, 275. Wells in eastern Virginia, 272-274. Mineral composition, granites, 18. Mineral springs, producing, list of, 260- 261. Mineral waters, 259-268. Chemical analyses, 261-267. List of producing mineral springs, 260-261. Production, 267. References, 268. Mineralogical and tin, 567-568. Minerals and ores of iron, 403-405. Minerals, associated, 526-527. Minerals, associated, barite, 317. Minerals, associated, pyrite areas, 196- 197. Minerals, gangue, gold deposits, 552-553. Minerals, metallic, 402-582. Mining, barite, methods of, 325. Mining, coal, methods of, 373-374. description of, chemical character, INDEX. Mining developments, gypsum, 329-334. Mining, iron, methods of, 479-485. Mining, manganese, methods of, 255-256. Mining, pyrite, methods of, 204. Mining, zinc, methods of, 544-545. Mississippian limestones, 156-159. Moccasin limestone, 139-140. analyses of, 140. Mode of occurrence, barite, 314-315. Mode of occurrence, pyrite, 190-191. Mode of occurrence, zine and lead ores, 527-528. Oxidized ores, 528. Sulphide ores, 527-528. Molding sand, 394-395. analyses of, 394-395. physical tests of, 395. Monazite, 303. analyses of, 303. Montgomery and Floyd counties, gold, 564. Montgomery county, iron, 447. Montgomery county, zine, etc., 530. Montgomery-Pulaski counties coal fields 349-352. analyses of coal from, 352. Moonstone, 389. Morris mine, iron, 453. Mount Sidney and vicinity, 115. analysis limestone, Weyers 115. Geologie section at, 115. Mountain, Appalachian, province, 7-12. Mountain Falls district, coal, 347. Frederick county, 347. Mountain province limestones, 73-83. Chickamauga limestone, 76-77. analyses of, 77. Greenbrier limestone, 80-81. analyses of, 81. Lewistown limestone, 77-80. analyses of, 80. Marble, 82-83. Cave (onyx) marbles, 83. Production, 84. References, 85. Shenandoah (Valley) limestone, 74- 76. Cave, 607 analyses of, 75. Uses, 83-84. Natural Bridge limestone, 94. analysis of, 94. Natural cement, 160-162. analyses of, and rock, 161. Natural cement rock, Balcony Falls, analyses of, 161. Natural cements, West Virginia—Mary- land, analyses of, 161. Natural coke (see under carbonate). Netherwood, granite, quarry, 25. Nelson-Albemarle counties soapstone belt, 293-295. Nelson county, iron mines, 469-470. Greenway mine, 469-470. Nelson county (phosphate rock), 300- 301. Nelson county, soapstone, 291. Nelsonite (phosphate rock), 300-302. Nelson county, 300-301. ; Roanoke county, 301-302. Newark (Jura-Trias) limestones, 73. Newark (Jura-Trias) sandstones, 58-59. New Canton mines, copper, 501. Newman limestone, 158. analyses of, 158. New River Mineral Co’s mines, zine, 538. Newton mine, manganese, 250. Nickel and cobalt, 578-582. Floyd county area, 580-582. General statement, 578-580. Reference, 582. Niobates and Tungstates, 298-299. Columbite, 298. analysis of, 298. References, 299. Sipylite, 298. analysis of, 298. Wolframite, 299. Niter (potassium nitrate), 304-305. Distribution, 304-305. Properties and occurrence, 304. References, 305. Nitrates, 304-305. Noes Siding mine, iron, 466. Nolichucky shale, 131. analysis of, 131. 608 Norfolk area and vicinity, clay, 185-186. Norma mine, iron, 458. North Mountain coal field, 348-349. Botetourt county, 348-349, analysis of coal from, 348. North River coal field, 348. Augusta county, 348. analyses of coal from, 348. Northwestern Virginia, Cambrian and Ordovician formations of, 91. Northwestern Virginia, structure tions in, 106. sec- Nottoway-Prince Edward counties area, granite, 29-30. Wingo quarry, 30. Occurrence, 278-279. and origin, talc and soapstone, 290. asbestos, 285-286. barite, 307-308. barite, Appalachian region, 320. etc., older crystalline limestones, 67-72. feldspars, 276. graphite, 188. lead and zine ores, 527-528. manganese oxides, 236-237. mode of, barite, 314-315. origin and, diatomaceous earth, 217- 218. origin and, gypsum, 328. origin and, marls, 396-397. origin and, ocher, 225. properties and, niter, 304. properties and, rutile, 232. pyrite, mode of, 190-191. tin, 568-577. Ocher, 225-232. Definition and properties, 225. Description of individual deposits, 226-231. Distribution and localities, 225-226. Origin and occurrence, 225. Augusta county, 229-230. Chesterfield county, 226-227. Loudoun county, 227-228. Page county, 228. analysis of, 228. INDEX. Rockbridge county, 231. Rockingham county, 229. analysis of, 229. Warren county, 231. analysis of, 231. References, 231-232. Uses, 231. Old Dominion Manganese Co’s mine, 249 Older crystalline limestones, 67-72. analyses of, 68, 70, 71, 72. Distribution, occurrence, ete., 67-72 General properties, 67. Marble, 70. Verd antique, 70. Older crystalline quartzites, 55-57. Oldfield area, clay, 185. Operators, Pocahontas coal field, 359- 360. Openings, copper, other, 498. Openings, copper, Stony Man, 510. Openings, zinc, etc., Forney, 531. Operations, Big Stone Gap coal field, 367. Orange county, copper, 518. Taylor’s copper mine, 518. Orange county, gold mines, 555-557. Chicago-Virginia mine, 556. Grasty mine, 555. Greenwood mine, 556. Melville mine, 556. Orange Grove, 556. Piedmont Mining and Metallurgical Corporation, 556-557. Randolph mine, 556. Vaucluse mine, 556-557. Ordovician, Cambrian and, formations of northwestern Virginia, 91. Ordovician rocks, near Middletown, sec- tion of, 107. ! Ore dressing, iron, 485-486. hematite, Blue Ridge, 418-419. hematite, fossil, 416-418. iron, impurities of, 405-407. iron, origin of, 407. iron, Oriskany, 408-410. limonite, Blue Ridge, 414-416. manganese, preparation of, 256. pyrite, 193-197. pyrite, associated minerals, 196-197. INDEX. pyrite, character and occurrence of, 193-197. pyrite, composition of, 196. zine, methods of mining, 544-545. Ore-bodies, pyrite, genesis of, 197. Ores and associated minerals, zine and lead region, 523-527. Ores, associated, 526. copper, Blue Ridge, character and occurrence, 505-506. copper, distribution of, 492-494. copper, Triassic, 518. iron, Virginia, classification of, 407- 408. lead, 523. lead and zine, alteration of, 527. lead and zine, origin of, 529-530. limonite, limestone, 410-414. relations of, to geologic structures, 529. zine, 524-526. zine, preparation and smelting, 545- 546. Oreton mines, iron, 464. Origin and occurrence, gypsum, 328. Origin and occurrence, marls, 396-397. Origin and occurrence, ocher, 225. Origin and occurrence of diatomaceous earth, 217-218. Origin, occurrence and, tale and soap- stone, 290. Origin of clay, 168. Origin of iron ore, 407. Origin of the ores, zinc and lead, 529- 530. Oriskany iron ore, 408-410. Oriskany mine, iron, 443-446. Ornamental (building and) stones, 16- 85. Other gneiss areas, 34-35. Other localities, tin, 577. Other openings, copper, 498. Other Valley deposits, manganese. 254- 255. Oxides, 216-275. Oxidized ores, zine and lead, occurrence, 528. Paddy Mills Manganese mine, 252. 609 Page county, copper mines, 509. Virginia Consolidated Copper Co’s mine, 509. Page county, iron mines, 431-433. Beverley, Kimball, and Shenandoah Iron Works mines, 432. Beyer mine, 432. Heiston mine, 433. Pit Spring mine, 433. Rileyville mine, 432-433. Vaughn mine, 433. Page county, manganese, 244-245. analysis of, 244-245. Page county, ocher, 228. analysis of, 228. Painter mine, iron, 457. Pamunkey (formation), 270. Parker barite mine, 312-313. Patrick county, iron mines, 474-475. Hairston mine, 474-475. Patrick county, soapstone, 293. Patterson mine, iron, 454. Peak Knob mines, iron, 451. Pearisburg, geologic section at, 137-138. Pearisburg limestone, 137-139. analyses of, 138-139. Geologic section at, 137-138. Pebble phosphate, 302. analysis of, 302. Pennington mine, iron, 465. Pennington shale, 158-159. Percival mine, iron, 459. Petersburg area, clay, 183. Petersburg area, granite, 19-21. Cook quarry, 20. Lassiter quarries, 20. Petersburg Granite Co’s quarries, 20-21. Petersburg Passenger Co’s quarry, 21. Petersburg Granite Co’s, granite, quar- ries, 20-21. Petersburg Passenger Co’s, granite. quar- ry, 21. Phillips barite mine, 311. Phosphate, pebble, 302. Phosphate rock (nelsonite), 300-301. Phosphates, 299-304. 610 Physical tests, molding sand, 395. Piedmont counties, iron mines of, 468- 477. Albemarle county, 469. Amherst county, 470-471. Appomattox county, 471. Bedford county, 471-472. Buckingham county, 470. Campbell county, 471. Carroll county, 475-476. Floyd county, 475. Franklin county, 474. Grayson county, 476-477. Henry county, 475. Loudoun county, 468. Louisa county, 469. Mecklenburg county, 470. Nelson county, 469-470. Patrick county, 474-475. Pittsylvania county, 472-474. Spottsylvania county, 468-469. Stafford county, 468. Piedmont magnetites, 421-422. Piedmont Manganese Co’s mine, manga- nese, 240-241. Piedmont or crystalline region, 542-544. Albemarle county, 542-544. Piedmont plateau limestones, 66-73. Newark (Jura-Trias) limestones, 73. Older crystalline limestones, 67-72. Distribution, occurrence, ete., 67- 72. analyses of, 68, 70, 71, 72. General properties, 67. Marble, 69-70. Verd antique, 70. Piedmont plateau province, The, 5-7. Piedmont plateau region, barite, 309-320. Piedmont plateau, sandstones and quartz- ites of, 55-59. Piedmont province, coal, 339-347. Piedmont region, manganese of, 238-243. Description of individual areas, 239- 243. Amherst county, 239. - analysis of, 239. INDEX. Appomattox county, 239. analyses of, 239. Buckingham county, 239. Campbell county, 239-242. analyses of, 240-241. Nelson county, 242-243. analyses of, 242-243. Pittsylvania county, 243. analyses of, 243. Introduction, 238. Pinchback mine, mica, 283. Pit Spring mine, iron, 433. Pittsville mine, iron, 472-473. Pittsylvania county, iron mines, 472-474 Barr limonite mine, 473-474. Barr magnetite mine, 473. Pittsville mine, 472-473. Pocahontas formation, coals of, 362-363 Poplar Camp mine, iron, 456. Porter bank, iron, 460. Porterfield mine, iron, 448. Porter mine, iron, 458. Posey mine, iron, 456. Position and_ extent, basin, 339-340. Position, geographic, of Virginia, 1. Post-Ordovician cement materials, 151. Potomac formation, 269-270. Potsdam sandstone (quartzite), 60. Potts Valley mine, iron, 441. Preparation and smelting the ores, zine, 545-546. Preparation, barite, 325-326. Preparation of the ore, manganese, 256. Prince William county pyrite deposit, 202-204. Cabin Branch mine, 202-204. Prince William, Louisa and, counties py- rite areas, geology of, 191-193. Prince William-Stafford counties slate belt, 51. Production, barite, 327. coal, 375-376. gold, 564-565. granite, 35. gypsum, 334-335. iron, 487-488. limestone, 84. Richmond coal INDEX. manganese, 257-258. mica, 284. mineral waters, 267. pyrite, 206-207. sand, 396. sandstone in Virginia, 64. soapstone, 296. slate, 51. Properties and occurrence, niter, 304. Properties and occurrence of rutile, 232. Properties, composition and, barite, 305. Properties, composition and, garnet, 287- 288. Properties, composition and, pyrite, 190. Properties, definition and, clay, 167-168. Properties, definition and, fullers earth, 296-297. Properties, definition and, ocher, 225. Properties, definition and, marls, 396. Properties, general, gypsum, 327-328. Property, copper, Ambler, 508. Property, copper, Rudacill, 507. Property, copper, Sealock, 507. Province, Appalachian Mountain, The, 7-12. Province, Coastal Plain, The, 3-5. Formations of, 4. Province, Piedmont Plateau, The, 5-7. Pulaski county, iron mines, 448-451. Clarks bank, 448-449. Clayton mine, 451. Farris mine, 449. Peak Knob mines, 451. Radford Furnace mine, 449. Reed Island mines, 450. Rich Hill mine, 449-450. Tasker mine, 449. Under Rock mine, 450-451. Pulaski county, zine and lead, 531. Delton mines, 531. Forney openings, 531. Pyrite, 190-207. Composition and properties, 190. Distribution and localities, 191. General geology of areas of, 191-193. Genesis of ore-bodies, 197. Louisa county pyrite deposits, 198- 202. 611 Arminius mine, 199-201. Historical, 198. Location, 198. Smith mine, 201. Sulphur mines, 201-202. Methods of mining, 204. Milling, 205-206. Mode of occurrence, 190-191. Prince William county, 202-204. Cabin Branch mine, 202-204. Production, 206-207. References, 207. The ore, 193-197. Uses, 206. Pyrite, analyses of, 196. Pyrite, gossan, 419. Pyrrhotite, 208-209. analyses of, 208-209. References, 209. Pyrrhotite gossan and pyrrhotite, 419- 421. Quarries, granite, Cartwright and Davis, 28. Quarries, granite, Lassiter, 20. Quarries, granite, list of, in Richmond, area, 23. Quarries, granite, Co’s, 20-21. Quarries, Richmond Granite Co’s, 26. Quarries, soapstone, list of, 295. Quarry, granite, Cook, 20. granite, Hoffman and Miller, 29. granite, McCloy. 24. granite, McGowan, 24. granite, McIntosh, 24-25. granite, Middendorf, 25. granite, Netherwood, 25. granite, Petersburg Passenger Co’s, 21. granite, Trip, 29. granite, Wingo, 30. granite, Winston and Co., 26. granite, Wray, 26. Quartz, 216, 386. Quartzites, sandstones and, 52-64. Radford furnace mine, iron, 449. Ramsay barite mine, 312-313. Petersburg Granite 612 Rappahannock county, copper mines, 508- 509. Ambler property, 508. Manassas Gap copper mine, 508-509. Razor bank, manganese, 254. Records of well borings, gypsum, 331-332. Reed Island mines, iron, 450. Reference, nickel and cobalt, 582. References, arsenopyrite, 211. artesian waters, 275. asbestos, 287. barite, 327. earbonite (natural coke), 379-380. cements and cement materials, 165- 167. clay, 187. coal, 376-378. copper, 519. corundum and emery, 224. crystalline siliceous rocks, 40-41. diatomaceous earth, 223. feldspars, 277. fluorite (fluorspar), 215. fullers earth, 297. garnet, 289. gem minerals, 391-392. gold, 566-567. graphite, 190. gypsum, 335. halite (salt), 215. iron, 488-491. limestone, 85. manganese, 258-259. marls, 400. mica, 285. mineral waters, 268. niobates and tungstates, 299. niter, 305. ocher, 231-432. phosphates, 303-304. pyrite, 207. pyrrhotite, 209. rutile, 235. sandstone, 64. slate, 52. soapstone, 296. tin, 577-578. zine and lead, 547-548. INDEX. Relation of ores to geologic structure 529. Residual clays, 169-172. analyses of, 170-172. Resources, diversity of, 15. Value of, 15. Rich Hill mine, iron, 449-450. Rich Patch mine, iron, 440. Richmond area, clay, 177-180. Richmond coal basin, 331-347. Coal beds of, 342-346. Analyses of coal from, 343. Depth of the coal, 345-346. Extent of the coal beds, 342-345. General geology of, 340-342. Historical, 340. Mines, 346-347. Position and extent, 339-340. Richmond area, granite, 21-26. McCloy quarry, 24. McGowan quarry, 24. Middendorf quarry, 25. Netherwood quarry, 25. Richmond Granite Co’s quarries, 25- 26. Winston and Co’s quarry, 26. Wray quarry, 26. Richmond area, list of granite quarries in 23. Richmond granite area, 21-26. Richmond Granite Co’s quarries, 26. Ried mine, iron, 443. Ries, H., acknowledgment to, xxx. Contribution of paper by, 167-187. Rileyville mine, iron, 432-433. Riverton and vicinity, 114. Riverville mines, iron, 470-471. Roanoke county, iron mines, 446-447. Castle Rock mine, 446. Gale mine, 446. Griffin mine, 446. Griffin specular mine, 447. Rorer mine, 446. Starkey mine, 447. Roanoke county (phosphate rock), 301- 302. Roanoke and Botetourt counties, zinc, ete., 530. INDEX, Bonsack prospect, 530. Martin prospect, 530. Roaring Run mine, iron, 443. Rockbridge county, iron mines, 436-437. Buck Hill mine, 437. Buena Vista mines, 436. Dixie mine, 436-437. Mary creek mine, 437. Midvale mine, 437. Victoria mines, 436. Rockbridge county, manganese, 253-254. analysis of, 253-254. Rockbridge county, ocher, 231. Rockingham county, iron mines, 433-434. Fox Mountain mine, 434. Rockingham county, manganese, 250-251. analyses of, 251. Rockingham county, ocher, 229. analysis of, 229. Rogersville shale, 129-130. analyses of, 130. Rocks, associated, barite, 315-317. Rocks, country, gold area, 551. Rocks, siliceous crystalline, 17. Rocks, trappean, 36-41. Rocky Mount mine, iron, 474. Rock salt, analysis of, 212-213. Rorer mine, iron, 446. Rudacill property, copper, 507. Rumsey mine, iron, 439. Russell and Tazewell counties, barite, 322-325. Russell county, iron mines, 463. Hall mine, 463. Russell county (see Scott and Russell counties). Russell county, zinc, 541. Russell shales, 128-129. analyses of, 129. Rutherford mines, mica, 282. Rutile, 232-235. Distribution, 232-234. Milling process, 234. Properties and occurrence, 232. References, 235. Uses, 234-235. Rutledge limestone, 129. analyses of, 129. 613 Rye Valley Mining Co’s mines, zinc, 540. Salt, rock, analysis of, 212-213. Salt brines, analyses of, 213-215. Sand, 392-396. Building, 395-396. Glass, 393-394. Molding, 394-395. Production, 396. Sand bank mines, iron, 442. Sanders mine, iron, 453. Sandstone, Bays, 141-142. Sandstone, Clinch, 142. Sandstones and quartzites, 52-64. Appalachian Mountain region, 59-63. Cambrian sandstone, 60. Potsdam sandstone (quartzite), 60. Carboniferous sandstones, 62-63. Mississippian group, 62. Pennsylvanian group, 62-63. Devonian sandstones, 61. Introductory statement, 59-60. Silurian sandstones, 61. Coastal Plain region, 54-55. Jura-Cretaceous, 54-55. General properties, 52-53. General statement, 53. Piedmont Plateau region, 55-59. Newark (Jura-Trias) sandstones, 58-59. Older crystalline quartzites, 55-57. Production, 64. References, 64. Uses, 63. Saunders barite mine, 311. Saunders manganese mine, 241-242. Schlegal mine, mica, 283-284. Scott and Russell counties, cement ma- terials, 148-149. Geologic section in, 148-149. Scott county, iron, 463. Sealock property, copper, 507. Seam, Edwards, coal, 368. Seam, Imboden, coal, 369, 371, 372. Seam, Jawbone, coal, 369-370. Seam just beneath the Gladeville sand- stone, 372. Seam, Kelly, coal, 372. 614 Seam, Kennedy, coal, 369. Seam, Lower Banner, coal, 368-369. Seam, Upper Banner, coal, 368. Section. generalized, Chambersburg for- mation, 97. Section, Ordovician rocks near Middle- town, 107. Sections, geologic, Big Stone Gap coal field, 366. Sedimentary clays, 172. Sequoyah and Tellowa formations, coals of, 364. Seven Fountains, analysis of limestone at, 153. Geologic section, vicinity of, 153. Sevier shales, 140-141. analyses of, 140-141. Shale, Athens, 134-135. Shale, limestone and, near Craigsville, analyses of, 155. Shale, limestones and, central western Virginia, analyses of, 123. Shale, Nolichucky, 131. Shale, Pennington, 158-159. Shale, Rogersville, 129-130. Shales, limestone and, vicinity Lurich, analyses of, 157-158. Shales, limestones and, Staunton, analy- ses of, 117, 118, 119. Shales, limestones and, vicinity Stras- burg, analyses of, 109. Shales, Russell, 128-129. Shales, Sevier, 140-141. Shenandoah county, iron mines, 430-431. Liberty mines, iron, 431. West mine, 431. Shenandoah county, manganese, 252-253. analyses of, 253. Shenandoah (Valley) limestone, 74-76. analyses of, 75. Shenandoah limestone, analyses of, 162. Shenandoah limestone group, 93-99. Buena Vista shales, 94. Chambersburg formation, 96-99. Generalized section of, 97. analyses of, 98-99. Geologic section, vicinity of Stras- burg, 95. INDEX. Natural Bridge limestone, 94. analysis of, 94. Sherwood limestone, 94. Stones River formation, 95-96. analyses of, 96. Sherwood limestone, 94. Silica, 216-223. Chert, 216. Diatomaceous earth, 216-223. Analyses of, 217-218. Distribution, 218-222. Origin and occurrence, 217-218. References, 223. Uses of, 222. Quartz, 216. Silicates, 275-297. Siliceous crystalline rocks, 17-41. Silurian sandstones, 61. Silver (see under Gold). Simmerman mines, iron, 457. Simpson mine, manganese, 242-243. Sims mine, copper, 510. Sipylite, 298. analyses of, 298. Sisk and Gray mines, iron, 457-458. Slate, 41-52. Description of areas, 42-51. Albemarle county belt, 46-47. Amherst county belt, 47-48. Buckingham-Fluvanna belt, 42-46. Arvonia, 44-45. Bremo, 46. Fauquier county belt, 49-50. Prince William-Stafford counties belt, 51. Production, 51. References, 52. Smith pyrite mine, 201. Smithsonite, 524-525. Smyth county, barite, 321-322. Smyth county, cement materials, 146. Geologic section in, 146. Smyth county, iron mines, 460-461. Crigger bank, 460. Curran Valley mine, 461. Home bank, 460-461. Porter bank, 460. INDEX. Smyth county, zine and lead mines, 540- 541. Rye Valley Mining Co’s mines, 540. Virginia Lead and Zine Co., 541. Soapstone, Albemarle county, 291. Amelia county, 291-292. Bedford county, 291. belt, Albemarle-Nelson counties, 293- 295. Campbell county, 291. distribution and localities, 290. Carroll county, 293. Fairfax county, 292. Floyd county, 293. Fluvanna and Buckingham counties, 290-291. Franklin county, 291. Henry county, 293. Louisa county, 292. Nelson county, 291. Patrick county, 293. Production, 296. Quarries, list of, 295. References, 296. Tale and, 289-296. Uses, 295-296. Southern Gypsum Co’s mine, 330-331. Southwestern Virginia, Cambrian and Ordovician formations of, 128. Southwestern Virginia, details of locali- ties, 142. Southwestern Virginia, structure sections in, 125-145. Southwest Virginia copper region, 511- 517. Description of mines, 514-517. Carroll county, 514-516. Floyd county, 517. Franklin county, 517. Grayson county, 517. General character of the vein, 512- 513. General geology, 511-512. General statement, 511. Gossan lead, 511-517. Speers Ferry, geologic sections, 136. Spelter, 547. 615 Sphalerite, 524. Spottsylvania county, 468-469. Spotisylvania county, gold mines, 554- 555. Chicago-Virginia mine, 555. Goodwyn mine, 555. Grindstone Hill mines, 555. Higgins mine, 555. Johnston mine, 555. Mitchell mine, 555. Pulliam mine, 555. United States Mining Co’s mine, 554- 555. Whitehall mine, 555. Springs, mineral, producing, list of, 260- 261. : Stack mine, iron, 440. Stafford county, iron, 468. Stafford county, gold mines, 553-554. Eagle mine, 553-554. Lee mine, 554. Monroe mine, 554. Rappahannock mine, 554. Rattlesnake mine, 554. Staples mine, copper, 501. Starkey mine, iron, 447. Statistics on coke, 382-383. Staunton, 115-119. analyses, limestones and shales at, 117, 118, 119. Geologic section at, 117. Staunton, analysis of travertine from, 160. Staunton, north of, western edge Valley, 119-123. Stones River formation, 95-96. analyses of, 96. Stony Man openings, copper, 510. Stony Point copper vein, 502-503. Stony Point mine, iron, 469. Strasburg, 107-109. analyses, limestones and shales, vi- cinity of, 109. Strasburg, geologic section in the vicinity of, 95. Stratigraphy, southwestern Virginia, 128. Strengite, 303. analysis of, 303. 616 Structure, Campbell-Pittsylvania barite area, 318. Structure, geologic, relation of ores to, 929, Structure sections in vicinity of Harri- sonburg, 112. Structure sections, northwestern Vir- ginia, 106. Structure sections, southwestern Vir- ginia, 125-145. Sturgeon Point area, clay, 184. Suffolk area, clay, 186-187. Sulpharsenides, sulphides and, 190-211. Sulphates, 305-335. Sulphides and sulpharsenides, 190-211. Sulphide ores, zine and lead, occurrence, 527-528. Sulphur mines, 201-202. Surface, features of, 1-12. Appalachian Mountain province, 7- 12, Coastal Plain province, 3-5. Formations of, 4. Piedmont Plateau province, 5-7. Syenite, 31-33. Table of Cambrian and Ordovician for- mations, 92. Tale and soapstone, 289-296. Tale and soapstone, composition of, 289. Tale, distribution and localities, 290. Tar, (Gas), and ammonia, 383-384. Tasker mine, iron, 449. Tassin, Wirt, acknowledgments to, 87. Taylor’s copper mine, 518. Taylor’s Valley mine, iron, 462. Tazewell county, cement materials, 142- 144. Geologic section in, 144. Tazewell county, iron mines, 462-463. Bell Hill mine, 463. May mine, 463. Tazewell, Russell and, counties, barite, 322-325. The Virgilina copper district, 494-499. Description of the mines, 496-499. Historical, 496. Individual mines, 496-499. Geology and petrography, 494. INDEX. Introductory statement, 494. Kinds and occurrence of ores, 494- 495. The veins, 495-496. Thompson barite mine, 312-313. Thompson Valley, geologic section north of, 144. Tin, 567-578. Historical, 568. Mineralogical and chemical charac- ter, 567-568. Occurrence, 568-577. Other localities, 577. References, 577-578. Tipton mine, iron, 454-455. Titaniferous magnetite, 422-423. Toneray mine, copper, 517. Toneray mine, iron, 475. Trappean rocks, 36-41. Diabase and basalt, 36-39. analyses of, 37, 38, 39. Diorite, 39-40. Gabbro, 40. References, 40-41. Travertine deposits, 159-160. analysis of, Staunton, 160. Trenton limestones, 100-101. analyses of, 101. Trenton shales, 100. analyses of, 100. Trip, granite, quarry, 29. Triassic area, barite, 308-30y. Triassic copper ores, 518. Culpeper county, 518. Loudoun county, 518. Orange county, 518. Truro mine, iron, 466. Tungstates, Niobates and, 298-299, Unakite, 30-31. Under Rock mine, iron, 450-451. United States Mineral Co’s mine, copper, 501. Upper Banner coal: seam, 368. Uses, arsenopyrite, 211. asbestos, 287. barite, 326-327. corundum and emery, 224. diatomaceous earth, 222. INDEX. feldspars, 277. fluorite (fluorspar), 215. fullers earth, 297. garnet, 289. graphite, 190. gypsum, 334. iron, 486. limestone, 83-84. manganese, 256-257. marls, 400. mica, 284. ocher, 231. pyrite, 206. rutile, 234-235. sandstone, 63. soapstone, 295-296. Utica shale, 101-102. analysis of, 102. Valley deposits, other, manganese, 254- 255. Valley region, marls, 399-400. Value of resources, 15. Vaughn mine, copper, 514. Vaughn mine, iron, 433. Vein, copper, Stony Point, 502-503. Vein, gossan lead, character of, 512-513. Veins, copper, Virgilina district, 495-496. Veins, gold, 551-552. Verd, antique marble, 70. Victoria mines, iron, 436. Virginia, cement industry in, 162-165. Virginia, central western, general geology and stratigraphy of, 103-105. Virginia, central western, limestones and shale, analyses of, 123. Virginia Consolidated Copper Co’s mine, 509. Virginia Lead and Zine Co., 541. Virginia, list of furnaces in, 479. Virginia, list of iron mines in, 477-478. Virginia, nortnwestern, Cambrian and Ordovician formations of, 91. Virginia, northwestern, structure sec- tions in 106. Virginia, Portland cement plant, 163-165. Virginia, western, clay, 187. Wadesville, 113-114. Geologic section at, 114. 617 Walton mine, iron, 453. Warm Springs to Mt. Grove, geologic section along, 154. analyses of limestone from, 154. Warren county, copper mines, 506-508. Bentonville-Overall district, 507-508. Dickey’s Hill mine, 507. Rudacill property, 507. Sealock property, 507. Warren county, iron mines, 430. Big Ike mine, 430. Happy creek mine, 430. Warren county, ocher, 231. analysis of, 231. Washington county, barite, 322. Washington county, cement materials, 144-146. Washington county, iron mines, 461-462. Golleher mine, 461. Holston mine, 462. Taylor’s Valley mine, 462. Water horizons in eastern Virginia, 269- 272. Chesapeake, 270-272. Pamunkey, 270. Potomae, 269-270. Weathering and erosion, effects of, 12-14. Welch formation, coals of, 363-364. Well borings, gypsum, records of, 331- 332. Wells in eastern Virginia, 272-274. West mine, iron, 431. West Virginia-Maryland natural cements, analyses of, 161. Western edge of Valley, north of Staun- ton, 119-120. analysis limestone near Stokesville, 120. Structure sections near Stokesville, 120. Western Virginia, clay, 187. Wild Cat mines, copper, 514. William Jackson mine, iron, 456. Wilmont area, clay, 176. Wilton mine, iron, 442. Winchester, 105-107. analysis of limestone east of, 107. Wingo, granite, quarry, 30. 618 Winston and Co., granite, quarry, 26. Winston mine, mica, 282. Wise county, iron mines, 463-464. Irondale mines, 464. Keystone mine, 464. Oreton mines, 464. Yeary or Bunn mine, 464. Wise formation, coals of, 372-3/3. Wolf Pit mine, copper, 514. Wolframite, 299. Wood mine, iron, 445. Woodstock and vicinity, 109-110. analyses of limestone at, 110. Wray, granite, quarry, 26. Wright, Dryden, barite mine, 312. Wright, Tom, barite mine, 313. Wythe county, barite, 320-321. Wythe county, lead and zine mines, 531- 540. Austinville lead and zine mines, 532- 537. Bertha zine mines, 532. Cedar springs zine mines, 538-540. New River Mineral Co’s mines, 538. Wythe county, iron mines, 451-460. Andis mine, 459. Barren Springs mines, 452. Bertha mines, 452-453. Carter bank, 453. Cedar Run mine, 453. Clarks Summit mine, 459. Crawford mine, 454. Foster Falls mines, 455. Ganaway mine, 459. Gregory mine, 457. Hematite mine, 455. Henson mine, 459. Hurst mine, 454. Indian Camp mines, 456. Ivanhoe mine, 457. Little Wythe mine, 458. Locust Hill mine, 459. Morris mine, 453. INDEX. Norma mine, 458. Painter mine, 457. Patterson mine, 454. Percival mine, 459. Poplar Camp mine, 456. Porter mine, 458. Posey mine, 456. Sanders mine, 453. Simmerman mines, 457. Sisk and Gray mines, 457-458. Tipton mine, 454-455. Walton mine, 453. William Jackson mine, 456. Wythe lead and zinc mines, 458. Wythe lead and zine mines, 458. Yeary or Bunn mine, iron, 464. Zine and lead, 520-548. Alteration of lead and zinc ores, 527 Bertha zinc smelting plant, 546-547 Description of the mines, 530-544. The Great Valley region, 530-541 The Piedmont region, 542-544. Distribution, 520-521. General geology, 521-523. Historical, 520. Mode of occurrence, 527-528. Methods of mining the ore, 544-545 Ores and associated minerals, 523 527. Associated ores, 526. Associated minerals, 526-527. Lead ores, 523. Zine ores, 524-526. Origin of the ores, 529-530. Preparation and smelting, 545-546. References, 547-548. Relation of ores to structure, 529. Spelter, 547. Zine ores, 524-526. “Buckfat,” 526. Calamine, 525. Smithsonite, 524-525. Sphalerite, 524. Zinc smelting plant, Bertha, 546-547. POR RARL ARDELL