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Readers are asked to report all cases of books marked or m ut i- lated. \ '• (l OnW«sltY L»' ary Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924004686329 MEMOIRS OF THE GEOLOGICAL SURVEY. SCOTLAND. THE ■ OIL-SHALES OF THE LOTHIANS. PAET I. THE GEOLOGY OF THE OIL-SHALE FIELDS. j By H. M. CADELL, B.Sc, F.R.S.E., AND J. S. GEANT WILSON. PAET n. METHODS OF WORKING THE OIL-SHALES. By W. CALDWELL. ; ' PAET III. THE CHEMISTRY OF THE OIL-SHALES. By D. R. STEWART, E.I.C. PUBLISHED BY ORDER OF THE LORDS COMMISSIONERS OF HIS MAJESTY S TREASURY. GLASGOW: PRINTED FOR HIS MAJESTY'S STATIONERY OFFICE By JAMES HEDDERWICK & SONS Ltd... At "The Citizen" Peess, St. Vincent Place. And to be purchased from ; JOHN MENZIES & Co., Rose Street, Edinburgh; E. STANFORD, 12. 13, and 14 Long Acre, London ; HODGES, FIGGIS & Co., Ltd., Grafton Street, Dublin j From any Agent for the sale of Ordnance Survey Maps ; or through any Bookseller from the Ordnance Survey Office, Southampton. 1906. Price, Four Shillings. I^jh^L. LIST OF PUBLICATIONS OF THE GEOLOGICAL SURVEY OF SCOTLAND. I.— Maps on One-inch Scale. 1. Wigtownshire, South- Western Districts. 4*. 2. Wigtownshire, South-Eastern Districts. 4s. 3. Wigtownshire, Western Districts. 6s. 4. Wigtownshire, East Part ; Kirkcudbright, portion of S.W. Division, 6s. 5. Kirkcudbrightshire, Southern Districts. 6s. 6. Kirkcudbrightshire, E. margin ; Dumfriesshire, S. margin. 4s. 7. Ayrshire, South- Western Districts. 6s. 8. Kirkcudbrightshire, Ayrshire, and Wigtownshire. 6s. 9. Kirkcudbrightshire, N.E.; Dumfriesshire, S.W. 6s. 10. Dumfriesshire. 6s. 11. Roxburghshire and Dumfriesshire. 4s. 12. Argyllshire (Kintyre, S. half of). 4s. 13. Ayrshire, Turnberry Point, and S. part of Arran (Solid and Drift editions). 4s. 14. Ayrshire, Central Districts. 6s. 15. Dumfriesshire, N.W. ; Ayrshire, S.E. ; and Lanarkshire, S. 6s. 16. Dumfries, Selkirk, Peebles, Lanark, and Roxburgh shires (parts of). 6s. \i. Roxburghshire, Selkirkshire, and Dumfriesshire (parts of). 6s. 18. Roxburghshire, E. part. 4s. 19. Argyllshire (S. part of May), 4s. 20. Argyllshire (Kintyre, Gigha I. , part of Islay). 4s. 21. Argyllshire ; Arran, Central and N. part ; Bute, S. part ; Cumbraes, Ayrshire (part of N.W.) (Solid and Drift editions). 4s. 22. Ayrshire, Renfrewshire, Lanarkshire (parts of). 6s. 23. Lanarkshire, Central Districts ; Ayrshire (part of W. ). 6s. ( 24. Peeblesshire, Lanarkshire, Edinburghshire, Selkirkshire (parts of). 6s. 25. Berwickshire ; parts of Roxburgh, Selkirk, and Edinburgh. 6s. 26. Berwickshire and Roxburghshire (parts of). 4s. 27. Argyllshire ; parts of Islay and Jura, Oronsay. 4s. 29. Argyllshire, Ayrshire, Buteshire, Dumbartonshire, and Renfrewshire (parts of). 6s. 30 Renfrewshire ; parts of Dumbarton, Stirling, Lanark, and Ayr. 6s. 31. Lanarkshire, Stirlingshire, Linlithgowshire, Dumbartonshire, Edinburgh- shire (parts of). 6s. 32. Edinburghshire, Linlithgowshire, Fifeshire, Peeblesshire (parts of). 6s. 33. Haddingtonshire and parts of Edinburghshire and Berwickshire. 6s. 34. Eastern Berwickshire. ; 4s. 37. Argyllshire (part of). 6s. 38. Perthshire, Stirlingshire, Dumbartonshire, Argyllshire (parts of). 6s. 39. Perthshire, Clackmannanshire, Stirlingshire, and Fife (parts of). 6s. 40. Fife and Kinross. 6s. 41. Fife, East part ; Haddingtonshire, North part. 6s. 46. Perthshire, Argyllshire (parts of). 6s. 47. Perthshire. 6s. 48. Perthshire, Forfarshire, and Fifeshire (parts of). 6s. 49. Forfarshire and Fifeshire (parts of) 4s. 55. Perthshire (Solid and Drift editions). 6s. 56. Perthshire, Forfarshire (parts of). 6s. 57. Forfarshire and Kincardineshire (parts of). 6s. 57a. Kincardineshire, S.E. corner. 4s. 65. Aberdeenshire, Forfarshire, Perthshire (parts of). 6s. MEMOIRS OF THE GEOLOGICAL SURVEY. SCOTLAND. THE OIL-SHALES OF THE LOTHIANS. PAET I. THE GEOLOGY OF THE OIL-SHALE FIELDS. By H. M. CADELL, B.Sc, F.R.S.E., AND J. S. GRANT WILSON. PAET H. METHODS OF WORKING THE OIL-SHALES. By W. CALDWELL. PAET III. THE CHEMISTRY OF THE OIL-SHALES. By D. R. STEWART, F.I.C. PUBLISHED BY ORDER OF THE LORDS COMMISSIONERS OF HIS MAJESTY'S TRKASrRY. GLASGOW: PRINTED FOR HIS MAJESTY'S STATIONERY OFFICE By JAMES HEDDERWICK & SONS Ltd., At " The Citizen " Press, St. .Vincent Place. And to be purchased from JOHN MENZIES & Co. , Rose Street, Edinburgh ; E. STANFORD, 12. 13, and 14 Long Acre, London ; HODGES, FIGGIS & Co., Ltd., Grafton Street, Dublin ; From any Agent for the sale of Ordnance Survey Maps ; or through any Bookseller from the Ordnance Survey Office, Southampton. 1906. Price, Four Shillings. TfY G^AS \HOC> A< 3AS0^ PREFACE. The following Memoir on the Oil Shale industry of Scotland is divided into three parts, and treats of the subject both in its geological and technological aspects. Part I. treats of the Geology of the Oil Shale-fields of the Lothians, and is the joint work of Mr. H. M. Cadell and Mr. J. S. Grant Wilson. After the opening up of the oil shale industry it became necessary to re-survey the portions of Midlothian and Linlithgowshire in which the shales occur. This work was done by Mr. Cadell, who, since its completion in 1887, has possessed an unrivalled knowledge of the geological structure of the various shale-fields. It is therefore a source of gratification that, notwithstanding his retirement from the Geological Survey, we have been able to secure his services in the preparation of this volume. The recent revision of the area in connection with the re-survey of the Scottish coal-fields has fallen to the lot of Mr. J. S. Grant Wilson, who thus naturally becomes associated with his former colleague. Part II., which deals with the methods of working the oil shales, and is, therefore, of a technological character, has been executed by Mr. W. Caldwell, whose training as a mining engineer and whose experience as mining manager in the Pumpherston field have given him special qualifications for the task. Part III. is concerned with the treatment of the material after its extraction from the mine, with the products obtained from it, and with the statistics of the industry. This is the work of Mr. D. E. Steuart, chemist to the Broxburn Oil Company, who is recognised as a leading authority on this branch of enquiry. Special thanks are due to Dr. Leonard Dobbin, chief assistant to Professor Crum Brown, F.E.S., The University, Edinburgh, for valuable suggestions in connection with the part dealing with the chemistry of the oil shales, and for kind assistance in revising the proof-sheets. The Memoir has been edited by Dr. Home. J. J. H. TEALL, Director. Geological Survey Office, 28 Jermyn Street, London. September 30th, 1906. CONTENTS. PART I. The Geology op the Oil Shale-fields op the Lothians. Introduction, . . i. Geological Position of the Shale Measures, . ii. Topographical Distribution of the Oil Shales. III. Physical Characters of Oil Shale, IV. Distinctive Geological Zones, V. General Geological Structure, i. District of West Lothian and the adjoining part of Mid-Lothian, ii. District of Straiton and Burdiehouse in Mid- Lothian, ..... iii. Burntisland District, . vi. Detailed description of the Shale-fields, i. West Calder, .... ii. Pumpherston and Mid-Calder, iii. Deans, Seafield, Breich, and Polbeth, iv. Livingstone, .... v. Newpark, ..... vi. Cobbinshaw and Tarbrax, . vii. Broxburn, ..... viii. Ecclesmachan, .... ix. Winchburgh, .... x. Philipstoun and Champfleurie, xi. Queensferry and Abercorn, . xii. Dalmeny, .... xiii. Ingliston and Dalmahoy, xiv. Burdiehouse and Straiton, . xv. Burntisland, .... Page 1 2 3 7 8 10 10 14 14 17 17 27 38 43 45 46 54 61 66 69 74 86 89 91 94 VI CONTENTS. PART II. Methods of Working the Oil Shales. Page, i. Search for Shale, ... . 98 II. Mode of Access, 100 in. Mine Driving, 103 iv. Level Driving, 105 v. Blasting and Explosives, ... . . 108 vi. Methods of Working, . . . . 110 vii. Timbering of Levels, &c, 120 vin. Gases and Ventilation, . . . 122 ix. Pumping Water, 127 x. Underground Haulage, .... . 128 xi. Inclined Shaft Winding, . . 131 PART III. The Chemistry op the Oil Shales. i. Introductory and Historical, . . . 133 ii. Statistics, . 135 III. Minerals now or formerly used, ... 139 iv. Chemical Composition of the Valuable Shales, . . 142 i. The Crude Oil or Ammonia of Shales determined in the Laboratory, ...... 142 ii. Analyses of Crude Oils from various Shales, . 155 iii. General Chemistry of the Shales, . . . 157 v. The Process of Manufacture, 166 VI. Products of the Manufacture, 183 i. Their Composition and Properties, . . .184 ii. Their uses, ........ 186 LIST OF ILLUSTRATIONS. Fig. 1. General Vertical Section of the Carboniferous Strata of Mid and West Lothian .... Section from Baads Mill to Limefield House . Section from Addiewell Bridge to Limefield Mains Section in Murieston Water, from Skivo to Kiprig Section from Nether Dechmont to Illieston . Section from No. 1 Bore, Milkhouses, to Raw Camps Quarry ........ Section from Station Road, Broxburn, to near Kilpunt Section from Newfarm to Camps Quarry, Mid-Calder Basin ....... Section from Deans to Tailend Blackburn House to Limefield House Section of Shale-field south of Blackburn House Section from Limefield Mains to Murieston . Section from Baads Mill to Cobbinshaw Hill . Section, Dechmont to River Almond Section, HTillhouse to Broxburn Anticline Section from Kingscavil to Drumforth . Section along the Shore from Midhope Burn to White house Point ...... Section, Queensferry to Wheatlands Section of Burdiehouse and Straiton Shale-field Section from Grangehill to Common, Burntisland . Plan of the Burntisland Shale-field (a) Represents a fold over ; (b) represents disturbed ground ; (c) represents Bore No. 2, having missed the shale ......... Trial Shaft, with a Level Cross-cut .... Mine driven in Oil-shale, at Pumpherston, with Level Cross-cuts ........ „ 25. Mine driven in Folded Oil-shale Strata, Drumshoreland Basin ......... „ 26. Vertical Shaft sunk in Oil-shales, Mid-Calder „ 27. Method of Timbering the Roof and Centre-propping in Mine-driving ........ „ 28. Cartridge in position in Shot-hole .... „ 29. Stoop and Room Method of Working Oil-shale „ 30. Plan and Section of Highly-inclined Stoops . „ 31. Creep of the Strata in Highly-inclined Mine . 11 2 11 3 11 4 n 5 ii 6 jj 7. ri 8. ii 9. ii 10. ii 11. ii 12. ii 13. it 14. ii 15. ii 16. ii 17. ii 18. 31 19. 11 20. ?J 21. 11 22. 11 23. 24. Page 4 18 21 25 28 31 32 34 39 41 42 45 48 55 62 70 73 87 91 96 97 99 100 101 101 102 104 108 111 112 113 Vlll LIST OF ILLUSTRATIONS. Fig. 32 J) 33. It 34. fi 35. J) 36. )5 37. '» 38. ») 39. »» 40. J) 41. !J 42. J? 43. J) 44. )) 45. »J 46. J1 47. )) 48. >> 49. )) 50. V 51. 7) 52. ») 53. JJ 54. >) 55. !) 56. )) 57. ?) 58. ;» 59. jj 60. ?? 61. 71 62. )) 63. iJ 64. Method of Removing the Stoops . Plan of Shale Mine worked on Longwall System Plan of Longwall Face ..... Section of the Fells Shale .... Method of Spragging Shale .... Special Method of Working Oil-shale in Steps Section of Dunnet Shale, Oakbank Pit, Mid-Calder Longitudinal Section, showing Method of "Working the Dunnet Shale, Mid-Calder Method of Working Vertical Seams of Shale . Roof supported by Crown Tree Roof supported by Vertical Prop . Roof supported by Steel Girder, supported by Vertical Props . . .... (a) Brick-arching ; (b) Brickwork and Girders Fan used in Ventilating Shale Mines (b) Brattice Boards ; (c) Brattice Cloth ; (p) Props Hand Fan ; Wooden Rhones Method of fixing Rhones in Upset Upset and Rhones in position Trap-door ........ Ventilation of Stoop and Room Workings Carriage for Self-acting Incline .... Plan and Elevation of Endless Rope Haulage Hauling by Endless Rope from Inclined Shaft Horizontal Retort ..... Old Vertical Retort . . ... Young and Beilby Retort .... Henderson Retort .... Bryson Retort . . . . Beilby Ammonia Column Still Henderson Ammonia Column Still. Two Trays Residue Still ...... Connected Boiler Stills .... Heavy Oil Still . . . . Page 114 115 116 116 117 118 118 119 120 121 121 121 122 123 124 124 125 125 126 127 129 130 132 167 168 169 170 171 174 175 180 180 181 AT END OF MEMOIR. 1. Tabular Statement of Oil-shales in the Shale-fields of the Lothians. 2. Table of Comparative Vertical Sections, etc. 3. Geological Map of the Oil Shale-fields of the Lothians. In the horizontal sections which accompany the detailed description of the Shale -fields the following abbreviations have been employed : — Abbreviations. H.L. . Hurlet Limestone. T.L. . Tartraven Limestone. C.L. (H.L.) Cobbinshaw or Hurlet Limestone B.B.I. . Black Band Ironstone. R.S. . Raeburn Shale. Ur. U.S. Upper Raeburn Shale. Lr. R.S, Lower Raeburn Shale. M.S. . Mungle Shale. 2 F.C. . Two-feet Coal. Pa. S. . Paper Shale. H.C. . Houston Coal. F.S. Fells Shale. B.S. . Broxburn Shale. D.S. . Dunnet Shale. Bar. S. Barracks Shale. B.L. . Burdiehouse Limestone. P.S. . Pumpherston Shale. C. Coal. O.S. . Oil Shale. O.F. . Ochiltree Fault. M.H.F. Middleton Hall Fault. C.F. . Calder Fault. M.F. . Murieston Fault. P.F. . Pentland Fault. F. Fault. PAET I. THE GEOLOGY OF THE OIL-SHALE FIELDS. Introduction. The Scottish oil-shale industry is now mainly located in a belt of territory about six miles broad that stretches from Dalmeny and Abercorn on the shores of the Firth of Forth, southwards across the fertile tract between the river Almond and the Bathgate Hills to the moorland district of Cobbinshaw and Tarbrax. Throughout this region there are various important mining centres, such as Broxburn, Uphall, Bast Calder, Mid-Oalrler, West Calder, and Addiewell, with large populations, mainly, if not wholly, dependent on this branch of economics for their support. The rapid development of this industry in the Lothians within the last forty years is strikingly exemplified by the fact that, when those portions of Midlothian and Linlithgowshire were first mapped by Sir Archibald Geikie on behalf of the Geological Survey in 1857, not one of the existing oil-shale fields in the Calciferous Sandstone Series was then being worked. The important discovery, which ultimately led to an active search for oil-shale, had been made, that oil could be obtained by distillation from the Torbanehill mineral, a seam near the base of the Coal-measures in West Lothian. In the first edition of Sheet 32 of the one-inch map of Scotland, the outcrops of the Houston Coal and Burdiehouse Limestone, two important horizons in the oil-shale group (Calciferous Sandstone Series) were indicated. While traversing that region Sir A. Geikie recorded on the six-inch maps various exposures of bituminous shales, which we now know to be outcrops of oil-shales whose horizons are well denned. In the Memoir on " The Geology of the Neighbourhood of Edinburgh," published in 1861, he referred to other prominent members of the same group, such as the Two-feet Coal, the Houston Marls, and the Binny Sandstone, all of which are of great stratigraphical significance in working out the structure of that region. From the map and memoir it is apparent that he fully realised the extensive folding of the strata in West Lothian. The subsequent development of the oil-shale fields necessitated a resurvey of those areas in Midlothian and Linlithgowshire, which was successfully accomplished between 1884 and 1887 by Mr. H. M. Cadell, when attached to the staff of the Geological Survey. By the courtesy of many interested in that industry, a large 2 Geological Position of the Shale-Measures. amount of mining information was then placed at his disposal, which enabled him to trace the outcrops of the various bands of oil-shale and to determine the position of the large faults affecting the structure of that region. The results of that resurvey were embodied in a second edition of Sheet 32, issued in 1892. In 1885, Mr. Oadell communicated a brief description of the results of his re-examination of the shale-fields to the meeting of the British Association at Aberdeen in a paper entitled " Recent Advances in West Lothian Geology."* He indicated the position of the various oil-shales then known in the course of mining operations, and furnished estimates of the thickness of the sub- divisions of the Calciferous Sandstone Series. Again, in 1901, he published a detailed account of the geological structure of the various fields in the Lothians and at Burntisland in Fife, accom- panied by horizontal sections, in the Transactions of the Institute of Mining Engineers,t and also in the Transactions of the Edin- burgh Geological Society. + These materials, together with the notes based on the original survey, have been largely used in the preparation of the geological portion of this memoir. In the course of the recent revision of the Carboniferous areas of the Lothians by the Geological Survey, Mr. Wilson re-examined the oil-shale fields, and obtained further information from the various mining managers and others interested in the industry. Among the more important results may be mentioned the more accurate determination of the outcrops of the strata and lines of fault owing to the recent developments in the Tarbrax, Cobbin- shaw, Pumpherston, and Breich fields, and the mapping of the new shale-field at Ingliston. The recent discovery near Dud- dingston, Linlithgowshire, of valuable oil-shale not far below the position of the Burdiehouse Limestone is of great economic importance and may have a vital bearing on the future develop- ment of the industry in the Lothians. J. H. i. Geological Position of the Shale-Measures. The shale-measures on which the oil industry depends form part of the Calciferous Sandstone Series of Mid and West Lothian and the southern coast of Fife between Burntisland and Inverkeithing, the geological position of which will be readily grasped from the following tabular statement. The Carboniferous system in Scotland may be arranged in descending order in four divisions as given below. 4. Goal-measures, comprising red sandstone, shales, and marls with no workable coals, underlaid by white and grey sandstones and shales with numerous valuable coal-seams and ironstones. * Report of Brit. Assoc, 1885. Trans, of Sections, p. 1037. t "The Oil-shale Fields of the Lothians." Trans. Inst. Min. Eng., 1901. J "The Geology of the Oil-shale Fields of the Lothians." Trans. Edin. Geol. Soc, vol. viii., part i., p. 116. Topographical Distribution of the Oil-Shales. 3 3. Millstone Grit, consisting of coarse sandstones with beds of fireclay, a few thin coals, ironstones, and thin limestones. 2. Carboniferous Limestone Series, embracing three subdivisions, the highest of which contains three or more limestones with thick beds of sandstone and some coals; the middle includes several valuable seams of coal and ironstone ; and the lowest is charac- terised by several beds of marine limestone, with sandstone, shales, some coals, and ironstones. 1. Calciferous Sandstone Series, forming two subdivisions. The upper, known as the oil-shale group, is over 3000 feet in thick- ness, and contains, in its higher part, beds of coal usually of inferior quality, and farther down, about six main seams of oil- shale, interstratified with beds of sandstone, shale, fireclay, marl, and estuarine limestones. The lower group, in which no oil-shales of economic importance have yet been found, consists of white sandstones and shales, passing downwards into grey, green, and red shales, clays, marls, and sandstones, with bands of argillaceous limestone or cementstone. (/See Note page 97.) In the accompanying vertical section (Fig. 1) the various sub- divisions of the Carboniferous system of Midlothian and Linlith- gowshire are represented, but it ought to be clearly borne in mind that, even within these limits, the rocks vary greatly in thickness from place to place. ii. Topographical Distribution of the Oil-Shales. Although the Calciferous Sandstone Series is well developed in other parts of Scotland, it has not hitherto yielded any oil-shale of economic importance beyond the limits of West Lothian, Mid- lothian and Fife. It is remarkable that though bands of this material are well developed along the western side of the Dalkeith basin, they either occur in an attenuated form or disappear on the east side of that syncline. Thin seams of oil shale belonging to this series, occur on the shore sections north of Gullane and near Cockburnspath, in the counties of Haddington and Berwick, but not of sufficient importance to be worked with profit. Again, the shale-measures of West Lothian, which dip westward under the Bo'ness, Bathgate, and Wilsontown coalfields and reappear some miles to the west without any oil-bearing shale, prove that, during a long interval in the Carboniferous period, the necessary physical conditions for the deposition of oil-shale of economic importance were confined to this limited area. Beginning first with the largest and most important areas in Linlithgowshire and the adjoining part of Midlothian we find that the western boundary of the shale-measures is marked by the out- crop of the Hurlet Limestone, which trends northward from the Cobbinshaw reservoir to the Firth of Forth— a distance of about fifteen miles. Along their eastern margin, between Hailes and the mouth of the river Almond, there is no well-defined limit, and the base of the productive shale-measures in that area is as yet largely conjectural. The shale-measures can be distinctly Section of Carboniferous Strata — Mid and West Lothian. Feet. C5 % 3 1 1 m §1 P-irfl S Red Sandstones. Horizon not proved. "Dalkeith" and Mussel- burgh Coalfield. Rosliu Sandstone. Coal. "Levenseat" Limestone. Coals. "Calmy" or Gail' Limestone / Wood Extra Limestone. \ Coal. South Parrot Coal. " Index " Limestone. "Edge Coals" aud Iron- stones, Loauhead. " BllstonBurn " Limestone. Vexhim Limestone and Coal. " North Greens " Limestone & Coal. Gilmerton Limestone. llaebnru Shale. Huns''' Shale. Two-Feet Coal. 3 Pj Co o <*- o 3 CD 3 s° s-BS. Houston Coal. — ( Grey Shale. tills Shale «V Llmestou c Rroxlmrn Shales. " Wee Kim net " Shale. Binny Sandstone. Diiimet Shale. ISarrack's Shale.r Bnrdio- .... ,-.. — i 1 house Oil Millie. "-Limestone Limestone. All Shale. I'liiiiphcrstoii Shales. Hailes Sandstone. Wardie Shales. Granton Sandstone. Abbeyhill Shales. Arthur's Seat Volcanic Group. Cementstone Group or "Ballagau " Beds. Upper Old Red Sandstone. W a' rc © a CO 2 - a. Fig. 1. — General Vertical Section of the Carboniferous Strata of Mid and West Lothian. Topographical Distribution of the Oil-Shales. 5 traced across the river Almond into the western part of Edinburgh- shire, but on account of the deep covering of drift and the rarity of natural sections, we have no means of ascertaining the exact relationship between the strata of the shale-fields and the under- lying rocks in the neighbourhood of Edinburgh. The question is one of great scientific and economic importance. A brief con- sideration of the nature and distribution of the respective sub- divisions of the lower portion of the Oalciferous Sandstone Series may throw some light on this problem. Since the discovery of fish remains of Upper Old Eed Sandstone age, in the sandstones at Craigmillar and beneath Salisbury Crags, the base line of the Carboniferous system in the Edinburgh district has been drawn at the bottom of a group of grey, green and red mudstones, shales and cement-stone bands, with occasional sand- stones and rarely some thin seams of dark carbonaceous shale yielding plants. These sediments, which have a wide distribution in Scottish Carboniferous areas and are typically represented at Ballagan north of Glasgow, are well developed in the old town of Edinburgh between the Castle and Holyrood Palace, in the Dry Dam east of Salisbury Crags, in certain stream sections on the north-west side of the Pentland Hills and in the Linhouse Water two miles south of Mid-Calder. The representatives of this group pass underneath an important series of volcanic rocks — -lavas, tuffs, and agglomerates — which appear on Arthur's Seat, the Calton Hill, and south-westwards at Craiglockhart. Far to the south-west they occur in their normal position, on Corston Hill and in the Linhouse Water south of Mid-Calder ; and still further south on Black Hill and Torweaving Hill east of Cobbinshaw reservoir. Within the city of Edinburgh the volcanic rocks of Arthur's Seat and Calton Hill are surmounted by the Abbeyhill Shales, which, in turn, are overlaid by the white and grey sandstones of Granton and Craigleith. Prom an economic point of view these sandstones are of great importance as the greater part of the new town of Edin- burgh has been built of this material. Next in order comes a group of argillaceous strata, containing fish remains and plants, locally known as the Wardie Shales, which are exposed on the shore at Wardie near Granton to the north of Edinburgh. They underlie most of the new part of the city of Edinburgh and are laid bare in the Water of Leith below Dean Bridge. In the new tunnel of the North British Railway, between the Haymarket station and Princes Street Gardens, a splendid section of these beds was exposed in 1893, and, during the progress of the tunnelling operations, Mr. H. M. Cadell examined the cuttings to ascertain if the strata included any mineral of economic importance. Con- sisting of laminated sandy shales, or fakes, argillaceous shale or blaes with ironstone nodules, hard ribs of "kingle," thin sand- stones and a few streaks of coal from one to three inches in thick- ness, the series contained no traces of workable oil-shale, coal, limestone, or ironstone. At various localities round Edinburgh seams of coal, one foot or more in thickness, have been met with in the Wardie Shales, but none of sufficient value to be worked 6 Topographical Distribution of the Oil-Shales. with profit. As there is no evidence of workable oil-shale in this series of argillaceous strata, Mr. Cadell infers that the base line of the oil-shale group must be drawn above the horizon of the Wardie Shales. Still it is worthy of note that some of these beds may be regarded as impure oil-shales. (See Note page 97.) The Wardie Shales apparently pass underneath a higher set of sandstones extensively quarried at Hailes and Redhall, about three miles south-west of Edinburgh, and as these strata contain a band of oil-shale, they are probably situated at or near the base of the oil-shale group. Hence the line marking the eastern boundary of the western shale-field must be drawn somewhere near the outcrop of these beds, that is approximately between Hailes and the mouth of the river Almond. If this line be accepted as the eastern boundary of the main shale-field, then it is probable that there is still a considerable area round Ratho, which has not been tested, so far as known by boring, in which oil-shale may reasonably be expected to occur in workable quantities. The future exploration of this large district is of prime importance, as the extent of the available shale-bearing ground has a vital bearing on the development of the shale industry, and no writer or mining engineer has hitherto studied the subject with the attention which it deserves. The south-eastern side of the West Lothian shale-field is defined by the Murieston fault (page 11) between Currie and Harburn, and, from this point to the southern edge of Sheet 32, by the out- crop of the Burdiehouse Limestone. On the south-east side of the Pentland Hills the oil-shale measures again appear, near the great dislocation that truncates the Old Red Sandstone rocks of that range. A glance at Sheet 32, one-inch, shows that on the west side of the Mid- lothian basin a strip of Calciferous Sandstone strata intervenes between the Carboniferous Limestone Series and the volcanic rocks of the Pentland Hills, which contains representatives of the oil-shale group with oil-bearing shale. The proved portion of the field extends from Long Loan near Gilmerton to Seafield Muir, a distance of two and a half miles. Here shale has been worked at Burdiehouse and Straiton, four miles south of Edinburgh, by the Clippens Oil Company, but owing to protracted litigation as to anticipated surface-damage to water-pipes belonging to the Edinburgh Corporation, the mines have not been in operation for several years. Like the coal-seams in the Carboniferous Limestone Series the oil-shales dip at high angles along the line, so that mining in these measures is both difficult and costly, and the shale must be of high quality to be extracted on a profitable scale. The volcanic rocks of Arthur's Seat and the Calton Hill, as already indicated, pass under the Craigleith Sandstone and Wardie Shales, and as the dip is to the north-east on the western side of the great Pentland fault, it is possible that the base line of the oil-shale group may be reached before we arrive at the shore between Leith and Portobello. Oil-shale, indeed, is said to have lately been struck in excavations connected with the new dock at Physical Characters of Oil-Shale. 7 Leith, so it is possible that there may be a small shale-field under this part of the Firth of Forth ; but it need hardly be added that the probability of successful mining here is not very great even if the shale were of good quality. On the north side of the Firth of Forth the top of the oil-shale group is not yet clearly defined, and further exploration is necessary •before it is definitely established. A seam of shale — probably the Dunnet — is exposed in the Fordel colliery railway cutting, north of St. David's, and while conducting some boring operations on the sea-floor for the War Department at Port Laing, near Inver- keithing, in 1900, Mr. Cadell met with a seam of oil-shale, dipping westward at a low angle under the basalt cliffs of North Queens- ferry. The thickness of this band was not ascertained, as the borings were not made for mining purposes, but this outcrop was almost in line with that of the Fordel railway cutting, and was interesting geologically as indicating the nothern extension of the oil-shales of the Dalmeny district. Oil-shale has been found both in the Coal-measures and in the Carboniferous Limestone Series of Scotland, and has been wrought at various localities together with seams of coal and ironstone. At present, however, not one of these shales is considered workable, and the seams of value all occur in the Calciferous Sandstone Series. iii. Physical Characters of Oil-Shale. Oil-bearing shale, as known in the Lothians, is a fine black or brownish clay-shale with certain special features which enable it to be easily distinguished in the field. Among Scottish miners it is termed " shale," and the stratified rock described by geologists as " carbonaceous shale " is distinguished as " blaes," from the bluish colour, which it often assumes, especially when decomposed into clay. This distinction is a convenient one in several ways, and will be adopted in this memoir. These two types are readily recognised in the field, but bitumin- ous blaes may graduate into regular oil-shale in such a way that it is impossible sometimes to draw the dividing-line between them. Bituminous blaes if fairly rich in ammonia and volatile hydro- carbons may pass for shale if a practical test proves it to be workable for oil and ammonia on a profitable scale. As a general rule, good oil-shale can be distinguished by its brown streak, toughness and resistance to disintegration by the weather. Ordi- nary black blaes is more or less brittle and often gritty, and when exposed to the air it cracks and crumbles into fragments which ultimately revert to their original condition of clay or mud. Oil- shale, on the other hand, resembles hard dark wood or dry leather, and its quality in the field is measured by the degree of facility with which it can be cut and curled up with the edge of a sharp knife. It is free from grittiness, and is often flexible as well as tough. Some seams, such as those that crop out on the shore at Society, near Hopetoun House, instead of breaking up like blaes, 8 Geological Zones. form slabs sometimes a couple of feet in length, that are washed about and rounded on the edges by the waves. Miners draw a distinction between "plain" and "curly" shale, the former variety being flat and smooth, and the latter contorted or " curled " and polished or glossy on the squeezed faces. The same seam may be partly plain and partly curly, and the curly beds are often richer in oil than the plain portions. Shale is probably curly because it is rich, as the higher percentage of hydro-carbon in some beds may have rendered them more easily crumpled than the stronger but poorer bands alongside of them. In internal structure, oil-shale is minutely laminated, which is apparent in the " spent shale " after distillation, when it is thrown out in fragments composed of extremely thin sheets, like the leaves of a book or flakes in a piece of pastry. In thickness, the shale-seams vary greatly. At certain localities they disappear and pass into ordinary carbonaceous blaes, and at others they swell to six, ten, or perhaps fifteen feet in thickness, with subdivisions of barren blaes or ribs of hard calcareous or quartzose " kingle." iv. Distinctive Geological Zones. Reference has already been made to the fact that many ot the prominent zones of the oil-shale group in the Lothians were recog- nised by Sir A. Geikie during his survey of the ground about fifty years ago. Certain of these occupy well-known horizons, are remarkably persistent, and are of great service in elucidating the structure of the various shale-fields. (See Fig. 1, page 4.) Burdiehouse Limestone. — The lowest of these is the Burdiehouse Limestone, which lies below the oil-shales that have hitherto been discovered, except those of Pumpherston, and in general it occupies a position which varies from 2,300 to 2,600 feet below the Carbon- iferous Limestone Series at the top of the oil-shale group. This bed is an estuarine or fresh-water limestone long known on account of its remarkable assemblage of fossil fishes, and distinguished by the abundant remains of a small ostracod crustacean Leperditia Okeni var. Scoto-burdigalensis. It is occasionally associated with cherty bands, and at present is wrought at Harburn Head, New- park, and Camps for iron smelting, and at Burdiehouse and Straiton for building, gas purification, and general purposes. Binny Sandstone. — The Dunnet and Broxburn oil-shales are separated by an important zone of sandstones, of variable thickness with. some blaes and marls both above and below, which are known locally as the "Binny," " Hermand" or "Humbie" Sandstones. As this rock was first and most extensively wrought at Binny this name has been selected to identify this horizon. The material obtained from Hermand quarry is a first-class building stone, con- tains nearly 95 per cent, of silica, is very compact and not liable to be affected by the weather. It is grey in tint, and its architec- tural qualities can be studied from the following buildings in Edin- burgh, all of which have been exposed to the weather for more than Geological Zones. 9 20 years, namely : — The new part of the Oalton Jail ; St. Andrew's Free Church, Drumsheugh Gardens ; the western section of the Royal Scottish Museum, Chambers Street ; and the Bank of Scotland, George Street. At Binny, the quarries which supplied the freestone for many of the finest buildings in Edinburgh during the first ha\{ of the nineteenth century, such as the Scott Monument, are now totally abandoned and full of water. The rock, which lies in thick beds separated by bands of blaes, is grey in hue and very strong and durable. It is hard and well adapted for lasting monumental work ; but its hardness, like that of the celebrated Craigleith free- stone, makes it costly to hew, and the quantity of unproductive blaes between the beds, together with the increasing thickness of overlying material, have rendered the quarrying of it too expensive to be longer payable at Binny. When the quarries were in opera- tion, blocks were obtained weighing as much as 17 tons. There were 26 feet of good building stone of a fine white colour below and grey above, overlaid by 3 feet of hard sandstone, covered by 31 feet of blaes. On the north side of the Edinburgh and Glasgow, and Forth Bridge loop line, a quarry has recently been opened in the Binny Sandstone to the south of Swineburn. The rock is of excellent quality and colour, and large blocks can be obtained from the various beds. At Dalmeny this sandstone was extensively worked in the past, and the material was said to be superior in quality to that of Binny. Among the Edinburgh buildings erected with Dalmeny stone are the Palace Hotel ; Union Bank, George Street; the east side of Palmerston Place, and nearly all the east side of Coates Gardens. The sandstone is in thick massive beds with partings of blaes, and the upper part of the section shows much grey bituminous shale full of entomostraca, thus resembling the sequence at Binny. The Binny Sandstone is also strongly deve- loped in the Philpstoun district, where in the railway cutting and in bores it is at least 300 feet thick. Broxburn Marls. — The Broxburn oil-shales are surmounted by a characteristic set of beds locally known as the Broxburn marls, which comprise greenish, marly, or ashy clays, interbedded with carbonaceous shale and ribs of very hard, unfossiliferous cement- stone or calcareous bands that vary in thickness from an inch to over a yard. All over the West Calder district the top of the series is characterised by a band of cream-coloured or grey lime- stone, 3, 4, or 5 feet thick, lying almost immediately under the Fells Shale, and in boring for the latter seam this limestone is regarded as the infallible " mark" of its position. No sandstone is found among the Broxburn marls as a rule, and this curious series of beds points to a period of tranquillity over a wide area, succeeding the time of rapid currents that rolled along the pebbles and grains of sand during the deposition of the Binny Sandstone. Houston Coal.— Though a few thin coal seams have been opened out below this horizon, the Houston coal is practically the lowest bed of workable coal in the Scottish Carboniferous system. With the exception of the insignificant Two-feet Coal-seam above the Houston 10 General Geological Structure. marls, the next bed of workable coal, situated in the Carboniferous Limestone Series, is separated from it by over 2000 feet of sedi- mentary strata. The Houston Coal is pyritous, of inferior quality, and, on account of its bad roof and soft pavement and the quantity of blaes interbedded with it, has seldom in recent years proved remunerative. That it was formerly extensively wrought near the surface is proved by numerous old outcrop-pits. The last attempts to work this seam were made by several of the oil-shale companies to obtain cheap furnace fuel, but the results were unsuccessful, and the pits and mines are now dismantled. Houston Marls. — The Houston marls (so called), overlying the Houston Coal, are green or reddish, massive, amorphous, mudstone- like beds, which are hard when fresh, but crumble down on exposure to the weather. The individual bands are often a few feet in thickness, and are separated by thin partings of hard kingle or cement-stone that resist the weather and project in ribs beyond the decaying matrix. The Houston marls appear to be unfossili- ferous, and point to a complete change in the geological sequence of events over a wide area. In the West Calder district they reach a thickness of 150 to 200 feet or more, and they clearly indicate a long cessation of the conditions necessary for the deposition of oil- shale in that area. The occurrence of regular well-defined parallel beds and bands of different colour points to aqueous action, and the absence of shaly intercalations suggests that the accumulation of this particular material must have been more or less continuous. Although locally called a "marl," it is doubtful whether this is a correct description in the true acceptation of that term, as marl is a mixture of clay and lime, usually derived from finely divided organic remains, and the only external resemblance between the two rocks is their light colour, amorphous appearance, and the way in which they both crumble down under the influence of the weather. This deposit is not a true marl or mixture of clay and lime, as the chemical analyses which have been made show that the proportion of silica to alumina is too high for ordinary silicate of alumina, which constitutes the basis of pure clay, and the per- centage of lime seems too low to class it among true marls. v. General Geological Structure. 1 . District of West Lothian and the adjoining part of Midlothian. Disregarding local details, there are certain broad general features which may be said to characterise the geological structure of the shale-measures of West Lothian and the adjoining part of Midlothian. On referring to Sheet 32, it will be seen that along the western margin of this area between Abercorn on the Firth of Forth and the Cobbinshaw reservoir the members of the oil-shale group pass underneath the Carboniferous Limestone Series with the associated lavas and tuffs, while to the east thereof they are arranged in a series of folds, the axes of which generally run in a General Geological Structure — Main Faults. 11 N.N.E. and S.S.W. direction. By means of these undulations the oil-shales are spread over a belt of country several miles in width, and hence the mineral wealth of that district has been greatly increased. These arches and troughs are traversed by several more or less powerful faults, traceable for miles, which, at certain localities, produce large displacements of the strata. THE MAIN FAULTS. In these regions there are four important dislocations, all of which have a general easterly or north-easterly trend, and, with one exception, have a common downthrow to the north. In the sequel it will be shown that though they profoundly affect the geological structure of the various mining districts, the axial folds can in many cases be traced across their path. The most southerly of these parallel lines of disruption is the Murieston fault, which has a downthrow to the north and runs from near Baads Mill, north of Cobbinshaw reservoir, in a north-east direction by Murieston House towards Kirknewton. That it must have a large amount of displacement is evident from the fact that, near Skivo, about three miles south-west of Mid-Oalder, it brings the Burdiehouse Limestone and associated strata on the north into contact with the lavas and tuffs of Corston and Linhouse Water, which have been correlated with the volcanic rocks of Arthur's Seat. Further east, between Kirknewton and Dalmahoy Mains, it lets down the oil-shale measures against the Cement-stone group. The next dislocation is the Calder fault, which has a nearly parallel course to that just described, with a smaller downthrow in the same northerly direction. At Mid-Calder it truncates the basin of oil-shales on the south, and there brings down beds overlying the Broxburn Shale against strata below the horizon of the Burdie- house Limestone — a displacement, probably, of about 900 feet. South-westwards it has been traced across the West Calder field by Hermand and Little Hartwood to the north of Baads Mill, where it apparently dies out. Still further north we find the Middleton Hall fault, which extends from near Dechmont about a mile and a half north of Livingston, in an E.N.E. direction to Middleton Hall. At the latter locality its trend becomes more easterly, and by means of bores and mining operations it has been traced eastwards towards the Almond railway viaduct. The amount of displacement at Middleton Hall is 1566 feet, where beds not far below the horizon of the Hurlet Limestone are brought against strata associated with the Broxburn -Shale. Further east, at Kilpunt, between Broxburn and the river Almond, the downthrow is about 1128 feet. The fourth important line of disruption, which differs from the others already mentioned in having a displacement to the south or south-east instead of towards the north, occurs in the northern part of the shalefield and is termed the Ochiltree fault. Beginning at the point about a mile W.N.W. of the village of Ecclesmachan, near Wester Ochiltree, it trends E.N.E. by Craigton and Westfield 12 General Geological Structure — Main Flexures. to Dalrueny. The evidence points to the conclusion that its amount of downthrow varies considerably owing to the folding ot the strata, for at Craigton it is about 900 feet, at Westfield 1350 feet, and at Dalmeny about 1600 feet. These major fractures are accompanied by a series of east and west faults which shift the outcrops of the oil-shales to a con- siderable extent at Midhope, Niddry, Ecclesmachan, and Addiewell. THE MAIN FLEXURES. The series of faulted outcrops of the oil-shales along the west margin of the West Lothian field between Abercorn and Cobbin- shaw reservoir, may be regarded as forming part of the eastern limb of the great basin in which lie the Stirlingshire and Lanark- shire coalfields. The most striking feature, however, of the West Lothian field is the system of folding which may be said to characterise the whole area. Though, as a rule, the undulations are normal, yet in some instances, the western limb is more highly inclined than the eastern, and in one or two cases is vertical or inverted (Pig- 12). About midway between the Firth of Forth and Cobbinshaw reservoir, the most prominent of the anticlinal folds is that of Pumpherston, in the centre of which we find the lowest beds of the oil-shale series, in the form of a narrow ellipse whose major axis runs north and south for two miles (Fig. 5). On either side of this arch the strata form deep synclinal folds. The eastern basin, which underlies the drift-covered plain of Drumshoreland Muir, south of Broxburn, trends southward for three miles to Mid-Calder, where it is clearly seen in the excellent sections of the Linhouse and Murieston Waters, and in the workings of the Oakbank Oil Company at the confluence of these streams. The eastern trough is straight and narrow, while the western, extending from Pum- pherston beyond Houston Wood to Dechmont, is broad and deep, being covered in the centre by a sheet of intrusive dolerite, 200 feet thick (Fig. 5). This basin, which has an outcrop of the Burdiehouse Limestone on either side, runs northward for a distance of three miles from the river Almond at Livingston to near Uphall. Crossing the line of the Middleton Hall fault, we find the northern prolongations of the flexures just described with some important modifications. The Pumpherston anticline is continued in the low arch that extends for about two miles from Broxburn to Niddry, on either side of which the principal workings in the Broxburn Shale have been prosecuted. West of the Broxburn arch there is the deep basin that stretches northwards from Middleton Hall to Newbigging, which is beyond doubt the northern prolongation of the trough west of Pumpherston. It is interesting to observe that the beds in the centre of the syncline at Middleton Hall, are, in consequence of its great depth, the highest in this district ; indeed, had the depression been a few feet deeper an outlier of the Carboniferous Limestone Series would have occurred between General Geological Structure — Main Flexures. 13 Broxburn and Uphall in the midst of the oil-shale field, about four miles distant from the main outcrop of that series. Again, on the east side of the Broxburn anticline there is a shallow basin in the oil-shale group which has been proved by mining operations to occur at Bast Mains. It is not improbable that this flexure is continued northwards by Niddry Mains to Westfield, about a mile west of Dundas Castle, where it is intersected by the Ochiltree fault. When we cross the Ochiltree fault which traverses that region for a distance of nine miles in a general E.N.E. direction, we find an important series of flexures, some of which may be the northern prolongations of those already described near Broxburn and Pumpherston. For example, at Hopetoun House there is a well- marked anticlinal fold, running north and south, on either side of which the Burdiehouse Limestone dips to the east and west respectively. The eastern outcrop passes underneath the shallow Duddingston basin occupied by members of the oil-shale group, including the Dunnet Sandstones, Shale, and Binny Sandstone. East of Banks the Burdiehouse Limestone and associated sediments reappear along a second anticline, the centre of which is occupied by a sheet of intrusive igneous material. Eastwards this flexure is followed by the compound synclinal basin of South Queensferry. On referring to the map it will be seen that it is not improbable that the Hopetoun arch and the adjoining Duddingston basin to the east may be the northern continuations of the Pumpherston and Mid-Calder flexures respectively. West of Hopetoun House the Burdiehouse Limestone and over- lying strata are inclined to the north-west and trend south-west- ward to Philpstoun, where there is a low flat anticline, on either side of which there is a good outcrop of the Broxburn Shale. Between Philpstoun and the base of the Carboniferous Limestone Series with the overlying Bo'ness coalfield, there is a tract of drift- covered land not yet satisfactorily explored, in which shale may be discovered at greater depths when the shallower fields are exhausted. In the southern portion of the district between Livingston and Cobbinshaw reservoir, the West Calder shale-field is of great economic importance owing to the repetition of the various oil- shales by folding and faulting. The geological structure of the field is rather complicated owing to the numerous faults that intersect the area and the irregular dip and strike of the strata. The principal tectonic features are two deep basins at Polbeth and Hartwood respectively, with an intervening low anticlinal ridge at West Calder village. The field is traversed by two large faults trending north-eastwards with a downthrow to the north-west and by numerous smaller dislocations. Along its western edge the strike of the beds becomes more regular ; indeed, it is worthy of note that beyond the lower limestones of the Carboniferous Lime- stone Series the strata of the overlying coal-bearing group to the west have the same regular strike without any folding, and are interrupted only by dip faults, some of which are the western continuations of those in the West Calder shale-field. 14 General Geological Structure — Igneous Boclcs. Southwards towards Cobbinshaw there are few natural sections owing to the covering of drift and peat throughout the moorlands of that district, but mining operations prove that the Houston Goal and the upper oil-shales extend southward to within the borders of Lanarkshire. 2. District of Straiton and Burdiehouse in Midlothian. On the west side of the Midlothian basin, as already indicated, the Burdiehouse Limestone and overlying oil-shales rise from underneath the Carboniferous Limestone Series with a persistent dip to the south-east, but recent developments point to the con- clusion that these strata are repeated to the west in the Burdie- house Burn and near Kaims by means of an anticlinal fold which is evidently the southern continuation of the flexure beyond Gilmerton. The north-west extension of the field beyond Kaims must be comparatively limited owing to the oil-shale group being abruptly truncated by the great fault along the south-east margin of the Pentland Hills. (Fig. 19, page 91.) 3. Burntisland District. On the north side of the Firth of Forth representatives of the oil-shale group again appear in the core of the great anticlinal fold at Burntisland, where they are overlaid by the thick series of contemporaneous volcanic rocks which intervene between the shale- bearing strata and the Carboniferous Limestone Series. The geological structure of that district has been described in detail by Sir A. Geikie in his " Memoir on the Geology of Central and Western Fife." He clearly showed that, in Midlothian, an import- ant anticlinal fold coincides with the general line of the Pentland Hills, along which Upper Silurian and Lower Old Red Sandstone rocks are brought to the surface, while the various members of the Carboniferous system are there thrown off on either side. He further pointed out that this axis is prolonged across the Forth to Burntisland and thence to the hills beyond Markinch* IGNEOUS ROCKS. The igneous rocks which come within the limits of the oil-shale measures of Mid and West Lothian may be grouped in the follow- ing order: (a) contemporaneous, represented by volcanic tuffs interstratified with the sediments; (/;) intrusive, comprising (1) necks of tuff or agglomerate ; (2) sheets or sills of dolerite, basalt, and diabase. As the petrography of these volcanic materials will be described in the memoir of Sheet 32, only a brief description of their distribution and mode of occurrence will here be given. Contemporaneous Tuffs. — The interbedded volcanic tuffs lie immediately above the Two-feet Coal (see Fig. 15), and are found at different localities between Dechmont and Binns Hill in Lin- * " The Geology of Central and Western Fife and Kinross," p. 44. General Geological Structure — Volcanic Necks. 15 lithgowshire. They are generally fine-grained, and when decom- posed are easily mistaken both by geologists and mineral borers tor the Houston marls which lie below that coal seam. Volcanic Neclcs.— The ash necks which pierce the oil-shale measures are seven in number and occur at the following localities, viz.:— (1) Ecclesmachan ; (2) Niddry Castle; (3) near West Binny ; (4) Gallowscrook, near Philpstoun; (5) Binns Hill; (6) at West Shore wood, about a mile west of Abercorn ; (7) near Society, east of Hopetoun House. It is a significant fact that these vents are situated in the northern portion of the Lothian shale area. At Ecclesmachan village, a mile north of Uphall, one of these volcanic orifices forms the Tar Hill, which is an oval-shaped, smooth-backed knoll of yellowish tuff, containing baked fragments of the surrounding rocks, and shaped like an old hill-fort, flanked on its northern, western, and southern sides by a broad hollow, but sloping gently to the east. A spring of sulphuretted-hydrogen water, known as the Bullion Well, bubbles up at its southern edge, and probably rises from the fissure between the volcanic plug and the surrounding sedimentary beds. The Houston coal-seam has been worked in old pits up to its edge on the eastern side, and the neck cuts through the Fells Shale on the north and west. A typical example, which is pierced by two plugs of basalt, occurs at Niddry Castle. The general inclination of the beds around Winch- burgh is north-west, but for some distance all round this orifice they dip towards its centre. The matrix of this ash is sandy and felspathic, and contains fragments of black shale and ironstone. The neck on Binns Hill forms a prominent feature in the land- scape. The rock is a greenish grey felspathic tuff, frequently veined with carbonate of lime, and contains fragments of baked shales and ironstone. A small plug of basalt occupies the highest portion of this hill. Another example of special interest occurs below Gallowscrook, half a mile north-east of Philpstoun station, where a stone mine was driven through the volcanic orifice in 1896 by Messrs. James Boss & Co., Philpstoun. While driving a level in the Broxburn Shale, at a depth of about 120 feet below the surface, the miners found that the inclination of the strata suddenly changed from north to east. The trend of the level course (which coincides with the strike) was at first, roughly speaking, nearly east and west, and as the level was being driven towards the east the change of dip caused it to swing round to the south. A cross-cut was then carried south-eastwards from the roof of the seam horizontally through the strata, and after penetrating a few yards into the overlying beds the miners were suddenly confronted by a vertical wall of hard volcanic material, somewhat slickensided, like the face of a fault. The mine was driven right through this obstruction, and after about a year and a half of laborious work the shale was found on the other side in good condition, but dipping towards the north- west at a steep angle. The walls of the neck in the mine were quite perpendicular, and the thickness of the volcanic plug was 360 feet from wall to wall along this line of section. The neck, 16 General Geological Structure — Intrusive Sheets. however, is oval-shaped, and measures about 700 feet along its major axis. When the mining operations were in progress Mr. Cadell care- fully examined the rock section, and found little or no evidence of contact-metamorphism or thermal action. The oil-shale was almost unaltered to within one or two feet of the neck, but in places it showed signs of induration by heat in the immediate neighbour- hood of the ash. The line of division was perfectly sharp and regular, and the volcanic rock showed signs of having subsided after consolidation and drawn down the surrounding strata, so as to make them dip inwards on all sides like a funnel. The actual junction was occupied by a few inches of crushed shale or soft breccia, as is common along the walls of faults. The tuff itself varied greatly in character and structure. It was mostly fine-grained and light-coloured, and was in places exces- sively hard, almost flinty in texture, but when exposed to the weather it soon crumbled down into sandy mud. Here and there, it was impregnated with iron-pyrites, and contained large blocks of black shale and other sedimentary materials ; or again, it was inter- spersed with small drusy cavities or veins of pitch or solid paraffin, derived no doubt from the distillation of the hydrocarbons in the shale.* Sills. — The oil-shale field of Mid and West Lothian is invaded by one well-marked sheet of dolerite and several minor intrusions of a similar character. This sill, which enters so prominently into the geological structure of the district, covers a large area west of the Pumpherston anticline, where it occupies the position of the Broxburn Shale, and if the mass east of Livingston represents its southern extension, it must at this point have descended to near the horizon of the Burdiehouse Limestone. On the north side of the Middleton Hall fault it appears on the east side of the Brox- burn anticline, where the Broxburn Shale has been rendered useless. Further west it gradually rises through the various members of the group till it almost reaches the Mungle Shale at Uphall, whence it suddenly plunges downwards below the position of the Broxburn Shale to reappear in the west as the igneous intrusion of Binny Cottage. North of the Ecclesmachan dislocation this sheet of igneous rock forms the picturesque escarpment of Binny Craig, where it occurs between the Fells and Broxburn Shales. West of that hill it appears below the Broxburn Shale, while to the east it rises to this position in the shallow synclincal fold south of Little Ochiltree. Eastwards this intrusion comes to the surface to the south-west of Winchburgh in association with the Fells Shale. At Dundas Castle a sill occupies the centre of the dome of Binny Sandstone, and has been proved by bores to occupy a similar horizon between Wester Carlowrie and Craigie south of theDalmeny shale-field. One of the interesting features of these intrusions, close to the Firth of Forth, is the repetition, on successive anticlinal folds * This neck is fully described in the Trans, of the Geol. Soc, Edin , vol vii., p. 477. Geological Description of the Shale-Jields. 17 between Bambougle Castle and Hopetoun House, of the great dolerite sill of Mons Hill. At the latter locality it dips to the west, and lies several hundred feet below the Burdiehouse Limestone. Beyond Queensferry it reappears in the arch between Echline and Duddingston, where at one point it pierces this limestone. Plunging down to the west, below the Duddingston basin, it is again exposed at the surface in the centre of the Hopetoun anticline, where it dips to the east and passes beneath beds on nearly the same horizon as those at Mons Hill. The position of the small intrusions to the west of Winchburgh is uncertain, and those of Wester Ochil- tree intersect strata between the Fells Shale and Hurlet Coal. In the detailed description of the different districts the effect of these sills upon the various strata will be more fully described. vi. Detailed Description of the Shale-fields. 1. "West Calder Shale-field. The West Calder shale-field includes the area which lies to the north of the Cobbinshaw field as far as the Brotherton and Wester Breich faults, and is bounded on the east by the -Murieston fault and on the west by the outcrop of the Hurlet Limestone. GENERAL SECTION OF WEST CALDER SHALEFIELD. Table 2. Hurlet Limestone and Coal. Feet. Inches. Strata — Blaes, ironstone ribs, thin coals, with bands of pebbly sandstones, Raeburn Shale, Strata — Blaes, fireclay, fakes and ironstone bands, 126 feet to Mungle Shale, 1 foot 7 inches to ... Strata — Blaes, fakes, fireclay and ironstone bands, Two-feet Coal, 7 inches to Strata— Houston Marls, 204 feet to Grey Shale, ■ - - Strata — Fireclay, with blaes partings, 50 feet to Houston Coal in bands, 4 to 6 feet, Strata— Thin laminated sandstone, dark faky blaes, and clay-band ironstones, 150 feet to - Fells Shale, 2 feet 6 inches to - Strata— Broxburn Marls, 250 feet to Broxburn Shale, 4 feet to Strata, including Hermand or Binny Sandstone, Dunnet Shale, 6 feet to Strata, - Shale (New ?), Strata— Green felspathic sandstones, with con- glomerate bands and shale partings, about Barracks Shale, Burdiehouse Limestone, 20 feet to SOUTHERN PORTION. For convenience of description this field is divided into two portions, and the southern area which lies between the Muneston and Mid-Calder faults will be first described. 450 9 11 150 2 130 1 2 230 1 8 73 6 200 7 275 6 420 10 52 4 6 600 4 40 18 Geological Description of the Shale-fields. | TAN 3V0B \ 1 > » * The accompanying section (Fig. 2) has been drawn across the strike of the beds from Baads Mill to a point near Hermand House, where it crosses the Mid-Calder fault and terminates on the outcrop of the Burdiehouse Limestone to the south of Limefield House. A glance at the section shows that between Hermand and Hartwood the various seams lie in a deep basin crossed by several, faults, while to the west of the latter point the beds rise in the form of a low anticline, which is also traversed by a disloca- tion. From West Hartwood farm to Baads Mill the upper members of the oil-shale group are gently inclined to the south-west and pass under the Carboniferous Limestone Series to the west of the mill, which forms the eastern edge of the Bathgate coal- field. This portion of the shalefield is intersected by the Hartwood and Murieston Waters, both affording excellent natural sections. Eighty yards to the north of Dyke- foot, and in the bed of the Hartwood Water, a good oil-shale of consider- able thickness is exposed, which lies 52 feet below the outcrop of the Dunnet seam, and probably repre- sents the "New Shale," eight feet thick, in the Mid-Calder basin. The Dunnet Shale, ten feet thick, is well seen on the banks of the stream below Dykefoot, where it is overlaid by several feet of grey marly blaes or fireclay, locally known as the Dunnet marls, which, in the Pumpherston district, attain a thick- ness of several hundred feet. Here these beds are succeeded by siliceous strata representing the Binny Sand- stone, consisting of scattered outcrops of grey and greenish sandstones with shale and ironstone bands. In the middle of the series there is a siliceous limestone one foot thick, overlaid by thin black bituminous shale with a sandy band, both con- taining entomostraca. The thickness West Colder Shale-field — Southern Portion. 19 of strata between the Dunnet and Broxburn Shales is here estimated to be about 420 feet. The Broxburn Shale is not now exposed at its outcrop, but its " waste," where the seam has been worked out, is visible just above the bridge which carries the West Calder and Harburn road across the Hartwood Water. South-eastwards its outcrop has been fixed by mining operations between the Mid-Calder and Slateheugh faults. This seam has always been an inferior one in the West Calder district, its average thickness being generally below three feet, with a yield of about 20 gallons of oil per ton. To the south-west of Danderhall a mine was driven into this shale, and proved it to be six feet thick. The Broxburn marls lie immediately above the Broxburn Shale, and are well exposed in the bed of the Hartwood Water when the stream is low, where they reach a thickness of 275 feet. Here the beds are chiefly bluish and greenish grey shales and marls, with numerous bands of shaly sandstone alternating with ribs of hard cement-stone varying in thickness from one inch to three feet. Towards the top of this series many seams of shale with ironstone bands occur, and in the middle there is a coarse dark limestone from six to eight feet thick, which passes upwards into a soft green calcareous shale with bands and irregular nodules of calcareous ironstone or cement-stone. This limestone bed contains lepidodendra, fish scales, and entomostraca. Above these Broxburn marls comes the well-known, cream-coloured, unfossiliferous lime- stone, from twenty to thirty-six inches thick, which constitutes the " Index " to the Fells Shale and lies immediately below that seam. The Fells Shale, as seen in the Hartwood Water, is at least six feet thick. In the stream and a short distance from its outcrop, the dip changes from south-west to south-east and becomes much steeper, while at the bridge below Westmuir the fissile sandstone, which forms the roof of this shale, can be seen dipping to the south-east at 45°-50°. The continuation of this outcrop to Little Hartwood has been inferred from the known positions of the upper seams. The South Hermand field, in the neighbourhood of Birnie Hill, was worked both by pits and mines for some years by the Her- mand Oil Co., Limited, but has been abandoned " on account of the number of faults which intersect the ground and the heavy pumping that was necessary to keep the workings dry" (Cadell, Trans. Ed. Geol. Soc, vol viii., p. 129). The faults on the east side of this basin between Danderhall and Birniemill have been laid down from evidence obtained from the mining plans of that period. The Fells Shale is separated from the Houston Coal by 200 feet of strata, which, from boring records and surface evidence, consist of fissile grey sandstones and dark faky blaes with several clay-band ironstones. This coal seam has been proved in two old pits on the west side of the Hartwood basin and, in this portion of the field, its quality is superior to that in the immediate neigh- 9 6 6 2 1 8 2 10 2 1 20 Geological Description of the Shale-fields. bourhood, being well suited for steam and, to some extent, for domestic purposes. The section given below, furnished by the late Mr. Williamson, Mining Engineer, Edinburgh, shows the character of the Houston Goal in this district. Feet. Inches. Coal, Clay, Coal, Sklut, Coal, Clay, Coal, - Head Sklut, Coal, To the south of Hartwood House the Houston marls have been bored, consisting of a series of green fakes, light and brown fireclays, with cement-bands, 230 feet thick, which are succeeded by the Two- feet Coal. This seam has a bad roof, has been little wrought, and is valuable only as an index to the position of the shales above. The Mungle and Eaeburn oil-shales with the normal thickness of intervening strata also occur in the Hartwood basin, the latter seam yielding the following section in several bores : — Roof Shaly Blaes. Shale, Brown Blaes, Shale, Fireclay, Shale, with ribs, Shale, soft leafy, 9 11 Three and a half fathoms below the leafy shale is another oil-shale, 42 inches thick, which may be the representative in this field of the lower Raeburn Shale of Tarbrax. In the early days of shale- mining this upper seam was regarded as the richest oil-producer in the West Calder district. It is worthy of note that in the centre of the Hartwood basin there is a thickness of 1040 feet of strata above the Dunnet Shale together with 63 feet of surface deposits. Had the centre of this fold been two hundred and fifty feet deeper it would have contained a small outlier of the Hurlet Limestone. (Fig. 2.) The position of the S.E. and N.W. fault with a downthrow of 17 fathoms to the north, between Mid-Hartwood and Hartwood, is inferred from the bores put down many years ago over this ground. At the former locality, a pit, 10 fathoms deep, was sunk to the Houston Coal, and a short distance to the N.W. the Fells Shale was opened out by a small mine about 230 feet long, and from the bottom of this incline about 300 yards of levels were driven. Feet. Inches, 3 1 1 3 10 4 9 3 8 West Calder Shale-field — Northern Portion. 21 3 yog 3V09 3V0B \ s 3 bo I T3 CO 6 M In the early days of shale-mining this seam was termed the " Hart- wood" Shale, but afterwards it was correctly correlated with the " Thick " Shale (Fells) of the West Calder district. The face of this seam had 4 inches of "Plain" Shale on top and 18 inches of " Curly" below, which is much less than the average thickness in this district. A small bench of retorts of the type then in use was erected close to the mine mouth, and the yield of oil from the " Curly : ' portion of the seam is reported to have been about 40 gallons per ton. The underlying Broxburn marls, about 40 fathoms thick, are well exposed in the stream below Moss- end, being similar to those already described lower down this water. In the centre of these marls the lime- stone already mentioned with ento- mostraca, fish and plant remains, is seen at the junction of the small stream below Mossend. At .their base the crest of the anticlinal fold between the Calder and Mid-Hart- wood faults carries a small outcrop of the Broxburn Shale, which, in old mining reports, is called "Thorntons" Shale. NORTHERN PORTION. This part includes the area be- tween the Calder fault and the dis- location which extends from Wester Breich to Brotherton, where the various seams lie in a series of synclines and anticlines. To the north-east of West Calder the Burdiehouse Limestone crops out between these two faults, and from this point there is a steady upward succession of the strata to the Houston Coal. To the south- west of West Calder the anticlinal fold of West Harwood continues on the north side of the Calder fault, which brings the Broxburn Shale to the surface close to West Calder, 22 Geological Description of the Shale-fields. while to the north-east and north-west of the village the strata lie in a series of shallow synclinal folds. To the west of West Oalder the upper seams have a general westerly dip, and after a series of gentle undulations pass under the overlying Hurlet Limestone. The south-west portion of this area is intersected by several easterly and westerly faults. (Fig. 3). The Burdiehouse Limestone, which is exposed in the railway cutting at Blackmire forms the eastern margin of this area. Here it is 40 feet thick, and, after a short distance, is succeeded by nearly 500 feet of strata, composed of green felspathic sandstones with fine conglomerate bands and shale partings. On the Hart- wood Water, above Limefield House, this limestone is overlaid by a bed of yellow sandstone succeeded by 4 to 6 feet of curly oil- shale, which doubtless represents the Barracks seam of the Deans district. It is surmounted by a grey sandstone, about 70 feet thick, a portion of which was extensively worked on both sides of the railway. Six hundred feet of siliceous strata with some green and red marls separate the Burdiehouse Limestone from the Dunnet Shale in the Hartwood Water, the latter seam being well exposed in the stream to the north of Hermand, with 25-30 feet of grey sandy marls on top. In one of the shale mines to the north this seam has the following section : — Roof, Shaly blaes. Feet. Inches. Shale, plain, 4 4 „ curly, 2 ,, plain, 2 8 Pavement blaes. The Dunnet Shale is succeeded by the Binny Sandstone Series, beds of which have been extensively quarried to the north of Her- mand House, where a thick post of yellow and light grey sandstone forms the bottom of the quarry, as shown in the subjoined section. The excavation is now filled with water, but the total thickness of the various beds of sandstone which were worked could not have been less than 90 feet. (Fig. 3). Shale, with ironstone bands, Blaes and bands, Flaggy sandstone and shale partings, - Blaes and bands, Sandstone, Green and marly blaes, with ribs, Sandstone, flaggy, Blaes, Sandstone beds, The outcrop of the Broxburn Shale is not seen in the Hartwood Water, but the seam has been wrought to a considerable extent in eet. Inches. 10 2 10 2 9 6 5 1 6 90 West Colder Shale-field — Northern Portion. 23 the vicinity of Chapelton, and a measured section in one of the mines gives the following sequence : — c,, , , Feet. Inches, shale top, q g Blaes, 1Q Fake, u Shale, good, 3 » Rib, blue, q g Shale, bottom, q g Pavement, fireclay. To the south-west of West Calder, as already indicated, the Broxburn Shale comes to the surface upon the centre of an elongated anticlinal fold (Pig. 3), where it was recently opened out ; at first it was irregular and intermittent, but when followed to the dip it improved in quality. The bore-section, given below, is interesting when compared with the development at Broxburn. Shale, grey, Shale, - Shale (curly), Shaly blaes. Shale, Blaes and ribs, Shale (Brox.), Blaes, Shale, Before this seam was correlated with that at Broxburn it was locally known as "Thorntons" Shale, or the "Under Shale" of Addiewell. The position of the Calder fault at Hermand, about half-a-mile east of West Calder, has been definitely fixed by mining operations, and the amount of the displacement has been ascertained to be 587 feet, or nearly 98 fathoms. The Fells Shale is the principal oil-producing seam in the West Calder district, and in the early mining days was known as the "Thick Shale of Addiewell." It varies from 2£-3£ feet in thick- ness, but at some places is as much as seven feet. To the north- east of the village it occupies a shallow basin about 200 feet deep, towards the centre of which there are several faults that have seriously interfered with mining operations. This part of the basin has been extensively bored, and the shale usually consists of softer and harder bands, the lowest of which is separated by seven feet of blaes from its index, — the yellow limestone on top of the Broxburn marls. In the portion of the syncline which lies to the south-east of Westwood this seam has been worked across an anticlinal ridge not sufficiently high to bring this shale to the surface. This fold is coincident with a large "want," and is accompanied by several small flexures. The Fells Shale outcrop to the south-east of West Calder towards Hartwood is indefinite, as no information has been obtained by the survey about the ground around West Muir. Feet. Inches. 1 9 20 1 6 10 1 1 4 3 6 11 2 3 24 Geological Description of the Shale-fields. To the south of Burngrange, in the West Calder burn, thin laminated sandstones with shaly partings intervene between the Pells Shale and Houston Coal. A pit sunk 25 yards to the west of this coal outcrop, alongside the public road, reached the shale at 32 fathoms, and here the vertical distance between shale and coal is 150 feet. On both sides of the Breich Water the Houston Coal was at one time extensively wrought, as shown by the numerous pits and mines defining its outcrop between the Blackbrae and Mid-Breich faults. In this district it is about six feet thick, with about one foot of stone in the centre. Beds of sandstone with fireclay and shaly partings and two thin coals, with a total thickness of 73 feet, separate the Houston Coal from the Grey Shale, "which is one foot eight inches thick - and composed largely of entomostraca." (Cadell, Traits. Ed. Geol. Soc, vol. viii., p. 131.) Young's " Section of Addiewell " shows that 204 feet of green, brown, dark and light marls with blaes and fireclay bands compose the Houston marls and lie directly above the grey shale. They are exposed in the Breich Water above Breich Mill and are followed by the Two-feet Coal, which, up to the present, has not been worked in this district. In the stream below Breichdyke it is seven inches thick and is overlaid by black blaes with several seams of good clay-ironstone, followed by blaes, fakes, and fireclays with occasional beds of sandstone. From the Blackbrae fault the outcrops of this seam and of the Houston Coal have a general trend towards N. 10° W., but to the south of Wester Breich a shallow synclinal fold carries them for a short distance to the south-west. The strata between the Two-feet Coal and the Mungle Shale are here estimated to be 130 feet in thickness. The latter seam varies in thickness from twenty inches to two feet, and was worked by shallow pits on both sides of the Breich Water, where it appears to be about 20 fathoms below the Baeburn Shale, and in all probability represents the Lower Bae- burn Shale of Cobbinshaw. At the present Addiewell Oil Works there is a dismantled shaft, 12 fathoms deep, to this seam and little is known about its quality. The Baeburn Shale, the highest of the oil-bearing seams, was known in the Addiewell district first as the " Dam Shale " and subsequently as the " Upper Shale of Addiewell." The section of this seam at Addiewell is as follows : — Roof, blaes, Shale, good, ,, soft, „ good, Shaly blaes, Blaes and fireclay, Shale, 4 8 The Baeburn Shale is about 75 fathoms below the Hurlet Lime- stone at Addiewell bridge and the strata between these two Feet. Inches, 1 7 2 10 6 9 10 West Galder Shale-field — Northern Portion. 25 k 8! O CM' 5 ft: 8 *3 u IS 5S •a AV703vuro I s 030 HSU S7 NO 030 HSU 4! horizons consist chiefly of blaes with ironstone ribs, several thin coals, one fresh water limestone, and a few beds of sandstone, some- times coarse and pebbly. The Blackbrae fault is a very important one in the West Calder field. Commencing at the railway bridge to the east of Addiewell Chemical Works, it is joined by the Muirhall fault at the cross- roads, and in a short distance the Two-feet and Houston Coals are brought into conjunction, showing a displacement of 46| fathoms to the south. Between this point and the fault at Baads Mains the seams have a westerly dip and general north and south strike. The Fells Shale was extensively worked at No. 15 pit, situated 400 yards to the north-west of Baads, which was sunk 150 fathoms to the Broxburn Shale, and a level cross-cut mine was driven at this depth to the Fells Shale. This shaft passed through the fault, with a downthrow of 30 fathoms to the north, which appears a short distance to the north of Baads, and runs at a slightly oblique angle to that of Blackbrae in a westerly direction. This dislocation, like that of Blackbrae, dies out rapidly to the N.N.W., as it does not reach the neighbouring lime-works at Muirhall. The mining operations in No. 22 pit, 600 yards to the north-east of Baads, proved the continuation of this fault to the south-east, and also its lateral branch that pa sses directly through the farm steading. The Fells Shale was extensively worked in this field to a depth of 150 fathoms, while the Houston Coal and Raeburn Shale were also opened out to some extent. 26 Geological Description of the Shale-fields. GROUND BETWEEN HARTWOOD BASIN AND MURIESTON FAULT. Owing to the importance of the Murieston fault that truncates the West Oalder shale-field and forms its southern boundary, & description of the section in the Murieston Water and Bog Burn is given, in view of the evidence it affords as to the position of this dislocation. (Fig- 4, p. 25.) In the Murieston Water above Skivo bridge the green and brown sandstones that overlie the Burdie-house Limestone dip gently for some little distance to the south-west and then suddenly become vertical. This change of dip marks the exact position of the Murieston fault at this point, which brings the Burdie- house Limestone into conjunction with the volcanic rocks of Oorston that must lie more than a thousand feet below the Burdiehouse Limestone. The lava is succeeded by some beds of sandstone with a band of felspathic ash. A cliff below Skivo gives an ascending sequence of dark grey shales with remains of fishes, entomostraca and plants, and thin laminas of tuff. A short distance higher up the stream, black shales supervene with fireclay and ironstone bands and a second fish bed. These sediments, about 150 feet thick, probably represent the Abbeyhill Shales of the Edinburgh district. Following the stream to the south, we find that this shale series is succeeded by thick grey and yellow sandstones with some fireclay partings, which, to the east of Canniehole, are repeated by a fault. Where the parish boundary joins the Murieston Water there is a bed of fireclay with large intercalated masses of sandstone and also fragments of coal, and as these arenaceous beds are correlated with the Granton Sandstones, those fragments of coal may probably represent the thin coals of War die and Craiglockhart. At Broadshaws bridge these sandstones dip below a set of shales which may represent those of Wardie. Southwards these sandstones, sometimes conglomeratic, and shales, both repeated by faults, are met with in the stream, till we reach a point near Coalheugh Head where the oil-shale beds appear (see Fig. 4). From Camps bridge to this point the Murieston fault must lie on the west side of the Murieston Water, but here it crosses to the east side and continues to the south-west towards Kiprig. Just below Coalheugh Head there is a good exposure of an oil- shale from 12 to 15 feet thick, which was quarried for cover-plates for the field stone-drains of the district. In a burn section between this farm and Broadmeadow it is overlaid by a series of soft green marls, succeeded by at least 200 feet of grey felspathic and flaggy sandstones. There can be no doubt that this band represents the Dunnet Shale with its characteristic overlying marls, followed by the Binny Sandstone, which, with the under- lying strata, are faulted against beds that have been correlated with the upper portion of the Granton Sandstones, a displacement of at least 250 fathoms. Near Bast Torphin the Binny Sandstone Pumpherston and Mid-Calder Shale-jield. 9.7 is well developed and has been extensively quarried on both sides of the burn for estate purposes, where it consists of a coarse, gritty, felspathic sandstone with conglomerate bands. These beds show signs of considerable disturbance, due probably to the proximity of the Murieston fault. To the south of West Torphin there is a steady ascending section of coarse green felspathic sandstones, which are overlaid by green sandy shales with a thin seam of coarse limestone. The Broxburn Shale is not seen, but these shales may represent the Broxburn marls. About one-third of a mile to the south of West Torphin a thin, fresh-water limestone was at one time quarried and burnt which may represent the yellow limestone which lies below the Fells Shale. Above this point the section ends, and the Murieston fault must cross to the west side of this stream, as the Burdiehouse Limestone has been mined at the forking of the waters east of Kiprig. (Fig. 4). 2. Pumpherston and Mid-Calder Shale-field. This shale-field embraces the triangular area that lies between the river Almond and the Middleton Hall fault westwards as far as the Houston Wood west of Pumpherston, together with a small tract at Mid-Oalder. Pumpherston District. A glance at the horizontal sections (Figs. 5 and 6), which refer to this portion of the shale-field, clearly shows that in the centre of this area we find the well-marked arch of Pumpherston, whichbrings to the surface the lowest productive seams in the oil-shale measures as yet worked in the Lothians. The surface of the ground in this district is very level, with few natural exposures ; but the structure of the field has been thoroughly proved between Powflats and Pumpherston by the numerous mines, pits, and bores which have been driven, sunk, and drilled over this area. Between the Edinburgh and Bathgate railway, and a point to the north of Pumpherston farm, the anticlinal axis runs almost due north and south. About 700 yards to the north of Pumpherston farm the beds begin to pitch to the south, and, m^the shale workings, this inclination attains an angle of 25° to 35°. Hence, the shale outcrops on each side of this fold rapidly wheel round to the south and meet each other about 400 yards to the north of this farm. On the north side of the Pumpherston Oil Works the beds begin to pitch to the north about 500 yards from the Edinburgh and Bathgate railway. At this end of the arch the angle of pitch is low, and hence the east and west outcrops of the different seams, forming the Pumpherston Shale group, open out as they bend round the northern portion of the fold. On the west side of the anticline the strata above the Pumpher- 28 Geological Description of the Shale- fields. ston Shales, including the Burdiehouse Limestone and Barracks Shale, dip at an angle of 45° beneath the dolerite sill of Houston \ \ \ \ \ sbob^ »5 3BOB ^yio sonpoa ^ loN3BOB * I •6 6N 31/0 a NOJ.S 3 mi via EeNsyoB f/OSSAIItOA Z6N3B0B S3 BOB 3 a inoarj/007, 96 N <4 °> *** 3 BOB no (j CA/y73yo//SW/7BO j* 5 1 S3 HIT OH I6N3B0B wo I S3 bob iiAinya sa / / I' I' I' / \ Pumpherston District. 29 Wood and reappear between Knightsridge and Livingston on the east side of the Middleton Hall fault (Pig. 5). On the east side of the Pumpherston anticline a synclinal fold extends from Broxburn Hall to a point south-east of Mid-Calder. On the south side of the Middleton Hall fault this flexure is comparatively shallow and narrow, but it becomes deeper and wider towards the south. The mining and boring operations at Pumpherston and the Koman Camp have proved that the Pumpherston Shales lie 800 feet below the Burdiehouse Limestone. The seams which compose this group were at first worked opencast, and afterwards mined, in some instances, to a vertical depth of over 1 ,000 feet from the surface. The section (Pig. 5), which crosses the northern portion of this field from Nether Dechmont to Illieston, shows that the dip of the strata on the west side of the Pumpherston anticline is 45°, as compared with 35° on the eastern limb. About 200 feet from the surface, the inclination of the eastern side becomes much steeper as the Pumpherston Shales plunge down below the basin of Drumshoreland moor. The following section (Fig. 6) runs diagonally across the southern portion of this elliptical outcrop of Pumpherston Shales, and it shows how they become vertical, or possibly inverted, for some distance before they pass underneath the basin of overlying strata at Clapperton Hall. Pumpherston Shale. — The Pumpherston Shales include five workable seams in a vertical thickness of 92 feet of strata, as shown in the subjoined tabular statement. SECTION OF PUMPHERSTON SHALES. No. 1 Mine — Pumpherston. Hard calcareous band or limy rib, Shale No. 1. Jubilee Seam, Blaes, 9 ins. "I 5 1 „ fCurly, z J Plain, Shale No Maybrick Seam. I pj ai * n No. 3 or Curly shale. 2 ft. „ „ 2 Rib, Blaes and balls. Rib, Blaes, Rib, Blaes, Rib, Blaes, Rib, Blaes, Shale, plain, 1 ft. 1 in. 5 ft. 3 ins. : Fakes, Blaes, curly, 1 plain, 1 rib, plain, 3 . 7 ft. 5| ins., Feet. 7 14 O 6 2 1 16 5 Inches. 4 1 8 3 7 H 2 10 3 3 11 54 Feet. Inches, 7 8 1 1 6 1 1 1 5 4 2 1 2 6 2 3 6 30 Geological Description of the Shale-fields. No. 4 or Plain Shale, Rib, Faky Blaes, Blaes, Shale Shale, Blaes, Rib, Soft blaes, Blaes, Rib, Blaes, No. 5 Wee or Under Shale, 4 3 At present, not one of the Pumpherston seams is worked around the south side of the anticline, but at the north end the Broxburn Oil Company work all the beds with the exception of the Maybrick seam at the Roman Camp Mines. No. 3 mine, worked by the Broxburn Oil Company, has been driven from the south side of the Edinburgh and Bathgate railway in the direction of Powflats where it passed through the east and west dolerite dyke, about 100 feet broad. The shale on both sides of this igneous intrusion was burnt, and the operation of driving a mine through this dyke proved a laborious one. These shales have been proved by boring to lie to the north of Powflats, and will in all probability extend as far as the Middleton Hall fault. Between Powflats and Stankards south of Middleton Hall the structure of the ground is rather obscure. The old mine workings in the Broxburn Shale, at the latter place, proved that this seam dips east at an angle of 15 c , while the Pumpherston Shale around Powflats dips north and north-west. A new pit is at present being sunk to the Broxburn Shale, a short distance to the south- east of Middleton Hall, and when its underground workings are opened out they will doubtless throw light upon the structure of this area. To the east and north-east of the mined ground of Pumpherston no bores have reached the Pumpherston Shales with the exception of the Nos. 9 and 3 diamond bores of Illieston (Fig. 5). Both of these bores passed through two dolerite sills which are intruded at this point along the top and bottom of this shale series, the higher one being seen in the bed of the river Almond below the canal. The evidence shows that the oil-shales have been rendered useless by the intrusions. Across Drumshoreland Moor, between Pumpherston and Illieston, a series of bores and a trial pit have proved the structure of this portion of the ground. Here the Pumpherston Shales are at least 200 fathoms deep and lie on the eastern limb of the Clapperton Hall basin. The beds above the Pumpherston Shales consist, for the first 500 feet, chiefly of blaes with thin bands of sandstone and very hard quartzose or calcareous ribs known as " kinglestone" or "kingle." Higher up, towards the Burdiehouse Limestone, sandstones pre- Pumpherston District. 31 32 Geological Description of the Shale-fields. dominate with bands of fakes and sandy blaes all more or less calcareous, but hitherto no beds of workable oil-shale have been met with. Kecently, boring operations have been made at Pumpherston to discover the two seams of oil-shale that occur beneath the Burdiehouse Limestone on the coast section between Hopetoun House and Whitehouse Point, but without success. Burdiehouse Limestone. — The Burdiehouse Limestone lies 800 feet above the Pumpherston Shales, but in this district it is never seen at the surface. On the west side of the Pumpherston anticline this bed occurs immediately below the Barracks Shale and has been proved in two bores near Milkhouses (see Pig. 5). At the latter locality it forms a series of bands about 20 feet thick. The bores which have been put down over this district show that the beds between the limestone and the intrusive sill are chiefly blaes and fakes with beds of sandstone and thin conglomerate, and there are also several beds of limestone a few feet thick and many calcareous ribs through the whole section. South-east of Knightsridge the position of this limestone is more or less conjectural. On the south side of the Pumpherston ridge its position has been traced to the north-west and south-east dolerite dyke, and a diamond bore 500 yards north of Bridge-end, Mid Calder, has also passed through this bed. The mining and boring operations at Olapperton Hall north of Bast Calder have proved the outcrop of this limestone along the western side of that basin, while farther to the north its position is inferred from the known outcrops of the Pumpherston Shales which lie between Drumshoreland moor and the Edinburgh and Bathgate railway. Its position between the east and west whinstone dyke north of the Bathgate railway, and the Middleton Hall fault is not yet proved, but future mining operations by the Broxburn Oil Company will doubtless throw light upon the structure of this portion of the mining field. Close to the road which leads from Broxburn to Drumshoreland station, and alongside the Beugh burn, a bore reached this limestone at a depth of 66 fathoms. «- IV.f7S. K1LPUNT Fig. 7. — Section from Station Road, Broxburn, to near Kilpunt. Between the Station Boad, Broxburn, and Kilpunt (Fig. 7) the position and extent of the northern portion of the Olapperton Hall and Mid-Calder basin have been proved by bores. Here this fold Pumpherston District — Olapperton Hall Bonn. 33 has a breadth of over one mile, and the Burdiehouse Limestone is about 100 fathoms deep in its centre. Two bores put down to the east of Kilpunt reached dark blaes with limy ribs, 40 fathoms below this horizon. From Kilpunt the Burdiehouse Limestone has been traced by- numerous bores along the eastern edge of the Clapperton Hall basin across Drumshoreland moor to its outcrop above the railway viaduct over the river Almond. Barracks Shale. — On the west side of the Pumpherston anticline the Barracks Shale is wrought at No. 4 mine, east of Milkhouses, where the seam is about seven feet thick with a fireclay pavement and a shale roof. Its quality varies there from good to medium, and a large field yet remains to be explored from this mine. On the east side of the same fold this shale has never been opened out; indeed, several bores put down to the Burdiehouse Limestone prove its absence in this portion of the oil-shale field. Bunnet Shale. — A glance at the map will show that on the east side of the Pumpherston anticline the Dunnet Shales occupy the centre of the Clapperton Hall basin. (See Figs. 5 and 6, pp. 28, 31.) The axis of this fold extends from near Broxburn Hall to a point midway between East and West Calder, being truncated on the north by the Middleton Hall fault and on the south by the Oalder dislocation. On the south side of the river Almond this flexure is sufficiently deep to contain the Broxburn Shale with the overlying strata. On the north side of the river Almond, where the Dunnet Shale is extensively mined in the Olapperton Hall area by the Pumpherston Oil Co., there are three thick shales, as given in the annexed Table, all of which are worked. Section Clapperton Hall. Section Mid-Calder Basin. Strata, marls, (1) Big dirt shale, - Strata — rotten, shaly, blaes, and ribs, (2) Dunnet shale, Strata— chiefly fireclay, (3) Lower Dunnet, Strata, Burdiehouse Limestone. A comparison of these two sections is very instructive, as they show a considerable variation in the strata associated with the oil- shales. For example, at Clapperton Hall there are 180 feet of Dunnet marls, as compared with 90 feet at Mid-Calder, while the thickness of strata between the Lower Dunnet Shale and Burdie- house Limestone is 325 feet and 492 feet respectively. Again, at Clapperton Hall and also over Drumshoreland moor the strata C Feet. Feet 180 Strata, marls, 90 5 (1) Dunnet shale, • 6 Strata — marly blaes, 54 54 8 (2) New shale, 8 83 Strata — blaes and shale, with rib, 69-i H (3) Shale, with fireclay rib, 6] 325 Strata, Burdiehouse Limestone. 492 Geological Description of the Shale-fields. 5:* 5 ■is 3U08 sure 7 ff jsynoo 13/137 H; 3SVn03 73/131 2 3U0B9 1IJ HNVBXVO =5 f o •XI s 3 c s between the Dunnet and Lower Dunnet Shales (Nos. 2 and 3) are almost entirely composed of pure fireclay, which, at Mid-Oalder, is represented by blaes. A section of the mined portion (see Fig. 25, Part II.) of this field situated half a mile to the south-east of the oil-works shows that No. 3 shale is vertical and No. 2 inverted, for some distance, from their respective outcrops. The deepest portion of the basin is about 480 feet from the surface. For some distance from this point the shales are nearly flat, and they rise to the east at angles varying from 15° to 27°. The numerous bores put down over the southern portion of Drumshoreland moor prove that the strata are covered by about 100 feet of superficial deposits, which now fill a portion of the old pre-glacial valley of the river Almond. Halfway along the road that crosses this moor from the Pumpherston Oil-works to Look- aboutye, the Broxburn Oil Go. some time ago put down several bores and sunk a trial pit to ascertain the northern extension of this basin, which here proved to be both narrow and shallow. Only one band of oil-shale was found which was identified as the equivalent of the Lower Dunnet seam (Fig. 7). This trough has been traced northwards till it meets the Middleton Hall fault to the south-east of Broxburn Hall. Along the western limb of the Pumpherston arch the Dunnet Shale is very poor and unwork- able. It was identified by the Pumpherston Company in a crosscut mine which was driven through to the Binny Sandstones and onwards to the dolerite sill of Houston Wood. The Broxburn Shale was not found. Mid-Calder Shale-field — Crofthead to Raw Camps. 35 Mid-Calder District. The area under description lies between the river Almond and the Calder fault, and extends from Crofthead in the west to Eaw Camps quarry in the east — a distance of four miles. The structure of this portion of the oil-shale field is very simple. At Mid-Calder there is a deep synclinal fold containing the various strata from the Burdiehouse Limestone to the Broxburn marls, with minor folds on either side (Pig 8). Burdiehouse Limestone. — Near Crofthead, in the western part of the area, there is an old abandoned quarry in the centre of a small basin of the Burdiehouse Limestone, where the strata on both sides dip towards the centre at an inclination of 12°. Im- mediately to the east of the outcrop of the limestone a bore was put down in blaes to a depth of 30 fathoms. In the vicinity of Newfarm several bores pierced a mass of dolerite, which may be the southern prolongation of the large intrusive sheet of Houston Wood, on the north side of the river Almond. On the south side of the public road at Newfarm a bore shows that this sill is over- laid by 51 fathoms of strata, containing an oil-shale 14 inches in thickness. From this point eastwards to the proved outcrop of the Dunnet Shale there is no section or record of any bores, but as the southern extension of the axis of the Pumpherston anticline should pass through this tract the theoretical position of the Burdiehouse Limestone is indicated on the horizontal section (Fig. 8) by a dotted line. The following Table * gives the section of the strata proved by the mining operations of the Oakbank Oil Company at Mid-Calder and by a bore sunk by that Company, in 1892, from the bottom of their pit shaft to the Burdiehouse Limestone. It will be seen that the latter horizon was reached at a depth of 564 feet below the New Shale. Section of Oakbank Pit and Bore, Mid-Calder. No. Description of Strata. 03 1. Broxburn marls, 2. Wee shale, 3. Strata, blaes and lime ribs, 4. Big shale, 5. Strata, 6. Lower Big shale, 7. Strata, shaly blaes, 8. Curly shale, 9. Strata, blaes, - 10. Broxburn or M'Lean shale, 11. Strata, chiefly blaes, - 12. Wild shale, 13. Strata, blaes, Binny sandstones and marly beds, 14. Dunnet shale, 15. Strata, marly blaes, - U6. New shale, bottom of shaft, - Thickness of Strata. Ft. Ins. 46 1 6 13 4 6 12 6 10 6 5 4 16 4 288 6 45 8 Depth from Surface. Ft. Ins. 46 47 6 60 6 65 77 83 93 99 104 108 124 128 416 422 467 475 ' Cadell, Trans. Min. Eng., 1901-2, p. 32. M Thickness Depth from of Strata. Surface. Ft. Ins. Ft. Ins. 65 9 540 9 2 542 9 22 564 9 6 3 571 5 1 576 1 7 10 583 11 18 3 602 2 5 607 2 3 610 2 190 2 800 4 16 816 4 222 8 1,039 24 1,063 12 1,075 36 Geological Description of the Shale-fields. Description No. of Strata 17. Strata blaes, - 18. Shale, 1 9. Strata, blaes and shale, with ribs, 20. Shale, with fireclay rib 1 inch thick, - 21. Strata, blaes and hard ribs, 22. Sandstone, 23. Very hard white whinstone or kingle, 'g -( 24. Hard faky sandstone, 25. Limestone, hard, 26. Sandstone, very hard, with hard blaes ribs, - 27. Conglomerate, fine, 28. Sandstone, faky blaes and hard ribs, 29. Burdiehouse limestone, 30. Fakes and sandstone, This bore and pit section are situated near the centre of the basin, but the deepest part of the syncline lies farther to the east, where the Burdiehouse Limestone is 1200 feet from the surface. In the river Almond, just above the railway viaduct, there is an excellent exposure of this limestone, where its thickness varies from 25 to 30 feet. The bottom portion is rather coarse, with chert bands and a lumpy mammilated surface, while the upper beds are regularly banded grey limestones. From this point south- wards to the Calder fault its position is inferred from the proved outcrops of the Broxburn Shales. On the east side of the Mid- Calder basin between East Calder and the Baw quarries, where the strata form an arch, it was at one time extensively wrought. At Baw quarries it occupies a synclinal fold about 118 feet deep with a small fault intersecting its western limb. The basin is also traversed by an east and west dislocation with a downthrow of 15 fathoms to the north, the effect of which is to widen the trough in the latter direction (see geological map and Fig. 8). The limestone was formerly worked opencast round this area and burned on the spot for building purposes in the surrounding district, but it is now mined and raised to the surface by means of a shaft 180 feet deep, and is used entirely for iron-smelting at Coatbridge. East- wards at Baw Camps quarries another synclinal fold repeats the Burdiehouse Limestone, where it occupies a complete basin 120 feet deep and is intersected by the east and west fault already mentioned. The limestone is 42 feet thick and rests upon its characteristic pavement — a band containing the small gasteropod, Platyostomella Scotoburgidalensis, locally known as the " Buckie fake." The stone was partly conveyed to the west for iron-smelting purposes and partly burnt at the quarries for lime. It is now entirely worked out all round its outcrop, while towards the centre of the basin, which was mined, only the stoops now remain and the quarries are filled with water. On the top of this mined area there is a thick bed of dark blaes with calmy ribs and iron- stone balls covered with boulder clay. Mid-Calder Shale-field. 37 Oil-Shales above the Burdiehovse Limestone. — The blaes overlying the Burdiehouse Limestone at the Raw and Raw Camps quarries contains "a seam of shale eight feet thick, yielding 22 gallons of oil," which is regarded as the local representative of the Barracks seam (Cadell, Trans. Qeol. Soc. Edin., 1901, p. 142.— Trans. Inst. Min. Eng., 1901-8, p. 321). In the river Almond section the blaes occupying the same position contains a similar bed of oil- shale, which, in the Mid-Calder bore, is not represented. The strata between the Burdiehouse Limestone and the New Shale in the Mid-Calder field are chiefly composed of hard sand- stones with a bed of fine conglomerate 16 feet thick, and near the top of this section there are two bands of oil-shale measuring two feet and six feet three inches in thickness, which respectively lie 120 feet and 149 feet below the Dunnet Shale. They are of inferior quality compared with the rest of the seams in this basin (see Section of Oakbank Pit and Bore, pp. 35, 36). The New Shale and the Dunnet seam, overlaid by the Dunnet marls and Binny Sandstone, are here represented. The Wild Shale below the Broxburn group is at present extensively worked at Mid-Calder, where it is found to be of medium quality. A comparison of the oil-shale seams and strata which compose the Broxburn Shales at Mid-Calder and Broxburn gives the following results : — BROXBURN SHALE GROUP AT MID-CALDER AND BROXBURN. Ft. Ins. Ft. Ills. Shale (Wee), - 1 6 1 1 Strata, 13 12 3 ("Shale 8 Shale, (Big), - 4 6 \ Limestone 6 (. Shale 1 6 Strata, 12 3 10 Shale (Lower Big), 6 (Grey) 5 10 Strata, - 10 5 4 Shale (Curly), 6 5 6 Strata, 5 4 Shale (M'Lean), 4 (Broxburn) 5 62 40 6 Mid-Calder. Broxburn. Ft. Ft. Ins. Oil-shale, 22 Oil-shale, 19 7 Strata, 40 Strata, - 25 11 62 40 6 111 the Broxburn suite of shales at Mid-Calder all the beds are being rapidly worked out, the upper seams being of good quality and the Curly and Broxburn seams excellent. At Mid-Calder the oil-shales of this group are slightly thicker than the cor- responding seams at Broxburn, but the proportion of intervening strata is in the ratio of about 2 to 1. Next in order come the Broxburn marls, which are well exposed in the Linhouse and 38 Geological Description of the Shale-fields. Murieston Waters opposite Oalder Hall. The former section shows that they are more calcareous here than elsewhere in this district. They dip gently to the south-east, but become flat opposite the pit, and with a reversed dip the " Wee Shale " rises from underneath these beds in the stream near Oalder Hall. Higher up the glen a small fault shifts the outcrop of the M'Lean seam to the west side of the stream, and at the waterfall below Hoghill this ravine is crossed by one branch of the Calder fault. About 300 yards above this point there is another fault with down- throw to north. Between these two fractures the strata consist of beds of blaes, pebbly and gritty sandstones, with 6 to 10 feet of grey limestone in several beds. Southwards, another fracture occurs, visible in both the Murieston and Linhouse Waters, which has also a downthrow to north, and is the most southerly branch of the Mid-Calder fault. On its south side there is an interbedded, fine-grained, light-banded ash, which may represent the upper portion of the volcanic series of Corston Hill. If this be the case, then the combined movements of these faults at this point bring the Broxburn Shale within a short distance of the Oorston Hill volcanic rocks, — a displacement which may not be less than 500 fathoms. 3. Deans, Seafleld, Breich, and Polbeth Shale-fields. Beans Shale-field. This shale-field lies to the north of the east and west fault near Starlow and extends as far as the Edinburgh and Bathgate road beyond Caputhall. It forms the northern portion of the West Lothian shale-field. In this area the strata dip westwards as far as Deans, where the inclination changes to the north-west. The field is intersected by several easterly and westerly faults. The subjoined section was compiled by Mr. William Caldwell, Pumpherston Mining Office, from the various plans of the seams now worked at Deans. GENERAL SECTION OF THE DEANS SHALE-FIELD. Houston coal, Strata, Fells shale, Strata, Broxburn shale, Strata, Dunnet shale, Strata, Barracks shale, - Strata, Burdiehouse limestone, Ft. Ins. Ft. Ir.s. 3 6 to 4 178 4 to 4 6 144 5 6 245 8 52 4 to 4 6 12 8 665 6 Deans and SeajieM Areas. 39 ^ ^ ! £ 5 q •s y vg lidsa J. Id on «0 -HriN3yOS F. When the oil-shale in- dustry in this district was first developed the Dunnet and Barracks Shales were worked opencast to the north-east of Deans. The latter seam (the Barracks) was at first locally named the "Pattison" Shale, the surname of one of the first pioneers of the oil-shale in- dustry in this district. The Dunnet, Fells,' and Broxburn Shales are all mined in this field, and some years ago a pit was sunk to the west of Caputhall to the Houston Coal. Here the seam, although of average thickness, proved unworkable, partly on account of its bad pavement and roof and partly owing Lo its poor quality. The Baeburn and Mungle Shales are not known to the west of the outcrop of the Houston Coal, but the oil-shale measures probably occupy the surface as far as the edge of the Bathgate volcanic rocks which lie to the west of Duncross. A comparison of the General Section of the West Lothian shale -field with that of West Calder shows that there is a great thinning of the strata between the various seams, and more particularly between the Dunnet Shale and Bur- diehouse Limestone. Seafield Shale-field. This field lies immediately to the south of Deans. The Long-side and Seafield fault, with downthrow to south, may be taken for descriptive purposes as its southern boundary. The position 40 Geological Description of the Shale-fields. of this fault where it crosses the Breich Water into Linlithgow- shire is well denned both by the mining and surface evidence, for in the stream the Two-feet Coal on the south side of this fault is nearly vertical. Half a mile to the east of Blackburn House this fracture crosses the river Almond, and on its north side some of the oil-shale beds are vertical, while two other shale outcrops are folded into sharp synclines. The eastern limit of this field is defined by a fault which originates on the north side o'f the Long- side fracture to the south-east of Seafield and runs northwards by Cousland. The mined portion of this area is intersected by an east and west^ fault, on the south side of which lies a shallow syncline. and on its north side the various beds dip regularly to the west. The triangular area which is situated between Seafield and Cousland has not been opened out, but, at the latter point, the outcrops of the Fells and Broxburn seams have been proved by bores. At the oil-works a north-east fault with a downthrow to the north shifts the outcrops of the Breich field a considerable distance to the east. To the north-west of Cousland there is a small but well-defined basin with the Houston Coal in its centre, and the Pells, Broxburn, and Dunnet Shales on the east side. On the west side of this fold a reversal of the dip from east to west repeats the outcrop of the Houston Coal, which is succeeded by the Two-feet Coal and Baeburn Shale. These beds are inclined to the west, and pass under the Hurlet Limestone to the north-east of Blackburn village. On the north side of this basin the various shales and coals from the Dunnet to the Baeburn seams dip in the same direction (see map). Breich Shale-field. The structure of this area, which lies between the Seafield and West Calder shale-fields and extends as far east as Easter Breich, has not yet been definitely ascertained. At Easter Breich the Pells Shale, as given in the subjoined section, crops out along the crest of a narrow anticline. Between this point and the north side of the fault at Mid and Wester Breich this seam has been extensively worked, and has been proved to lie in a series of gentle anticlinal and synclinal folds. SECTION OF FELLS SHALE AT EASTER BREICH. Roof blaes, Shale, plain, ,, curly, ,, plain. Ball, ply, Shale, inferior, Holing blaes. Ft. Ins 8 1 2 1 11 6 6 Breich and Polbeth Am 41 is S S 1 Id 3UOB 3VOS S3MK/ AlA/n 3HQ9 M !jK J./d 1VIVJL +z 6N 3 yog y ■ltd 7f/yA A portion of the Broxburn seam has also been worked below the Breich field. Between the mined area and the river Almond the structure of the ground is rather ob- scure, but at present it is being bored by the Pumpherston Oil Co. {See Fig. 10.) On the north side of the river Almond the structure of the North Breich field has been recently deter- mined by a series of diamond bores and trial pits, as represented in the accompanying section (Fig. 11), which shows that the Fells Shale dips to the west at 40°, the Broxburn at 60°, while the Dunnet seam is almost vertical. This portion of the shale-field is to be immediately opened out by a mine which will begin some dis- tance to the east of the outcrop of the Dunnet Shale. To the north-east of Blackburn House a trial pit pierced the Dunnet Shale at 11 fathoms, and a bore from the bottom of the shaft reached the Barracks Shale and Burdiehouse Limestone. (Fig. 10.) In this district no shale is known between the Fells and Baeburn seams. The out- crop of this latter band has been traced between Starlaw and Gardners Hall, and in a bore near the former locality it is one foot nine inches thick, and was worked near Starlaw by a small mine. Its general dip is westerly and in the Almond section it is estimated to lie 83 fathoms below the Hurlet limestone. Polbeih Shale-field. The Polbeth shale-field lies to the east of the Breich area, being bounded on the north by the Long- side and Seafield fault and on the south by the east and west dislocation near Polbeth. The 42 Geological Description of the Shale-fields. strata form a deep basin — a continuation of the one already described in the West Calder section. The lowest beds exposed >4 to I 1 40 ir 183° o SO wo Fig. 11. — Section of Shale-field south of Blackburn House. on the east side of this fold immediately underlie the Dunnet Shales, while in the centre of the basin the strata above the Eaeburn Shale are reached (Fig. 10). In the Hartwood Water, north of the Brotherton fault, there is a good section of the beds beneath the Dunnet Shale, consisting of green sandy shale with green and grey sandstones. The only outcrop of this seam, composed of " plain " and " curly " bands, is seen on the left bank of the ravine, the overlying beds being faulted in several places. The Longside fault passes through a gap in the section, but this dislocation and the Dunnet Shale have both been proved in the mine to the south of Longside. The workable area of this shale, as compared with that of the upper seams, is considerably diminished by the Longside and Brotherton faults, which have each a considerable hade and displacement in opposite directions, with the result that the mining area diminishes as the depth of the mine increases. On the north side of the Longside fault, whose displacement cannot here be less than 200 fathoms, the Dunnet Shale is at present being opened out by the new the shale, as indicated below, varies from working thickness is about 10 feet. is Gavieside mine, where 6-16 feet, but its general Roof shale, Top shale, plain, Shale, curly, ,, plain, Bottom shale, Feet. 6 4 2 1 3 16 The Livingston District. 43 From indications in the new mine and from the dip of the strata in the stream to the south-east of Gavieside, it is probable that the outcrop of the seam will probably turn from north-east to south-west for some little distance round the axis of an anticlinal fold to the east of Gavieside. In the mine the dip of the Dunnet Shale at the surface is 19°, but this inclination rapidly decreases, and the centre of the basin, which extends from Gavieside to the river Almond, will probably lie to the south-west of Howatstone. In the river Almond between the weir and the ford west of Livingston, the lower Dunnet Shale is seen in the stream, while one of the upper Dunnet seams was proved several years ago by trial pits and an opencast working. To the east of this weir the Dunnet marls together with conglomerate bands and limy ribs of sandstone are exposed along the north bank of the stream. This mine at Gavieside is the first attempt to develop on a large scale the area which lies to the south of Livingston, which may prove to be a valuable one in the future. The outcrops of the Broxburn and Fells Shales are exposed in the West Calder burn, both dipping in a westerly direction at angles varying from 27° to 30°. The distance between the two seams is 175 feet, considerably less than the average thickness in the West Calder field. The Broxburn marls are also seen in this burn, and the outcrop of the Two-feet Coal coincides with, and lies almost directly above the 100-fathom level in the Fells Shale. 4. The Livingston Shale-field. This area extends from the river Almond northwards to the Middleton Hall fault and from the Deans and Seafield shale-fields on the west to the large dolerite sill of Houston Wood. From Knightsridge in the north to Tailend in the south the position of the Burdiehouse Limestone, as shown on Sheet 32 one-inch of the Geological Survey, is well defined by means of a chain of old quarries, the beds at the north end dipping to east, while in a southern direction the inclination gradually changes to south by south-east. At the southern extremity of this out- crop near Tailend, the Burdiehouse Limestone has been opened out in several quarries where it is inclined to the south and south- east. It cannot be traced farther to the west, as it is probably cut off by a fault with downthrow to east, its strike being almost at right angles to the outcrop of the Dunnet Shale on the west side of Tailend (see Fig. 9). This fracture is probably the same fault that truncates the west side of the Dechmont dolerite sill. Between Tailend and Deans a reversal of the dip occurs, and at the latter place the Burdiehouse Limestone dips to the north-west below the Barracks Shale, from which we may infer that the structure of the ground between Deans and a point to the west of Knightsridge is that of a broad arch intersected by a line of fault. 44 Geological Description of the Shale-fields. The strata between Tailend and Deans must therefore lie beneath the Burdiehouse Limestone, and at Upper Barracks there are beds of coarse felspathic sandstone and fine conglomerate which contain fragments of a flinty limestone reminding one of the limestone near Selms. To the west of Knightsridge the Middleton Hall fault, with downthrow to the northwest, cuts off the Burdiehouse Limestone and also the south end of the Dechmont dolerite sill. Beyond this latter point it cannot be traced and it must die out to the south- west. In view of this evidence it is quite possible that, within this area, future boring operations may prove the occurence at a reasonable depth of the two shales which lie below the Burdie- house Limestone on the coast section together with those of Pumpherston. At Tailend 1| miles W.N.W. of Livingston a pit, 10 fathoms deep, has been sunk to the Barracks Shale where the seam varies in thickness from 32 inches to 48 inches and lies 12 fathoms above the limestone. It is again seen in the burn which falls into the river Almond at Livingston, and lower down the stream the Dunnet Shale appears in several bands. The latter seam has been followed for some distance to the west, and a bore proved the upper leaf to lie 156 feet above the Burdiehouse Limestone. Between East and West Long Livingston the ground on the north side of the public road has been bored for this shale by the Pumpherston Co., but nothing was found but sandstones and fakes. On the west side of the Tailend road the shale, six feet thick, again appears, and its outcrop has been traced to the Cousland dolerite. Between this point and the foot of the Living- ston burn an E.N.B. fault, with a downthrow to the north, repeats the outcrop of this seam. In the Livingston burn the highest leaf of the Dunnet Shale is overlaid by its characteristic marls, succeeded in turn by nearly 400 feet of sandstone beds with greenish fireclay and blue shale partings, resembling the same series at Binny and Hermand. Towards the foot of this burn these sandstones are overlaid by black blaes. Here there are traces of old crop pits which were sunk before the beginning of the oil-shale industry, probably to discover the Houston Coal. An oil-shale, possibly the Broxburn seam, is known to occur beneath the village of Livingston, but up to the present it has not been worked. A bore, the details of which are given below, put down at Livingston Offices, proved the existence of a seam, which may be the Pells Shale with its index limestone. Feet. Inches. Shale, 4 Strata, 3 Limestone, 5 6 The ground on the west side of the great intrusive sheet extend- ing from near Livingston by Houston Wood to Stankards has been New Pari District. 45 77/ft uosyoo s 1 CO -J «3 J. l J J ^.. 31/08 s 3 ^j N0IJ.33S AVM7IVU explored, chiefly by the late Holmes Oil Co., from which it appears that the Binny Sandstone Series covers this portion of the country, while some of the bores reached the Dunnet and Barracks Shales, and also the Burdiehouse Limestone. Here the Dunnet Shale appears to lie less than 200 feet above the Burdiehouse Limestone, which proves that, in this district, the thickness of the strata between these two horizons is much less than that in the West Calder area. 5. New Park Shale-fleld. §1 S This district includes the area -S that lies between the shale-fields J of Polbeth and the Murieston ^ fault, the structure of which is 2 rather obscure, chiefly owing to % the thick covering of drift that g conceals the faulted and plicated 15 strata. A section line (Fig. 12) S has been drawn from Limefield H Mains quarry north-east to New § Park, thence southwards to Wester '■§ Murieston. The various positions w occupied by the Burdiehouse Lime- '. stone within this district are - 1 represented to illustrate the pro- s' bable structure of this area. The ^ section in the railway at Black- mire has already been described, and as the Burdiehouse Lime- stone and its overlying beds, exposed in the Hartwood Water, are again repeated in the cutting, a fault with a displacement of at least 800ft. must intersect the ground between these two points. Between Blackmire and New Park House a basin of the Burdie- house Limestone has been extensively quarried on both sides of the public road which leads from the railway station to Bell's quarry. On the west side of this fold the limestone is either at a high angle or in some cases is slightly inverted, while to the south-east of Bell's quarry it "forms a sharp synclinal fold on the north limb of which the beds are quite vertical and even a little inverted at Brucefield quarry " (Cadell — Trans. Ed. Geol. Soc, vol. viii., p. 142.— Trans. Ins. Min. Eng., 1901-02, 46 Geological Description of the Shale-fields. vol. xxii). These quarries are now partly filled up, and this basin is separated by the Calder fault from the other two depressions which lie on the south side of the railway. The section line (Fig. 12) has been drawn across the largest of these folds as far as the Murieston fault. Here the limestone was originally worked open-cast, but it is now won by a shaft, 37 fathoms deep, near the centre of the basin. The stone, which is very pure, varies in thick- ness from 20 to 26ft., and is used entirely for smelting purposes by Messrs. Baird & Co., Gartsherrie. Underneath the limestone is a seam of fireclay, but the "Buckie fake," which lies near the bottom of this fireclay at Camps quarry, has not been found in this working. This basin has nearly vertical sides, and the excavations show that its bottom consists of a succession of smaller undulations. The southern portion of this fold is intersected by the Murieston fault, and here the Burdiehouse Limestone is let down against the upper part of the volcanic rocks of Corston Hill, which is equal to a displacement of at least 300 fathoms. To the east of Crofthead there is an old quarry, now filled up, where the Burdiehouse Limestone is reported to have been worked. Several bores have been put down and trial pits sunk on the estate of Alderstone, which have proved that oil-shale measures occupy this district as far south as the Calder fault. In one bore three thick shale beds of good quality have been found. The strata are considerably disturbed to the north of Bell's quarry, and the large faults to the west already described probably pass through this area, but as there is no direct evidence on account of the thick covering of drift their position is not shown on the map. At present boring operations are being carried on around Alderstone by Young's Oil Company. 6. Gobbinshaw and Tarbrax District. This district includes all the oil-shale measures on the south- east side of the Murieston fault, between Harburnhead and Auchingray, and is bounded on the N.E. by the outcrop of the Burdiehouse Limestone as shown on the one-inch map (32). GENERAL SECTION OF COBBINSHAW AND TARBRAX DISTRICT. Table 1. Hurlet limestone and coal. Feet. Inches. Strata — Chiefly blaes, with occasional thin coals, limestone, fireclay, and marl bands ; also ball and ironstone ribs, 450 Raeburn shale (upper), - 4 g Strata — Blaes, with two thin coals, 96 Raeburn shale (lower), 2 6 Strata — Blaes, with ironstone bands, 108 Feet. Inches, 1 9 132 1 8 66 40 6 115 3 6 750 23 Cobbinshaw and Tarbrax District. 47 Table I. — continued. Mungle shale, Strata— Blaes, with ironstone bands, and » few beds of fireclay and sandstone, Two-feet coal, Strata — Houston marls, Fireclay, fakes and blaes, Houston coal, Strata — Sandstones, with faky and shaly partings, Fells shale, Strata — Marls, followed by a sandstone series, estimated at Burdiehouse limestone, 8 feet to There are few natural sections in this field, but, as it has been extensively bored and opened out by pits and mines, its structure is now well determined. The northern portion of this area forms a broad, synclinal fold, with Cobbinshaw reservoir in its centre, while to the west the beds pass by a series of gentle undulations underneath the Hurlet Limestone. It is worthy of note that in the direction of Tarbrax and Auchingray the oil-shales become attenuated (Fig. 13, p. 48). This basin is intersected by several north-west and south- east faults, the largest of which (the reservoir house fault), with a downthrow to the south-west estimated at 1 00 fathoms, extends from the Murieston dislocation to the west of Kiprig, and runs towards the head of the Green burn. On the south-west side of Pearie Law another fault, with a down- throw to the south-west, begins at the Murieston dislocation and runs parallel to the one already described as far as North Cobbinshaw, where it bends round to the east and approaches the reservoir house fault near the Green burn. To the east of South Cobbinshaw this fracture brings the Upper Raeburn Shale within ten fathoms of the Houston Coal, so that its displacement at this point is 59 fathoms. Two E.S.B. and W.N.W. step-faults to the south-west of Cross- woodhill House shift the outcrop of the Fells Shale a considerable distance, but as the strata are very nearly flat their downthrow cannot be large. At Tarbrax an east and west fault, with a dis- placement of 45 fathoms to the south, traverses the Hurlet Lime- stone and crosses the mining field at Tarbrax. Burdiehouse Limestone. — In the Bog Burn below Kiprig the Burdiehouse Limestone has been mined, and on the east side of the railway it was worked opencast, its thickness in both sections being about 17 feet. To the south-west of Harburnhead it was first opened out by a large quarry, but on account of the increasing thickness of the peat and drift it is not now mined. Here it is 23 feet thick, with a fireclay pavement and roof. The Barracks Shale is not represented and its position is occupied by 48 Geological Description of the Shale-fields. r ?yoB xvt/Byvj. 'O'H SIS "5" S/ dA/ svoa \ lyOS OH 3NI9H3 J± to l:v 1 1 o 77/wsavyg kingle and sandstone beds. From this mine the lime- stone outcrop curves round to the south and extends to the reservoir-house fault on the west side of the Green burn, as proved by a series of bores. Between the outcrop of the Burdiehouse Limestone • just described and the reser- g voir-house fault there is a rt well-defined basin with _g about 700 feet of overlying Jj strata in its centre. The S Harburn and Oakbank bores ■"1 prove that this portion of -§ the Gobbinshaw field is com- w posed of hard, greenish, gritty, and faky sandstones, _; with a few thin coals, but no 3 recognisable traces of the £ Dunnet andBroxburn Shales JS were found. 3 In the Oobbinshaw basin x\ south-west of the reservoir- o house fault, the upper shales 3 appear, together with the 3 Houston and Two-feet coals. ^ Oobbinshaw reservoir occu- -§ pies the centre of this fold, fg with the Pells Shale about g 1000 feet below the surface J2 of the water (Fig. 13). g Fells Shale. — The lowest '-3 workable seam in this dis- £ trict is the Fells Shale; ^ indeed it is the principal ^ oil-bearing seam in this 8 field, and has been wrought by mines to the south of Kiprig, Oobbinshaw Hill, and at Tarbrax. On the east side of the Oobbinshaw basin, as shown in the Table below, its average thickness is about 3 feet, with 3 feet 6' inches of shaly blaes above. On the west side of the basin the shale appears Gobbinshaw and Tarbrax District. 49 to be somewhat thicker and contains a rib of ironstone while the fireclay floor has disappeared. West Side. East Side. Roof blaes. Ft. Ins. Roof shaly blaes. Ft. Ins. Shale, - 1 11 Shale (good), 2 4 Blaes, 5 Shaly blaes, 8 Ironstone, Shale, Ft. Ins. 1 11 5 7 10 4 1 Pavement blaes. Pavement fireclay. All over the field a band of cream-coloured grey limestone, about two feet thick, lies below this shale and affords an excellent index to the seam. Various companies have conducted mining operations over the area, but in the north-west portion no work has been done for many years. At present the Tarbrax Oil Co. is erecting retorting plant at Tarbrax to deal with the output from the mines and pits in that district. The Broxburn Shale has never been reached in this field. At North Gobbinshaw mine, a bore was drilled in the Broxburn marls to a depth of 350 feet below the Fells Shale without reaching that seam. Prom the available evidence it is probable that there is little chance of its occurrence in this area. Houston Coal. — As shown in the section of this district (page 46) the Houston Coal is separated from the Fells Shale by sandstones with shaly partings. It has been wrought in the North and proved in the South Cobbinshaw fields, its average thickness being about six feet. A section of one of the South Cobbinshaw bores is given below. Roof faky blaes or fireclay. Coal, Fireclay, Coal, Fireclay, Coal, Dark Fakes, Coal, 5 10J Pavement fireclay. Houston Marls. — About 40 feet of fireclay, sandy fakes or blaes, immediately succeed the Houston Coal in the Cobbinshaw district, and these are in turn overlaid by the Houston marls. The grey shale shown in the general section (page 17) is absent in this field. The Houston marls are not exposed in any natural sections, but numerous bores show that these peculiar beds consist of grey, dark, greenish and brownish marls, accompanied by bluish fireclays with hard limy ribs. The average thickness is about 11 fathoms, but to the north of Cobbinshaw Station they are 15 fathoms thick Feet. Inches 1 1 4 1 3 H 6 10 1 7 50 Geological Description of the Sliale-fields. and take the place of the 30 feet of sediments which, in the South Cobbinshaw field, rest directly on the Houston Coal. Two-feel Goal— The Two-feet, locally known as the "Wee Houston " Coal, with a soft fireclay pavement and roof, defines the top ot the Houston marls. It varies in thickness from 9 to 20 inches, and, although useless for economic purposes, forms a valu- able geological horizon. Mungle Shale. — In a bore put down at the dismantled brick- works on the west side of Cobbinshaw reservoir, the Mungle Shale, 1 foot 9 inches thick, has been proved to lie 22 fathoms above the Two-feet Coal. It is separated from the coal by an alternat- ing series of blaes with ironstone bands, accompanied by a few thin beds of fireclay and sandstone. Lower Raebum Shale. — This seam, which was worked by some of the small companies 30 years ago, is a good curly shale about 2 feet 6 inches thick, but varies considerably as the following two comparative sections show : — On West Side of Basin. On East Side of Basin. Ft. Ins. Ft. [ns. Shale, - 1 3 Shale, 1 3 Fireclay, 2 Iron ball, 2 Shale. 1 5 Shale, 6* 2 10 1 10J Upper Raebum Shale. — This seam is a good plain shale about 4 feet 6 inches thick, with a roof and pavement of blaes, and its " index " in bores, in this district, is marked by the thick " roof post" of blaes with two ribs of coarse ironstone. The west side of the Cobbinshaw basin is crossed by a diagonal fault running in a N.N.W. direction between South Cobbinshaw and the Murieston dislocation, whose downthrow is about 15 fathoms to the north-east. In this small field old pits were sunk to the Houston Coal, and to the north of the railway station, two, to the Raeburn Shale. The South Cobbinshaw bores demonstrate that the Upper Rae- burn seam lies 75 fathoms below the Hurlet Limestone, the strata between these two horizons consisting mainly of shale, and also including several thin coals, limestones, fireclay, and bands of marl, with balls and ribs of ironstone. The shale-field on the south side of the Pearie Law fracture is traversed by three easterly and westerly faults. The two which lie some distance to the north of Tarbrax have both a downthrow to the north, and hence the outcrops of the various shales have been shifted to the east in the direction of Crosswood Hill. This area is at present being opened out by the Tarbrax Oil Company, a pit having been sunk 64 fathoms to the Fells Shale, half-a-mile to the E.S.E. of the village of South Cobbinshaw. Here, one of these east and west faults was proved to have a displacement of 12 fathoms, and in the workings the strata dip to W.N.W. at 6°. To the north of Tarbrax village the seam was worked to a con- Cobbinshaw and Tarbrax District. 51 siderable extent by the late Caledonian Oil Company, its thickness varying from 2 feet 8 inches to 3 feet 8 inches. The fault, with a downthrow to the south of 45 fathoms, which passes through Tarbrax, shifts the outcrop of this seam some distance to the east. A mine has recently been opened out on the south side of this fracture, but the strata are disturbed in the direction of Lawhead. This shale has been traced by bores to a point midway between Tarbrax and the Easterhouse and Dykehead roads (Sheet 24), which is the most southern point to which the Lothian shale- field is known to extend, but future boring operations may prove the existence of workable shale under the obscure ground covered by the Stallashaw and other peat mosses to the north of Carnwath. In the South Cobbinshaw field the Houston Coal lies 17 fathoms above the Pells shale, but it has never been worked. The two Upper Kaeburn shales have been traced by bores and pits from the Pearie Law fault to near the south-west of Tarbrax.* The section of No. 1 pit, Cobbinshaw, together with that of the diamond bore of Tarbrax, given in the subjoined Table, affords a correct record of strata in the South Cobbinshaw field from the Houston marls to the beds beneath the Burdiehouse Limestone. * Note. — While this Memoir has been passing through the press, an important development has taken place in the South Cobbinshaw field, where the Tarbrax Oil Company have opened out an oil-shale, termed the " Fraser " Shale, after the surname of the managing director of that company. It lies from fifteen to eighteen fathoms above the Raeburn Shale, and is designated the Upper Raeburn seam by the Geological Survey, having been formerly worked on the Greenfield estate. The shale is of excellent quality. [Table. 52 Geological Description of the Shale-fields. Cobbinshaw and Tarbrax Section, compiled from Section No. 1 Pit, Cobbinshaw, and No. 1 Diamond Bore, Tarbrax, 1902. Thickness. Depth. STRATA. 1 GO s o 03 01 A 43 X JS 43 A 43 4 S Marly sandstone, .... 1 4 144 3 4 ,, red blaes, .... 1 1 145 4 4 Sandstone, coarse, with pebbly bands, . 4 5 150 .*) 4 Fakes, ..... 1 3 152 4 - Sandstone, coarse pebbly, 2 4 154 4 4 Fakes, .... 4 155 2 4 Marly red fireclay and fakes, 4 8 159 3 Fakes, ..... 1 160 3 00 Sandstone, coarse pebbly, 1 160 4 CD a Fakes, dark, .... 4 161 2 3 m Sandstone, coarse pebbly, Fakes, dark, .... 2 2 3 163 164 4 1 a Sandstone, faky, . . . • 2 6 164 3 6 OS CD „ coarse pebbly, , , conglomerate, . ,, coarse, 2 3 5 2 6 9 6 167 167 171 3 5 9 3 p , , with faky ribs, 1 4 172 4 3 ,, coarse pebbly, ,, finer, . 4 5 6 176 177 4 3 3 9 „ coarse pebbly, 5 4 6 183 2 3 Fakes and balls, . . • ■ 2 185 2 3 Sandstone, ... 1 186 2 3 .Fakes and balls, .... 4 9 187 1 §«> ("Limy fakes and blaes, 1 5 6 189 6 |J J Blue blaes,. . 1 6 189 2 M | ] Limestone, .... |a (.Limy blaes, . . . • 4 190 4 190 4 Green fakes and balls, , , , , and ribs, 1 2 191 193 4 4 Marly fakes and red fireclay, 1 1 2 4 195 196 4 6 o Sandstone, faky, . Fireclay and balls, Limy sandstone, faky, Sandstone, Fakes and balls, • Marly fireclay, . . • • 1 3 '0 1 3 4 4 6 6 197 200 201 202 202 202 5 5 2 5 Green whinstone, 5 Total, 202 54 Geological Description of the Shale-fields. A comparison of this section with others of the oil-shale group demonstrates the varying types of sedimentation in different portions of the Lothian shale-field. In the 22 fathoms of strata which lie above the Houston Coal only 6 - 4 per cent, is marl, the remainder being grey fakes and sandstone. In the rest of the shale-field the proportion of marl averages 50 per cent. The Houston Coal has its full thickness, but the thickness of strata between this coal and the Fells Shale as compared with that in the West Calder section is in the proportion of 1 to 2. Below the Fells Shale there is a series of marls, marly fakes, and blaes, with some fakes and sandstone bands. The marly beds compose 61 per cent, of the total thickness of this group, and evidently represent the Broxburn marls. The Broxburn Slude is absent. From a depth of 110 to 187 fathoms the strata consist of fine and coarse sandstones, with pebbly and conglomeratic bands and some red and marly fireclays and fakes. The siliceous beds compose 75 per cent, of the whole, and are probably the local representatives of the Binny sandstones, together with the sandstones below the Dunnet Shale. The number and thickness of the coarse pebbly and conglomeratic bands, the attenuation of the strata between the Houston Coal and limestone, and the absence of the Dunnet, Broxburn, and Barrack seams indicate that this area lay close to an old shore line during the deposition of the strata between the Burdiehouse Limestone and the Fells Shale. 7- Broxburn Field. This area includes the districts of Broxburn, Uphall, and New- liston, and lies between the Middleton Hall fault and the Ecclesmachan and Niddry Castle dislocations to the north. General Section, Broxburn Shale-field* Hurlet limestone (position not proved). Strata — Estimated at, Black band Ironstone, - Strata — Blaes and fireclays, Raeburn shale, Strata — Blaes and balls, Mungle shale, Strata — Chiefly blaes, Two-feet coal, Strata — Houston marls, blaes at base, Houston coal, Strata — Sandstone, with blaes at base, Fells shale, Strata — Broxburn marls, from 135 ft. to 246 ft. Broxburn shale, - j Strata — "Binny Sandstone" blaes, and marls on top, 510 Dunnet shale, Strata — Sandstone, blaes, with limy ribs, - Barracks shale, Strata — Blaes, Burdiehouse limestone, - Strata — Blaes, with thick sandstones in centre, Pumpherston shales, * The thicknesses of the strata between the Dunnet seam and the Pumpherston shales have been obtained from the journals of the Dramshoreland, Powflats and Kilpunt, bores. Feet. Inches, 150 1 6 258 2 11 190 2 186 3 3 222 5 240 3 186 o 25 ,510 o 10 375 6 57 45 678 83 The Broxburn Shale-field. 55 b s-gjosod ,, 3 V 08 via 11 j.Nn 5 45 4 On the eastern limb of the Broxburn anticline the curly shale has been wrought to a considerable depth, and near East Mains it is rendered useless by the intrusive dolerite sill (Fig. 14), which lies a short distance above it. "Ab the mouth of the " Albyn " mine this intrusive sheet is in two thin bands and in close proximity to the shale. The lower one was found to be full of cavities coated with calcite, filled in the heart with mineral wax, yellowish-grey when fresh, and brown after exposure to the air. On analysing the hydrocarbon, Mr. Stewart, chemist, Brox- burn, found it to consist of carbon (84 - 35 per cent.), hydrogen (12 - 83 per cent.), and nitrogen (1-68 per cent.), with traces of sulphur in some specimens. The shale was worthless near this rock, and the hydrocarbon was clearly derived from its distillation, and was subsequently accumulated in the cavities of the igneous material." (Cadell, Trans. Min. Enq., 1901-2, p. 35.) Still farther to the east, the East Mains diamond bore proved that, at a depth of 50 fathoms, this sill occupies the position of the Broxburn Shale, with the Dunnet Shale 92 fathoms below it. The evidence clearly shows the intrusive nature of the igneous rock, for it not only transgresses the bedding planes, but adds here a portion of its own thickness of 9 fathoms 5 feet to the distance between the Broxburn and Dunnet Shales as compared with the " Hut " open-cast bore, where the sill is absent, and the distance between these two shales is almost 84 fathoms. It is a typical example of an intrusive sill penetrating highly carbonaceous beds, for it has absorbed or more probably dissipated as gas 30 per cent, of the original thickness of this shale. The ground between the East Mains farm and the Edinburgh and Glasgow railway has been well proved with bores, and the position of this igneous intrusion below the drift-covered surface of the ground to the south-west of Newliston has been thoroughly ascertained. The sill here is about 80 feet thick, and lies both above and below the Broxburn Shale which has been rendered useless. Between Stewartfield and the Middleton Hall fault there is a considerable " want " in the Broxburn seam. 58 Geological Description of the Shale-fields. Broxburn Marls. — -The Broxburn marls, which vary from 22| to 4>1% fathoms in thickness, lie immediately above the highest shale bed of the Broxburn series, and have been proved in many bores. Fells Shale. — The average thickness of the Fells Shale in this field is about 3 feet, and it is usually found with its index lime- stone below. The west limb of the Broxburn anticline dips gently at 11° for one and a half miles to the centre of the Fivestanks basin. The axis of this fold (with pitch to S. 20° W.) extends from Middleton Hall to the Bcclesmachan fault near Hayscraigs. For some distance north from the Middleton Hall fault the west side of this basin is very steep, with the strata inclined at angles of 60° to 65°. On the north side of the east and west fault at Old Uphall the dip becomes much less. The east side of the Fivestanks basin is intersected by two faults ; the larger, near Holmes, has a displacement of 20 fathoms, and the other, in the Houston Coal, is of smaller amount. Fells Shale. — To the south of Hayscraigs and to the west of Uphall there are some old crop pits on the Fells Shale, which, at present, is too thin to work, but its position at the top of the Brox- burn marls forms a valuable index in boring operations. The dolerite sill already mentioned, which lies partly above and also occupies the position of the Broxburn seam, in the Newliston field, is intruded between the Fells Shale and the Houston Coal between Hayscraigs and the Middelton Hall fault. On the north side of the Bathgate road its position is marked by a series of bare rock knolls which are situated on the eastern side of the outcrop of the Houston Coal. Houston Coal. — An average section of this coal in the Broxburn field is as follows : — Feet. Inches. Coal, 2 3 Blaes, 1 5 Coal, 1 4 5 The position of the seam is well defined by the line of the old crop pits, which can be traced from the Middleton Hall fault to to the east of Holmes, thence round the north and down the west side of the Fivestanks basin to near Curledubs, where the dolerite sill of the east side of the Broxburn field partly occupies its position and lies above it (see sheet 32). Six hundred yards to the north-east of Fivestanks a ,bore proved that the dolerite sill has rendered the coal " blind" and the overlying Houston marls hard. From Uphall to Newbigging it forms a series of picturesque crags along the western side of the Fivestanks basin, on one of which the hamlet of Uphall is situated, and at the foot and western side of the cliff (where a small fault probably exists) the Houston Coal was found nearly vertical. The sheet is truncated by the Middleton Hall fault, and near The Broxburn Shale-field. 59 Uphall it plunges down below the Houston Coal, and in a bore to the south-west of Houston House it is 62 fathoms from the surface. This intrusion is evidently the same as that met with in the basin west of Pumpherston. In the Broxburn shale-field it passes from one horizon to another, for at Newliston it occupies the position of the Broxburn Shale, and westwards it gradually creeps up through the superincumbent strata till, at Uphall, it rises above the horizon of the Houston Coal. Westwards the bore between Houston House and the " Mains " shows that it has again descended nearly to, and at one point occupies, the position of the Broxburn Shale. (See Fig. 14.) On both sides of the Middleton Hall fault it was originally a single sheet intruded into the strata, which probably were then more or less horizontal. It must have shared in the movements which folded and faulted the oil-shale measures, and is thus older than the combined series of faults and flexures so largely represented throughout the district. In the vicinity of Houston House and to the south of Houston Mains the Houston Coal lies in two basins. (See Fig. 14.) The seam first obtained its name from the working and development of this colliery, and although not the lowest worked coal in Scotland, it proved in the past a sufficiently valuable seam to supply this district with fuel. With the advent of canals and railways and the cheap transport of a better class of coal from the west, the working of the colliery proved unremunerative. Mr. Forsyth, in his account of the Houston Coal (" Mines, Minerals, and Geology of West Lothian," Trans. High, and Agric. Soc. Scot., 1847) states that in the east basin there were two pits, 22 fathoms deep. The seam was divided by a band of stone, six- teen to eighteen inches thick, the upper portion being a household and the lower an excellent smithy coal. The total thickness was 5^ feet, and 300 yards from the bottom of the shaft the seam is " blind," — a change doubtless due to the intrusion of the dolerite. Houston Marls. — The Middleton Hall bore, situated at the Lodge to the west of Holmes, proved the Houston marls to be 37 fathoms thick and overlaid by the Fivestanks shale, which is here the representative of the Two-feet coal. Two-feet Goal. — A mine driven into this bed to the east cf Curle- dubs shows it to be composed partly of a hard, coarse, splintery shale and partly of a coarse parrot coal. Its composition varies considerably, and in one of the Fivestanks bores it yields the following section : — Section of Two-feet Coal. Coarse Blackband Ironstone Shale, good, ,, fair, Shale blaes, Coal, with black band Ironstone, ?eot. Inches. 5 8 10 1 4 Feet. Inches, 4 if 1 if 2 60 Geological Description of the Shale-fields. Mungle Shale. — Eight feet above the two-feet coal lies a thin oil- shale, succeeded by 27 fathoms of brown, dark, and grey blaes with some sandstone ribs. Next in order comes the Mungle Shale, which is represented in the Middleton Hall bore by 3 feet of inferior shale. Raeburn Shale. — Blaes and ironstone balls supervene, followed by the Raeburn Shale, which, in the Middleton Hall bore, is 2 feet 11 inches thick, and lies 24 fathoms above the Mungle seam. This bed was at one time worked open-cast in the vicinity of Fivestanks. The highest bed of economic interest in the Broxburn district is a blackband ironstone which occurs in the basin round Middleton Hall, a section of which is given below : — Blackband Ironstone, Coal and blaes, B.B. Ironstone, Fireclay, A trial pit proved its thickness to be eighteen and a half inches. Its position is 145 fathoms above the Houston Coal, and the topmost beds, which occupy the centre of this basin, cannot be very far below the Hurlet limestone. The estimated distance between the ironstone and limestone is 25 fathoms. On the south side of the Middleton Hall fault the outcrop of the Broxburn Shale has been proved, at Stankards, close up to the fracture. At this point and on the north side of the fault the crop of the blackband ironstone lies a little to the east, from which it appears that this fracture has a downthrow to the south of 261 fathoms. At Kilpunt the displacement is calculated to be 180 fathoms. From Uphall to East Bangour the Fells Shale has a sinuous out- crop, and the seam has been worked in the past by several shallow pits to the north of Forkneuk. Northwards, between Old Uphall and Curledubs, lies an east and west fault, on the south side of which there is a minor fold of the Broxburn Shale. This seam is at present worked in the Forkneuk pit, where the mining operations show that it lies in a synclinal fold towards the western extension of this east and west fault. To the south-west of this sinking the Broxburn Shale is rendered useless. Northwards, between Wyndford and Curledubs, the Broxburn Shale crops out and dips to the east on the eastern limb of the arch, which is traversed by the east and west faults near Curledubs. Beneath this horizon the famous Binny sandstone, formerly exten- sively quarried at Binny, a mile north of Uphall, crops out along the crest of a low anticlinal dome, the centre of which crosses Binny Burn at Binny Bridge, near Wyndford. The Broxburn shale appears at Wyndford, in the bed of the burn, a short dis- tance above the sandstone, so that there can be no doubt as to its exact position in the section. Eccksmachan District — Broxburn Shale. 61 8. Bcclesmachan District. This district includes the area which lies between the Eccles- machan and Winchburgh faults, and extends westwards to the Ochiltree dislocation. A small portion occurs on the south side of the Bcclesmachan fault, around Broadlaw. At the western edge of this area, to the south-west of Little Ochiltree, the Broxburn Shale folds round a well-marked anticline that pitches to the north. A steady dip to east continues for some distance towards the centre of a synclinal fold, whose axis stretches from Oatridge to Little Ochiltree. As the pitch of this fold is also inclined to the north, the highest beds, namely, those above the Two-feet coal, are found next the Ochiltree fault, to the south-east of Gateside (see sheet 32). To the east of this synclinal fold the Broxburn Shale next ap- pears on the crest of a dome, and then plunges below two shallow basins, situated respectively around Hillend and Hillend pit, the highest economic bed being the Houston Coal. Beneath this coal these two basins merge into one another, and are succeeded to the east, first by an anticlinal and then by a deep synclinal fold of the Broxburn shale, situated to the south of the Hopetoun oil-works and on the north-west side of the Broxburn anticline. Broxburn Shale. — The Broxburn seam is the lowest mined shale in this district. In the Mains Burn, to the north of Hangingside, it is represented by black parroty blaes overlaid by marls, which are altered by a small basalt dyke. Its outcrop has been traced by means of bores round the apex of the anticlinal fold already noticed, with both limbs inclined at a high angle. The underlying strata in the burn dip 75° to the west. To the south of Little Ochiltree two bores have been drilled. The one to the south-east of the farm shows that a basalt sill occupies the position of this seam, while the one to the south-west of the steading passed through the position of the Broxburn Shale before it entered the basalt at 82 fathoms, but the shale was unrecognisable on account of the burnt condition of the strata. This igneous intrusion probably represents the Binny Craig sheet, which, at this point, is the most north-westerly extension of the Broxburn and Houston Wood sills. At Hangingside, this intrusive sheet forms the bold escarpment of Binny Craig, and probably the irregular patches at Niddry and Winchburgh. " The heated mass has been injected among shales and beds ofbituminous blaes, and has raised the temperature of these strata so as to distil their hydrocarbons and drive them into any available cavity, where they have cooled in the liquid or solid form. This is a characteristic feature of the Broxburn district, and deserves special notice. In 1890, a diamond-bore hole was made near Little Ochiltree, about one mile north of Binny Craig, which, after passing through the Houston marl, Houston coal, and Fells shale, struck a thick sheet of intrusive dolerite situated near the position of the Broxburn Shale. It was noticed that the whinstone- 62 Geological Description of the Shale-fields. 3H0S 3uoa i 1V00.Z JJfll 030038 \ !fc?e!8 IB N <5 §■ I M O u w 3 O M a o o M Fcclesmachan District — Fells Shale. 63 core, brought up from a depth of over 600 feet, was cracked in places, and the fissures were full of a soft yellow substance like vaseline or wax, which melted in the sun and spread in an oily film over the stone. This was, we may well believe, nothing but the result of distillation by the trap of the hydrocarbons in the shale, and, as was therefore to be expected, when the seam or its repre- sentative was penetrated, it was found to be quite worthless as an oil-producer." (II. M. Oadell, Trans. Min. Eng.. 1901-2, p. 34.) On the east side of the Little Ochiltree basin and near Drumforth, Messrs. James Eoss & Co. have mined the Broxburn Shale (No. 5 mine) from its outcrop to a depth of 150 fathoms of vertical distance from the surface. At first the dip of the mine is very steep till it reaches the shale (see Fig. 15), but it becomes less (about 1 in 4) as the workings advance to the north-west. The Broxburn Shale in this mine has the following section : — Feet. Inches. Roof blaes, Shale, Rib, Shale, Rib, Shale, 3 6 Oi 1 10 Oi 2 6 10| Pavement daugh. This seam was next worked to the east of the two Hillend basins by a mine two-thirds of a mile to the south of Glen- devon, which was driven to a depth of 45 fathoms from the surface, but the workings are now abandoned. Another mine to the north-west of South Greendykes has opened out the same shale as far as Pyothall, and No. 2 pit, 70 fathoms deep, on the north side of the Niddry fault at Hopetoun oil-works, has proved the steep syncline (see Fig. 15) on the north-west side of the Broxburn anticline. The Niddry fault begins in the anticlinal ridge which lies between Glendevon and South Greendykes, and the amount of displacement rapidly increases eastwards. It truncates the north side of the Broxburn anticline, but its downthrow there is not known. Fells Shale.— All over this district the Fells shale is not worked, but its position at the top of the Broxburn marls has been proved ,in numerous bores, and its outcrop has been shown on the Geo- logical Survey Map (32 one inch). A glance at the map shows that its outcrop follows that of the Broxburn Shale round the various anticlines in which the latter zone comes to the surface. In the diamond bore at Little Ochiltree, 202 feet of strata separate the Broxburn and Fells shales. Between the approximate position of the Fells shale m the Mains Burn west of Ecclesmachan village and the Houston Goal, the section shows that faky sandstones and beds which contain plant remains lie between these two horizons. eet. Inches. 2 6 6 1 3 1 l 64 Geological Description of the Shale-fields. Houston Coal. — The Houston Coal appears in the various basins between the above anticlines. In the largest basin, that of Little Ochiltree, at the west end of the district, it lies 41 fathoms above the Pells Shale. In the Ochiltree diamond and adjacent bores it furnishes the following section : — Coal, Shale, Coal, ,, Gas, On the west side of the basin, a little to the west of Little Ochiltree, the Linlithgow Oil Company drove two mines into this coal and used it for furnace and retort purposes. About the year 1832, two pits were sunk towards the south side of this basin, one 20 fathoms deep, east from Oatridge farmhouse, and the other close to the steading (" Mines, Minerals, and Geology of West Lothian," by Mr. Charles Forsyth,- Trans. High, and Agric. Soc. Scot., 1847, p. 259). In this report it is stated that " one foot of coal was found and the rest of the bed passed into shale," which was probably blaes. South of Oatridge the basin is truncated by the Ecclesmachan fault, which brings up the upper portion of the Binny Sandstone Series against the Houston coal, a displacement probably of over 80 fathoms. On the east side of this basin the coal was wrought at a very early period by means of a day level at East Binny, where the quality was good. From this point to the Ecclesmachan Burn there were two crop pits on the coal, and the workings to the north-east of Oatridge were drained by a pump driven by a water-wheel on the Ecclesmachan Burn. The Binny fault appears to fork from the east end of the dolerite sill of Binny Craig, and to send a branch towards East Broadlaw. On the north side of this farm and between the public road and the igneous material there are traces of old quarries now filled up. Scattered pieces of rock, containing Ostracods, Palaeoniscid fish and Lepidodendron, were here picked up on the surface by Sir A. Geikie during his survey. These quarries probably mark the position of the bed of limestone " 200 yards south from Binny Craig which has been wrought at Broadlaw, 1 1 feet thick and of a blackish colour," mentioned by Mr. Charles Forsyth in his report. (See reference on p. 5.) It may be remarked that if this bed represents the same fossiliferous horizon as that found in the Broxburn marls to the south of West Calder, the Broxburn Shale may yet be found at or near the surface on this anticline. Forsyth mentions that the Houston coal was worked at West Binny. In the Ecclesmachan Burn, one quarter of a mile west of the village, there is a fine section of green and red marls with bands of pale green micaceous sandstone, which form the Houston marls. Ecclesmachm District — Houston Coal. 65 The actual position of the coal can be seen in the stream, and it is overlaid by a band of black shale containing entomostraca. From this point to the south of Three-mile-town traces of numerous old crop pits indicate the actual position of this coal, and several bores in the overlying marls have passed down into the old wastes. Between these two points the dip of the seam is a little north of west, and, as the outcrop is continuous, it proves that the Winchburgh fault does not extend so far west. The following section occurs at Drumforth, on this line of outcrop : — Feet. Inches. Coal, - 13 Dirt, 3 2 Coal, 1 10 6 3 To the east of Waterstone a smaller and complete basin of the Houston Goal occurs at Hillend. The section of the seam in the dismantled pit is as follows : — Feet. Inches, Soft coal, 3 Parrot or cannel-coal, 4 Soft coal, 1 Fireclay with ironstone-nodules, 2 Fireclay, holing, 2 Soft coai, 1 foot 6 inches to 2 Total thickness of seam, 5 9 The roof of the seam is generally weak, and the coal itself is so full of pyrites and ribs of stone as to be unprofitable for mining purposes except during times of scarcity and high prices. The basin of the Houston coal, east of Waterstone, is about 18 J fathoms deep. On its south side the outcrop is shifted by a small strike-fault, and, between this point and Hillend, a fold in the strata brings in the second basin, situated to the east of Tar Hill, which is veiy shallow, for a bore south of Hillend reached the Houston coal " waste " at 25£ feet. In both areas the outcrop of the Houston Coal has been proved by many old workings, and all the pits have been abandoned long ago. To the east of the village of Ecclesmachan the outcrops of the Houston Coal and Fells Shale approach one another in such a manner as to suggest that a north and south fault with a down- throw to the east intervenes. To the north-east of the outcrop of the Houston Coal in the basin of the Hillend pit a roll over of the strata takes place, which brings in a narrow field of this coal on the south-side of the Winchburgh fault. The area lies between Lampinsdub and the point where this fault crosses the canal below Winchburgh House. Here the outcrop is seen in close proximity to this dislocation, and the coal was worked in a pit just above the canal. Orey Shale. — To the south-east of Ecclesmachan village a small area of Houston Coal lies on the north side of the Ecclesmachan fault, and, among the overlying beds, we find the Grey Shale nine E 66 Geological Description of the Shale-fields. fathoms above the coal. This shale forms the base of the Houston marls, and is separated from the coal by flaggy, dark, sandy fakes and blaes. Houston Marls.— The Houston marls appear to occupy the whole of the large basin around Oatridge, and to extend as far as the Ochiltree fault to the north of Three-mile-town. Two-feet Goal.— The Two-feet Coal appears to be represented by a volcanic series, consisting of both lavaform and fragmental rocks. A good example of the latter is the purplish sandy and felspathic ash, exposed in the old quarry to the north-east of Little Ochiltree, which has a rudely confused dip and contains abundant fragments of black shale (Fig. 15). Owing to the covering of drift and absence of bores there is no information as to the nature of the overlying strata. 9. Winohburgh District. This district embraces all the ground between the Ochiltree and Winchburgh faults as far east as Dundas Castle and Kirkliston. In the western part of the area the lowest beds appear to be situated at "Winchburgh, on the south side of the Edinburgh and Glasgow Eailway. From this point to the Ochiltree fault the strata have a north-west dip and there is an upward succession to the Houston Coal. Eastwards, the beds appear to be folded round a dome of the Binny sandstone surrounding the dolerite sill of Dundas Castle. Burdiehouse Limestone and Bunnet Shale. — At Winchburgh Station we find a thick series of carbonaceous shales, largely quarried for brick-making, which seem to occupy the position of the Dunnet seam, but no good oil-bearing shale has yet been discovered here. In the summer of 1890, the arched roof of the tunnel at Winchburgh, which is 1100 feet in length, gave way, and Mr. H. M. Cadell had an opportunity, while the building was being repaired, of examining the overlying rock. No oil-shale or limestone could be seen, but near the southern end there was some grey freestone under beds of blaes dipping north-westward at 10° to 20° in some places, and flat in others. At the northern end a good deal of white trap was visible and white shaly and marly beds, apparently altered by the intrusive rock. " When the tunnel was originally made, a thick bed of limestone was cut below thick blaes dipping westward at the south end of the opening. The limestone rested on sandstone-beds, and had a crystallized burnt appearance, probably due to the proximity of the trap of Winchburgh Hill."* It is quite possible that this bed may have been the Burdiehouse limestone, in which case the displacement of the Winchburgh fault down to south cannot be less than 225 fathoms. This fault does not extend as far west as the outcrop of *" Mines, Minerals, and Geology of West Lothian," by Mr. Charles Forsyth, Transactions of the Highland and Agricultural Society of Scotland, 1847, page 259. Winchburgh District — Binny Sandstone — Broxburn Shale. 67 the Houston Coal near Waterstone, and hence the dislocation must rapidly increase in downthrow in an easterly direction. Immediately to the west of the junction of the Edinburgh and Forth Bridge loop-lines, the railway enters a deep cutting, 2 miles in length, which terminates at Philpstoun Station. It is almost entirely in solid rock, and when first completed in 1842 very few retaining walls were built. Since then atmospheric denudation, and the vibration produced by the numerous daily trains which pass through this excavation, have caused frequent falls from the rock faces. About four years ago the greater portion of this most interesting section was covered with masonry. The map used by Sir A. Geikie during the original survey records the section as it existed in 1855. Binny Sandstone. — To the north-west of Glendevon there is an old sandstone quarry in which the beds are reported to lie 20 fathoms below the Broxburn Shale. Immediately to the west of the junction of the Edinburgh and Glasgow, and Forth Bridge loop-railways, sandy shales are apparently overlaid by 56 feet of massive sandstones with thin shaly partings. Between the rail- way and Tottywells this series seems to roll over to the east, and an excellent quarry has been recently opened a little to the south-west of Swineburne. The dip of the strata is E.N.E., at angles varying from 8° to 15°, and their aggregate thickness is over 60 feet. The highest bed in the quarry is about 152 feet below the Broxburn Shale. The Winchburgh fault is exposed in the railway cutting at the south end of the tunnel, and if it continues its east and west course, it will pass some little distance to the north of Kirkliston. Oraigend and Humbie quarries are both situated on this horizon, and the latter supplied the stone which was used in the large viaduct that carries the North British Railway across the Almond Valley at Newliston. The upper beds consist of white sandstone with thin seams of shale, and the lower ones of " Liver rock " like that at Craigleith. Broxburn Shale. — At the west end of this area, near Glendevon, the Broxburn Shale is at present worked by three mines which start from a common centre, one being driven down the dip slope, and the other two slightly oblique, with the result that the work- ing faces have an extension of two-thirds of a mile. This mine is connected with the pit, 72 fathoms deep, at Trinlymire. In the railway section, 80 yards on the east side of the bridge that spans the track at Auldcathie, the outcrop of the Broxburn Shale is represented by 9 to 12 feet of black bituminous blaes with thin oil-shales. This band is succeeded by grey marls with thin calcareous beds, and, close to the bridge, we find shale and blaes from 4 to 6 feet thick, which probably represent the Grey Shale of the Broxburn field. To the north-east, between the railway cutting and Duntarvie Castle, a large number of bores have been put down, none of which has proved the position of this seam. A little farther to the east, and north of Swineburn, bores have proved two oil-shales, measur- 68 Geological Description of the Shale-fields. ing 6 feet and 3 feet 9 inches, above the outcrop of the Binny sandstones, thus suggesting that a small basin of the Broxburn Shale may lie between the quarry already described and the Ochiltree fault. At present boring operations are being prosecuted by the Oakbank Oil Co. to trace the outcrops of these shales to the east. Broxburn Marls. — The railway bridge already mentioned at Auldcathie stands on the Broxburn marls, east of which point the " grey shale " of Broxburn is succeeded by greenish marls, and on the west side these marls contain thick calcareous bands. These beds extend for about 100 yards along this excavation, where they are cut off by a fault with a low hade and a downthrow to the west, which brings the marls against a series of grey blaes with ironstone bands. Fells Shale. — The Fells shale is not worked in this district, and its position in the railway section at Auldcathie is probably just beyond where the rock exposure is walled up in the cutting on the east side of the aqueduct. A little to the west the Houston Coal crops out in the section, and a strike-fault with a downthrow to the north-west must lie between these two seams, as there is not sufficient space to admit all the intervening strata. Houston Goal. — Bast of Three-mile-town, at the side of the Edinburgh and Glasgow road, a pit, 15 fathoms deep, was sunk in this seam, which at one time supplied this district with coal. From this point to Craigton numerous crop pits indicate its exact position, and on " the south side of the canal it was wrought by a shaft 16 fathoms deep." [Mines, Minerals, and Geology of West Lothian, by Mr. Charles Forsyth, Trans. High, and Agric. Soc. Scot., 1847.] This pit is interesting as marking the farthest point to the north-east where this coal has been wrought in the Lothians. To the east of Craigton House, on the south side of the Ochiltree fault, its position has been proved in numerous bores, and the journal of a bore in Duntarvie gives the following record : — Houston Coal. Roof fireclay. Coal, Fireclay, Coal, Fireclay, Coal, Fireclay, Coal, foul, Fakes, - Ironstone rib, Fakes, black, Coal, 7 4 Between Tottywells and Westfield the outcrop of this coal is said to have been got. Fragments of coal have also been picked up there on the surface, which affords additional evidence of the Feet. Inches, 1 10 2 5 1 7 2 6 1 3 3 1 2 11 Philpstoun and Champfleurie Shale-fields. 69 extension of the basin already mentioned as containing the Brox- burn Shale. The overlying Houston marls are exposed in the railway cutting below Craigton House and are the northern extension of the out- crop already mentioned as occurring in the Little Ochiltree basin. At this point they are composed of green and red marls with ironstone bands. 10. Philpstoun and Champfleurie Shale-fields. These shalefields lie to the north-west of the Ochiltree disloca- tion, and occupy the ground from Wester Ochiltree to the branch of the Ochiltree fault which runs in a north-west direction to Midhope, near Abercorn. This field has been extensively developed by the mining operations which were carried on in the Champfleurie district by the late Linlithgow Oil Company, and those at present vigorously prosecuted in the Philpstoun area by Messrs. James Eoss & Co. Between Philpstoun and a point one mile to the south-west of Gateside the general structure is that of a broad, flat anticline, with its centre in the vicinity of Gateside. The strata on this fold are abruptly truncated on the south-east side by the Ochiltree fault. When followed to the E.N.E. of Philpstoun, this arch disappears, and the various seams dip regularly to the north-west. To the south-west, at Wester Ochiltree, the Gateside anticline is succeeded by a syncline containing the Fells Shale and Houston Coal. Westwards these seams are repeated by another anticlinal fold, and are eventually overlaid by the Carboniferous Limestone series of Linlithgowshire. Binny Sandstone. — The Binny sandstones are the lowest beds in this field, and occupy the angle between the two boundary faults in this area. There is an excellent exposure of this series on the west side of the Ochiltree fault in the railway cutting at Craigton, where the Houston marls are brought against the Binny Sandstone, the displacement being not less than 150 fathoms. These beds of sandstone dip continuously westwards for a distance of over 500 yards at angles which vary from 10° to 22°, so that the total thickness exposed cannot be less than 370 feet. Here the Binny Sandstone is considerably thicker than in the Binny and Broxburn sections. Carbonaceous and marly shales compose the partings of these massive beds, two of which were quarried for some years, one on the north side of the cutting near Craigton and the other on the south side of the canal to the east of Cockmuir. The highest bed was opened out some time ago at White Quarries for estate purposes, where it is a strong massive rock, but owing to its jointed character it does not form a good building stone. This series has been traced to the north-east through Hopetoun Wood, where the Woodend and Midhope fault separates the Binny sandstone from the Burdiehouse limestone and its under- lying strata. 70 Geological Description of the Shale-fields. I t 1 3 i 3HOB 3&oa t *; 5 w s «. 5= N ■.'.: H S .£ w m Wee Dunnet Shale. — When the Linlithgow Oil Oo. carried on operations it worked an oil-shale about seven feet thick, rich in am- monia, and situated in the Champneurie field, about 30 fathoms below the Broxburn Shale. This seam was then erroneously supposed by the company to be the "Dunnet" shale (Oadell, Trans. Ed. Geol. Soc, vol. viii., p. 153 ; Cadell, Trans. Inst. M. Eng., 1901; Wilson, Sum. Prog. Geol. Survey, 1902, p. 116), but a more pro- bable correlation is with a thin shale, two feet thick, in the Brox- burn district, about 20 fathoms below the Broxburn seam, called the " Wee Dunnet." At Champfieurie it is exposed in the Haugh Burn below Bridge- end, where it is sepa- rated from the Brox- burn seam by a series of blaes with some sandstone bands. In the Linlithgow Oil Co.'s field a cross-cut mine was driven be- tween the Broxburn Shale and this seam, in which the " blaes " was replaced by a coarse limy grit. Two deep diamond bores recently put down by Messrs. James Eoss & Co., Philpstoun, have conclusively proved that this so - called " Dunnet " seam lies Philpstoun and Champfleurie Shale-fields. 71 above the Binny sandstone, and that the marly and blaes strata below the Broxburn shale and the top of the Binny sandstones, are much thicker in this district than elsewhere. Broxburn Shale. — On the eastern limb of the Gateside anticline there are two small areas of the Broxburn Shale, which lie to the east and south of Gateside and on the north side of the Ochiltree fault. The shale was of excellent quality, and both these areas are now worked out. On the western limb of the Gateside arch the outcrop of this shale starts from the intersection of the Ochiltree fault and the public road between Wester and Little Ochiltree. It has there been worked by the two companies, which have developed the field from this point to the vicinity of Philpstoun House, a distance of three miles measured along the outcrop. The mining informa- tion over this area is very complete, and consequently the structure of this portion of the shale measures is well known. The variation in thickness and composition of the strata between the Broxburn and Dunnet shales already mentioned is also accompanied by a considerable difference in the Broxburn Shale itself in the short distance between Champfleurie and Philpstoun. Champfleurie. Philpstoun. Ft. In. Ft. In. Shale, 8 1 ti Roof blaes. Roof blaes, 4 a pq Shale, plain, 1 61 x' Shale, 2 > h 8 ft. 5 ins. ., curly, 6 Blaes, dark, 4 ,, plain, 1 3 - „ 6 ft. 11 ins Shale, - 2 9J Dirt, 1 2 §• Shale, plain, 2 6 p. Blaes, 4 Blaes, 3 to 5 Shale, plain, 1 6 Shale,Broxbum,6 Cement rib, Oi Shale, plain, 1 1 S3 u Cement rib, Shale, plain, 0} 6 -| 5 feet. ., curly, 4 „ plain, 9 „ curly, 9 Pavement 1 daugh, j 23 5 16 11 The levels in No. 7 mine of the Linlithgow Oil Co. in the Brox- burn Shale, and the position of the Houston Coal, prove that on the east side of Ochiltree Castle this seam lies in a shallow syn- cline, which, on the west side of the Castle, is succeeded by an anticlinal fold. These two flexures continue in the Houston Coal to within a short distance of the Edinburgh and Glasgow road, but they disappear in the deepest mine level in the Broxburn shale workings of the Linlithgow Oil Co. to the south-east of Kingscavil. At Bridge-end the east and west fault, with a downthrow to the north of 20 fathoms, shifts the outcrop of the Broxburn Shale for some distance to the east, where it has been traced by several bores and one mine to the bridge across the railway at Philpstoun Station. At this point the outcrop folds round the anticline, back 72 Geological Description of the Shale-fields. to the Bridge-end fault some distance to the north-east of Gateside. Here this seam occupies a shallow synclinal fold, where several acres were worked open-cast, on the east side of which the north- eastern outcrop of the Broxburn Shale passes by Cockmuir and the railway section till it reaches the Midhope fault at Hopetoun Wood. In the underground workings some distance to the west of Philpstoun House a mass of mineral bitumen was got in some troubled ground in the vicinity of this shale. Broxburn Marls. — The " Grey shale," not workable, is found all through the Philpstoun field about four fathoms above the Brox- burn Shale, and occupies its usual position at the base of the Broxburn marls. The latter are well exposed in the railway cutting at Philpstoun Station, and consist of grey and green calcareous beds with calcareous bands which weather light yellow. Fells Shale. — This seam has not been worked in this district. In the Champfieurie area it lies about 40 to 45 fathoms above the Broxburn Shale, and from "Wester Ochiltree to the Bridge-end fault its position is inferred from the proved outcrop of the Brox- burn Shale and the site of the old crop pits of the Houston Coal. On the north side of the Bridge-end fault there is a continuous diminution in the thickness of the strata between the Broxburn and Fells shales. At Westfield the thickness of the Broxburn marls, with their underlying beds, is 17^ fathoms, while at Philps- toun House it is reduced to 15 fathoms. Houston Coal. — Little is known about the former working of the Houston Coal in the small syncline around Wester Ochiltree, with the exception of the traces which have been left of the old crop pits. On the north side of the Bridge-end fault its position has been proved by one pit and several bores near Pardovan ; while at the back of Philpstoun House its outcrop was passed in a well sinking. Two-feet Coal. — At the western edge of this area the inter- bedded ash, which lies above the Two-feet coal, is well exposed on the roadside between Riccarton and Wester Ochiltree. A short distance to the south of this road, and immediately below this volcanic horizon, an old day level is still visible, proving that this seam was at one time worked. At Binns Mill, underneath a similar ash bed, a band of ironstone with a thin coal was wrought forty years ago, which probably represents this coal. To the west and north-west of Champfieurie House and Midhope the base of the Carboniferous Limestone series has never been definitely fixed, and the line shown on the survey map is a con- jectural one. The area between this arbitrary line and the outcrop of the Houston Coal embraces several square miles which has never been systematically explored. The Raeburn Shale is said to have been proved in the vicinity of Pardovan (Cadell, Trans. Ed. Geol. Soc., vol.viii.,p. 153), but the only two economic minerals, which have been developed in this drift- covered area, are the two thick beds of sandstone at Pardovan and Kingscavil. As these are very different in character and com- Philpstoun and Champfleurie Shale-fields. t 1 i I Ui 2a 'Tff (UNNnaj'rs 3yo8'Via (iiNA/na/vs/ syyg % I y« 3 1 4 <± I i 3VOB 3 yog 3U0S | I svogv/a 3U0S so A Sff a a a CD CD a § s bounds the northern side of the Ingliston field. Half a mile to the north-east of Wheatlands this shale has been got, in a bore, below the dolerite sill of Craigie Hill with its characteristic marls on top and over 100 feet of Dunnet sandstone below. Another bore 500 yards to the north of this point shows that the sill of Oraigie Hill is 252 feet thick, and rests there on 90 feet of sand- stone and fakes, with a few feet of marly beds at the base. This sili- ceous series, in all probability, repre- sents the lower portion of the Binny sandstone, with a few feet of the Dunnet marls below. On the north side of Craigie Hill and south-west of Dolphington, another bore passed through 137 feet of sandstones and sandy fakes overlying 224 feet of the Craigie Hill dolerite, the bore terminating in this rock. Had this bore been carried further it might have proved the position of the Dunnet Shale below the sill at this point. " To the west of Dalmeny a bore from the outcrop of the Brox- burn Shale pierced a succession of beds of diabase several hundred feet thick at the base of the Binny Sandstone Series" (Cadell, "Oil-shale Fields of the Lothians," Trams. Mm. Eng., p. 55). The evidence furnished by these bores (Fig. 18) shows that the Dunnet Shale lies with a gentle dip a little distance below the southern edge of the Craigie Hill -intrusion, which cannot be less than 400 feet thick, and this intruded material, together with the Binny sandstone, must intervene between the Brox- burn and Dunnet shales in the south portion of the Dalmeny field. Though occupying a higher horizon on the south side of the Ochiltree fault, the sill of Craigie Hill is in all probability the southern exten- sion of the sheet which has been already described as intersecting the 88 Geological Description of the Shale-fields. Queensferry and Abercorn district between Mons Hill and Hope- toun House. Binny Sandstone. — The Binny Sandstone Series is exposed in an old line of quarries to the east and south-east of Dalmeny village, but at present these quarries are not worked. Here the beds, following the outcrop of the Broxburn Shale to the south, dip to the west and then to the north-west at an average angle of 30°. East of the old railway station at Dalmeny these quarries cease, and the ground is covered with drift. South of this station the dip must become very flat, and the Dunnet Shale (Fig. 18), which has been proved at Wheatlands, may continue beneath the Binny sandstone, without any large dislocation as far as this point. " These sandstones lie in thick beds with shaly partings, and the upper portion of the section shows much grey bituminous shale full of entomostraca such as is also met with at Binny" (Oadell, " The Oil-shale Fields of the Lothians," Trans. Min. Eng., p. 54). The Binny sandstones were also quarried at Craigend on the western side of this basin. Broxburn Shale. — The lower workings in this series of shales are in the " Curly" and " Broxburn" seams. The former, which is the higher of the two, is eight feet thick, and is separated from the latter by four feet of shaly blaes, forming the roof of the Broxburn seam. This lower section, the workable thickness of which is seven feet, is a little richer in oil than the overlying " Curly " seam, and produces 30 gallons of crude oil with 35 lbs. of sulphate of ammonia per ton. The Six-Feet seam is the highest of the group, which, at Dalmeny, yields 20 gallons of oil per ton, with 40 to 50 lbs. of sulphate of ammonia. Section of Broxburn Shale, Dalmeny. Ft. In. Roof hard limy freestone. - Black blaes, Six-Feetl Shale, Seam. 1 Blaes, '■Shale, - Blaes, (Shale curly, ,, plain, Blaes, Shale, Blaes shaly, Broxburn / Shale inferior, - Shale. \ ,, good, Blaes soft, Pavement black blaes, The mining of the Broxburn shale at Dalmeny has hitherto been confined to the south and south-east portions of this basin, and although the beds are known to strike south-westwards, and then to bend round and strike northward by Dundas Castle, the shale has not yet been found workable in that direction, as it is burnt by the dolerite of Craigie Hill. 2 6 2 6 4 3 5 8 2 3 1 4 3 4 2 6 4 12 Ingliston and Dalmahoy Areas. 89 The Ochiltree fault cuts off this field to the north, and as this dislocation has a low " hade " to the south, the workable area of the Dalmeny field has thus been considerably diminished. Fells Shale.— The Fells Shale is exposed in the cutting of the Dalmeny and Port Hopetoun Eailway, but in this field it is not of commercial value. Below this seam there are several thick beds of sandstone overlying the Broxburn marls. Houston Goal. — About 220 feet of strata, chiefly grey sandstone and fakes, separate the Fells Shale from the Houston coal. This well-known seam is exposed in the cuttings of the main railway and Port Edgar branch, but it is so thin and disturbed as to be quite unworkable. In both these cuttings it is surmounted by interbedded tuff and agglomerate, which probably represent the southern extension of the base of the Burntisland volcanic group, as the Houston Coal at Binnend, Burntisland, is directly overlaid by the interbedded volcanic rocks of the Kinghorn area (Fig. 21). The tuffs at Dalmeny are succeeded by 75 feet of blaes with sandy beds, which, in turn, are overlaid by the Houston marls with the" grey shale" of the West Calder and Philpstoun districts at their base. 13. Ingliston and Dalmahoy Shale-fields. Ingliston Area. — The centre of this field lies one mile to the south-east of Kirkliston and on the south side of the river Almond. The explored portion forms the western limb of a synclinal fold, the eastern limit of which has been partly determined by bores and one pit. This view is strengthened by the presence of an oil-shale in the Gogar Burn to the east. The seam of oil-shale at present worked at Ingliston by Young's Oil Co. is considered by this firm to be the Dunnet Shale. Its outcrop has been proved by bores to extend from the east side of Foxhall by Hallyards to the railway bridge a little to the west of Lochend. At Foxhall the northern end of the basin is probably intersected by an east and west fault with a downthrow to the north. On the south side of this fracture the eastern side of this basin appears to lie between Boat House Bridge and Lenny Moor. A pit sunk a few years ago at Lenny Moor soon exhausted the shallow field at this point. Between Brigs and Hallyards the western side of this basin is worked by a pit 62 fathoms deep, and the workings of this shaft show that the strata are inclined at an angle of 10° to the south-east for a distance of 500 yards from the pit bottom. The Ingliston and Newliston outcrops of the Dunnet Shale dip respectively to the south-east and north-west, and hence an anti- clinal fold must lie between the Ingliston and Newliston fields. This south-easterly dip brings on the Broxburn Shale to the north of Slatebarns, north of Ingliston House. The bores around Ingliston prove a great depth of superficial deposits, and no rock is seen till Gogar Burn is reached. It is quite possible that a large shale-field may be concealed beneath the drift in this district. 6 4 9 6 0. 6 1 2 4 1 5 90 Geological Description of the Shale-fields. Bunnet Shale.— The Dunnet seam in the Ingliston field has the following section. Here the six inches of grey blaes forms the "holing" and the one foot two inches of good shale below is afterwards removed : — Feet. Inches. Roof inferior shale. Parting, Shale (good), ,, (inferior), - Grey blaes, - Shale, plain, good, ("Blaes, Pavement-] Rib, (.Blaes, The evidence furnished by the bores indicates that this seam is the lowest of the Dunnet Shale series. The various strata with shale ribs and shaly blaes, which lie above it for eight fathoms, may be correlated with the three upper seams of the Mid-Calder and Clapperton Hall fields. These upper Dunnet Shales have been proved in several bores in the Ingliston field, as for instance in one at Hallyards, three quarters of a mile south-west of Boat House Bridge, the details of which are given below : — Surface and strata, Shale with dark ribs, Strata, Shale blaes, Strata, Shaly blaes with ribs, Strata, Shaly blaes and rib, Strata, Shaly ribs and blaes, Strata, Shaly blaes with limy ribs, Strata, Shale Dunnet, Dunnet Marls. — Next in order we find about 350 to 400 feet of dark limy ribs and blaes with limy sandstone bands, which occupy the position of the Dunnet marls. The Binny sandstones are not represented in this portion of the oil-shale field. Broxburn Shale. — The Broxburn Shale, which has not yet been worked in this field, lies on the top of the series of Dunnet marls, and has the following section : — Shaly blaes, Shale, - Shaly blaes, Dark blaes, Shale, Shaly blaes, Dalmahoy Aeea. — Three miles to the south of Ingliston and to the east of Raw Camps there is an outcrop of oil-shale in the Fms. Ft. Ins. 32 3 4 6 2 5 6 1 1 2 2 3 1 4 6 1 1 2 1 10 2 1 10 1 2 11 4 2 10 9 8 Feet. Inches, 1 6 4 1 2 6 3 9 1 3 Burdiehouse and Straiton Shale-fields. 91 Gogar Burn between Burnwynd and the Deer Park of Dalmahoy. In the park a steep rock escarpment runs along the south side of the stream, where an oil-shale from eight to ten feet thick rests on a band of marl two feet in thickness, while the lower portion of the cliff is composed of black blaes resting on marl. To the south of Burnwynd the Pumpherston Oil Co. put down some bores and made a trial of this seam several years ago, but the results then obtained did not justify further operations. There is no direct evidence whereby this shale can be identified. 14. Burdiehouse and Straiton Shale-flelds. All the shalefields described in the previous sections are situated to the west of Edinburgh and the Pentland Hills, while those now to be considered lie to the east of this range and about four miles south of Edinburgh. The Burdiehouse and Straiton fields (including that of Clippens) lie about one mile to the north-west of Loanhead, and extend for about two miles N.N.E. and S.S.W., being bounded on the west by the Pentland fault. N.E BROOMHILL STRAITOH S.W. LOANHEAD Fig. 19. — Section of Burdiehouse and Straiton Shale-field. The above section illustrates the relations of the strata as far as the area has been opened out. Along the western side the beds form a compound syncline, the western limb being inverted next to the Pentland fault. This fold is a continuation southwards of that of Gilmerton. Immediately to the east they roll over the steep anticline of Straiton and plunge beneath the Carboniferous Limestone Series of the Mid- Lothian basin. In the southern portion of the mined area, near Pentland Mains, the three seams are thrown into a sharp compound anticline, and after passing over this flexure the different outcrops, without any break, resume their former trend. 92 Geological Description of the Shale-fields. Comparative Table of Strata at Straiton and Broxburn. Broxburn Straiton Shale-field. Shale-field. Feet. Indies Feet. N. Greens Limestone — 1 Strata, 1,057 Paper shale — )■ 1,020 Strata, 133 1 Houston coal — J Strata, 51 8 1 Twenty-inch coal — I 243 Strata, 46 8 J Fells shale — Strata, 145 211 Broxburn shale — Strata, 13 6 1 tn " Limestone, 7 6 CO Strata, 10 6 Limestone, 16 Strata, 23 8 >"-! 520 Limestone, 17 0) Strata, 22 1 Binny sandstone 65 CO Strata, 89 9j oa __ Dunnet shale — Strata, 177 483 Limestone, Burdiehouse — Strata, about 550 761 Pumpherston shale — The above general section shows the succession of the beds in this field as exposed in the cross-cut mine at Pentland. Pumpherston Shales. — A diamond bore put down in the centre of the Straiton anticline proved the position of the Pumpherston Shales to be 550 feet below the Burdiehouse Limestone, which are here represented by three bands of thin oil-shale and shaly blaes. Burdiehouse Limestone. — On the eastern side of the Straiton arch the Burdiehouse Limestone has long been exposed between Burdie- house and Straiton in a series of quarries which date back to the early part of the last century. It is about 30 feet thick, and dips south-east at angles varying from 20° to 25°. It has a dull grey or cream colour, and some of the beds are well banded with layers of dark carbonaceous material. The limestone and some of the bands of overlying shale are very fossiliferous. At Burdiehouse Mains the north end of the outcrop is let down and concealed by a large east and west fault with a downthrow of 60 fathoms to the north. To the south of Straiton it has been traced to Pentland Mains. On the east side of this fold the limestone was at first worked open- cast, but is now mined both at Straiton and Burdiehouse. The position of this bed, as shown on the map along the western limb of the Straiton anticline, is inferred from bores. The productive part of the Burdiehouse and Straiton shale-fields lies to the east of the Straiton anticline. The worked portion of Burdiehause and Straiton Shale-Jields. 93 the field is intersected to the north by the dislocation which affects the limestone ; and it has not been mined farther to the south than Niven's Knowe. The field was worked till recently by the Clippens Oil Co., and the proved ground extends for a distance of two miles, with an average breadth of 600 yards. It contains three workable seams, and the outcrops on this section lie parallel to that of the Burdiehouse limestone. Dunnet Shale. — The Dunnet shale is the chief oil-producer in this district. It was originally termed the "Pentland" shale, is from 5£ to 6 feet thick, and lies 166 feet above the Burdiehouse limestone. It yields from 25 to 26 gallons of crude oil and from 20 to 23 lbs. of sulphate of ammonia per ton of shale, and is rich in solid paraffin. As the bed overlying this seam is composed of soft friable blaes it cannot be so economically mined as one with a stronger roof. Broxburn Shale. — On the east side of the Straiton anticline the Dunnet seam is separated from the Broxburn Shale by 258 feet of strata. The details of the section of this shale, as measured in the cross-cut mine, are shown below. Having a strong roof, it was more cheaply worked than the Dunnet seam, and gave from 20 to 22 gallons of crude oil and 20 to 21 lbs. of sulphate of ammonia per ton. Feet. Inches. Roof blaes. Shale, brown, Blaes, Shale, poor, ,, Broxburn, Pavement blaes, 7 5 Fells Shale. — The Pells shale lies 137 feet above the Broxburn seam, and the section exposed in the cross-cut mine is given below. Blaes, Shale, Fells, Fakes, Although its average thickness is about two feet, and though the shale is difficult to cut, its extreme richness, yielding as it does from 34 to 35 gallons of crude oil and from 10 to 19 lbs. of sulphate of ammonia per ton, makes this seam a profitable one for mining purposes. Houston Goal. — Two coals lie above the Fells shale, one twenty inches thick, and a seam that occurs on the horizon of the Houston Coal, with which, in all probability, it has been correctly cor- related ; but as both these coals are thin and impure they have never been worked in this field. Paper Shale. — Above the Houston Coal there is a thin finely- laminated oil-shale, locally termed " Paper Shale," which has never been worked, and may be the equivalent of the Mungle or Bae- burn shale of the west. 2 3 9 3 6 Feet. Inches, 11 1 8 8 10 94 Detailed Description of the Shale-fields. In the syncline on the west side of the Straiton arch, between Broomhills and the Pentland fault, a curly shale, four feet thick, was got in a trial pit and supposed to be the Dunnet seam. Fells Shale. — The strata in the Burdiehouse Burn, near Broom- hill farm, dip south-east at angles varying from 85° to 96°, and consist of black blaes with a bed of oil-shale thirty inches thick. At the side of this burn, below the farm, a mine has been driven for a short distance into the shale, which has been identified as the Fells. A quantity of it was tested at Pumpherston, but the results were not satisfactory. Comparison of the Straiton and Broxburn Fields. — The cross-cut mine at Pentland gives a complete section from the Burdiehouse limestone to the Fells shale, as shown in the comparative table (p. 92) and horizontal section (Fig. 19). At Pentland the Binny sandstone is represented by 65 feet of strata, as compared with 277 feet at Broxburn. For a time it was worked in a quarry at Straiton opposite the office of the Oil Company, but quarrying operations were abandoned, as the stone, after exposure to the weather, deteriorated on account of the crude oil, which it contained, oozing to the surface. Another marked difference in this eastern shale-field is the presence of the three limestones, with a total thickness of 41 feet, above the Binny sandstone. These are not represented in the Broxburn field, unless the marly fakes below the Broxburn Shale may be considered as their equivalent. Another distinctive feature is the series of marls overlying the Broxburn shales in the west, which are represented by 137 feet of sandstones and blaes at Straiton with no marls. In this field the Dunnet Shale has been mined to a vertical depth of 1 1 75 feet from the surface, where it was just as rich in oil and ammonia as when first opened out. In this respect it differs from the Linlithgowshire shales, which, with one exception, all depreciate downwards both in the yield and value of their pro- ducts. At St. Catherine's Well, west of Gilmerton, petroleum has been observed floating on the surface of the water, and the oil-shale series has been proved by bores and trial openings to exist in a narrow strip from Burdiehouse to the coast between the Edge coals and the Pentland fault. The extension of the Straiton field to the south-west alongside the Pentland fault is rendered probable, as oil-shales occur in the North Esk, near Carlops, and a seam about four feet thick has been proved in several bores near Rutherford. 15. Burntisland Shale-field. From the description given by Sir A. Geikie, it appears that there can be no doubt that the Grange limestone of Burntisland is the equivalent of the Burdiehouse Limestone of the Lothians * which affords an excellent base line with which to correlate this shale-field with those of the Lothians. * " The Geol. of Central and Western Fife and Kinross," Mem. Geol. Sur p. 46. Feet. Inches, 18 3to 4 30 7 6 6 2 Burntisland Shale-field. 95 Burdiehouse Limestone. — On the west side of the Binn of Burnt- island the quarries of Kilmundy and Grange give the following section : — Burdiehouse limestone, Shales, with fakes, False-bedded white sandstone, Burdiehouse limestone, Sandstone, Burdiehouse limestone, The Burdiehouse limestone is here represented by three beds, separated chiefly by arenaceous deposits, the uppermost of which was first quarried and is now mined by the Oarron Company, and the stone is sent to Carron for iron-smelting purposes. This limestone has also been opened out on the east side of Humbie Wood, due west of Glenshee, where it dips E.N.E. below a bed of sandstone, and is about 17 feet thick. A fault probably intervenes between the Humbie Wood outcrop and Dallachy quarry, and from this excavation it can be traced by Kilmundy and Grange quarries till it is cut off by the volcanic agglomerate of the Binn. The Newbigging mine of the Carron Company extends to within a short distance of the Kinross road below Loftheads, where the bed is 15 feet 6 inches thick. The air-shaft recently sunk to the north of Bankhead gives the following section : — Section in Air-shaft at Newbigging. Surface, Blaes, Shale, Dunnet, Sandstone, Blaes, Limestone, Thus it is clear that the Barracks Shale is here represented by the few inches of blaes on top of the limestone, and that the thick- ness of strata between the Burdiehouse Limestone and the Dunnet Shale is 147 feet 7 inches. On the east side of the Binn the highest bed of this limestone has been quarried at Berryhill and Dodhead quarries. The out- crop has a north-easterly trend for about two-thirds of a mile in the direction of Kinghorn Loch, and it abruptly turns to the south on the west side of Grangehill. Dunnet Sandstone. — Between the Burdiehouse Limestone and the Dunnet Shale lies the ; ' Grange sandstone," the equivalent of the Dunnet sandstone of the Lothians, which is well exposed in the Grange quarry, Burntisland, where it is 119 feet thick, the bottom not being visible. The Burdiehouse Limestone probably lies 20 feet below. The basal portion, about 70 feet thick, is an excellent " liver rock." It is a very pure greyish white sandstone, which is extensively used in Fife, Dundee, Edinburgh, and Glasgow for fine-dressed freestone blocks. The beds of sandstone, measuring Feet. Inches, 16 24 4 10 147 7 15 6 96 Detailed Description of the Shale-fields. 27 feet in thickness, above the fine building stone, are only suitable for rubble work. The remaining portion of the quarry- face, 22 feet, consists of limy sandstones and fakes. Dunnet Shale. — The Dunnet Shale in 'the Binnend field lies 100 feet above the Burdiehouse Limestone. Twenty years ago it was extensively mined by the late Burntisland Oil Company, and the following section has been drawn along the line of the longest mine. S.S.£ -» GRANGE HILL — AiN.IV. COMMON Fig. 20. — Section from Grangehill to Common, Burntisland. The shale varied in thickness from 4 to 7 feet, the bottom of the seam being curly and the top plain with two white ribs. The out- crop of this bed follows that of the Burdiehouse Limestone, and both are extensively affected by the north-east fault which runs through the mined field. The principal mine was situated on the west side of this dislocation, and it followed the shale for 2,700 feet from the mine-mouth. The seam dips to the N.N.W., the angle of inclination being at first 10°, but gradually increasing to 18° at the face, which lay 900 feet below the surface when operations were suspended. Two faults were crossed at distances from the mine- mouth of 1,075 and 2,060 feet running nearly due east and west, with a downthrow to the south of 60 and 51 feet respectively (Fig. 20). On the east side of the north-east fault the shale lies on an anticline, a mine being driven along the ridge of this flexure to the north-east, with a branch in an E.N.B. direction. The best shale was found at the bottom of this mine in the direction of Kinghorn Loch. On the west side of this field the seam deteriorated as it approached the volcanic neck of the Binn, east of which the shale is exposed on the top of the Grange sandstones, where it appears to be about 10 feet thick, but diminishing to the west, as proved by the air shaft section (p. 95). Some years ago a quan- tity of shale was extracted from two trial pits on the Newbigging estate, and practically tested at Pumpherston, but the results of the tests, combined at that time with the want of direct railway communication with the Lothian oil refineries, led to no further steps being taken to develop this field. Binny Sandstone. — Above the Dunnet Shale at Binnend lies the representative of the Binny sandstone, which forms a steep escarpment just above the old mine-mouths, and was quarried and used in the construction of the oil works. Here it is a very inferior stone. On the west side of the Binn the same bed Burntisland Shah-field. 97 appears at the foot of Silver Barton Hill, above the Grange sand- stone quarry. Fells Limestone. — At Binnend the Broxburn Shale is not repre- sented, but 210 feet above the Dunnet seam and close to Binnend farmhouse there is an exposure of a yellow, ochreous, fresh-water limestone about four feet thick, resembling the limestone which accompanies the Fells Shale in the Lothians. This correlation is rendered still more probable by the position of the Houston Coal 100 feet above this limestone. BURNTISLAND Fig. 21.— Plan of the Burntisland Shale-field. Houston Goal. — Before the Burntisland Oil Company ceased operations a cross-cut mine was driven into the shale above the Fells limestone in search of the Broxburn Shale. In doing so they broke into the old workings of the Houston Coal, which was found to be an inferior seam, 13 inches thick, and full of iron pyrites, with a blaes roof and pavement. This coal mine was regularly laid out " in stoop and room workings,'' but no record exists as to the period when it was worked. Immediately above the blaes roof of this coal we find the volcanic series of Burnt- island, which can now be correlated with the interbedded lavas and tuffs of Bathgate and Linlithgow Hills to the west. Note. — While this Memoir has been passing through the press, analyses of specimens of the Wardie Shales, collected by the Geological Survey, near Granton, have been made by Mr. Steuart, of the Broxburn Oil Company. The average results obtained are as follows :— Crude Oil, 11 "13 gallons per ton of shale ; Sp. Gr., '875 ; Setting Point, 85° F. ; Sulphate of Ammonia, 20"09 lbs. per ton of shale. PAET II. METHODS OF WOEKING THE OIL SHALES. i. Search for Shale. By a careful examination of rock exposures, and notably in the beds of rivers, sides of ravines, quarries, and railway cuttings, indications may be found which point to the existence of a seam of shale ; or the shale may be seen cropping out with shaly blaes interposed, and having an inclination ranging from horizontal to perpendicular. Having taken the inclination of the strata, the next step in the search for shale is to sink bore holes to the seam and obtain sample cuttings, whereby the depth of the seam from the surface is ascer- tained, and its thickness and quality at these particular spots. In the progress of the bore, however, wants, faults, slips or troubles may be encountered, and if these are present in the field and are not shown by the bores, all calculations as to the position of the shale will be upset. Heavy expenditure has often been needlessly incurred through insufficient boring. The bore holes should be put down in a straight line to the dip of the strata or at right angles to the " strike," and placed at a reasonable distance from each other. To trace the outcrop of the seam and ascertain its range of extension, a series of shallow bores is put down, and here again one may be misled by finding the shale to dip in the contrary direction to that expected. Should the strata be disturbed, either by faulting or by folding, the closer the bores are to each other the more trustworthy will be the information in regard to the position, dip, &c, of the shale. This also applies to highly-inclined strata, as the bore may be placed beyond the outcrop, and so miss the shale altogether. A study of the following sketches (Fig. 22) will show how easy it is to be led astray by evidence from bores, as one of them does not strike the shale at all, while others either pass into it too soon or meet it at an unexpected angle. When any indication of irregularity is shown, it is advisable to put down two or three bore holes not far from each other. A difficulty which presents itself to the borer is the distinction between shale and blaes. They are closely associated, and in the early days of the industry it was not uncommon for a borer to allow his chisel to pass through a seam of shale and record it as blaes in his journal ; but, fortunately, this is now of rare occur- rence. Similarly, we find seams of blaes recorded as shale in old Search for Shale — Methods of Boring. 99 a a .3 o o & CD o , 1 o M journals of bores. Borers can tell when they strike shale or blaes by the difference in the resistance offered to the chisel, and the rebound of the rods, both indications being quite perceptible to experienced men. Tho percussive method of hand boring is usually carried out in the shale dis- trict, the plant consisting of headgear, rods, chisel, &c. ; but of recent years the diamond bore has been extensively used, and from its revolving action, by means of a steam engine, a solid core is obtained which readily shows the character and inclination of the strata passed through. A " hand rig " diamond boring machine which can bore either hori- zontally or vertically has recently been at work in the shale district, and is giving highly satisfactory results. It is capable of boring to a vertical depth of 100 fathoms, produces cores up to 2£ inches in diameter, and, besides giving the core, does the work in half the time, for the same cost, as by the percussive method. Its porta- bility is a favourable feature, and unless for very deep bores it will probably supersede the steam-driven diamond rig, which necessitates a heavier plant, and consequently more expense in shifting from place to place. Cost of Boring. — (a) Percussive Boring. — The prices ruling in the shale district are from 4s. 6d. to 5s. 6d. per fathom for the first five fathoms, 9s>per fathom for the second five fathoms, and so on, increasing by 4s. 6d. per fathom on the completion of every five fathoms. (b) Rotary Boring. — The cost of this system is about the same as that of percussive boring. When a seam of shale has been found by boring operations, and the exact position and depth of outcrop determined, it is necessary, before sinking a mine, to put down a trial shaft for the purpose of making sure 100 Methods of Working the Oil-shales. as to the true gradient at which the shale is lying, and the thick- ness and quality of the seam. Fig. 23. — Trial Shaft, with a Level Cross-cut. Tig. 23 shows a trial shaft sunk to a seam of shale, with a level cross-cut driven to another seam in close proximity. A hand wind- lass is used to raise the material which is filled into buckets sus- pended by hemp, or small flexible wire ropes. After sinking to the seam, the custom is to extract from 50 to 100 tons for the pur- pose of testing the quality of the shale, and if the test gives a favourable result the mine is opened out as hereafter described. ii. Mode of Access. The mode of access to the seams of the Pumpherston shales is shown in Fig. 24. There are five seams, dipping from 29° to 38°, and the mine is driven in the middle seam — No. 3 — and continued in that seam. The other seams are entered by level cross-cut mines driven from one to another, as shown, and each is worked sepa- rately, the cross-cuts serving for purposes of communication and transit. Ventilation is effected by a fan placed at the top of a shallow pit sunk to one of the seams. Pig. 25 shows three seams of shale, worked by the Pumpherston Oil Company in the Drumshoreland basin, cropping out at the surface in a vertical position and gradu- ally taking a synclinal form, one side being vertical, the other rising towards the outcrop at an inclination of 24°. These are entered by a mine driven in the metals at an inclination so as to reach the bottom of the fold, the mine passing through the several seams, which are entered by breaking levels away at suitable intervals. At the other side of the basin these seams are entered by level cross cut mines, and are " won out " by driving headings to the out- crop, the shale being lowered by self-acting inclines, thence taken by pony haulage to the inclined shaft. Two pits, one on each side of the mine, are sunk to Nos. 2 and 3 Seams to give ventilation, and stone headings connecting the bottom of these with the work- ings are use'd as airways. Mode of Access to the Oil-shales. 101 > o a s :3 O a 8 IN d M 102 Methods of Working the Oil-shales. Another series of oil-shales in the same basin, known as the Mid Calder shales, is shown in Fig. 26, in which there are nine seams, ranging in thickness from 18 inches to 9J feet, and the mode of access is by a vertical shaft, that now passes through them all, but was originally sunk to the higher seams and continued to the others at later periods. For a short distance from both sides of the shaft the seams are flat, then gradually dip as shown in section (Fig. 26). The inclination in these workings is very irregular, varying from 28° to nearly flat, and the section given is probably the best that can be obtained. The shale is taken from the dip workings by main rope haulage. No. 5 was the first seam to be worked, those above it being entered by cross cuts off the level portion of that seam. (Fig. 26.) Fig. 26.— Vertical Shaft sunk in Oil-shales, Mid-Calder. Mine Driving in the Oil-shales. 103 iii. Mine Driving. Having at length chosen the most suitable site for entering the field and obtaining the shale, operations are begun by removing the soil, which is dug out to the required depth and gradient. Brick walls are then built on both sides, with an inclination corres- ponding to the floor of the excavation, and are spanned by a brick arch which covers the whole, giving it the appearance of an inclined tunnel. The entrance of the mine being now formed, sinking to or in the seam is begun. The usual dimensions of a mine, or inclined shaft, are: — Width, 10 to 12 feet, and height, 6 to 8 feet. Should the sides and roof prove to be of a soft nature, as is generally the case with shale at the crop, the brick walls are continued downwards until harder strata are reached, larch crowns, placed close to each other, being stretched from wall to wall to support the roof. But where the shale is hard and the roof good, side walling is not necessary, and a less costly method of timbering is adopted. In mine driving it is the usual practice to leave a portion of the seam on the roof, and. in such cases, larch crowns fixed at places according to discretion are sufficient to maintain it. Given a fairly good roof, free from fissures or cracks, the distance between the crowns may be from two to three feet, Both sides of the mine are " needled " to a depth of six inches to receive the crowns, but whatever system is adopted the timbering is continued with the sinking of the mine. " Centre-propping " is adopted in some mines. It divides the mine into two unequal parts, and gives better support to the roof. The smaller division has a width of three feet six inches, and can be used for haulage ropes and water-pipes, while the larger is for the winding. The centre props are of fir, set every three to four feet, and fixed to runners which have been placed against the crowns in a longitudinal direction, care being taken to have the props in such a position that they may not be thrust out when the superincumbent weight rests on them. Fig. 27 shows the method of timbering the roof and of centre-propping. As the driving of the mine proceeds, provision will require to be made for another outlet, which is obtained by driving a level in the shale, at a safe distance from the surface, for about 80 feet. A head- ing is then formed in the same direction as the mine, and driven to the surface, where a brick-walled exit may also be erected. In- stead of driving the outlet to the surface a vertical shaft may be sunk to meet the heading. During the progress of sinking, levels are broken away in the seam at regular distances and driven so as to get communication with, and drive headings to form, the outlet mine. The headings are driven in the same direction as the sinking mine, to the levels above, until they connect with the outlet mine or shaft, the process being commonly termed " turning the stoops." The outlet mine is then used for winding the shale ; the other is kept for sinking purposes, and is now known as the sinking mine, thus winding and sinking can go on simultaneously. Should a large daily output of 104 Methods of Working the Oil-shales. Mine Driving — Level Drivimj. 105 shale be required, sinking operations may be continued until a depth has been reached sufficient to meet the demand for some years, and winding can then be carried on regularly at both inclines. The driving of a highly-inclined mine is more difficult than driving a level or upset, this being chiefly due to the awkward position in which the men have to work. The tools used and the method of excavating the shale by gunpowder are the same in both cases. Ventilation is at first effected by air-pipes, fixed on the sides of the mine from sinking-face to surface, where they are connected to a small temporary fan driven by steam. When the outlet shaft has been made, and natural ventilation takes place, the temporary fan is discarded, the air being directed in its passage by means of bratticing so as to travel round the sinking-face. Steam-pipes which are led down to the sinking-pump help the ventilation ; but these are considered only temporary expedients until the perma- nent fan has been erected. The hutches containing the shale are either hauled direct to the surface or conveyed there by sinking-carriage. This carriage is used where the seam is lying at a steep angle, and is preferable to hutches on account of the greater safety to the men working at the face, as it is seldom derailed, and the danger of accident by pieces of shale falling from the hutches and running down the incline is almost entirely prevented. The carriage has two decks, the higher or top one being for the hutch, and the lower serving as a platform on which to throw the shale for filling the hutch. During sinking, the water is taken away from the face by pumps, various types and designs of which are used. A small " sinking " pump, which can be moved forward and connected easily as the sinking proceeds, is used at the face, and when it has reached the distance — i.e., vertical height — at which it can throw water to the surface, a lodgment or " sump " is formed in the side of the mine. The sinking-pump now delivers into the lodgment, and another pump is put down at that point to deliver the water at the surface. This is repeated as the mine proceeds, the water be- ing delivered at the surface in lifts or stages. iv. Level Driving. Level driving is carried on by hand labour with the aid of the hand-boring machine. It is important that the level course be maintained, as, if neglected, it will probably mean the curtailment of the size of the pillars or stoops caused by the convergence of the levels. When such a contingency arises, bearings are taken so that the convergence may be avoided ; but in some cases irregu- larities appear in the seam which would eventually run one level into another, and one has to be stopped so that the stoop may be left the requisite size. Before beginning to drive a level, the miner makes an examina- 106 Methods of Working the Oil-shales. tion of the " face" and decides on the portion of the seam likely to make the best holing-bed, off which to blow the shale freely ; but he will be guided as to the best position in which to place the holes when he has seen the effect of a few shots, the natural planes of divisions and joints being noted so as to obtain from them the greatest possible advantage. The number, depth, and direction of the holes depend upon the condition of the bed and the skill of the miner. Owing to the character of shale, smooth beds are often met with, and when these are "jointed" the shots do not have the same effect, and more are required to do the work. The series of holers are bored three and a half feet deep, with sufficient dip to reach the bed, off which the shale is to be blown. When the holes are in- clined towards each other, and one of these receives a heavier charge, it is termed a " burster." After the holing shots have been fired, two holes are bored, one in each corner of the place, to bring down the top portion of the seam. These shots, known as " brairders," are drilled about two feet from the sides of the level, and are driven about two feet deep, with sufficient angle to reach within twelve inches of the sides. When they have been fired, another series of " holers " and " brairders " are carried through until a depth of about five feet is reached. An excavation about five feet in depth by three feet high having now been made, attention is turned towards removing the five feet of shale still remaining. It will be necessary to remove it in two portions, the resistance being too great to permit of it being done in one operation. If there is too much resistance, the hole will act like a cannon, blowing out the stemming, and producing what is known as " a blown-out shot." Shots of this kind are of no ser- vice, and care ought to be taken to prevent loss of explosives through such a cause. The " lifting" shots are placed in nearly the same direction as the " brairders," but instead of both holes being inclined towards the sides, only one is in that position, the other being put in straight. These holes are drilled three and a half feet deep, both being placed about two feet from the sides of the level. The last or lower portion of the shale to be removed— two feet six inches high — is technically termed " bottoms," and also requires two shots, placed in practically the same position and direction as the lifters. The quantity of gunpowder used in each of the various holes, drilled in level driving, averages ; — Holers "Burster," - 2 to 24 lbs. ,, Ordinary, l| ,, Braiders, l| , , Lifters, 2 , , In the series of holing shots, the " burster " is fired and its effect noted before the ordinary holers are bored, the work done by the former guiding the miner as to the number and position of the latter ; but as shale seams requiring to be wholly blasted are not Level Driving. 107 all alike, the number of holes and quantity of gunpowder to be used must depend upon the prevailing conditions. Holes are bored by the barrel boring machine. A pit-prop, generally known as a boring-tree, is fixed in position by " stamp- ing " a hole in the bench and roof, and to this prop the machine is fixed at the barrel-end by a pointed piece of iron, which is sunk into the prop by two or three turns of the barrel. The other end is supported by the drill. Boring is now started by a backward and forward movement of the ratchet handle, and is continued until the screw is extended to its full length, when the barrel is unscrewed by hand and the drill taken out and a longer one put in its place. This process is repeated until the hole has been bored to the required depth. Some seams have a bed of " daugh " or other soft material embedded in the shale, or at the bottom of the seam, and when this occurs the holing can be done by the miner's pick, thereby saving the laborious process of boring. Less gunpowder is required in seams which have this holing. Driving "Ends" or Upsets. — The "ends," or upsets, leaving the levels at regular intervals, are driven by the same method as the latter. The miner, however, has not the same freedom in working the upset, on account of the difficulty in maintaining his footing on the incline ; but, in order to facilitate his movements, pit props are laid across the pavement at regular distances apart and fixed to the sides of the place. Stamp holes are also made in the pavement to give better footing, and ropes and chains afford considerable assist- ance as he ascends or descends the upset. The boring operations at face are facilitated by the erection of a simple " scaffold," consisting of two props placed vertically, with two or three laid horizontally against them, thus making a plat- form from which the miner can work freely. The inclination of the upsets causes the shale, when blasted, to run to the bottom, where it is placed in hutches, which are pushed or drawn out to the inclined shaft for conveyance to the surface. Driving Cross-cuts. — These are driven to obtain seams in close proximity to each other. They traverse the different beds, and are wholly driven by the use of the boring machine and explosives, their average width and height being about six feet. Labour Notes. — The number of men usually employed at driving a level is two or three — either one or two working at the face, and one placing the shale in hutches and " drawing " it to the inclined shaft. These men are known as contractors or placemen, shift facemen, and drawers, respectively. The contractor agrees to drive the level at a price, and is held responsible by the manage- ment for working it safely and properly. He pays the wages of all shift facemen and drawers, pays for all explosives, and supplies and maintains all necessary tools. The jate or speed at which a level is driven depends chiefly upon the nature of the seams, but is also affected by other conditions. In a fairly good seam with a level 12 feet wide and eight feet high, two feet per day or 12 feet per week would be considered a good 108 Methods of Working the Oil-shales, average distance, and by calculation the daily number of tons of shale won, assuming 20 cubic feet as being equal to one ton, would be 12 x 8 x 2 , or 9 tons 12 cwts. This would give an output of three tons per day for each of three men, and, while that figure is often exceeded, it may be taken as the average " darg" in the shale workings. v. Blasting and Explosives. Gleaning Shot Holes. — The shot holes having been bored to the requisite distance, the miner must clean them out before inserting the explosive charge. For this purpose he uses a tool termed a scraper or cleaner, which is made entirely of copper, and is about four feet long and ^ of an inch in diameter. One of the ends is flattened and bent over at right angles to the rod, giving it the appearance of a button with a diameter slightly less than that of the shot hole. The " button " end is put into the hole, and, when withdrawn, brings with it a portion of the dust, the process being repeated until the hole is quite clean' and ready for the explosive charge. Cartridges. — These are made of strong paper, and vary in length according to the amount of explosive required. Their diameter is slightly less than that of the shot hole, so that they may be easily inserted, as the Coal Mines Eegulation Act of 1887 prohibits an explosive to be forcibly pressed into a hole of insufficient size. This Act also prohibits the taking of explosives into a mine or pit unless in cartridges placed in a secure case or canister containing not more than 51bs. H*jgC&a&j5 ^ffe^^-Euaay Fig. 28. — Cartridge in position in Shot-hole. Charging and Firing. — The miner having determined the size ot cartridge to be used inserts a length of fuse into one end, and pushes the cartridge gently to the back of the hole by means of a " stemmer," the fuse being of sufficient length to project five or six inches beyond the mouth of the hole. The "stemming," Blasting and Explosives. 109 which is composed of the broken material and dust got from the hole, mixed with a little water to bind them together, is then rammed with the " stemmer " against the cartridge until the hole is filled to the mouth. The charge being now ready for firing, the fuse is lighted with the lamp used by the miners, who retire to a 3afe place until they hear the shot go off. Fig. 28 shows the cartridge in position and ready to be lit. The fuse burns at the rate of about 30 inches per minute", giving ample time for the men to place themselves beyond reach of the shot. It has a central core of gunpowder surrounded by cords of cotton or flax, which have an outer covering of tarred tape. For blasting in wet places the fuse may have an outer covering of two coils of tape with a layer of varnish between, or, as a further pre- ventive against dampness, these can be covered with gutta-percha. Accidents in Blasting. — Accidents occur from many causes, a few of which may be given. 1 . From break in continuity of fuse, dampness of fuse, or damage to fuse while charging shot-hole. 2. By men returning too quickly when a shot hangs fire. 3. Attempting to light more than two shots at a time. The number of accidents from the first cause is small, and in nearly every instance can be traced to the miner having returned to his working place before the time stipulated in the Act. The second cause has the same ultimate effect as the first, but the num- ber of accidents, fatal and otherwise, due to the carelessness or foolhardiness of the miners, has been much larger than should have occurred with ordinary precautions. The third cause was also a source of deep concern to those engaged in shale mining, as the men were not restricted to a given number of shots to be fired in any one place at any one time. Hence they frequently proceeded to light more than two shots, with the result that many serious accidents occurred, probably caused by the miner returning to the face in the belief that all the shots had gone off, while one failing to light properly, and exploding as he went forward, caused serious and, in some cases, fatal injury. With the view of doing everything possible to reduce these acci- dents to a minimum, Mr. Robert M'Laren, H.M. Inspector of Mines, East of Scotland District, had a conference with the mining managers of the shale industry about two years ago, and it was then agreed to put into force the following additional special rule 1 A. :— " Shot Firing. — Not more than two shots shall be charged and fired in any working place at any one time, except in upsets rising more than 1 in 3|, where four shots may be charged and fired, pro- vided that one person lights two shots only. Should the fuse of any shot mis-light, the person or persons firing shall leave the place, and shall not return for the period of 30 minutes." The adoption of this rule has had a marked effect, accidents from shot firing being now of rare occurrence. 110 Methods of Working the Oil-shales. It is worthy of note that miners are not allowed by the Act to have a naked lamp on their cap while placing fuse in cartridge. On the whole, it may be fairly stated that, considering the large quantity of gunpowder used in shale mining, the accidents from blasting are comparatively few. Explosives Used. — Except in special circumstances, gunpowder is the explosive used for blasting shale, its slow combustion causing a rending action and producing less small debris than any of the other known agents. The reduction of the small shale to the minimum is of great importance to the industry, on account of its packing closely in the retorts and preventing the heat from carrying out the destructive distillation. Dynamite is used in wet places, where gunpowder is not suitable, and in crossing hard beds of rock, but in ordinary working it shatters the rock too much. Ordinary mining gunpowder is of coarse grain, highly glazed, and the usual composition is 75 parts saltpetre, 15 parts carbon, and 10 parts 3ulphur. It is stored in magazines convenient to the various pits or mines, and given out in the quantities required by the miners employed on the different shifts. Quantity and Cost of Gunpowder cmd Fuse. — The quantity of gunpowder used varies according to the quality and position of the shale. The undernoted Table may be taken as an average of what is required in a blasting seam : — Shots fired per Day. Shale Got. Gunpowder Used. Cost of Gunpowder. Fuse per Ton cf Shale. Total Cost of Explosives per Ton of Shale. Per Man. Per Ton of Shale. 250 Tons. 475 Lbs. 375 7 31d. 3 16d. ■27d. 3-43d. vi. Methods of Working. There are two well-known methods of working oil-shale — (1) " Stoop and Eoom," and (2) " Longwall," each having its own advantages, according to circumstances. The shale seams vary from four to ten feet in thickness, say seven feet as an average, and on the whole are comparatively free from blaes, fakes, and ribs of unproductive rock. With a thickness of seven feet, experience shows that the method best adapted for the efficient working of the shale is stoop and room ; but in the case of two seams of shale, separated by a bed of fakes, or other foreign material, of sufficient thickness for packing, the longwall method may prove to be more suitable. Stoop and Room. — This method is more generally used through- out the shale district than the other, and will be first described. Its chief characteristics are (1) the "whole" or first working, and (2) the " broken " or second working. (1.) The " whole " working consists of a series of excavations made in the shale, whereby it is divided into rectangular blocks or pillars Stoop and Room Method of Working OiUshale, 111 (Fig. 29). These excavations are called rooms, one set being driven at right angles to the dip of the shale and at regular distances from one another and commonly called levels ; another set driven to the rise of these levels and at right angles to them, being commonly known as " ends " or upsets. The latter are broken off the levels at regular intervals and driven upwards to meet the levels above. Jl l^^^t^l^ Fia. 29.— Stoop and Room Method of Working Oil-shale. The nature of the roof and pavement will determine the width to which the rooms may be driven. In the event of a bad roof, with rooms driven 12 feet wide, falls would be more frequent, and more timber would be used than in rooms driven 10 feet wide ; therefore, it would be cheaper to curtail the width when the roof is not good. The width of levels and ends in the shale workings is 10 to 12 feet. As the pillars are for the purpose of supporting the superincumbent strata, their size calls for special attention. It has already been stated that with increased depth there will be increased pressure, and to provide for this contingency stoops of a requisite size should be formed. In highly-inclined workings the stoops, or pillars, are made longer to the rise than at right angles to the dip, because the inclination of the seam decreases the actual supporting area of the stoops, and inclined stoops under the great weight of the over- lying rocks have a marked tendency to slip. Fig. 30 is a plan and section of highly-inclined stoops. No rule can be given for determining the size of stoops ; in form- ing them one must be guided by prevailing circumstances. These are the condition of the roof and pavement, and the inclination and depth of the seam. It is evident, however, that by leaving large stoops, the ventilation of the ends will require special atten- tion. This will be dealt with under the heading of Ventilation. L12 Methods of Working the Oil-shales. Fig. 30. 7ltK.lt. Oft St-o-OffS. -Plan and Section of highly-inclined Stoops. Of all the difficulties associated with mining, whether the mineral be coal or shale, " creep " is about the most formidable, as when once started it is very improbable that anything can be done to check its destructive effects. The first indication of " creep " is given by the heaving or lifting up of the pavement of the rooms, causing the timber to bend and break and the rails of the hutch roadway to become twisted and displaced. It is primarily caused by leaving small stoops, which are unable to withstand the pres- sure they have to bear. When the weight of the overlying strata bears heavily upon these weak supports, they begin to sink, and in doing so bring down the roof, force up the pavement, and fill the rooms. A secondary cause of " creep " is found in a soft and yielding pavement. Pig. 31 shows a " creep " in its earlier (a) and in its final stages (b) in a highly inclined mine. (ii) Broken Working. — After the first or " whole " working has reached the boundary of the shale-field, or when sufficient ground has been opened out by that system, the " broken " working, or stoop- ing, is commenced. When stoops are kept standing too long they begin to show signs of the effect of the extra weight they have to Stoop and Boom Method of Working the Oil-shales. 113 support, and ultimately collapse, therefore the system of stooping a portion of the field as the " whole " workings proceed — always keeping a safe distance from these workings — is generally adopted. In seams where the shale is highly-inclined stooping should be begun as quickly as possible, in order to relieve the weight on the stoops that are left to support the inclined shaft ; and to avoid a " creep." There being considerably more danger from falls of the roof to the men employed in " broken " than in " whole " workings, it is im- portant that the timbering be skilfully done. Accidents sometimes occur, and shale is often lost, by carelessness on the part of the miner in not having his place securely timbered. Fig. 31.— Creep of the Strata in highly -inclined Mine. The extraction of the stoops must be carried out in a systematic manner, care being taken not to have one lagging too far behind another. From Pig. 29, it will be seen that the operations are carried on with the stoops in advance of each other, thus forming a diagonal line. To maintain this line the places should be equally manned and regularly worked. Methods of Removing the Stoops. — One method of removing stoops is to take a series of slices or " lifts " off them, the slices H 114 Methods of Working the Oil-shales. varying in width from 12 to 15 feet. Fig. 32a shows a 15-feet slice in process of removal. The roof within the area of the last slice is supported with timber, which is usually recovered and used over and over again. Where the roof is good this method has been very successful, and the cost for timber is small. J L J L__J L o \ " 1 o 1 °.o L 1 °°° K ? « e o Iff [ a a □ i Lsss i rT~i r i r~r~ i r Fig. 32. —Method of Removing the Stoops. When the seam of shale is highly-inclined another method of re- moving stoops — as shown in Fig. 32b — is carried out. The stoop is here split up into small pillars, about 13 feet square, by driving ends and cross cuts, which are removed by undermining at foot with the aid of explosives, and to prevent the waste above from coming into the workings, a rib of shale about 30 inches thick is left on the rise side pillars, as shown on plan. Operations are commenced at the top pillar — No. 1 — and are continued down- wards, this being repeated until all the shale in the stoop has been extracted. The removal of the stoops produces great disturbance of the surface of the ground, and the filling up of the huge holes often leads to much trouble and expense. Zongwall Working. — This method may be described as the ex- traction of the whole of the available shale in one operation by means of a long " face," which is moved forward with the wor-king. The space from which the shale has been wrought is filled up with the rubbish got from the seam, and is in Scotland termed the waste, but is known in England as the goaf. Roadways to the face are protected by means of buildings or "packs," the material for their formation being also got from the seam, or, failing this, by ripping or brushing the roof. Erections of timber filled in with the brushing are also used, and, when well built, they stand for a considerable time. Fig. 33 shows a plan of a shale-mine worked on the longwall system. Before commencing longwall working in shale-mines, pillars are formed on both sides of the inclined shaft and principal haulage roads, and are left intact during the first working, so as to give better support to the roof. After these have been made, the longwall method of working is begun, either level course ways nr to the rise. Longwall System. ^Mine mourn 115 i n Fig. 33. — Plan of Shale Mine worked on Longwall System. The size of the buildings or " packs" along the face depends upon the material available in the workings, and also upon the height of the seam, but generally they are from 6 to 12 feet along the face, and as they take the place of the shale pillars — before described as being left to support the inclined shaft, etc. — they should be sub- stantially built in order to sustain the pressure to which they are subjected. Fig. 34 shows a cross section and plan of a longwall face to the rise in the Pells Shale. Wooden pillars, measuring about three and a half feet square, are built on both sides of the roadway, and filled up with material got from the brushing and holing. The distance between the pillars is from three to four feet, the space between them, which extends back four and a half feet, being filled up and tightly packed with the brushing, thus making the length of building along the face eight feet. The " cundy " or space be- tween the " pack " or building is left unsupported so as to allow the strata to fall, thereby taking the weight off the face and pillars. The length of walls varies from 36 to 39 feet, and when the seam is inclined there is a greater length to the rise than to the dip. An average is 23 feet to the rise and 14 feet to the dip side. 116 Methods of Working the OiLshales. The roadways are seven feet wide, and are timbered as shown on cross section, the ordinary crown trees, supported by two props, being placed so as to prevent the pillars bursting out on the road. Cvoss- section parallel to face. Fig. 34.— Plan of Longwall Face. If the clod be soft enough, the holing is done with the pick, but if too hard blasting is resorted to. Fig. 35 shows a section of the Fells seam. 7Vt/Z«%_- S JkaxsXj z Fig. 35.— Section of the Fells Shale. While^ holing, the miner is protected by the erection of " sprags " placed at intervals along the face, the roof being tem- porarily supported by vertical props fixed close to the working Methods of Working the Oil-shales. 117 face, those nearest the "building" being removed and used again as the face is advanced. When the " sprags " are taken out the shale is blown down by means of gunpowder aud " backened," or thrown back to the road-head, where it is filled into the hutch. Fig. 36 shows the method of spragging and supporting the roof at face. tjra fc - ig^ - gr ^aaj&J^ 2 !^^ a.<«.-£p^£c3 j" -%L gfJLfegg^.^^.^j Fig. 38.— Section of Dunnet Shale, Oakbank Pit, Mid Calder. While the lower seam is being worked, the calmy blaes is sup- ported by props set at intervals, the roadways on both sides being built with old railway sleepers or old waggon timber cut to the Working Vertical Shale Seams. 119 required sizes, and formed into pillars three to four feet square, and erected from three to four feet apart. These pillars are in some cases placed near the face. When the shale is removed in the bottom working, the props are drawn, with the exception of a row standing about three feet from the face, which is left for the purpose of breaking off the calmy blaes and allowing the miner room to resume operations in this working. The props at roadhead are drawn last, and the calmy blaes, which parts freely from the top portion of the seam, is allowed to fall. The top portion of the seam is then dealt with, the roof being temporarily supported by props and an occasional timber pillar, until the calmy blaes has been brushed and built on the roadsides, when timber pillars similar to those in the bottom working are built up on the top of the blaes and close to the roof. Fig. 39. — Longitudinal Section, showing Method of Working the Dunnet Shale, Mid Calder. Fig. 39 is a longitudinal section of working. On reaching a distance of 100 yards the branch roads are cut off by levels, slopes or " cousie braes." Those leading to the working faces are sometimes driven level off the slopes, etc., in which case the larger part of the wall face is to the rise. Where the seam is dipping at an angle of about 28° the shale face is advanced to the rise, and " cuddie braes " or spouts convey the shale to the main levels. Working Vertical Shale Seams. — The Drumshoreland basin, which is a continuation of the Oakbank basin, was opened out a few years ago to the south of the Pumpherston anticline, three seams being found under quite unusual conditions at a vertical depth of 360 feet. The mode of access to these is shown in Fig. 25, and it will be seen that at one side of the basin they are in a vertical position. The following method of working is adopted. Levels are cut on both sides of the mine in the seams passed through, and, when driven a sufficient distance, cross-cuts are made to the other seams, this being repeated until all the vertical part is penetrated, one level being below another as shown in Fig. 40. Connection between the levels is got by driving steep upsets. 120 Methods of Working the Oil-shales. Fig. 40. — Method of Working Vertical Seams of Shale. In driving the levels, the shale is taken out to the thickness of the seam in its natural position, and the height is from 10 to 12 feet. This is properly called the first working, and when the levels reach the boundary, stooping is commenced by taking a slice 10 to 15 feet thick from the stoops and working out to a safe distance from inclined shaft. Another slice is then taken off, working in towards boundary and so on, until the whole of the available shale has been recovered, but to prevent the waste coming into the workings from the roadways above, it is found necessary to leave on a rib of shale, as shown in Pig. 40. Before beginning to take the second slice off the stoops " a cuddie brae " is usually laid on the top of the debris which has fallen from the sides and fills the space to a large extent. Failing sufficient debris for the " cuddie " and roadway, wooden pillars are inserted here and there. A scaffold is erected by the miner from which to work at the higher parts of the seam while stooping. vii. Timbering of Levels. As the levels advance, provision must be made for the roof being kept from falling, and this is secured by timber supports. Unfor- tunately the shale workings have not a firm roof like that in coal mines ; the blaes of which it is usually formed being soft and friable. Dislocations are common in some seams of shale, and when detected the part must be well timbered to ensure the safety of the workmen. Decay of Timber. — In addition to pressure the timber in mines suffers deterioration from the moisture in the air, principally in the return airways, and a squad of men termed roadsmen is constantly employed renewing it in the levels leading to the working places. Timbering of Levels— Steel Girder Roof Supports. 121 The simplest way to support the roof is to fix a crown tree (Fig. 41) to both sides of the level by making notches to receive its ends. This tree is fitted as closely to the roof as possible, any intervening space being filled with wooden wedges or splits, so as to distribute the weight. But where the levels are wide and the roof faulty, a prop placed vertically to support the crown, as shown in Fig. 42, gives additional security. Fin. 41. — Roof supported by Crown Tree. Fig. 42. — Roof supported by Vertical Prop. Steel Girder Hoof Supports. — The roofs of many of the principal roadways and headings are supported by steel girders, which are placed close to the roof, the sides of roadway being notched to receive them. Vertical props are set to them, as shown in Fig. 43. Steel girders have considerable advantages over timber, although much dearer at first cost. The advantages claimed are : — (1) Greater durability ; (2) much greater strength ; and (3) economy. Steel girders seldom break under sudden pressure, but give indication of excessive weight by bending to a considerable extent before breaking. Fig. 43. — Roof supported by steel Girder, supported by Vertical Props. Brick Walling. — In some mines the principal roads and landings are supported by means of brick arching, or side-walling, with steel girders stretched from wall to wall, as shown in Fig. 44, the thickness of walls averaging two feet. 122 Methods of Working the Oil-shales. <*> ■=» J3v?tc£-e(.rvJix>v*q It, = JSwickwork » 20 » >» 10 ) Average of 5£ feet, Oil. Galls, per Ton. 28-5 25-2 20-4 32 21-1 30-7 25-1 Sp. Gr. S. Pt ■879 84° F •874 68° „ •862 78° „ ■870 85° „ ■875 70° „ ■874 66° „ ■872 74° F. Sulphate of Ammonia. Lbs. per Ton. 11-8 14-1 24 19 "3 16 7 Plain. 16-7 Curly. 17-7 At Oakbank— Top, 2 feet 9 inches, 28-0 gallons Crude Oil. Bottom, 1 foot 11 ,, 21-12 ,, ,, 148 Yield of Crude Oil and Sulphate of Ammonia. The total nitrogen average of both top and bottom is 0-575 per cent. 11. The Broxburn seam varies from 40 gallons per ton, which has occasionally been obtained as the average of the total thickness of over five feet, to 20 gallons, and in deep parts at Linlithgow about 10 gallons. Selected parts of the shale have yielded 65-6 gallons per ton. The following is taken at random from many sections that have been tested in detail (laboratory tube) : — no Sulphate of Ammonia. Ft. Ins. Gallons. Sp. Gr. Lbs. Bottom, 6 27-4 •874 7 Next, 2 1 50-1 ■893 12-6 9 28-4 •886 130 1 2 32-4 ■891 10-4 Top, Average of 10 277 •897 12-5 5 4 37-3 11-6 At Pentland this seam was variable, and latterly the oil obtainable fell off to such an extent that it was no longer mined. Yield 20 to 24 gallons, and in places only 18 gallons ; sulphate of ammonia 20 lbs. The deterioration increased along the strike to the north- east. The following results from the Pentland field show the variation throughout the seam at the same place : — Sp. Gr. Oil. Sulphate of of Shale. Ammonia. Ins. Galls, per Ton. Sp. Gr. S. Pt. Per Ton. 1st Parting, 7 2-151 18 43 ■883 87° F. 17-14 2nd „ 2 1-940 29-27 •883 90° „ 16-99 3rd „ 5 1-980 31-47 •896 87° „ 21-94 4th „ 9 1-768 39-20 •896 83° „ 23-46 5th „ 12 2-193 16-10 •891 82-5°F. 21-25 6th „ 4 2-260 15 41 •892 85° F. 21-57 Total depth, 39 The M'Lean Shale at Oakbank, very little of which has been worked for some years, was five feet thick, and gave 38-40 gallons of crude oil per ton, and contained nitrogen 0'646 per cent. 12. Lower Wild Shale at Oakbank, five feet six inches thick, gives 19-25 gallons per ton. 14. The Dunnet Seam, near Queensferry, gave 33 gallons of oil and 33^ lbs. of sulphate of ammonia. At Duddingston, where this seam is worked by the Oakbank Company, it gives : — Yield of Crude Oil and Sulphate of Ammonia. 149 Top, 2 feet 4 inches, 3 .. o „ 5 ., o „ 1 » io „ 2 .. 8 „ 1 » 5 „ At Newliston one section gave : Oil. Sulphate of Ammonia. Top, 23 inches, Middle, 23i „ Bottom, 23| „ Average of 5 ft. 10 ins. Gallons. 32-9 41-0 27-0 Sp. Gr. ■877 •877 ■875 Lbs. (Lab. Tube). 12-8 110 12-6 33-6 •876 12-1 In the Broxburn field it varies in quality. At one place at 102 fathoms, when tested foot by foot, it gave 227, 27"9, 227, 18-5, 22-0, 20-0. 12-8 gallons. At Pentland, at No. 4 level, a section yielded : — Shale. Oil. Sulphate of Ammonia. 8 inc 4 , 9 . ?i , hes, Plain Shale (Bottom), Sp. Gr. 2-006 1-786 1-921 1-999 Galls. per Ton. 21-04 36-90 29-10 23-27 Sp. Gr. ■8934 ■8914 •889| •8S6J S. Pt. 91° F. 92° „ 93° „ 92° „ Lbs. per Ton. 20-17 2310 25-59 24-54 6 . 2 , ] Kib " } 2-262 16-82 •8854 94°,, 22-04 13 , Curly Shale, 1-906 3436 •881 95° „ 24-87 3 , 12 , , Eib \ Curly Shale J" Average of 5 feet 6J inches. 2 079 22-98 •885 •886 94° „ 93-4° F. 25-28 25-6 24-0 At Pentland, at No. 7 level, and therefore deeper than the pre- vious section, a section gave : — Shale. Oil. Sulphate of Ammonia. 2 feet 4 inches (Bottom), 2 „ 2 „ „ 6 „ 1 „ „ Curly Average of 6 feet. Sp. Gr. 1-830 1-733 2-298 1-823 Galls. 29-02 4217 14-58 3300 Sp. Gr. •880 ■875 •876 ■870 •876 S. Pt. 89° F. 87° „ 904°,, 91 „ 88i°„ Lbs. 22-90 2184 23-54 25-68 32-65 2306 150 Yield of Crude Oil and Sulphate of Ammionia. At Pentland at the extreme depth at the end of the working road : — Shale. Oil. Sulphate of Ammonia. 13 inches (Bottom) Plain Shale, 15 „ Curly, partly, 15 J ,, Plain, - 15 , , Curly, partly, Average of 4 feet 10J inches, Sp. Gr. 1-996 1-687 2-120 1-945 Galls. 25-77 46-32 21-15 34-83 Sp. Gr. •885 ■889 •883 •884 •885 S. Pt. 96° F. 96i° „ 94f°„ 98* ,, 96° „ Lbs. 20-60 28-06 20-07 20-33 31-35 22-0 The average yield at Pentland for some years was 28£ to 29 gallons of crude oil and 26 to 28 lbs. of sulphate of ammonia per ton, in the Young and Beilby retorts. In the laboratory retort of large size an average of 30 gallons was obtained. The yield of paraffin scale from this seam was very high : 15 to 16 per cent, on the crude oil in laboratory analysis. Of total products from the crude oil it gave 72 per cent, in the works. A seam, lower than the Dunnet Shale, which crops out near Pent- land Works, tried in one foot sections, amounting to 12 feet, gave the following results : — Shale. Oil. Sulphate of Ammonia. Sp. Gr. Galls. Sp. Gr. S. Pt. Lbs. 1 1-841 32-59 •886 911° F. 24-18 2 1773 30-46 ■888 91*° „ 26-72 3 2-092 17-76 ■885 ■ 9l|° „ 20-11 4 2-100 13-34 ■882 92° „ 19-73 5 2-238 8-71 ■883 90£° „ 20 02 6 2-128 17-24 •878 92° „ 20-13 7 2-099 17-22 •881 91*° „ 21-71 8 2-210 7-07 ■878 90° „ 21-30 9 2-282 2-45 ■881 81° „ 20-18 10 2-447 1-94 ■887 81£° „ 17-82 11 2-303 8-02 •884 89° „ 17-84 12 2-443 2-18 •880 92i° „ 13-89 At Oakbank the Dunnet shale, when divided into two parts, yielded : — Top portion, 3ft. Oins, Sp. Gr. of Shale, 1-8534, 32-80 gals. Crude Oil per ton. Bottom „ 2„8„ „ „ 2-0845,21-60 „ „ „ Nitrogen, 0-629 per cent. 15. Oakbank New Shale, eight feet six inches, gives 20-62 gallons of crude oil, and contains 0-548 per cent, nitrogen. _ 16. Barracks Shale at Duddingston gives 18-67 gallons of crude oil per ton. At Eaw Camps it gave 22 gallons. Yield of Crude Oil and Sulphate of Ammonia. 151 The Pumpherston or Drumshoreland seams, lying about 135 fathoms below the Camps or Burdiehouse Limestone, are charac- terised by a high yield of ammonia, with about 20 gallons of oil. 17. No. 1 or Pumpherston Jubilee Seam. — In the works retorts it gave 20-8 gallons of crude oil ; sp. gr. '883. Setting point 81, and 53*75 lbs. sulphate of ammonia. In laboratory tube seven feet at one place gave 17*2 gallons ; sp. gr. -886, and sulphate of ammonia 30 lbs. A section at south border of Holmes estate gave foot by foot by laboratory tube : — Oil. Sulphate of Ammonia. 1. Top, 2. 3. 4. 5. 6. 7. Average of 7 feet. Galls. 25-1 20-0 17-5 19-8 19-4 27-9 241 Sp. Gr. •889 •886 •893 ■883 •882 •888 •887 Lbs. 179 186 21-7 14-7 14-7 22-4 13-7 22 17 18. No. 2 Pumpherston or MaybricJc Seam. — At one place at Eoman Camp it gave 16 - 6 gallons of oil ; Sp. gr. •875, and 32 - 4 lbs. of sulphate of ammonia (lab. tube). 19. No. 3 or Pumpherston Curly Seam. — Tried by itself in works retorts it yielded 29 - 2 gallons in one trial, which is unusually high for this seam, 21 5 gallons in another. Sp. gr. - 874 Setting point 90 deg. F. ; 52 - 6 lbs. in one case, 67 lbs. in another, of sulphate of ammonia. A section of four feet from south border of Holmes estate, tried foot by foot, in laboratory tube gave : — Oil. Sulphate of Ammonia. 1. Top, 2. 3. 4. Average, Galls. 29-4 17-3 25-6 22-1 Sp. Gr. ■887 •880 •880 •881 Lbs. 16-7 18 28-0 24 23-6 21-7 A section at the greatest depth, No. 15 level, gave, foot by foot, ln.Tinrn.tnrv tllhe : — in laboratory tube : 152 Yield of Crude Oil and Sulphate of Ammonia. Oil. Sulphate of Ammonia. 1. Top, 2. 3. 4. 5. 6. Average of 7 feet. Galls. 15-93 24-76 15-56 11-1 12 3 8-48 Sp. Gr. •878 •878 •886 •888 ■888 •888 S. Pt. 79° 79° 78° 79° 78° 78° Lbs. 42-2 35-87 44-31 44-31 42-2 42-2 14-7 41-84' There is a thin stratum near the top of this seam containing fish remains which gave 3516 gallons. Sp. gr. -868. Setting point 87. Sulphate of ammonia 217 lbs. (lab. tube). 20. No. 4- or Pumpherston Plain Seam. — In works retorts it gave by itself 27 gallons of crude oil and 70 lbs. of sulphate of ammonia. A section, foot by foot, near south border of Holmes estate, gave in laboratory tube 11 7 to 30 - 9 gallons of crude oil and 15 to 32 lbs. of sulphate of ammonia. A section at greatest depth, from No. 15 level, yielded, foot by foot, 9 to 26 gallons and 36 to 45 lbs. respectively. 21. No. 5 Pumpherston Wee or Under Shale. — A section of 5^ feet, taken in five equal parts, gave in laboratory tube : — Oil. Sulphate of Ammonia. 1. Top, 2. 3. 4. 5. Average, 5J feet. Galls. 8-48 14-13 31-4 23-1 12-48 Sp. Gr. •884 •885 ■883 •884 ■876 S. Pt. 80° 78° 73° 75° 78° Lbs. 33 06 29-86 23-53 26-13 26-66 18 29 Sections taken from layers between the seams yielded six gallons of oil and 30 lbs. of sulphate of ammonia. A section stretching from the No. 4 or Plain to No. 5 or Wee Seam, taken foot by foot going downwards, gave 17-78, 13-44, 14-51, 11-12, 12-51, 5-41, 5-22, 580, 5-86, 13-36, 5-15, 5-31, 5-53. 11-32, 24-80, 23-87, 12-32, 16-68, 777, 10-72 gallons of oil, and 33-76, 33-76, 3376, 33-76, 29-54, 25-84, 25-32, 27-68, 31-56, 31-56, 31-64, 337, 33-7, 28-48, 23-20, 22-78, 22-98, 23-21, 35-84, 27"43 lbs. of sulphate of ammonia respectively. A section of seven feet tried between the No. 1 or Jubilee and No. 2 or Maybrick Seams gave, foot by foot, beginning at the top, gallons per ton 8-0, 9"6, 16-3, 7-0, 11-8, 11-8, 8-0, and sulphate of Analyses of Scottish Shales. 153 ammonia corresponding, 26-0, 32-5, 28-4, 25-0, 31-2, 26-3, 255 lbs. per ton. Sp. gr. of oil -870. Setting point 69° F. Some companies have worked as shale a considerable proportion of the intermediate strata between the recognised seams. The following analyses of Scottish shales are by Messrs. Mingaye, White & Greig, of the New South Wales Department of Mines Laboratory, and got from the " Memoirs of the Geological Survey of New South Wales : The Kerosene Shale Deposits of New South Wales," by J. B. Carne, F.G.S. These have been arranged according to their geological positions from above downwards, and the seams are numbered as in previous chapters. [Table. 154 Analyses of Scottish Oil-shales. B m P S o co % ■* & CO o 00 CO CD CM p l-H CO 1 1 CO 1 ? oo 3 CO p •* O CO CM 00 CM CO CM p CM CM t~ O CM 1 tJI CM CM - r- r- ■si IN CO iH s CO CO CO co m CM CO 00 00 CO 00 co CD CO o CO 00 os OJ p CO T" 3 ^~ p r- o T* 1 p 00 00 CO T* p 00 00 CO M 00 US CO 4* ■iji us •* us 00 00 us 4* 4* 4* c "3 3 CM CO CO !>. CD i(S us US CO CO I— »o 00 us o CO CO 1-* us CM o 7* 00 us p 00 p 00 p *# T" CO CO p 00 r-l 7*1 p go •* b CM b i> CM b CM CO t- CO us 4tl us CM 01 CO *3 P CO eo CO CO w CM eo » W _« ft u o £ o p O T-C CM eo CO ICS t> CM CM tH o t~- r^ US CM CM CM i> US o 2. a CO cp CO p o 7* 1 OS 7" CM =P r- us p p r- p T" Tfl 1" b b b CM rH r-l CM rH rH bflO $* £ 2*5 5 w -toi »*1 -4M -':i .HEh t- i> r-i CM oo 00 CM ■HH H s eS cu CO >> 1 *S 3 o _ 3 _o +3 ft 'E o CD Q *3 eg aT *3 .3 to aT .3 CO cu "3 .3 CO - o7 CO >> TI 3 o I s aT "5 3 o ft o H aT aT i £ o o 03 cp ■ 1 o H CO 3 03 X! CO V % a 1 <0 3 J3 CO s? O 3 o Eh s "3 ft o C s- 3 -a X p ffl D o s a, "3 S CO c tl 3 •s o cu CO 5? 1 CO "3 .3 CO c E 3 P - - JS CO 3 O CM S S "3 CO • a? c ■ • i i s i , , u US CO -» „ c a iU d 3 . - - *3 o o J is c o o o & i ~ S 4*1 cVj o CM t- £ o £ o a 3 -Q X t~ o (M CO 00 o CO - rH •* CO b OS o 5? CN rH T-H CO CO 3 1 Eh o O cq eC o o Eh l^ Oi Ol "* » ,_l o O CO T* CO cp CO o o cb CO rH £5 o ©1 CM SO CO ai *3 02 CO o 1 a Eh o OS CO o 00 CO 3 ^ s ~-£ - - » ^ « o -. « t- CB r-l £^ •** CD o £ o CM W CM 8 *■§ CO CO c.?. lis in rH S« ■^ H CO CO flao I- r— 3 « •s-s id o CO M| s op 13 a a> w ^—J*-^, Q O O lO • - » -# i-i .:: ■_•■:■ t- qo op 9° 00 u £ s - - 'cy is be ." to .5 w 1 =1 '5 O b< T3 QJ a CD 00 _- __. O bo : e cE § fH be O hi ■J" "6 5 c en "rf 01 b I 9 S 1 en s o H o . -a e o ■a s 1 3 o CO 1 o General Chemistry of the Shales. 157 ANALYSES 3F CRUDE OIL FROM THE DIFFERENT SEAMS. Broxburn Seam. Broxburn Seam, at Broxburn. In Hender- son's 1873 Retort. Broxburn Seam, at Broxburn. In Hender- ■ son's 1839 Retort. Broxburn Seam, at Pentland. Toung & Beilby Retort. Crude Oil, Sp. Gr., „ Setting Pt.,- Naphtha, Sp. Gr., -730, Burning Oil, „ -810, Medium Oil, „ -840, Lubricating Oil, ,, -865, '885 Solid'paraffin" -" - Bottoms, Total Products, Loss in Refining, - •865 74"F. 3-36»/ 40-59 „ 0-70 „ 0-70 „ 16-13 „ 1002 „ •871 M. Pt.,il6"F. 83"F. l-88°/„ 3023 „ 8-41 „ 17-24 „ 11-51 „ •884 •807 V -880 M. Pt., 115»F. 89°F. 19-49"/ 34 02 „ 14-56 „ 2-47 „ 71-50 „ 28-50 „ 69-27 „ 30-73 „ 70-64 „ 29-46 „ Dunnet Seam. Dunnet, Pentland. Dunnet, Broxburn. Dunnet, Queensferry. Crude Oil, Sp. Gr., „ Setting Pt., Naphtha, Sp. Gr., -740, Burning Oil, , -810, Medium Oil, ,, '840, Lubricating Oil, ,, '865, „ „ '885, Solid Paraffin, Bottoms, Total Products, Loss in Refining, - •870 .778 •807 | -876 M. Pt., 114°F. 84°F. 4-65°/ 21-14 „ 31-01 „ 16-82 „ 1-83 „ •872 M. Pt., 115»F. 89"F. 1-86%, 31-60 „ 4-86 „ 10-30 „ 10-08 „ 10-52 „ •876 M. Pt.', 115"F. 93»F. 2-37»/„ 31-98,, 320,, 12 15 „ 11-13 „ 11-59 „ 75-45 „ 24-55 „ 68-72 „ 31-28 „ 72-42 „ 27-58 „ Pumpherston Seam. Mixed from Holmes. Mixed from Pumpherston Mixed from Roman Camp Crude Oil, Sp. Or., „ Setting Pt., - Naphtha, Sp. Gr., -780, Burning Oil, „ -812, Medium Oil, „ -840, Lubricating Oil, „ -865, ,, „ „ '875, '885, Par. Scale, • Total Products, Loss in Refining, - ■867 M. Pt.,'il3i°F. 75°F. l-71"/„ 36-28 „ 276 „ 1-38 „ 376 „ 14-13 „ 9-83 ,, •876 M. Pt.',115°F. 73«F. 0'68»/„ 3053 „ 1-78 „ 8-93 „ 18-33 „ 11-66 „ •877 ■740 •810 •840 ■865 ■885 M. Pt.','ll6<>F. 84»F. l-86»/„ 28-79,, 9-18 „ 1-88,, 18-37 „ 10-04 „ 6985 „ 3015 „ 71-91 „ 28-09 „ 70-12 „ 29-88 „ The results of crude oil analyses are not absolute, so that different analysts obtain somewhat different figures for the same oil. iii. General Chemistry of the Shales. The Chemical Composition of Shale. The ultimate composition of the Broxburn seam with dried shale (which had contained 272 per cent, of moisture) was — Carbon, 19-12 per cent. ; hydrogen, 2'94 per cent.; nitrogen, - 54 per cent. The nitrogen, if it were possible to convert all into ammonia, corresponds to 57'3 lbs. of sulphate of ammonia per ton, or 2 - 56 per cent. The proximate composition of shale, not dried, by ignition in a closed crucible was — Volatile matter, 25'5 per cent. ; fixed, 74 - 5 per cent., of which 4-95 was carbon and 69 - 55 ash ; sulphur by Carius's method, 1*44 per cent. . -No. 2., ,, ,, „ „ No. 2., fresh, Falkirk Coal Co., Walker & Cameron, Gallons per Ton. 31-37 24-63 24-3 20 9 28-1 Sp. Gr. 1-040 1-051 1-020 1-014 1-064 9-5 8 6 10-3 10-0 8-0 Per Cent. 56-23 56-86 60-2 61-7 58-5 Mr. Stoddart of Howden has kindly supplied the following figures regarding yields of oil from coal got by Dr. Penny about 1860. The gallons of crude oil per ton amounted to — Boghead 128, Wemyss 70'4, Methil brown 90, Methil black, 52, Capeldrae 1st quality 81, 2nd quality 63, Overton 64, Wellwood 46, Rochsoles 72, Auchenheath 78, Knightwood 36. The specific gravity of the crude oil of Torbanehill mineral and the upper shales being higher than that of common shale, depends, no doubt, on the higher proportion of compounds of the benzene- ring type. The more ancient shales give a greater proportion of the chain or paraffin type of compounds. Petroleum from the ancient formations belongs to the simpler paraffin type, while from the more modern they tend more to the more complex ringed type of compounds. * The composition of the organic constituents of good average shale, repre- senting the kerogen referred to in this memoir, is given by Dr. Mills, F.B.S. (Destructive Distillation, 4th Edition, 50) : — Carbon, 25-27 per cent. Hydrogen, 3-67 Oxygen, 5-65 Nitrogen, 1-14 Sulphur, 0-49 36-22 Part of the nitrogen and sulphur are no doubt in combination in the kero- gen ; but excluding the ash, nitrogen and sulphur, the percentage composi- tion is : — Carbon, - 7305 Hydrogen, . 1062 Oxygen, 16-33 100-00 This corresponds to C„H 10 O. The proportion here between carbon and hydrogen is 100 carbon to 14-5 hydrogen. The Chemistry of the Oil-shales. 165 Origin of Petroleum in West Lothian Oil-Shale. Regarding the origin of petroleum which is represented in our field, it may be noted that all ordinary fermentations and decom- positions on the surface of the earth are the result of microbe action ; and they may also be involved in the changes that take place in the strata below the surface. Kerogen and petroleum may possibly originate from the same kinds of organic matter, but acted on by different microbes, soon after deposition or subse- quently. It is highly probable that when the Coal Measures were laid down there was a much larger proportion of carbonic acid gas in the atmosphere than now, which, on account of the power of this gas to absorb radiant heat, would produce the warm moist climate that generally prevailed in the Carboniferous period, and also from its solvent action would increase the salts in solution in the ocean and lakes, and influence the microbes. Petroleum everywhere seems associated with brine or salt from an ancient sea. The anti- septic action of the brine would kill off many kinds of microbes and give the advantage to others that would multiply and might thereby produce petroleum. At Broxburn, as already indicated (p. 141), the petroleum exists in association with a strong brine in a bed whose position is ten fathoms below the Dunnet Shale, and in the locality of the petroleum the Dunnet seam looks as if half-burned, and produces about 1 2 gallons of crude oil. In this case it is probable that the petroleum was not the product of ordinary distillation of the shale by the heat of intruded igneous rock, never far distant in this field. It is more likely that the brackish lagoon became charged with sea-water and was separated from the ocean. Concentration then took place, and. the petroleum here, as elsewhere, was formed at a not very high temperature. E. W. Binney (Proc. of Manchester Lit. and Phil. Soc, III., 136) described petroleum from a peat bog, which he believed to be subject to infiltration of sea water, thus probably giving rise to the circumstances necessary for the production of the petroleum. There would be no chance of the high temperature required for ordinary distillation in this case, and we may have here the specific action of definite microbes at ordinary temperature. Even if the effect of the concentrating brine in an inland sea were to destroy all microbe life and leave the organic matter to pure chemical reactions, we might have products of destructive distillation in the depths of the earth, at far lower temperatures than we require in the laboratory. There is a general law to the effect that reactions which take place instantly or speedily at a high temperature take place also at rapidly decreasing ratios as the temperature falls ; about twice as slow for a lowering of 10° C. (Holleman's Inorganic Chemistry, 16). In many cases the reaction has practically ceased for ordinary time at ordinary temperatures ; but in geological time the reaction tells particularly at the increased temperatures got deep in the earth. We may remember also, in this connection, the molecular and atomic mobility in solids, as shown, for instance, in metals. 166 Natural Qas in West Lothian Oil-shale. As already indicated, there are examples of true high-tempera- ture products in the Broxburn neighbourhood which are not found in the sediments, but in pockets or cracks of the igneous materials (page 142). Oxidised substances of a bituminous nature may be got from oxidation of hydrocarbons ; or, in other circumstances, as organic matter so far on the way to produce petroleum. Heavy hydrocarbons, liquid or solid, may be direct productions from organic matter, or they may in other cases be built up from light hydrocarbon gases by polymerisation, or oxidation, or cumulative resolution, under pressure, etc. Natural Gas in "West Lothian Oil-Shale. Natural gas is plentiful in the Broxburn district. Twenty-five years ago water issued from many of the old bore holes charged with large quantities of gas, which was odourless and combustible. In course of time, owing to the mineral workings, the water ceased to rise, and the bore holes were covered with soil, but the gas con- tinued to reach the surface, reacted on it, and caused a smell like that of a choked sewage pipe, with sulphuretted hydrogen present. Thus long narrow strips through the fields were rendered barren for some years. The waterlogged strata that had previously held down the gas had been drained dry by the workings, sometimes more than a mile away, and the gas escaped along the outcrop of certain porous rocks. From a bore hole at Middleton Lodge, about thirty years ago, there was a constant flow of water, and, regularly every month, gas was evolved with considerable force and noise, which, on lighting, burned for a day or two as a great column of flame seen from afar. At one natural vent at Broxburn the chemical reactions going on have caused the surface soil to have a temperature of 40° F. (22° 0.) higher than that of the ordinary soil of the neighbourhood. There are two sources for the natural gas of this field — viz., the fire damp given off by the coal and oil shale, and also the permanent gas created by the molten igneous rock when intruded into positions occupied by oil shale. v. The Process of Manufacture. (1) The crude oil works consist of benches of retorts, the condensers, and the ammonia house. They are generally placed in the middle of the shale field, and much of the shale is tipped from the miners' hutches into the breaking machine. As it is expensive to haul it far underground, pits or mines are sunk over the field, and the shale is brought in railway waggons to be emptied by hydraulic machinery into the breaking machine, but not from a greater distance generally than four miles. If shale lies several miles distant, a crude oil work is built and the crude oil is sent to the refinery by tank waggons. The shale is broken into small pieces by passing between two toothed drums, being too tough to break like road metal. From Development of Retorts. 167 the breaker it falls into hutches (small waggons), which are taken up an incline by wire rope or chain to the top of the retort-bench, and emptied into the retorts. Development of Retorts. The first retorts tried by James Young were of the horizontal iron type, like those employed at the time in the manufacture of coal-gas. Ooal is distilled in gas-making at a very high tempera- ture with the object of making permanent gas, and as little liquid, product as possible. Shale, on the other hand, is distilled at a low temperature to obtain liquid and solid products, and a small quantity of gas. Horizontal retorts (Fig. 55) were improved in shape, size, and build, and were used in several of the smaller works till about 1880. They gave a large yield of burning oil, as, for example, 27 gallons of crude oil were obtained from the Broxburn shale, which yielded 51^ per cent, burning-oil and naphtha, five per cent, of medium oil, 10 per cent, of lubricating oil, and only five per cent, of paraffin scale — total products, 71| per cent. w^ Fig. 55. — Horizontal Retort. Young soon discarded this form of retort, and adopted the vertical type (Fig. 56). It was a vertical tube about 10 feet long and a foot in diameter, with a hopper on top from which the shale could be dropped without escape of gas, and it ended below in a trough of water, through which the spent shale was drawn every hour. New shale was dropped from the hopper at hourly intervals, half an hour after the drawing, and the shale remained about eight hours in the heat. About 1860 steam was introduced into the bottom of the retort, which greatly improved the quantity and 168 Development of Retorts. quality of the crude oil as it diffused and moderated the heat and swept the products rapidly out of the high temperature. Old vertical retorts, improved in form and lengthened, were used by some until 1880. Fig. 56.— Old Vertical Retort. Many forms of retort were tried, each introducing some new fea- ture. One, which was highly successful and widely adopted for a time, was patented by N. M. Henderson, in 1873. It was made of cast-iron, one and a half inches thick, 15 feet long, of oval section two and a half feet by one foot. The charge was 18 cwt., which lay 16 hours without movement in the retort, distilling off the crude oil, ammonia water, and permanent gases. Thereafter the spent shale, which contained about 12 per cent, of carbon, was dropped into the furnace below to act as fuel for the next charge. Pour retorts were built into one oven and over one furnace, and one of the four was dropped every four hours to maintain the succession of heat. The permanent gas of the distillation was burned in the furnace or in the oven above, and steam superheated in this oven was introduced into the retort. This type required much less fuel and at the same time made an easily-refined crude oil, richer in heavy oil and solid paraffin than the crude oil of the older retorts. The old vertical type, fired by coal alone, was dependent on the attention of the firemen, whereas Henderson's retort gave the right temperature Development of Retorts. 169 mechanically. The distillation was downwards. A little coal was generally used as extra fuel. Fig. 57.— Young and Beilby Retort. The Young and Beilby retort (Fig. 57) was patented in 1881. Four metal retorts were connected with a large hopper above, com- mon to the four. The distillation was upwards through the cold shale of the hopper, where the crude oil was condensed and redistilled. Each retort had a metal upper part where the oil was distilled from the shale at a low temperature. After being practi- cally spent of oil, the shale passed down through a lower part of the retort built of firebrick, where it was subjected to as high a temperature as possible without fusing, and was there acted on by steam. Thus the carbon was converted into a mixture of car- bonic acid and carbonic oxide (the temperature was not high enough for perfect water gas), and the steam giving up its oxygen to the carbon yielded nascent hydrogen to combine with the nitrogen to form ammonia, and the excess of hydrogen went for fuel. The lower part is therefore a producer of ammonia and gas. The shale lay 18 hours in the retort. This type greatly in- creased the permanent or fuel gas, and gave a larger yield of sulphate of ammonia. At intervals in the bench of retorts there was one for coal to act as a gas-producer- to supplement the retort gas, and the ammonia from it was also saved. 170 Modem Retorts. The retorts now in operation are framed on the Young and Beilby principle, two of which are described as examples. The Henderson Eetort, No. 6726, 1889 (Fig. 58), in its newest form (Patent No. 26,647, 1901) has two toothed rollers at the bottom that support the weight of the column of shale, and, revolving at_ a regulated pace, keep the shale always in motion, which is dis- charged into a hopper below. There is a large hopper above to do Fig. 58. — Henderson Retort. away with charging by night. The products come off at the bottom of the top hopper. As regards aid from coal, Mr. Hender- son adopted a separate gas-producer (the Wilson). Compared with previous types, the length of this retort was greatly increased, as the cheapest way of exposing the shale to a larger heating surface for a longer period, and thereby increasing the ammonia, while working at a temperature low enough to diminish wear and tear Modern Retorts. 171 aud ensure long life to the retort. In this type the flattened form is adhered to, so that, even in the centre, the shale is never far from the heat, and thus any necessity for overheating the outside is avoided. The present length adopted is 14 feet for the upper or iron part and 20 feet for the brick part. The section is oblong, two feet nine inches by one foot three inches at the top of the metal part, and four feet eight inches by one foot ten inches at the bottom of the brick part. The total height from the ground-level to top of the hopper is 63 feet, and about 15 tons of shale are placed in it at a time. The shale remains in the heat of the retort for 30 hours. Thus the yield of oil was augmented by several gallons and the ammonia greatly increased, and the labour expenses much reduced. Each retort puts through over four tons per 24 hours, and enables the crude works to be made very compact. The retort patented by Messrs. Bryson, Jones, & Fraser, and generally called the Bryson Retort, Patent No. 7,113, 1895 (Pig. 59), is also a very long one, and diners from that last described in having a circular cross-section. It has a table below to support the 172 Modern Retorts — Retort Condensers. column of shale, and there is a revolving arm to keep up the movement of the shale downwards. The bottom hoppers converge so that a single line of rails under the centre of the bench receives the spent shale from both sides in a hutch. By these means labour is reduced to a minimum. The retorts described are all of the continuous-working variety, except Henderson's 1873, and the horizontal types, which were intermittent. The old vertical retorts gave a crude oil that was dark and tarry, sp. gr. -880 to "895. Henderson's 1873 pattern gave a green coloured crude oil sp. gr. "865 to - 870, with 2\ per cent, more solid paraffin, a lubricating oil that was much more viscous, and 1\ per cent, more total products. The newer retorts give more crude oil per ton, which is not quite so easily refined and involves more loss in refining ; but the total refined products are more on the whole, and, what was not anticipated, the solid paraffin is increased. Long exposure to high heat tends to make paraffin break up into paraffin and olefine of smaller molecule, defines by deposit- ing carbon can become converted into paraffin. defines at moderately high temperatures sometimes contract in volume and form condensation products containing paraffin. Retort Condensers. A main, common to a bench of many retorts, is led to the conden- sers from the retorts. On the way the vapours are chilled by passing through a tower in which water for the steam boilers is heated in pipes. The condensers are great stacks of vertical four-inch pipes, and the ammonia water and crude oil collected from them are run through a box called a separator, in which the water at once goes to the bottom and is run into one tank, while the oil rises to the sur- face and is run into another. The old vertical and Henderson retorts gave less than 3,000 cubic feet of permanent gas per ton ; the new ones, of the Young and Beilby type, give about 14,000 cubic feet. This gas on leaving the condensers is scrubbed from ammonia and naphtha by passing up water towers, and finally up a heavy oil tower. The heavy oil showered down catches the light naphtha, which is afterwards distilled from it. The permanent gas, thus freed from all condensable matters, is caught by a fan which, giving a few inches of suction on the side next the condensers, forces the gas under a few inches pressure into the main that supplies the burners at the bottom of the retort flues. There is £-inch suction on the retort main that receives the retort exits. These modern types, with a good shale, require no help from coal in the distillation, except at the beginning. J. J. Coleman invented a method of extracting gasolene from the permanent gases by compression and cooling. The final cooling was made from 40° to 50° below zero P. (43° to 46° 0.) by expansion of the compressed cooled gases. Young's Company found that \\ gallons were obtained at a cost of 2^d., while by the oil tower, f of a gallon was got at a halfpenny per gallon. The oil Retort Condensers — Besults of the Shale Distillation. 173 obtained had sp. gr. 700 to 715. Coleman's method was soon given up. The brick part of the modern retorts is a gas-producer, in which the carbon is consumed by steam. Under 1,000° F. the action of steam on carbon gives carbonic acid, C0 2 , and hydrogen. At 1,000° F. (538° C.) a little carbonic oxide, CO— a combustible gas — is formed. Higher temperatures increase the proportion of carbonic oxide. At 1,800° F. (782° C.) the action is practically complete, only a small proportion of carbonic acid being formed. The shale in the brick part of the retort rises perhaps to 1,300° F. (704° C). At that temperature steam acts on carbonic oxide, CO, to form carbonic acid gas, C0 2 , and hydrogen. Ammonia gas by itself begins to break up into its elements about 900° F. (482° C), and the decomposition is complete at 1,400° F. (760° C). But protected by sufficient steam, the ammonia can exist at a much higher temperature. With great excess of steam, all the nitrogen goes into ammonia quantitatively. With the compara- tively small excess of steam that is practicable in a working retort, a proportion of the ammonia formed is decomposed into its ele- ments, but the greater the excess of steam the smaller is the loss. The quality of the crude oil depends much on the temperature at which it is formed and to which it is afterwards exposed — a high temperature being injurious. An extreme case is using shale for gas-making. The shale of the Broxburn seam, when distilled in the gas works at a bright red heat, gave nine gallons of crude oil (or gas tar), sp. gr. '952, which was a thin mobile liquid containing little solid paraffin; and sulphate of ammonia 8 J lbs. per ton. This is the result of high temperature and absence of steam. Steam is a powerful reagent at the temperature of the retorts. Tervet increased the yield of ammonia by passing hydrogen into the re- torts. Irvine increased the solid paraffin by introducing ammonia. This action of ammonia partly accounts for the higher yield of paraffin in the recent type of retorts. Beilby found that a limited introduction of air increased the solid paraffin. Sulphur acts on paraffin at a high temperature to give sulphuretted hydrogen, H 2 S, and olefine. Free sulphur is sometimes got in the condensers and crude oil. Ammonia or a little oxygen in the retort unites with the sulphur and keeps it from attacking the hydrocarbon molecules. In the Henderson 1873 type, with its mild temperature and excess of steam, the shale of the Broxburn seam that contained l - 5 per cent, of sulphur dropped l - 4 of it into the furnace in the spent shale, and it contained 1 per cent, even when taken from the furnace. - 25 per cent, went to the permanent gas, - 028 to the crude oil, and 0'02 to the ammonia water. In the present retorts much more sulphur is lifted in the retorts and sent into the crude oil, water, and gas. Results of the Shale Distillation. The results of the shale distillation are : — Spent shale, that is of no value at present, whose removal involves expense ; permanent gas used as fuel for the retorts themselves ; crude oil ; and ammonia water. 174 Distillation of Ammonia Water in Tower Stills. Distillation of Ammonia "Water. The ammonia water is now distilled in tower stills, the first used being that of Beilby (Fig. 60). Fig. 60. — Beilby Ammonia Column Still. There are others now in operation, of which the Henderson type is an example (Fig. 61). The ammonia water heated by interchange of heat with the spent ammonia water is run on at the top, and goes from tray to tray, acted on by steam of 30 lbs. pressure, blown in at the bottom of the column. Hence the water boils, and the volatile ammonia com- pounds are expelled as gas and caught in sulphuric acid. The sulphuric acid used to refine the oil is separated from the tar by washing with hot water, and the recovered acid is saturated with the ammonia gas and sent into the market as sulphate of ammonia. This recovered acid gives a solution which has to be boiled down to obtain the salt, but the quantity got only serves for a fraction of the ammonia. The rest is passed into a cracker-box of fresh sul- phuric acid, in lead pipes, with holes in the part laid along the bottom, where there is a constant stream of sulphuric acid flowing Distillation of Ammonia Water 175 in, and also a constant current of ammonia gas. The sulphate forms as salt, and falls along a sloping bottom into a well, from which it is lifted by a steam injector and thrown into a box at the side to receive it. The acid requires to be diluted with water, and instead of fresh water the solution of sulphate made from the recovered acid is run in, and the separate evaporation of it saved. In the ammonia water from the retorts, there is fixed ammonia n n nnWLLk. n n o nVHTLLfL Fig. 61.— Henderson Ammonia Column Still. Two Trays. equal to 1 lb. per ton of shale, sometimes more if there is insuction of air anywhere, which is sometimes recovered by putting lime into the tower. In the water there are sulphur compounds, sulphide, sulphite, hyposulphite, and persulphides, and in the heat of the tower-still these react on each other to give free sulphur, which collects in masses and tends to choke the passages of the still. The milk of lime run into the tower helps to keep it clear. Comparison of Crude Oil and Petroleum. The crude oil of petroleum is got without the expense of mining and retorting. A bore is put down and is tubed, and the oil flows like a fountain, or is brought to the surface by a pump. Ihe 176 Comparison oj Crude Oil and Petroleum — The Refinery. gentle processes of nature used in creating petroleum, extending over long periods of time, give a crude oil much easier to refine than that produced by the rapid and violent method of the shale retort, which yields unsaturated hydrocarbons and a little sulphur in some molecules. Crude petroleum in its first distillation separates a considerable proportion of burning oil which requires only one treatment each with oil of vitriol and with soda to render it fit for the market. Our burning oil requires three or four dis- tillations, and hence the battle of competition is fought at a great disadvantage. A gigantic bench of 60 retorts, say, with 250 tons of shale put through per day, gives a very thin stream of crude oil and ammonia water. One compensation is the presence of am- monia ; another is, that the repeated distillations enable much more homogeneous products to be made. The great secret of oil-refining is thorough separation of one product from another. Naphtha renders burning oil dangerous, and intermediate oil hinders it from rising in the wick, and light oil in lubricating oil reduces its viscosity. Petroleums vary in composition. That from Pennsylvania con- sists principally of the paraffin series, and the heavy oil at the end of a distillation contains solid paraffin. Ohio and Canadian petro- leum consists largely of paraffins, but they have more sulphur compounds, which necessitate a special finishing treatment, or chemicals in the distillation ; but the sulphur compounds are easily struck out. Californian petroleum has a greater mixture of different series of hydrocarbons, and gives asphalt at the end of the distillation instead of paraffin. The Californian petroleum, from the Tertiary strata, seems much nearer the original organic compounds in its nature than the Pennsylvanian petroleum from the Devonian rocks. Some petroleums cause the plane of polarisation of light to rotate to the right, others to the left, which is almost conclusive proof that these petroleums, at anyrate, are not of purely inorganic origin. The Refinery. (2) The refinery consists of (1) stills for the repeated distillation of the oil ; (2) stirring-tanks, in one set .of which the oils are treated with strong sulphuric acid, and in* another with caustic soda ; (3) paraffin-house, in which the heavy oil containing the solid paraffin is cooled and pressed, and where there are great refrigerating machines ; (4) paraffin refinery ; (5) stock tanks for the finished product ; (6) filling shed with cooperage, where the products are filled into barrels and tanks to send to the customers ; and sometimes (7) a candle-house to make the solid paraffin into candles, and occasionally (8) vitriol chambers to make the sulphuric acid required, and concentrating plant. Further, there are engi- neers' shops, smithies, carpenters' shops, saw-mills, plumbers' shops, clerks' offices, etc., etc. All have to be arranged for convenience] cheapness of communication, and safety from fire. The crude oil is settled from the ammonia water and shale dust, and pumped up into a high charging tank, from which the oil can Refinery Operations. 177 flow by gravitation into the stills. There are heat interchangers on the top of the stills, so that the cold oil-feed flowing in is heated by the vapours distilling out. There are high charging tanks behind each bench of stills and low tanks to receive the distillates. With every distillation, steam, more or less superheated, is introduced into the stills ; hence there are steam-boilers at hand. Water converted into steam expands about 1700 times. Our oils expand only one or two hundred times, and when distilled without steam a great deal of oil has to be evaporated before the vapours mount up to the exit pipe. Their specific heat and heat of vaporisation are not great, and they readily condense on the top of the still to fall back and be redistilled with some decomposition. When steam is introduced it cushions and protects the gaseous molecules from decomposition, and rapidly sweeps them into the condenser. Further, the presence of steam lowers the boiling point of the oil in much the same way as a vacuum or reduced pressure. Refinery Operations. Distillations and Chemical Treatments. The crude oil distillation is meant to be a destructive one to some extent, and the steam admitted is limited. If the crude oil be treated directly with oil of vitriol and caustic soda the loss is very great. Or if too much steam is used in the distillation the loss with the treatments is great, as the steam drives the oil over unchanged. The distillation converts tarry or resinous matters capable of uniting with the chemicals into the required hydro- carbons. Steam is limited when near the end of the second dis- tillation also ; but when the bulk of the heavy oil and paraffin is passing over the proportion of steam is high. The once-distilled oil is stirred up with oil of vitriol and settled from the black viscous tar, The oil is run by gravitation into another tank, where it is treated with caustic soda, and here another black viscous tar is separated. The settled oil is pumped up to the charging tank of the next distillation. The stirring with chemicals is sometimes done with mechanical stirrers, but oftener with air, pumped into the bottom of the tanks. At each distillation a fractionation is made, that is to say, the oil is separated into naphthas, burning oils, and heavy oils. In the crude distillation sometimes only the naphtha or spirit is separated, and all the rest distilled together as " green oil." The burning oil is left with the heavy oil and paraffin so as to keep it liquid at a comparatively low temperature for the acid treatment, otherwise a high temperature would be required to keep it liquid, and this would cause the acid to attack the defines. The amount of oil of vitriol used is limited for the same reason, as well as for economy. After the first treatment with oil of vitriol and soda, the next distillation separates burning oils of various gravities and the heavy oil containing paraffin. The burning oils are distilled again, sometimes repeatedly. The oils vary in specific gravity in different 178 Refinery Operations — Separation of the Solid Paraffin. works, and at different times in the same works, to suit the requirements of the market. Separation of the Solid Paraffin. The heavy oil is cooled in shallow tanks set in sheds open to the wind, and afterwards with freezing machines. The old cooling drums, dipping into the oil and paraffin and raising a film to be scraped off at the other side, are no longer used, as they chill the mixture too rapidly and prevent proper crystallising of the solid. Ammonia machines are now always used, some begin- ning with ammonia solution, and others with dry gas liquefied by pressure. The ammonia solution machines cool a solution of chloride of calcium which cannot be frozen by the machine, and this chilled brine is put into a tank filled with alternate compart- ments ; wider ones for the oil and paraffin and narrower ones for the brine. The oil and paraffin lie there for hours exposed to the cold, and the solid paraffin separates out in good crystals. In the Beilby cooler, the paraffin mass lies undisturbed until chilled to the extent required. In the Henderson cooler, a scraper goes slowly round, removing the chilled mass from the cold plate and letting the warmer material forward to the cold. Paraffin is a bad con- ductor of heat, and, in the Beilby cooler, the paraffin mixture requires to lie a long time and necessitates a large plant, but gives a better crystal. In the Henderson cooler much more can be put through and yet a sufficiently good crystal is obtained. Some works utilise the cold more by passing the paraffin mixture through pipes, chilled directly by the evaporating ammonia gas, which pro- duces more sudden chilling, and causes some paraffin to thicken in an amorphous state difficult to separate from the oil. From the cooling machines the paraffin mass, alter being broken up by machinery, is pumped through filter presses. The paraffin cake collects in the press and the oil flows into its own tank. When the cooling is done by the ammonia gas without the interposi- tion of the brine, many more filter presses are required on account of the amorphous paraffin. The paraffin from the filter presses is generally further squeezed in cloths in hydraulic plate presses. At this stage it is called " paraffin scale," from the scale-like appear- ance of the flattened plastic crystals. The heavy oil separated from the solid paraffin is called " blue oil," which is treated with oil of vitriol and soda, and is distilled again and separated into the various fractions according to gravity required. These, after cooling and pressing from soft paraffin, and when further treated with oil of vitriol and carbonate of soda, are ready for the market. The more thoroughly the solid paraffin is separated from the lubricating oil, the latter becomes proportion- ately heavier in gravity and more viscous, and the setting point is lowered. The solid paraffins are refined by a sweating process. In some works the cakes of paraffin scale from the filter presses are not squeezed in hydraulic plate presses to separate the oil, as this process requires much hand labour, and the paraffin, with a pro- Refinery Operations — The Stills. 179 portion of oil, passes directly from the filter presses to the paraffin refinery. The paraffin is melted, cooled into cakes, and put on wire-gauze shelves in a house kept warm by steam pipes. As the temperature rises the oil sweats out and also the softer paraffin, leaving the hard paraffin on the shelf freed from colouring matter. The process is repeated to improve the colour. N. M. Henderson has a sweating apparatus that reduces the labour to a minimum. The house containing the apparatus is filled with great trays several inches deep, in which wire-gauze shelves are placed two inches up. Water flows into each tray up to the shelf, and two inches of melted paraffin are run on the top of the water. The doors are open, and the wind cools and solidifies the paraffin. Artificial wind is created to help the cooling. When the paraffin is solid, the water is run off below, which leaves the great cake of paraffin lying on the wire-gauze shelf. The doors are shut, spent steam from pumps and engines is turned into the heating pipes, and the paraffin is gradually sweated. The sweatings are run into receivers according to melting point and colour. When finished, the wax is melted out by putting steam from the boilers into pipes, which are used as supports for the trays, and the refined wax is run into its own tank. Some paraffin is refined by mixing with about 30 per cent, of naphtha; it is then cooled in cakes and pressed, the naphtha flowing out and carrying the colouring matters. The cakes of paraffin are melted, and the naphtha is distilled off and condensed. The paraffin is thoroughly steamed till the smell of naphtha dis- appears. In all cases the melted paraffin is stirred with animal charcoal, settled, and filtered through paper. It is then ready for the market or the candle-house. The Stills. In the distillations the bulk is distilled off from boiler-stills, which are cylinders lying horizontally, the charge being two or three thousand gallons, and the residue is run into round cast-iron- bottomed stills (Fig. 62) to be distilled to dryness and coked. The still coke of the crude oil is valuable. When the coking is in pro- gress, much permanent gas is given off, of high luminosity, valuable for lighting or fuel (Beilby and M' Arthur). N. M. Henderson connects boiler-stills into a series (Fig. 63), the oil flowing from one to another, and each giving off a distillate of a fixed specific gravity. They are worked continuously, save when temporarily stopped for cleaning operations. At the end of the series is a residue still with cast-iron bottom, which, when charged, is disconnected and another residue still is put on to the series. By this method twice as much oil is put through, and the distilla- tion is more perfect and requires less oversight. In a crude oil distillation by the old method, naphtha passed oyer first, and was run into its own tank. At a certain specific gravity the distillate was run into another tank. The temperature in the 180 Refinery Operations — The Stills. still gradually rose, together with the sp. gr. of the distillate, the latter giving in succession burning oil, intermediate oil, heavy oil with paraffin, and at the end still grease. The specific gravity had to be constantly tested to fix when the materials should be turned into another tank. With the connected stills, the first always discharges naphtha, the second burning oil, the third intermediate oil, and' the fourth heavy oil and paraffin. There is considerable power of adjustment to suit what is required. Fig. 62.— Residue Still. In the manipulation with oil of vitriol, the tar from the finishing treatment is used to give a first treatment to the crude oil distillate. The tar from this oil is washed with hot water to separate the sulphuric acid to send to the ammonia house, and the tar, neutra- lised with soda tar, is settled and burned as liquid fuel under the stills, being blown into spray with superheated steam. It burns —7 7—p ///////// Fig. 63.— Connected Boiler Stills. Refinery Operations — The Stills. 181 like a jet of gas, with smokeless flame, and the chimney gases have no more sulphur than from coal. To the crude oil distillate is given acid, equivalent to more than 2 per cent, of oil of vitriol, the after treatments of the light oil £ per cent., and the finishing treatment of burning oil 1 to 2 per cent., according to previous treatment, etc. The blue oil receives about 1 per cent, of oil of vitriol and a finishing treatment after fractionation from 2 to about 4 per cent, oil of vitriol. The caustic soda treatments are about 1 per cent, of solution of 60° Tw., or 13 sp. gr., except in the finishing treatment, when the burning oils receive very weak caustic soda, and the lubricating oils carbonate of soda solution. To the blue oil is given dry caustic soda in the still, from 2 to 5 lbs. to 100 gallons. The form of still is shown in Fig. 64. Fig. 64.— Heavy Oil Still The following is a scheme of refinery operations. Oil of Vitriol, and O.S. Caustic Soda :— O.V. means (Table. L82 Diagram showing Processes of Manufacture « E-i O ft, D O CO W o o OS ci la o K cc S P5 O <$ 03 o o o -3c3- go n d t3 ~ bed s> «d s"o< ci .,3 15 l>t> _o bo Constituents of Crude Oil. 183 The crude oil obtained from shale is substantially a mixture of the paraffin and olefine series, with a small admixture of naphthenes and benzenes, which constitute the finished products. Both the paraffin and olefine series occur in the naphthas and burning oils ; but when we come to the heavy products there is a separation, for the solid paraffin consists of members of the paraffin series alone and the lubricating oil separated from it, of defines with admixture of liquid paraffins. In addition to these products, the crude oil contains the materials of the tars separated by the chemicals, in which there are no doubt many compounds not yet determined, for their investigation is both difficult and disagreeable, and some of them decompose very easily. There are phenols, cresols, and hydrocarbons with less hydrogen than defines ; there are pyrene and chrysene ; there are also the quinoline and pyridine series of bases. These last are difficult to decompose, and can be got by themselves for separation from each other and examination. The leucoline (quinoline) series was investigated by Eobinson and Goodwin (Trans. Roy. Soc. Min., Vol. XXVIII., -p, 561; Vol. XXIX., pp. 265, 273), and the pyridine series by Garret and Smythe (Trans. Ohem. Soc, 1902, 1903). Shale or naphtha contains one- half per cent, of pyridine bases. Dr. Thomas Gray investigated the phenols of naphtha soda tar (Jour. Soc. Ohem. Industry, XXI., 845). The members of the olefine series have a higher specific gravity than those of the paraffin series, and the series with still less hydrogen than the defines possess an even higher specific gravity. These last are struck out by the oil of vitriol, which reduces the specific gravity of the oil left. The more unsaturated hydrocarbons and the sulphur compounds have an odour like garlic. A small trace of these gives the penetrating smell to paraffin oil, and its removal, without destroying any of the right products, is the pro- blem of the refiner. The oil of vitriol used in refining combines with the pyridine bases and other basic substances, the bulk of the phenols, the sulphur compounds, and the hydrocarbons that are less saturated than defines. The caustic soda solution extracts phenols and acids. If the defines are not attacked by excess of oil of vitriol, the caustic soda tar is black. In the finishing treatments an effort is made to extract the last traces of the compounds more unsaturated than olefines, and also the sulphur compounds, and for this purpose sufficient acid is given to attack a little of the olefines. Hence compounds are formed which give a white emulsion with soda solu- tion. Any trace of the soda sulpho-compound left in the burning oil causes crust in the wick of the lamp, and care has to be taken to wash it all out. VI. Products of the Manufacture. The products of manufacture will be discussed under two heads, (1) their composition and properties and (2) their uses. 184 Products of Manufacture. The Composition and Properties of the Products of Manufacture. 1 . The Permanent Gases of the Retorts. — These are used for fuel. The composition varies with the state of the retort at the time and with other circumstances. Excess of nitrogen indicates that air has been sucked in by the action of the exhauster. Young & Beilby Retort. Hermand Type. Prof. W. Foster. Henderson's 1873 Retort. Henderson's New Retort, 1901. Bryson Retort. Bryson. Carbonic Acid and H 2 S, defines, - Oxygen, - Carbonic Oxide, C 0, Marsh-gas, Hydrogen, Nitrogen, 20-7 1-6 3-6 116 8-66 21-68 42-6 18-0 5-0 2-0 o-o 38-4 28-7 7-9 26-0 1-2 1-0 7-8 9-2 38-6 16-2 22-08 1-88 1-18 9-77 3-70 55-56 6-33 100-0 100-0 100-0 1000 2. Shale Naphthas are thin, limpid, mobile, colourless liquids, completely volatile at ordinary temperatures. They generally consist of 60 to 70 per cent, of defines and other hydrocarbons acted on by fuming nitric or sulphuric acid ; the rest being prin- cipally of the paraffin series. Broxburn Naphtha, sp. gr. -735, was subjected to many fractional distillations in the Le Bel Henniuger apparatus of 6 bulbs. The olefines, etc., were separated with concentrated sulphuric acid, and what remained was washed with water and soda solution. The results were as follows : — Range of Temperature. Volumes. Loss by Treatment. Volumes. Paraffins. Per Cent. Olefines, &c. 1. 2. 3. 4. 5. 6. 7. 26 to 27°C - 37 „ 45 „ - 45 „ 58 „ - 58 „ 65 „- 65 „ 67 „ - 67 „ 69 „ - 69 „ 72 „ - 4,000 5,000 2,275 9,300 4,900 14,200 10,110 2,800 3,200 1,225 5,125 2,600 7,200 5,160 30 36 46 45 47 50 49 70 64 54 55 53 50 51 In the oil from the Henderson 1873 retort, there was often no benzene, but in the oil from the existing retorts the benzene series is distinctly represented. In Broxburn Naphtha, sp. gr. "735, the fractions boiling between 55° and 75° 0. gave 2'6 per cent, benzene, and the fraction 100° to 105° C. gave 2 - 5 per cent, toluene. The members of this series were found to distil at temperatures under their boiling points when distilled pure; and, where they were expected, fractions sometimes showed no trace of them. The Composition and Properties of Products of Manufacture. 185 naphthenes methyl-tetramethylene, pentamethylene, and hexame- thylene were got in distinct quantities. (B. Steuart, Jour. Soc. Chem. hid., XIX., 986.) Friedrich Heusler has examined the fraction of Scottish paraffin oil boiling below 110° C. (naphtha or spirit), and found paraffins 42 per cent; naphthenes 10 per cent.; aromatic hydrocarbons 7'3 per cent.; defines 39 per cent. He proved the presence of benzene, toluene, metaxylene, and cumene, and the absence of naphthalene. The corresponding figures he obtained for Saxon lignite — of vegetable origin — were : — Paraffins 16, naphthenes 4, aromatic hydrocarbons 45, and defines 31 per cent. 3. The Burning or Lamp Oils are transparent, nearly colourless, thin liquids, having both the paraffin and define series in large proportion. There are 30 to 40 per cent, of unsaturated hydro- carbons that can be taken out with fuming sulphuric acid. 4. The Lubricating Oils are transparent, yellow-coloured, bright liquids with considerable viscosity. For oils from the same source, the viscosity varies with the specific gravity ; but for oils from different sources the specific gravity is no gauge for the viscosity, as the lower gravity of oil may have the higher viscosity. They are to a large extent defines, but mixed with liquid paraffins. 5. The Solid Paraffins are colourless, tasteless, odourless bodies, composed of saturated hydrocarbons. They are able to resist the action of the strongest chemicals, which makes them useful for many purposes. They are good insulators. They are somewhat plastic for a good many degrees below their melting points, and hence low melting point candles sometimes bend with their own weight in hot weather. The flashing point of wax of 128° F. (53° 0.) is 375° F. (190° C). The solid hydrocarbon we now call paraffin was extracted from Tegernsee petroleum by Fuchs in 1809. Buchner separated it in comparative purity in 1819. Eeichenbach, in 1830, obtained it from wood tar, investigated its properties, and called it by its present name. About the same time Sir Robert Ohristison of Edinburgh extracted it from Rangoon petroleum. Laurent got it from bituminous shale in 1830, and Dumas in 1835 from coal-tar. Selligue, in France, seems to have been the first to manufacture it for sale ;' and Rees Reece first made paraffin candles, in 1850, from paraffin obtained from Irish peat. Young obtained some paraffin from his Alfreton petroleum in 1848, and he was the first to manu- facture paraffin in large quantity— viz., in connection with the Scottish paraffin oil industry. The following table gives the properties of average samples of the usual products : — [Table. 186 Properties of Products of Manufacture. Sp. Gr. Flash Point Tint. No. 500 glass Boiling Point Viscosity by Range. Lovibond. 2-inch Cell. Kange. Pipette. Spirit or Naphtha, •786) •740f Lowest Colourless. 140°F.-320°F. - temperatures. 180 „ 380 „ Special Oil, or Waterwhite Oil, - ■785 106°F.-120°F. 310 „ 500 „ Crystal Oil, •800 115 „ 125 „ 0-5 340,, 575,, No. 1 Burning Oil, •805 110 „ 135 „ 0-75 310 „ 580 „ Lighthouse Oil, - ■810 145 „ 160 „ 1-0 390 „ 573 „ Mineral or Marine Sperm, •830 200 „ 230 „ 2-0 450 „ 675 „ Mineral Colza, •840 220 „ 240 „ 5 500,, 700,, Gas Oil, ... •855 200 ,, 230 „ 450 „ 710 „ Gas Oil, Grease Oil, Cleaning Oil, ■870 276 „ 300 „ 500 „ 720 „ Lubricating Oil, - - - - •865 275 „ 300 „ 15 575 „ 710 „ 44 seconds. " ■875 300 „ 310 „ 18 J-ineh Cell. 575 „ 800 „ 47 „ •885 320 „ 340 „ 15 650,, 870,, 65 „ „ •890 330,, 350,, 16 720 „ 875 „ 70 „ . In determining the flashing point the Abel apparatus is used ; the whole apparatus for the lower flashing burning oils, and the cup of it for heavy oils. The tint is taken by different methods. The method of taking the boiling range most recognised is that of Engler. The viscosity or body is generally taken with a pipette, each company having its own standard tube. There are viscosi- meters by Redwood and by Engler that are used as standards of reference. The boiling range of oils, taken with a new Baly & Chorley high temperature sodium-potassium thermometer (1893), is set forth in the annexed table : — Lub. Oil. Lub. Oil. Lub Oil. Oil. Oil 890/6 885/90 866 840 830 Temp. Sp. Gr. Temp. Sp. Gr. Temp. Sp. Gr. Temp. Sp. Gr. Temp. Sp. Gr. First drop over, 725°F. 675»F. 575"F. 450°F. 500»F. 1st. 10 per cent, over, 745 „ •886 705 „ •878 600,, •856 500,, •806 510,, •818 2nd. 10 745 „ •888 715,, •880 605 „ •857 530,, ■823 515,, •821 3rd. 10 750,, ■889 720,, •882 610,, •858 545 „ •829 520,, •824 4th. 10 760,, •891 730,, ■884 615,, •860 560,, •836 530,, •826 5th. 10 770,, ■895 740 „ ■887 620,, •861 570,, •839 540,, •829 6th. 10 780,, •898 755 „ •890 630,, •863 585 „ •843 550,, •830 7th. 10 790,, •901 775 „■ •893 635,, •864 605 „ •847 565 „ •831 8th. 10 805 „ •904 795 „ •898 650,, ■868 630,, ■852 585,, •832 9th. 10 820,, ■907 830,, ■904 670,, •872 660,, ■856 615,, •834 (95 , , > 830,, 840,, 680,, 675,, 630,, (97-5 , , ) 850 „ 850,, 695,, 690,, 645 ,, 10th. 10 ' 875 „ •919 880,, •912 710,, •879 700,, •863 675 „ ■841 10,000 fluid grains were distilled from a copper flask, and the distillate was collected in 10 per cent, fractions and the sp. gr. of each fraction taken. The Uses of the Products of Manufacture. Naphtha or spirit, completely volatile at ordinary tempera- tures, is got at different specific gravities and boiling points' according to requirements — -660 for gasolene, for instance, and •690 for motor spirit. Ordinary naphthas, 725 to '745, are largely used for lighting purposes in special lamps in workshops, ship- Uses of Products of Manufacture. 187 building yards, etc. ; and, for solvent purposes, in dissolving indiarubber, for water-proofing, etc., and removing grease from clothes, etc. ; for dissolving gums and resins, wool-washing, paint- mixing, in the preparation of varnishes and of alkaloids, extraction of oils and fats, in linoleum making, and largely also for the refining of paraffin wax. It has been employed for freezing machines, and also as a local anaesthetic. Burning oils are used for lamps of many forms, sp. gr. varying from -785 to -830, and flashing point from 105° F. (40° C.) to 230° F. (110° C). Scottish oils have been free from lamp-accident fatalities since their manufacture over 50 years ago. The special, or water-white oil (sp. gr. 785), is serviceable for continuous burn- ing lamps for buoys, lightships, etc., which can be retrimmed only at long intervals, from a week to a month, and also for petroleum engines. These burning oils are also utilised for combustion in oil engines. Lighthouse oil is specially safe for lighthouses. Marine sperm is employed on board ships, with lamps slightly modified to suit the heavier oil, and it does not give off vapour that can ignite until much above the boiling point of water. Mineral colza (sp. gr. -840) is used also with special lamps. Intermediate oils (sp. gr. -840 to -870) are used for gas-making. They are very pure, require no refining for the gas, and are em- ployed where gas-lime is objectionable. They produce gas of high illuminating power and they are largely used for enriching coal or water gas, and also for combustion in oil engines. Mineral oils of all kinds, but chiefly the intermediate oils, are used for cleaning purposes, for removing rust from iron, and gummy matter which collects on machinery bearings when vege- table or animal oils are used as lubricants, &c. Intermediate oils are also employed for grease making. Lubricating oils are made with sp. gr. varying from '865 to '910. and are used either alone or mixed with vegetable or animal oil. Mineral oil prevents vegetable or animal oil from undergoing spontaneous combustion on cotton waste, » V CQ^ T3 ■a > £ d O O bo d O bo 3: 3 *5b KJ G O O O O a- 2S,» P O C5 Ions hale of Ions CD p P P P p P P 5— c H ? 5 "3 60 -g 60 l>- -^ 00 O 4 ■* CM ^ -4-3 t«-l CO O-s r— ( Mi CO a a 3 § CD d . © 'rt -■*> « d ffl O o 6 P d P Upper R Shale Lower R Shale Fells Shale m a u a .0 CD i "3) C a 3 3 O +-> 0) a a a P CD OJ CD «4 ■a a 13 ,a co ho M "5 (72 "3 ja CO (l 3 .0 M O CD CO -p -2 0) ■a CO c u +3 s J-> " |p. J? (D a a CO GO to 2 X CD a <» 7i «3 " ,c J3 CO CO *tH (3 O CD O O Sulphate Ammoni per ton Shale. 5 lbs. each earn. CO » r- CO O CO O — is 2 13 •« »< ■^ CO co in ^D CO 10 ■^i ^ O O £ £ = *M CO V) ^ 3 3 8/SJS 2 gallon each seam. ^2 = - " ^ - ^ " " " u Galloi Oil] ton Sha 13 bD O CM CO O CM 1 CO CN CO CM CO Cj, CO 00 ia CM rH CO 5 ?! (M CO CM CI ,-H 1— I r-t i-H i-H 1A CO 10 *5 - r" <- J GO EC 1 ■S IS a 3 a '3 3 ft. each seam. 3 ft. 6 in. 3 ft. 9 in. 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CO +^ ID '- , ^ Tj< (M Th ■* CO CO t- -a d d a. £ • fl d s ^ £ -'■:■■ , , i p i. o on; c 00 oo 00 1— 1 CO CO co CO o3 M V d d fl d A d A 0) CD & £ 2 CD 1> « J3 CO fl ? o ffl « fl O Q H O u § o «+- H to o ■+-3 00 CO 3 SO CO CO o o I-- CO Upper Shal Lower Sha Fells SI 3 CD d d ■r. Be- 3 M o m o c A s © 0. ft t> ' e a h b 3 s -a CO a - -w rG 0) J3 CO s 0) "3 -_ CO a u X Q u M CD CO J2 cy is CD *d CO d u £ - r ; $ * fc H » - ( ° » ° i ■ i i i boo!? %tl .o o L. CO a CO © 60 3 6 (1) d d a C/3 *CD rO o pq c d fl A X o PS - c c 3 fl - I ija fl c fl s 2 i £ 1 s a & 6 | A 3 Ph CD 1 o 13 C 5 a 3 CD S5 c o "Si a • ' ■ I K J i > Si! ^S^ a, s £ « i (fi ■ ■ • ■ * * ? 9 o aiJJJ^, 0. a P f F " g ° S CI i O U w C fl V d »4 3 X Li M +3 CD ««-■ 35 (3 M O m CO a a A © d JS CO d 3 .Q O bi PS o O o A o A o fl c a s fl Upper Raeburn Lower „ Fells Shale . CD CO d Pi d O P§ CD lib c 3 +3 © e c fl j - i 1 o 4 s 6 O 6 o d j d (3 o o o o j 3 M 15 -< ■4 a CO "o 1 1 H ^ 0- a a p ^ P 3 o •< o eS o P. a 6 Missing Page Missing Page lAtt of Publications of the Oeologiml Survey of Scotland — continued. 66. Kincardineshire, Forfarshire, Aberdeenshire (parts of). 68. 67. Kincardineshire and Aberdeenshire (parts of), is. 70. Inverness-shire (West-Central Skye, with Soay). 6a. 75. Inverness-shire, Elginshire, Banffshire, Aberdeenshire (parts of). 6s. 76. Aberdeenshire, Kincardinoshire. 6s. 77. Aberdeenshire, S.E. part ; Kincardineshire, N.E. corner, is. 81. Boss-shire, S.W. ; Islands of Raasay and Rona, part of Skye. 6s. 85. Elginshire, Banffshire, Aberdeenshire (parts of). 68. 87. North-East Aberdeenshire and Banffshire (detached portions). 6*. 91. Boss-shire (part of). 6s. 94. Boss-shire, Cromartyshire, Sutherlandshire (parts of). 6s. 95. Elginshire, Banffshire (parts of). 4s. 96. Aberdeenshire, Banffehire (parts of). 4*. 97. Aberdeenshire and Eastern Banffshire (parts of). 4s. 100. K.W. Boss-shire (part of). 4s. 101. Boss-shire, Cromartyshire, and Sutherlandshire (parts of). 6s. 103. Sutherlandshire, E. 6s. 107. Sutherlandshire (part of). 6s. 113. Sutherlandshire, N.W. (part of). 4s. 114. Sutherlandshire (part of N.). 6s. 115. Sutherlandshire, Caithness-shire (parts of.) 6s. II.— Maps on Six-inch Scale, illustrating the Coal-fields. Edinburghshire. Sheets 3, 8, 14, 17. 4s. Sheets 2, 6, 7, 12, 13, 18. 6s. Sheets 1, S.W., S.E. ; 3, N.W., S.W. ; 4, N.W., S.W., S.E. ; 8, N.E., S.W. ; 14, N.W., N.E., S.W., S.E. (revised editions). Is. 6d. (uncoloured). Haddingtonshire. Sheets 8, 13. 4s. „ Sheets 9, 14. 6«. Fifeshire Sheets 33, 37. 4s. „ Sheets 24, 25, 30, 31, 32, 35, 36. 6s. Ayrshire. Sheets 9, 26, 31. 4s. Sheets 7, 8, 11, 12, 13, 16, 17, 18, 19, 22, 23, 24, 27, 28, 29, 30, 33, 34, 35, 36, 40, 41, 42, 46, 47, 50, 52. 6s. Renfrewshire. Sheets 13, 14, 17. 4s. Sheets 7, 8, 11, 12, 15, 16. 6s. Lanarkshire. Sheets 1, 2, 3, 4, 5, 10, 49. is. Sheets 6, 7, 8, 9, 11, 12, 13, 16, 17, 18, 19, 20, 23, 24, 25, 31, 32, 37, 38, 41 42. 6s. Dumfriesshire. Sheet 1. 4s. „ Sheets 5, 6, 7. 6s. Dumbartonshire. Sheets 19a, 20, 24, 26, 28, including 29. 4s. Sheets 23, 25. 6s. Stirlingshire. Sheets 25, 33, 36. 4s. Sheets 17, 18, 23, 24, 27, 28, 29, 30, 31, 32, 35. 6s. Linlithgowshire. Sheet8. 4s. Perthshire. Sheets 135, 139, 141, 142, 143. 4s. SheetsJSS, 134, 140. 6s. IIa.-Maps on Six-inch Scale, illustrating Structure of N.W. High- lands- Sutherlandshire. Sheets 5, 71. 6s. Skye. Sheets 38, 39, 44, 45. 6s. III.— Horizontal Sections. 5s. per Sheet. Sheet 1. Edinburghshire and Haddingtonshire. „ 2. Edinburghshire, Haddingtonshire, Berwickshire. „ 3. Peeblesshire, Edinburghshire, Linlithgowshire. hist of Publications of the Geological Survey of Scotland — continued. : Sheet 5. Ayrshire Coal-fields (east side). „ 6. Renfrewshire,, Dumbartonshire, Ayrshire. „ 7. Cheviot and Lammermoor Hills. ,, 8. .Clyde Coal-field and Carapsie Hills. „ 9. Ayrshire Coal-fields (Muirkirk and New Cumnock). IV.— Vertical Sections. 3s. 6d. per Sheet. Sheet 1. Edinburgh and Haddington Coal-field. 2. Fife Coal-fields. 2a. Fife Coal-fields. . 3. Kilmarnock Coal-field. 4. Clyde Basin Coal-field. 5. Stirling and Clackmannan Coal-fields. 6. Muirkirk, Lesmahagow, and Douglas Coal-fields. 7. Lanarkshire Coal-fields (Rutherglen and Carluke). V.— Memoirs of the Geological Survey of Scotland. (1.) General Memoir: — Silurian Rocks of Britain. Vol. I. Scotland. 15s. (2.) Economic Memoir: — The Oil-Shales of the Lothians. 4s. (3.) Museum Guide: — Guide to the Collections of the Geological Survey. 2d. (4.) District Memoirs: — Cowal, Argyllshire. 6s. East Lothian (out of print). Central and Western Fife and Kinross. 5s. 6d. Eastern Fife. 8s. Skye. The Tertiary Igneous Rocks of. 9s. (5.) Sheet Memoirs: — Sheet 1. Wigtownshire, South- Western Districts. 3d. \ ,, 2. Wigtownshire, South-Eastern Districts. 3d. „ 3. Wigtownshire, Western Districts. 3d. „ 4. Wigtownshire, E. part; Kirkcudbrightshire, portion of S.W. Division. 9d. „ 5. Kirkcudbrightshire, Southern Districts. Is. 6d. „ 7. Ayrshire, South- Western District. 3d. „ 9. Kirkcudbrightshire, N.E. ; Dumfriesshire S.W. Is. „ 13. Ayrshire, Turnberry Point. 3d. ,, 14. Ayrshire, Southern District. 3d. ,, 15. Dumfriesshire, N.W. ; Ayrshire, S.E. ; and Lanarkshire, S. 3d. ,, 21. Buteshire (Arran, Central, and N. and S. Bute), Argyllshire, Ayrshire i (parts of). 4s. ! „ 22. Ayrshire, Northern District, and parts of Renfrewshire and Lanark- shire. 3d. „ 23. Lanarkshire, Central Districts. Is. ,, 24. Peeblesshire, Lanarkshire, Edinburghshire, Selkirkshire (parts of). 3d. „ 31. Lanarkshire, N. ; Stirlingshire, S. ; Linlithgowshire, W. 2s. 3d. ,, 32. Edinburghshire and Linlithgowshire. Out of print. New edition in preparation. ,, 34. Eastern Berwickshire. 2s. „ 37. Mid- Argyll. 3s.' « ,, 55. Perthshire, The Country round Blair- Atholl, Pitlochry, and Aber- feldy. 3s. * " ' ; ,, 70. Inverness-shire. West-Central Skye, with Soay. Is. 6d. i „ 75. Invorness-shire, Elginshire, Banffshire, Aberdeenshire (parts of). Is. J ,, 76. Aberdeenshire, Central. Is. ' ,, 85. Elginshire, Banffshire, Aberdeenshire (parts of). Is. 6d. „ 87. Aberdeenshire and Banffshire (parts of). 9d. „ 97. Northern Aberdeenshire. Eastern Banffshire, id. A detailed Catalogue may be had on application to Messrs. J. Menzies & Co. , Rose Street, Edinburgh, or 90 West Nile Street, Glasgow.