P»:il Jrm VP 3<>/4i *fk*€ 4f i\ a** hK j. i • i f 1 Calcareous Tufa. Pleisto- j Post-glacial ) ( Cave Deposits. CENE «• Glacial Boulder Clay, with Sand and Gravel. TABLE OF FORMATIONS. Solid Formations. Trias. Permian. Bunter Pebble Beds Lower Mottled Sandstone Middle Marl and Sands ... Lower Magnesian Lime- stone. Basement Beds ... I Carboni- ferous. Intrusive Rocks in Carboni- ferous Limestone. Middle Coal Measures ... Lower Coal Measures ... Millstone Grit Series Limestone Shales Carboniferous Limestone with contemporaneous Volcanic Tuff and Lavas Sandrock with pebbles. Red and variegated soft sandrock. Red marl and sand. Dolomitic limestone. Grey marl with limestone bands, Breccia and Quicksand. Shale and sandstone with many coal seams. Shale and sandstone with gannister and few coal seams. Coarse sandstones with shale. Dark shale with thin limestone bands near base. Pale hard limestone with darker limestone and chert in upper part. Doleritic tuff and olivine-dolerite Olivine-dolerite ... ... Dark hard basaltic rock. Volcanic Agglomerate ... Coarse doleritic breccia CHAPTER II. LOWER CARBONIFEROUS: CARBONIFEROUS LIMESTONE SERIES. General Structure West op the Coalfield. Folding. In its main features the structure of the Lower Carboniferous area forms part of the Pennine system of north-and- south folding, which system at its southern end divides into a number of minor diverging folds. The Carboniferous Limestone of our area owes its elevated position to the south-eastern spur of the main Pennine uplift, and exhibits two anticlinal elevations separated by a faulted synclinal depression, the whole trending but little south of east (see Plate III, fig. 2 ; but the section takes in only the crests of the folds). Curving around the eastern end of the double anticline but separated from it by a broad irregular syncline, a well-defined, long, narrow, sinuous anticline extends for a distance of about 14 miles from the neighbourhood of Belper (Sheet 125) northwards through Crich and Ashover to Uppertown (Sheet 112). It has its maximum uplift at Crich and Ashover, at which places it brings up inliers of the Carboniferous Limestone (see Fig. 2 and sections on Sheets 112 and 125). Eastward of this anticline small subsidiary folds are seen north-east of Crich and south-east of Ashover. North of and complementary to the anticlinal mass of the lime- stone of Wirksworth and Matlock, there occurs a shallow east-and- west syncline which lies mainly outside our area. Between the northern termination of the sinuous anticline beyond Uppertown and the anticline o£ Brimington (see p. 46) in the Coal Measures, a broad synclinal trough, convex to the west in hori- zontal section, extends east-south-east into the Coal Measures. The anticline of Brimington forms part of a long horse-shoe-shaped saddle, convex to the west, and extending from Unstone in the south-east by Holmesfield and Totley Moor to Houndkirk Moor, where it culminates in elevation, and thence eastward by Millhouses to Norton Woodseats. This horse-shoe-shaped saddle enfolds a syncline of Coal Measures, which stretches eastward from Totley through Dronfield (p. 48). The northern of the two main saddles forming the compound anticline of the limestone in the south-west of the district is relatively high and narrow, with a well-defined axis, running roughly from west to east throngh the dolerite sill of Bonsall and through High Tor. It dies out along the northern edge of Riber Hill in the Millstone Grits. It is diversified by one or two shallow minor folds on its northern flank, which has on the whole a rather high dip. The southern anticline forms a broader and rather lower feature, but its anticlinal structure is shown by the uplift of the lowest beds of the sequence in the middle, and by its marginal fringe of the upper cherty beds. The relatively narrow syncline between these two principal anticlines is occu- pied by a fault of some importance, described elsewhere as the Bonsall Fault (p. 11). The maximum displacement of this fault is influenced by a sharp monoclinal accentuation of the southern limb of the northern anticline. This monocline GENERAL STRUCTURE OF MATLOCK DISTRICT. Fig. 2. — Plan of the surface of the Carbonifehous Limestone, partly restored, with theoretical contour-lines at 200 ft. intervals showing the arrangement of the folds and faults. (C B. Wedd.) ROWSLEY Scale : 1 inch=2 miles. Present outcrops of the Limestone lie within dotted lines. - Contours- down- to sea-level-shown -by thin unbroken lines ; below sea-level, by broken lines. 10 LOWER CARBONIFEROUS. produces the steep downward bend of the limestone at the south end of Matlock Dale and along the Heights of Abraham, but terminates at the fault. It is accompanied on the south by a syncline increasing eastward and continuing as the trough in the Kinderscout Grit of Riber Hill, and further south by the gentle anticline of Matlock Bath (see Fig. 3, p. 15) trending south of east. Another fault, but with north-easterly downthrow, runs parallel to the Bonsall fault from the Derwent valley at Willersley, north of Cromford. It does not extend far, but between the two fault-planes which if produced upward would intersect, the sharp ridge of Harp Edge stands up as a 'horst of the pale limestone above the upper lava. On either side the higher cherty limestones dip inwards at a lower level. The anticline of Belper and Ashover increases gradually to two points of exceptional elevation at Crich and Ashover. The relative uplift of the highest bed of the limestone in the anticline, between Wheatcroft and Doehole, may be estimated as roughly 800 ft. less than at Crich and 600 ft. less than at Ashover. These features are illustrated by the diagram, Fig. 2, p. 9. The uplift, except near its terminations, shows on its east flank a rather high dip, especially steep in the middle part of its course between Crich and Ashover. Moreover, the dip on the convex or outer side of a bend is always higher than on the opposite side ; and in one case, the higher dip on the convex bend occurs on the west side of the fold, in the northern part of the Crich limestone, where however it may have bee a influenced by the downward drag of the Southern Crich fault. This anticline bears an evident relationship to the folding of the south-eastern spur of the main limestone mass to the west. It will be seen from the diagram, Fig. 2, that the general trend of the sinuous anticline, with its outward bends at Crich and Ashover, and its slight inward curve between them, recalls the principal features of the folding as seen in the limestone to the westward. With a general trend at right angles to the axes of folding in the limestone of Matlock and Wirksworth it conforms to the outlines of these folds, to which it is evidently complementary, and dies out as soon as it passes beyond their influence. The result is such as might be expected if the east-and-west stresses that produced the Pennine uplift, were diverted to a north and south direction, so as to give rise to a " couple " of stresses, the components of which acted in opposite directions but not in the same line. The east-and-west folds are supplemented by an anticlinal wrinkle curving around their eastward termiua- tions. and dying out immediately beyond the limits of their influence. The wrinkle, as might be expected, is strongest at points where it passes around the termination of folds, and at those points it brings up the limestone- inliers of Crich and Ashover. It is perhaps significant that the south-eastern spur of the Pennine axis, the one most distorted from the normal trend of the Pennine folding, is the one that shows this complementary wrinkle curving around its termination. A group of small folds subsidiary to the long anticline is found on the east side of it between Crich and Ashover, where its elevation is relatively low but its easterly dip is high. These lead to a great increase in the width of out- crop of the Coal Measures below the Wingfleld Flagstones. The synclinal basin eroded in shales north-east of the Crich limestone is almost or quite enclosed by the agency of an anticlinal ridge which brings up sandstones on its east side. The small syncline trending south-eastward from Crich 1 seems to have an analogy in a similar fold trending northward at Stone Edge north of Ashover. Thus a certain symmetry is observable in the folding around the ends of the main folds in the limestone. Faults. The majority of the faults affecting the district have a north-westerly direction, but several, chiefly minor faults in the west, follow north-easterly or easterly courses. It is noteworthy that except where it is dislocated south of Crich by the great south-westerly downthrow of the Southern Crich fault, the Crich- Ashover anticline is nowhere crossed by faulting of any magnitude. But further north, in Sheet 100, an important belt of frequent north-westerly faulting, with downthrows in either See ' Southern Part of the Derbyshire, etc., Coalfield,' Mem. Geol. Surv., 1908, p. 136. PRINCIPAL FAULTS. 11 direction, continues across country through Holmesfield and the tract of Lower Coal Measures and Millstone Grit west of it. Faults trending in several directions have cut out the higher beds of the Millstone Grit Series and the lowest Coal Measures in the neighbourhood of Houndkirk Moor and Whirlow. The Bonsall Fault ] enters the limestone in a WNW. direction at Cromford Market-place. The main fault runs along the northern brow of Bonsall Hollow to Bonsall Church. In this part of its course it throws down the cherty beds of the higher part of the Lonsdalia-floriformis subzone on the south successively against the upper and lower lavas and underlying limestone in the neighbourhood of the church, where its displacement must have reached a maximum of something like 400 feet. Here it bends more to the west, and there is some reason to believe that it forms the southern boundary of the Bonsall sill. Its exact position hereabouts is difficult to define, but it clearly continues along the synclinal valley further west and throws down strata above the lower lava • on the south against the anticlinal beds of Blakelow Hill, which lie below that lava. The Bonsall Fault has the same general trend and throw as the Southern Crich Fault, 2 the two together producing a powerful south-westerly downthrow for a distance of seven miles or more. The Gulf Fault, 3 forming a long cliff of limestone, extensively quarried, as the western boundary of ' the Gulf,' continues an irregular north-westerly fault-belt mapped in Sheet 125. Bending further west at Middleton and crossing the Via Gellia valley, where the limestones on both sides are closely sheared in a north-westerly direction, it appears to die out before reaching Whiteclifle Farm. From the Via Gellia southwards its throw is considerable, and in the neighbourhood of the Jackson Mine it must have an easterly down- throw of approximately 480 ft., as shown by its displacement of the lower lava. The parallel Rantor Fault with westerly downthrow forms the eastern limit ' of ' the Gulf,' and beyond it three other parallel faults affecting the limestone throw down alternately north-east and south-west. The north-westerly fault next eastward from the Rantor, where exposed in a limestone quarry, intersects an east-and-west fault, inclined at a low angle to the horizontal, which on the E. side of the NW. fault brings unfossiliferous dark pyritous shales in apparently conformable but deceptive sequence above massive white limestone. The cherty limestones and the higher thin limestones alternating with shale, which should be present, in this section are missing, and the shale is strongly slickensided along its bedding planes. But immediately west of the W. fault this shale abuts against alternating dark limestones and shales with a Cyathaxonia fauna, and underlain by a small thickness of blue limestone, the whole dipping off massive white limestone similar to that on the other side of the NW. fault. It is evident that we have here an east-and-west ' drag-fault,' in which upon the flank of the uprising anticlinal limestone the overlying beds were dragged down, and the cherty limestone smeared out. The general evidence in this case points to the conclusion that movement took place along the two directions of faulting simultaneously or alternately. The east- and-west fault that carries the Gang Vein forms the northern termination of ' the Gulf ' and has a southerly downthrow in the western part of its course, but a northerly at its east end, where it passes into the Limestone Shales, a change of throw noted by Dr. Strahan. 4 Of the belt of faults, mostly north-westerly, that traverse the Millstone Grits between the Sheaf and Derwent valleys, few have any great displacement, though some can be traced at the surface for several miles. The most con- spicuous of these are the jsouth-westerly downthrows that depress the Ohatsworth Grit towards the Derwent valley in the neighbourhood of 1 ' Summary of Progress for 1907,' Mem. Geol. Sure., 1908, p. 13. - See ' Southern Part of the Derbyshire, etc., Coalfield,' Mem. Geol. Surv., 1908, p. 138. :i J. Farey, ' General View of the Agriculture and Minerals of Derbyshire,' 1811. p. 265 ; A. Strahan in 'Carboniferous Limestone, &e., of North Derbyshire,' Mem. Geol. Surv., ed. 2 1887, p. 150 ; also T. I. Pocock in ' Southern Part of the Derbyshire, etc., Coalfield,* Mem. Geol Sure , 1908, p. 175. '■> ' Carboniferous Limestone, See., of N. Derbyshire,' Mem. Geol. Surv., ed. 2, 1887, p. 150. 9-,97r. B 12 LOWER CARBONIFEROUS. Longshaw Lodge and Fox House. The elevated n ° rt £; ea ^™ ^wiithrows grit on Burbage and Houndkirk moors is bounded «»'«>'*" a £ d the highest which have f o? the most part cut out the lowest Coal Measures ana Millstone Grits. Carboniferous Limestone Series. Introduction. The Carboniferous Limestone Series exposed in the district of Matlock, Crich, and Ashover (SW. pait ; oi : bheet 112), consists of a thick lower group of massive whiti sh blue 01 grey limestones with intercalated volcanic rocks and a , ±ct thin bands of shale (the Carboniferous limestone proper) succeeded by a group composed mainly of shale, with a few thin limestone bands near the base (the Limestone Shales). . rwu^i,:,.,, Owing to the periclinal arrangement of the series in Derbyshire its basal beds are nowhere exposed, so that we have no knowledge either of its total thickness or of the nature and age oi the rocKs below. Its upper part, however, affords abundant facilities tor examination. The ascertained thickness of actual limestone that crops out amounts to about 1,500 ft. 1 or somewhat more, and there is no reason to suspect the immediate proximity of^ the base otthe formation where the deepest exposures are seen. To this thickness intercalated igneous rocks make locally a not inconsiderable addition. . Within the area with which we are here concerned, rather less than half this thickness crops out, while a further 200 ft. or so has been proved in mining. Yet the whole sequence of Carboniferous Limestone known in Derbyshire appears to represent only the uppermost or Dibuno- phyllum zone (D. of Dr. Vaughan's classification) of the limestone series as it occurs in the south-west of England and Wales. Ine fossil-evidence of the lowest strata in other parts of the county is scanty, but within our district it may be stated confidently that the Dibunophyllum zone is alone represented. 3 The topmost beds of the limestone often show by the intercala- tion of more and more bands of shale a gradual upward transition into the Limestone Shales. The line of division between the lime- stone and shale formations therefore becomes in places rather indefinite. „ The highest beds of the limestone always contain layers oi tabular or nodular chert, which follow the lines of bedding. Occa- sionally two of these bands by approximating to each other betray a lenticular bedding not otherwise discernible. The greater part of the limestone — roughly speaking, all but the upper beds, which are of a dark bluish-grey or even black and include the main cherty limestone — consists of a pale rock, creamy 1 See T. P. Sibly, ' The Faunal Succession in the Carboniferous Limestone (Upper Avonian) of the Midland Area (North Derbyshire and North Stafford- shire)', Quart. Journ. Geol. Soc, vol. lxiv, 1 908, p. 37. \ 2 ' The Palaeontological Sequence in the Carboniferous Limestone of the Bristol Area,' Quart. Journ. Geol. Soc, vol. lxii, 1 906, p. 379 ; also T. F. Sibly, op cit. 3 Short accounts of the zonal stratigraphy of this part of the limestone have appeared in 'Summary of Progress' for 1904 (p. 8) ; for 1905 (p. 14) • and for 1907 (p. 9). s - C ; GENERAL ACCOUNT OF CARBONIFEROUS LIMESTONE. I'i white, light bluish-grey or fawn-coloured. It is a comparatively pure limestone where not subsequently dolomitized or silicified. In microscopic structure it ranges from a very fine-grained calcareous mud, with sponge-spicules and foraminifera, through microgranular and micro-oolitic types to more coarsely granular limegtone with rolled shell-fragments and little pellets of detrital limestone. 1 Parts of it have a coarsely crystalline appearance owing to the inclusion of innumerable calcite-organisms, chiefly crinoid ossicles. The dark parts of the limestone probably owe their colour to argillaceous impurity, and it is often noticeable that this colour is deeper near shale bands, and that the rock for a few feet above a toadstone has a much darker tint than the succeeding beds. Dolomitization, which does not follow stratigraphical lines though it has affected some groups of strata more than others, locally involves great masses of the limestone over a considerable area. The more dolomitized limestone generally takes a light brown or yellowish hue. Minute quantities of petroleum and bitumen sometimes partially fill the cavities of brachiopods. In the case of corals, it is chiefly in the more dolomitic rock that the spaces between the tissues are hollow and contain specks of bitumen. "W hile the limestone and its fauna suggest formation in a com- paratively shallow sea, occasional evidence is afforded of the proximity of land, e.g., by the local occurrence of an underclay with catamites above the upper lava, 2 and of a thin coal and under- clay in the higher beds of the limestone. 3 A bed of rolled shells in the highest part of the limestone at Castleton and similar accumulations elsewhere have been described as a ' beach-deposit,' 4 but no evidence of any such continuovis deposit has been detected in the district, though masses of rolled shells may occur here and there. Subdivision of the Limestone. Apart from an obvious Hthological division of the limestone into an upper more or less thin-bedded blue cherty type and a lower more massive pale chertless type, further classification can be founded on faunal changes, and the presence of contemporaneous igneous sheets. The following table gives a general view of the downward succession. Zone of Dibunophyllum (D). Subzone or Phase of Cyathaxonia (D3). (e) Thin-bedded blue limestone with chert and thin shaly partings. Charac- teristic fauna including Cyathaxonia rushiana "Vaughan, Densiphyllum and Zaphrentis enniskilleni ? E. & H., with Productus giganteus Mart, and P. concinnus J. Sow. Thickness about 35 ft. exclusive of the part within the overlying Limestone Shales. 1 See H. H. Arnold-Bemrose, ' Notes on the Microscopical Structure of the Derbyshire Limestones,' Sep. Brit. Assoc, Dublin, 1908, p. 702. 2 A. H. Green, 'Carboniferous Limestone, &c, of North Derbyshire,' Mem. Geol. Surv., ed. 2, 1887, p. 23. 3 Sir H. T. De la Beche, ' The Geological Observer,' ed. 2, 1853, p. 560. 4 J. Barnes & W. F. Holroyd, ' On the Occurrence of a Sea Beach at Castle- ton, Derbyshire, of Carboniferous Limestone Age,' Trans. Manchester Geol. Soc, vol. xxv, 1898, pp. 119, 181 ; vol. xxvi, 1900, p. 466. 25276 B 2 14 LOWER CARBONIFEROUS. Subzone of Lonsdalia floriformis (D2). (d) Limestones usually thin-bedded, cherty and blue in upper part like those of («), but passing down irregularly into, and locally replacing entire y, more massive chertless rock of a pale-blue, f a wn or cream colour. Abundant fauna of corals, crinoids and brachiopods : Lonsdalia floriformis Flem., Dibunophyllum turbinatum (M'Coy), including the form U. mat- locbense Sibly, B. muirheadi Nich. & Thorns., Cyathophylh, m regmm (Phill.), Lithostrotion, Syrinoopora ; giganteid and other forms of Product™ throughout. Lonsdalia cf. duplicaia (Mart.) and Products giganteus Mart, (type) chiefly or only in upper halt. Maximum thickness about 115 ft. Upper lava (toadstone), where present. Thickness up to 80 ft. Tuff of Ashover ; approximate position, where present. Thickness more than 210 ft. (c) More or less massive limestone, usually pale or whitish, but upper part replaced locally by blue cherty limestone. Fauna similar to that of lower part of (d) and equally abundant do^vn to base. Thickness pro- bably varies up to 150 ft. Lower lava (toadstone) : maximum thickness about 100 ft. Subzone of Dibunophyllum 9 (£>1). (6) Massive pale and whitish limestones, for the most part of more homo- geneous texture than the higher beds ; occasional thin shale bands : fauna scanty : Dibunophyllum of simple structure, doubtfully recognised and certainly rare ; Cyathophyllum, including C. murchisoni E. & H. more abundant ; also Lithostrotion, Syringopora, giganteid Productus, Cyrtina spptosa Phill. Thickness probably nearly 350 ft. (a) Very compact and fine-grained pale limestone (Holystone) of porcellaneous aspect, with occasional oolitic bands and finely granular beds. Fora- minifera abundant ; other fossils scanty except in higher beds, and similar to those of (b). Thickness seen, more than 100 ft. The sketch-map, Fig. 3, represents the superficial distribution of the three limestone groups constituted by the cherty rock, and the chertless limestones above and below the lower lava. In a general way the lithological divisions thus indicated compare approximately v\ ith the three palaeontological subzones, except that the bottom of t'ne chert-beds is not a stratigraphical line, and lies usually lower thaa the base of the Cyaihaxonia subzone. PalaeontologicaJly the lowest subzone, that of Dibunophyllum ' 0,' contrasts strongly with the others by its relatively imfossiliferous character. Macroscopic fossils are generally few and widely scattered, but here and there more fossiliferous horizons are met with. Further particulars of these subdivisions will now be given in ascending order. (a) The subzone of Dibunophyllum ' 6 ' contains two rather strongly contrasted lithological types, which, however, merge into one another. The lower rock (a), locally known as ' holystone,' is unlike any other limestone in the district. It is a pale massive smoothly-fracturing rock. The ooliths of the oolitic bands are not readily distinguishable by the naked eye; for they are firmly cemented in a matrix of the same pale colour, and do not stand out on a fractured surface. The granular appearance of other beds chiefly found m the upper part of this rock, is due to the presence of minute joints of crinoids. Except these and foraminifera, fossils are not frequent. Near the top, however, one or two beds of the more granular type contain corals, gasteropods and brachiopods in some abundance. STRATIGRAPHY OF MATLOCK DISTRICT. 15 Fig. 3.— Geological Sketch-map op Matlock (C B. Wedd) reproduced from ' Summary of Progress for 1907 ', Mem. Geol. Surv., p. 12. 'l * -T—H lltiLe. Millsttmje Grits Lirn*est*mje StoaL&s ■-Vt* rt oPD' TuJV rftSF Jig qhorr^er cubes DoLeriJbe- silLs 4—4 — f_| — « ♦ ♦ AnilcJinxil txacas j 'X I I — J i 1 SyoxHxr>-aL cuxes 16 LOWER CARBONIFEROUS. (6) The succeeding beds are massive and fine-grained, of pale shades of bluish and creamy grey. Many parts are full ol little crinoid ossicles, but there is a general absence ol tne laiger crinoids so conspicuous in certain higher beds, borne bands near the top are strongly oolitic. In the lower part are occasional shale bands, locally three or four feet thick. One or two horizons contain abundant brachiopods, gasteropods and corals, but beds ol this character are rare. Near the base a small development ol pale shert occurs locally. (c) The massive limestones that occupy the interval between the two lava flows, of a pale colour, sometimes almost white, but usually of a dark blue for a few feet above the lower lava, are much more fossiliferous, and contain numerous thick beds full of brachio- pods, corals and crinoids, which occur in less abundance almost throughout the group. These limestones are often much dolomitized and in that state preserve fewer and less perfect fossils. Locally, some of the lower beds closely resemble limestones below the lower lava. The above description applies to all the beds between the two lavas except in the south-west, where the cherty type has encroached downwards. But the lower development of cherty rock contains the usual fauna of these beds (c). (d) The massive pale limestones next above the upper lava often present much the same character as those below, but here and there are crowded with large and small crinoid ossicles. A small develop- ment of pale-coloured chert is sometimes seen between 30 and 40 ft. above the upper lava, and in the south-west part of the area the pale chertless limestone is entirely replaced by blue cherty beds. Occasional thin beds of shale occur in the upper part in places. The group is fairly fossiliferous as a rule, and at several horizons abounds in brachiopods and corals. (c) The thin-bedded blue cherty limestones contrast strongly in appearance with the massive pale chertless rock below : the change from one type to the other sometimes takes place with alternation of darker and lighter shades and with a gradual and irregular incoming of chert. Near the top of the group, where the colour of the limestone is generally deepest, thin dark shales usually appear, and become more numerous upwards. The cherly group is highly fossiliferous throughout, with abundance of brachiopods, corals and crinoids. The lower and greater part, where the cherty beds are not exceptionally thin, belongs to the subzone of Lonsdalia flori- formis, while the highest beds, those assigned to the Cyathaxonia subzone, show a partial and rather sudden change of fauna. Palaeontology of the Limestone. The lowest two divisions {a and b), assigned to the 'Lower Dibunophyllum ' subzone, contain comparatively few fossils ; which are most abundant in the upper part of (b), at one or two horizons towards the base of that division, and in the higher part of (a). Of corals, species of Cyathophyllum, Lithostrotion and Syring'opora are most commonly found. Cyathophyllum murchisoni E. and H. and its variants are the corals most characteristic of these lower lime- stones, ui which they are relatively more abundant than in ' D 2.' PALAEONTOLOGY OF THE LIMESTONE. 17 Lithostrotion is represented somewhat scantily by L. irregulare (Phill.) or allied forms, L. junceum (Flem.) and L. martini E. and H. ; Syringopora chiefly by S. geniculata Phill., and variants. A Carcinophyllum and a species doubtfully referable to a Dibuno- phyllum 1 of somewhat simple structure, occur rather rarely at least as far down as the lowest beds of (b). Alveolites septosus (Flem.) is not infrequent, while Zaphrentis omaliusi E. and H., Aulophyllum and probably Campophyllum have been found. Of brachiopods, one or more forms of giganteid Productus are present at several horizons throughout, but not in large numbers ; P. cf . hemisphaericus J. Sow. is locally quite abundant ; and a few other species of Productus are sometimes met with, including P. edelburgensis Phill., P. cf. costatus J. Sow., and P. cf. latissimus J. Sow., together with Brachythyris planicostata M'Coy, Spirifer bisulcatus ? J. de C. Sow., and occasionally Schizophoria resupinata (Mart.). Dr. Sibly informs us that he noted Cyrtina septosa Phill., a characteristic ' Lower Dibunophyllum ' brachiopod, in beds not far below the lower lava at the Hoptonwood Quarries. Small gasteropods doubtfully referred to Bellerophon, Loxonema and Straparollus are rather frequent in the upper beds of («) : while foraminifera, including Endothyra globulus (d'Eichwald), abound in the lower porcellaneous limestone. Beds full of crinoid ossicles, mostly small, occur at various horizons. This somewhat scanty fauna affords in itself no conclusive evidence for assigning the whole of the divisions (a) and (b) to the Dibunophyllum zone. But it is closely related to the rich fauna of the subzone of Lonsdalia fioriformis ; it includes one or two species especially characteristic of the subzone of Dibunophyllum 9 ; it contains no forms typical of any earlier zone ; and it is preceded in other parts of the limestone area by several hundreds of feet of limestone equally devoid of any suggestion of an earlier zone. 2 We have therefore little hesitation in grouping the whole thickness of the lower limestones (a and b) of this district in the Lower Dibunophyllum subzone. Immediately above the lower lava a well-marked faunal change takes place. The characteristic fauna of the Lonsdalia Jhriformis subzone comes in suddenly in great abundance at the base of (c), just above the lower lava, and contains numerous clisiophyllid corals, lithostrotions, Diphyphyllum and Syringopora associated with many brachiopods, chiefly of the genus Productus. Of the clisiophjllids the group of Dibunophyllum turbinatum (M'Coy) is the most abundant, and includes frequent examples of the particular form described by Dr. Sibly as D. matlochense ; 3 while D. dicki (Thorns.) and D. muirheadi Nich. & Thorns., with kindred forms, are found less frequently. A large coral referable to Caninia or Campophyllum is characteristic of these beds ; Lithostrotion is represented in great numbers by L. junceum, L. irregulare 1 Dr. Sibly found a Dibunophyllum of simple type, rare throughout, in other parts of the limestone district. Op. cit., p. 43. 8 See T. F. Sibly, op. cit., p. 43. 3 ' The Faunal succession in the Carboniferous Limestone (Avonian) of the Midland Area (North Derbyshire and North Staffordshire),' Quart. Journ. Geol. Soc ., vol. lxiv, 1908, p. 74 and PI. 1, Fig. 2. 18 LOWER CAEBONIFEKOTTS. with variants and L. martini; Syringopora l ^^f° nn ^fj m \ S. cf. geniculata and other species. Lonsdalia j%r if or mts * lem. is present, though not abundant at this or at ^%™} h ™™?™\ also Aulophyllum cf. pachyendothecum &™*'\ ^Sni^ paracida (M'Coy), Cyatkophyllum regium Phdl., C. muictesoni ana Campophyllum. Productus giganteus Mart, is usually the most plentiful of several species of the genus found in the lower beds of the subzone. This characteristic fauna is well represented at many horizons throughout, but it is probable that certain other clisio- phyllids, including variants of Dibunophyllum muirheadi JNicb. & Thorns, are relatively more abundant in the upper part of the subzone, in which part also Cyatlwphyllum regium seems to be more frequent. Productus giganteus, with variants, is abundant all through, but especially in the highest beds, where it is often crowded in vast numbers and of the typical form with undulating surface, probably not to be found lower. With it are associated in less numbers P. cf. hemisphaericus, and semireticulate forms such as P. antiquatus J. Sow., P. productus Mart, and P. cf. semireticulatus Mart., with other species ; Brachythyris planicostata, Spirifer bisulcatus and Martinia ovalis (Phill.) occur frequently; also Schizophoria resupinata, chiefly in the higher beds. Many thick beds, especially near the horizon of the upper lava, are crowded with crinoids, often of large size. Where the subzones of Lonsdalia floriformis and Cyathaxonia can be studied at their junction, a partial change of fauna, chiefly in the corals, takes place sometimes rather suddenly. Cyathaxonia of more than one species, including C. rushiana Vaughan and C. cornu Mich. ; Densiphyllum including D. charlestonense Thorns. ; Zaphrentis allied to Z. enniskilleni E. & H., Z. costata M'Coy and Z. disjuncta Carr., together with Caninia cornucopiae Mich., come in without any obvious lithological change, except where the base of the blue cherty type of limestone happens to coincide with their incoming. At the same time Lonsdalia floriformis disappears : Cyathophyllum regium, Campophyllum and probably Litlwstrotion martini have not been found in association with the Cyathaxonia fauna in this district ; while Dibunophyllum becomes rare, and the forms of it that are found in the Floriformis subzone probably do not persist upward for more than a few feet further. But Lithostrotion junceum is still plentiful. Lonsdalia cf . duplicata Mart, usually abounds at the junction of the Floriformis and Cyathaxonia subzones, but chiefly within the latter, 1 in which Amplexus coralloides J. Sow. is also rather common locally. The brachiopods show little change ; but Rhipidnmella aff. micfielini Leveille is of frequent occurrence and Productus concinnus J. Sow. sometimes fills thin beds near the top of the limestone to the exclusion of all other fossils. The limestone immediately below the lower lava is too seldom exposed to admit of a positive statement that the rich coral fauna of the Floriformis subzone comes in quite abruptly. But the faunal change just above that lava is so great, and apparently so sudden, as to suggest the possibility either of a pause in sedimentation or of a change of conditions at that horizon. And it is not 1 .See also T. F. Sibly, ,,p. cit., p. 45. PALAEONTOLOGY OF THE LIMESTONE. 19 impossible that the outpouring on a shallow sea-floor of a lava-flow, which when consolidated was at least 100 feet thick, may in itself have produced a local variation of life-conditions. Dr. Sibly noted a similar faunal change in Grratton Dale at the level of the same toadstone at its furthest known outcrop, 1 but found the line of demarcation between the two subzones less definite where that toadstone is absent. 2 The transition from the Floriformis to the Cyathaxonia subzones is well-defined and abrupt at Matlock Bridge, where it practically coincides with the base of the cherty limestone, so that about 30 ft. of the highest limestone must there be assigned to the Cyath- axonia beds ; and it is equally well-defined at Cromford. But on the other hand at Crich and Ashover, at both of which the Cyathaxonia fauna is present, the separation of the two subzones is less clear, and it is doubtful whether more than a very few feet of the lime- stone belongs to the higher subzone (see p. 36). The Cyathaxonia fauna ranges upwards in this district beyond the main mass of the Carboniferous Limestone. As this fauna shows a predilection for dark muddy limestones and calcareous shale, its incoming is evidently determined in part by a change to more argillaceous conditions, and does not denote simply a chronological succession. For, where no obvious change accom- panies the first appearance of this fauna, the limestone has already become darker and less pure, in the upward succession. A comparison of the palaeontological and lithological divisions here with those of other parts of the Derbyshire limestone-massif brings out certain points of difference as well as a very general agreement. The south-eastern part of the limestone-outcrop is specifically poor in brachiopods, but rich in corals, as compared with the western and particularly the south-western parts: While it contains several clisiophyllid corals not found in the south-western district, it exhibits none of the peculiar brachiopod-beds that seem to be con- fined to that neighbourhood. 3 In our area the subzone of Lonsdalia floriformis does not exceed a thickness of about 260 ft. Dr. Sibly estimates it at 400 or 500 ft. further north between Longstone and Burton. 4 There is thus a notable thickening of this division in a northerly direction. In this connexion we may recall the suggestions of lenticular bedding already mentioned (see -p. 12). The variation in thickness of beds referable to the Cyathaxonia subzone below the top of the limestone-massif .is susceptible of a different interpretation. These beds in the south-east probably seldom exceed 30 ft. in thickness ; but lack of opportunity to -examine the passage down into the Floriformis subzone makes it impossible to speak positively. In the extreme south of the lime- stone outcrop their thickness is much greater, 5 while north of our district, at Ashford, it appears to be more than 150 ft. 6 The rapidly varying nature of the passage from limestone to shale ' Op, cit., p. 55. * Op. cit., p. 39. 3 See T. F. Sibly, op. cU., p. 47. 'Op. cit., pp. 38-41. 5 See Dr. Sibly's note on the Crake-Low Cutting, op. cit., p. 59. 6 Vid. op. cit. p. 58. 20 LOWER CARBONIFEROUS. renders it likely that this difference of thickness may be due partly to the circumstance of the lithological upper limit of the limestone-: massif not lying everywhere at precisely the same stratigrapnical horizon. . . For a detailed comparison of the zonal succession in the Derby- shire limestone with that of the south-west of Britain the reader is referred to Dr. Sibly's paper. 1 Chekt-Beds and Silicified Limestone. The range of the chert bands in the upper part of the limestone has been outlined in the foregoing description. The bands set in at rather widely different horizons in different parts of the outcrop, but the variation from place to place is always gradual. On the west side of the limestone-massif the chert-bearing rock may attain a thickness of some 400 ft. ; but in this south-eastern part it is usually about 50-60 ft. thick in the neighbourhood of Matlock, Cromford and Crich. South-westward, however, on Middleton Moor, the cherty condition descends gradually lower until it comes within 50 ft. of the lower lava {see below, p. 30), so that it affects some 200 ft. of limestone ; while at Ashover in the north-east it affects about 150 ft. On the other hand, on the north side of Matlock the cherty limestone has for some distance a thickness of little more than 30 ft. There are moreover within our district one or two small local developments of chert at a much lower horizon, one as much as 400-500 ft. below the top of the limestone. The colour of the chert has some relationship to the colour of the limestone in which it occurs, being black or dark blue in the darker beds, usually grey or mottled in beds of intermediate tint, while in its rare local developments lower down in the pale lime- stones it is pale and sometimes almost white. The nodules and tabular sheets of chert are usually denned clearly by sharp margins. But another phase of silicification in the same beds produces an ill-defined mass without any definite boundary. A further crystalline silicification affects the limestone locally. The aggregation of minute secondary and often bipyramidal quartz- crystals, not uncommonly disseminated in Carboniferous and other limestones, has proceeded on the flank of Masson Hill, Matlock, to such a degree as to produce, first, a limestone full of these little crystals, and, finally, irregular masses of a quartz-rock in which the original limestone has suffered so complete a replacement as to consist almost entirely of interlacing and interpenetrating quartz-crystals, 2 in the beds below the cherty limestone. In the cherty beds cherty silicification usually attacks first the calcareous tissues of corals and brachiopods before filling their cavities ; but in the lower chertless limestones a more crystalline silicification occasionally shows itself in very small quantities inside corals, where it forms first within the inter-septal spaces and seems to be limited by the septa and tabulae. 1 Op. cit., pp. 64-7. 2 See H. H. Arnold-Bemrose, Quart. Joum. Geol. Soc, vol. liv, 1898, p. 169 METALLIFEROUS VEINS, ETC. '^1 DOLOMITIZATION. Dolomitization appears to be here in the main a secondary character, which has locally affected large masses of the limestone more or less completely. But no particular horizon is continuously dolomitic. For instance, a great thickness of limestone above and below the lower lava on the high ground west of Middleton Moor, and the whole of the limestone between the two lavas at Matlock Bath are thoroughly dolomitic, and appear as an opaque yellow rock (' dunstone ') ; but the same beds elsewhere have been dolomitized but little or not at all. Smaller masses are locally dolomitic at several other horizons ; while the bounding walls of veins some- times show more dolomitization than the surrounding rock. On the whole it may be said that a considerable proportion of the lime- stone in this district is in a more or less dolomitic state. Mineral- Veins and Minerals. In the limestone of Matlock, Middleton and Wirksworth, as well as at Crich and Ashover, mineral deposits have a wide distribution as the filling or lining of fissures and other cavities in the limestone, the mineral-bearing fissures continuing occasionally for a short dis- tance into the overlying shales, and somewhat rarely traversing the toadstones. The vein-minerals of chief economic importance are lead, fluorspar and zinc, with which are associated calc-spar and barytes in great quantity and other minerals locally in small quantity. The veins are variously filled with deposits on the walls. The ' gangue ' of a vein may consist of calcite, barytes or fluor- spar, or any combination of these minerals in alternate layers, which may more or less completely fill the fissure for a considerable part of its vertical range. With these are associated lead-ore, chiefly as galena (sulphide), but sometimes as cerussite (carbonate) ; and less frequently zinc-ore as blende (sulphide) or calamine (car- bonate) : cerussite and calamine appear to be secondary forms of the ores, which are found as layers or small inclusions amongst the more bulky gangue-minerals. Silver is met with locally in small quantities associated with lead. Ochre and wad (black oxide of manganese) are also found. Of the rarer minerals matlockite (oxychloride of lead) and phosgenite or cromfordite (oxycarbonate of lead) may be mentioned as occurring near Cromford. The practically complete absence of quartz from the mineral-veins is a striking fact 1 ; it is seen sometimes as strings traversing * the intrusive sills, and in the limestone where there is much replacement by secondary quartz. In this district all important minerals take the form of true fissure-deposits. While metasomatic replacement of the fissure- walls has certainly taken place to a slight extent, it has not been responsible for the production of workable ore. There is no limitation of the veins to any particular trend or set of fissures. The fault-fissures and joints run in several directions, an approximately east-and-west strike being the prevalent one for 1 C. B. Wedd and Gr. C. Drabble, ' The Fluorspar Deposits of Derbyshire,' Trans. Inst. Min. Eng., vol. xxxv, 1908, p. 508. 22 LOWER CARBONIFEROUS. the larger veins in the Derbyshire limestone generally. But within this district smaller veins approximating to a north-westerly trend are more numerous. Fluorspar occurs principally in the uppermost 300 or 400 ft. of the limestone (i.e., it is found mainly above the lower lava) and appears to be entirely confined to the highest 550 or 600 ft.' ; while lead has a wider, but nevertheless restricted vertical range : for it is well known that the lead-veins become impoverished in depth 2 : indeed there is very little lead in the lower strata of the known thickness of limestone in Derbyshire. Besides the vein-minerals, minute quantities of petroleum and bitumen are sometimes found, partially filling the cavities of brachiopods. In the case of corals it is chiefly in the more dolomitic limestone that the spaces between the tissues are hollow and contain specks of bitumen. Elastic bitumen (elaterite) has not been noted within the district. Large solution-cavities often occur in the limestone on the lines of mineral-bearing fault- or joint-fissures. These large cavities usually contain a great store of mineral-deposits on their walls. Some of them, laid open by denudation, or more commonly reached only by fissures or mining adits, form extensive caverns. Igneous Rocks Associated with the Limestone. Included igneous rocks (' toadstones ') constitute an important feature of this limestone- area. These have been studied in recent times chiefly by Sir A. Geikie 3 and Dr. H. H. Arnold-Bemrose. 4 They are all basic in composition, and show five different habits : (a) lava-flows and ()3) ashes or tuffs, and tuffaceous limestones, all contemporaneous ; (7) masses of igneous and calcareous agglomerate, regarded with varying degrees of probability as volcanic necks; (8) intrusive sheets or sills, and very rarely (e) dykes, the last two necessarily younger (and perhaps very much younger) than the limestone and its comtemporaneous volcanic rocks. (a) Lava-plows. — The two sheets of igneous rock that have the widest extent in the district have long been recognised as contemporaneous lava-flows for the following reasons : — they have the same structure and composition as other basic lavas ; they con- tinue for long distances at the same stratigraphical horizon ; and they produce no contact-alteration in overlying strata, while a slight marmorization of the underlying limestone surface has been detected. Both sheets consist of olivine-dolerites of the same composition and appearance. The lower lava, apparently the more extensive of the two, lies at about 300 ft. below the top of the limestone : it must have spread over almost the whole limestone area forming the » _ 1 C. B. Wedd and G. C. Drabble, cjp. cit., p. 517. A. M. Finlayson, ' Problems of Ore-Deposition in the Lead and Zinc Veins of Great Britain,' Quart. Journ. Geol. Soc, vol. lxvi, 1910, p. 320. 2 Sir H. T. De la Beche, Geological Observer, ed. 2, 1853, p. 682. A. Strahan in 'Carboniferous Limestone, &c, of Noith Derbyshire,' Mem. Geol. Surv., ed. 2, 1887, p. 122. 3 ' Ancient Volcanoes of Great Britain,' vol. ii., 1897, pp. 8 et seqq. 4 ' The Toadstones of Derbyshire : their Field-relations and Petrography,' Quart. Journ. Geol. Soc, vol. lxiii, 1907, p. 241. CAKBOjSTFEEOUS volcanic hocks. 23 south-western corner of our district, but dies out just within it. On the north side it continues much further west and crosses Gratton Dale beyond Elton. 1 Of its northward and north-eastward con- tinuation nothing is known, but south-eastward it is almost certainly prolonged as the toadstone of Crich, which occupies the same stratigraphical position. The upper lava coincides only partially in area with the lower (see Fig. 4). Coming in about 150 ft. below the top of the lime- stone, it covered roughly speaking the north-eastern half of the main limestone tract in this district and apparently never extended in a south-westerly direction as far as the lower flow. It continues northward at least to Hillcar Wood; and Dr. Arnold-Bemrose considers with some reason that it may be the lava of Bradford Dale near Youlgreave. 2 But it is absent at Wirksworth, Middleton, Cromford and Crich, and perhaps at Ashover. Fki. 4. — Ground-plan showing extent of Upper and Lowee Lava-plows (Toadstones). (C. B. Wedd.) Upper Lava indicated by Vertical Lines. Lower Lava „ „ Horizontal Lines. V fam u • y Ashover ^332, 1 1 Iatlo ok BriAae \ ^ / \ liorvsalL •L IJ I,T1 / \ s MatlochJJatH: \ y '-J 1 r u ^ Jr 'omrord, • \ <£/> 'MiddietorL ">P *fy \ Crtch, — • w ir ksi vor ■tl V ^\ — The rather complex outcrop of the lavas is largely the effect of the erosion of deep valleys across slightly folded and faulted strata. (j3) Tuffs. — At Ashover a thick deposit of bedded volcanic ash or tuff is exposed in the core of the eroded anticlinal limestone, but is not present at the other limestone outcrops in the district. Sn H. H. Arnold-Bemrose, op. cit., p. 258. Op. Clt; P. 24 LOWER CARBONIFEROUS. An unsuccessful attempt to penetrate it proved an incomplete thickness of 210 ft., 1 where the dip of the beds is slight. The position of the tuff agrees closely with that of the upper lava of Matlock, but the thickness of overlying limestone is about 30 ft. greater. The tuff of Shothouse Spring, 2 which lies outside our area, can be traced up to the margin of this area, where it comes almost into contact with the edge of the intrusive sill of Ible (see Fig. 3, p. 15). Its stratigraphical position will be considered below (p. 32). Another bed of tuff only a few feet in thickness and not distinguished on the one-inch map, is seen to overlie the lower lava near Tearsall Farm, Brightgate. 3 There are moreover at least two beds of tuffaceous limestone, one associated with the Ember Lane agglomerate, another above the Shothouse Spring tuff. (7) Agglomkrates. — Three or four masses of volcanic agglomerate, variable in composition, occur around Bonsall. Some of these Derbyshire agglomeratic rocks have been regarded by Sir A. Geikie and Dr. Arnold-Bemrose as accumulated in volcanic vents, on evidence strong in the case of the Grange Mill agglom- erate, in others admittedly inconclusive. The Grange Mill rock, just outside our area, has been fully described by these authors. 4 (S) Intrusive Sills. — Two large intrusive sheets, known respectively as the Bonsall and Ible sills, 5 crop out within the district. The Bonsall sill clearly transgresses the bedding of the limestone on its east and west sides, on the east to the extent of 200-300 ft. It apparently passes under limestone on both sides, certainly on the east. On the north it comes in contact with the lower lava without transgressing it. It is probably bounded on the south by the Bonsall Fault (we p. 11 ; also Fig. 3, p. 15). The Ible sill also passes eastward under limestone, and apparently north-westward too, but with considerable transgression. On the south, limestone, more or less completely marmorized 6 near the junction, seems to underlie the sill, which must have a maximum thickness of 100-200 ft., but thins out rapidly south-eastward. 1 A. Strahan in ' Carboniferous Limestone, &c, of North Derbyshire,' Mem. Oeol. Surv. ed. 2, 1887, p.154. Jukes records (' A popular sketch of the Geology of Derbyshire,' Analyst, vol. viii, 1838, p. 232) that the Townstead [Townhead] shaft was sunk 375 ft. in this toadstone, and that boring 30 or 40 ft. deeper failed to get through it. However, another record of a deep shaft on the Townhead Yein gives, Shale 60 ft., Limestone 180 ft., Toadstone ; so that some doubt arises as to the correctness of the great thickness of toadstone recorded by Jukes. 2 H. H. Arnold-Bemrose, op. cit, p. 263. 3 H. H. Arnold-Bemrose, op. cit., p. 258. 1 See H. H. Arnold-Bemrose, 'On the Microscopical Structure of British Carboniferous Dolerites,' Quart. J own. Geol. Soe., vol. 1, 1894, pp. 633-5: Sir A. Geikie, ' Ancient Volcanoes of Great Britain,' vol. ii, 1897. pp. 13-5 : H. H. Arnold-Bemrose, ' Sketch of the Geology of the Lower Carboniferous Rocks of Derbyshire,' Proc. Geol. Assoc, vol. xvi, 1900, pp. 198-200 ; ' The Toadstones of Derbyshire : their Field-relations and Petrography,' Quart. Jown. Geol. Soe., vol. lxiii, 1907, pp. 262-3. 6 See H. H. Arnold-Bemrose, ' The Toadstones of Derbyshire, etc.,' Quart. Joum. Geol. Soe, vol. lxiii, 1907, pp. 275-7. 6 Op. cit., p. 275. PETHOLOGT OF IGNEOUS HOCKS. 25 Both sills appear to range in the limestone from a horizon 200 ft. or more below the lower lava approximately up to the level of that lava ; and both may be parts of the same intrusion, dislocated by the Bonsall fault. The rock of the Ible sill, wherever seen, is an ophitic olivine- dolerite : that of the more extensive Bonsall sill shows in great part the same character, but has a wider range of petrological structure, the central part being on the whole coarser-grained and the outer parts finer. A very fine-grained rock at Low Farm is represented on the map as a marginal phase of the Bonsall sill. Petrology of the Igneous Rocks. The Lavas. The Derbyshire toadstones were first examined petrographically by Allport, 1 and in recent years have been fully described by Dr. Arnold- Bemrose, 2 on whose descriptions the following account is based. The lavas are olivine-dolerites ranging in specific gravity from about 2 - 67 to about 2'80 in the case of the lower lava, and 2"55 to 2 - 80 in that of the upper : but it is not clear that the apparent discrepancy is more than accidental. The olivine-dolerite consists of augite in grains, olivine in idiomorphic crystals, plagioclase giving lath-like and tabular sections, and magnetite or ilmenite in rods and grains. The lavas, of a dark greenish colour when fresh, are vesicular in varying degree, the vesicles in the fresh rock being usually filled with crystalline calcite. The Ashes, etc. The Ashover tuff, ranging in specific gravity from 2'18 to 2'49, and showing dull shades of green and purple in colour, is " laminated and contains fragments of chert, of limestone often rounded, also blocks of amygdaloidal dolerite, and is traversed by veins of calcite. The matrix is composed of lapilli, cemented with volcanic dust and calcite." 3 Of the lapilli Dr. Arnold-Bemrose remarks : — " The fantastic outlines show that they cannot have been formed by the trituration of a compact lava. They are differentiated from the substance of the solid rock in the dolerites and basalts of the district by their preponderating glassy base more or less altered, the presence in it of a large number of skeleton-crystals and crystallites, and by their numerous amygdaloids. Their form and structure prove that they are true volcanic ejectamenta, and not the product of broken-up lava -streams. They vary in magnitude from very small fragments up to about the size of a pea." J Of the lapilli of the Ember Lane agglomerate and ashy limestone (see p. 29), Dr. Arnold-Bemrose states that they are often vesicular and under the microscope are seen to contain olivine and felspars in a dusty brown or black base. (Op. cit., p. 633.) He notes that in the Ashover tuff the lapilli fall into two classes, one of which contains olivine, while the other does not. (Op. cit., p. 641.) Intrusive Sills. The rock of the Ible sill, wherever seen, is described by Dr. Arnold-Bemrose as " an ophitic olivine-dolerite, rich in olivine-phenocrysts. The olivine occurs in large idiomorphic crystals measuring up to 5*5 millimetres in length, and in groups or nests of crystals. It is embedded among the felspars, and present in the ophitic plates of augite. In the more altered portions of the rock the olivine and augite are replaced by calcite." 5 The same author notes that the rock of the more extensive Bonsall sill " varies from a very coarse-grained dolerite without olivine, through an ophitic and subophitic olivine-dolerite, to an olivine-dolerite with granular augite." " The ophitic type is rich in olivine-crystals, which attain the size of 3'3 X 2 - 25 millimetres. The olivine occurs both as idiomorphic crystals, and in groups or ' ' On the Microscopic Structure and Composition of British Carboniferous Dolerites,' Quart. Journ. Geol. Soc, vol. xxx, 1874, p. 529. 4 ' On the Microscopical Structure of the Carboniferous Dolerites and Tuffs of Derbyshire,' Quart. Journ. Geol. Soc, vol. 1, 1894, pp. 608-9. 3 ' The Toadstones of Derbyshire, etc.,' Quart. Journ. Geol. Soc, vol. lxiii, 1907, p. 266. * ' On the Microscopical Structure of the Carboniferous Dolerites and Tuffs of Derby- shire,' Quart. Journ. Geol. Soc, vol. 1, 1894, p. 640. 5 ' The Toadstones of Derbyshire, etc.,' Quart. Journ. Geol. Soc, vol. briii, 1907, p. 275. 26 LOWER CAEBONIFEEOTJS. nests of crystals among the felspars and in the augite-plates." " The coarse- grained dolerite . . . consists of augite, plagioclase-felspar, and magnetite or ilmenite, with patches of (probably) interstitial matter." (p. 276.) The very fine-grained rock of Low Farm is an olivine-basalt, with a ground- mass consisting of magnetite in small cubes and crowds of augite-pnsms, and a felspathic or colourless glassy material without microhths. It contains olivme- phenocrysts up to Oo millimetre in length, (p. 277.) Limestone Shales. The change in conditions o£ sedimentation at the close of _ the ■ limestone phase shows varying degrees of rapidity in closely neigh- bouring localities. Sometimes the passage is gradual from thin- bedded limestones with intercalated shales to shales with thin limestones, but occasionally the change takes place abruptly. For the greater part of the shale series contains no bands of limestone ; nor have the sandstones so well developed on the west side of the Pennine axis any certain representative here, nor perhaps anywhere on the east side of that axis. 1 The shales are for the most part of a dark blue colour, but often become black in the lower part, in which thin bands of dark blue or black earthy chertless limestone occur sparingly. But layers of , calcareous and ferruginous nodules may occur at any horizon. The outcrop of these shales is confined to three areas along the margin of the limestone in the Derwent valley, and around the inliers of Crich and Ashover. The upper limit of the division is vague, and the line drawn upon the map merely aims at marking approximately the horizon of the lowest of the impersistent sand- stones that constitute the Shale Grits. As the development of these grits varies greatly from place to place, the line in question has no strict stratigraphical value. Under the circumstances it is impossible to assign exact figures to the thickness of the Limestone Shales. The Moletrap Mine east of Cromford Station passed through 300 ft. of shale before reaching the limestone, and is situate about 100 ft. below the lowest grit ; so that 400 ft. appears to be the approximate thickness there. 2 The old engine-shaft on the Gregory Vein south-west of Ashover gives much the same thickness, if 320 ft. is allowed for the lower grits, since the shaft starts in the top beds of the Kinderscout Grit and is said to reach the limestone at 720 ft. West of Darley Dale the old Millclose Shaft south-west of Cowley Hall stands about 100 ft. below the lowest grit close at hand — an amount doubtless increased by dip in the intervening distance — and enters the limestone 240 ft. down, so that here again the total thickness is probably much the same. The shales are undistinguishable lithologically from those of the Millstone Grit Series, and thin films of coal foreshadow the conditions that later produced the coal-seams* But palaeontologi- cally the distinction is marked. Marine forms predominate, 1 See A. H. Green, ' Carboniferous Limestone, etc., of North Derbyshire,' Mem. Geol. Sun:, ed. 2, 1887, p. 7. 2 A. H. Green, op. cH., p. 75 ; also T. I. Pocock in ' The Southern Part of the Derbyshire and Nottinghamshire Coalfield,' Mem. Geol. Surr., 1908, p. 21. LIMESTONE SHALES. 27 especially in the lower part of the Limestone Shales, while the estuarine or freshwater lame! libranchs of the Coal Measures are not found. The marine fauna presents two distinct facies : the one, comprising goniatites and. lamellibranchs that come in with the argillaceous conditions and persist in part into the Coal Measures ; the other, brachiopods and corals that survive from the calcareous conditions and characterize the Cyathaxonia subzone or phase of the limestone, but disappear coincidently with the limestone-bands. And these two types of marine fauna sometimes co-exist in the lower part of the Limestone- Shales. The argillaceous type, embracing principally Pterinopecten papyraceus, Posidoniella of two or three species, and several goniatites of which Glyphioceras phillipsi is the commonest, occurs the more frequently in the lower beds. The Cyathaxonia fauna, which in this district appears to occupy a much less thickness of strata than elsewhere in Derby- shire, 1 still includes in the lower part of the shales Cyathaxonia and Zaphrentis, small species of Productus and Chonetes, and Mar- tiaia glabra. It is of interest that Posidonomya becheri, found by Dr. Wheelton Hind 2 to be so characteristic of the lower beds of the shale series on the west side of the Pennine axis and elsewhere, has not been found as a characteristic fossil of the lowest shales, and it is possible that its horizon is not represented by shale in this district. Owing to poverty of exposure of tbe goniatite- bearing shales, no sufficient evidence has been obtained to test the zonal succession of goniatites adopted by Dr. W. Hind. 3 But Glyphioceras phillipsi appears to be especially characteristic of the lower shales, while G. spirale has not been noted within the district, and G. bilingue, J . Salt., occurs chiefly in the Millstone Grit Series. Local Details. Lowest limestones {a and b) with included igneous rocks, traced from the south. The outcrop of the lowest limestones occupies threu separate areas (se? sketch- map, Fig. 3, p. 15), the most important of which lies in the Via Oellia valley and on the high ground on both sides of its upper part. In the south-western portion of this outcrop a great thickness of the limestone is strongly dolomitized and appears at the surface as a dull yellowish rather porous rock (' dunstone '). The shaft of the G-olconda Mine south-west of Hopton Wood and just outside the border of Sheet 112 starts at a horizon close to that of the lower lava and passes through 312 ft. of dolomitic rock overlying 108 ft. of unaltered limestone. 4 But on the east side of the tributary valley of the Via Grellia at 1 See T. F. Sibly, ' The Faunal Succession in the Carboniferous Limestone of the Midland Area,' Quart. Journ. Geol. Soc, vol. lxiv, 1908, pp. 58-9. 2 W. Hind and J. A. Howe, ' The Geological Succession and Palaeontology of. the Beds between the Millstone G-rit and the Limestone-Massif at Pendle Hill, and their Equivalents in Certain other Parts of Britain,' Quart. Journ. Geol. Soc , vol. lvii, 1901, pp..347-404. See also A. Vaughan, ' Faunal Succession in the Lower Carboniferous . (Avonian) of the British Isles,' Rep. Brit. Assoc, Winnipeg, 1909. Table ILL, pp. 187-91. 8 'Life-Zones in British Carboniferous Rocks,' Naturalist, 1906, p. 334, 1907, pp. 90-917 ' - 4 A. Strahan in ' Carboniferous Limestone, etc., of North Derbyshire,' Mem. Geol. Surv., ed. 2, 1887, p. 152. 25276 C ; f 1. 1 ' ... 210 Bearing Clay ' ... 5 ... 36 — 1 ... 60 ... ... ... 22 9 ... ... •■• ... 13 28 LOWER CARBONIFEROUS. Hopton Wood, these beds in the Hopton Wood Quarries are not dolomitized. In the neighbourhood of the Snake Mine, situated south of the quarries, Dr. Strahan has recorded the following sequence 1 :— ft. in. Toadstone Limestone Clay, 1 ft. Limestone, Clay 1 ft. Limestone ' Tumbling Clay ' Limestone ' Ten-fathom clay ' Limestone Black beds ' Holystone,' a fine-grained limestone ... 119 + The ' Holystone,' the lower lithological subdivision (a) of these beds, crops out principally in the upper continuation of the Via Gellia known as the Griffe Grange valley, where it is extensively exposed ; also in the lower part of the Hopton Wood Quarries at their north end, where it passes upward through a more granular rock into the overlying ' Hopton Wood Stone ' (5). The clay-bands of the above section, said to be traceable for some distance, 2 are visible in the northern part of the quarries, whence the higher one, probably the ' Bearing Clay,' can be seen to continue along the slope of ' Nimblejack.' At horizons from 55 to 18 feet below the lowest strong clay-bed in the quarry three f ossilif erous beds yielded Cyathophyllum murchisoni and Carcinophyllum sp. in some abundance, Syringopora reticulata ?, Lithostrotion Martini, Bellerophon ?, Loxonema ? and Straparollus. Lower down the Via Gellia valley on its south side a thin local development of pale chert comes in probably about 200 ft. below the lower lava, and continues for some distance west of the Gulf Fault. At approximately the same horizon a coral doubtfully referable to a simple type of Dibunophyllum occurs, together with Cyathophyllum murchisoni?, Lithostrotion martini, Aulophyllum, and Brachythyris planicostata • while not many feet lower Productus cf. hemisphaericus is abundant in a quarry by the roadside. It is in this limestone (6) that the Ible sill is intruded higher up the valley on its north side. The igneous rock forms a bold feature above the brow of the valley, its surface rising somewhat above the neighbouring limestone. At a dolerite quarry the base of the sill is displaced by a small fault, and it is possible that the south-west margin may be faulted. The limestone in contact with the sill on the south is marmorized. 3 Small strings of quartz traverse the dolerite. The sill thins out rapidly south-eastward, but it is remarkable that no trace of it has been detected on the south side of the valley. The limestone in this neighbourhood shows irregular dips and slight undulations. The same limestones crop out again along the denuded crest of the northern anticline (see Fig. 3, p. 15) in two tracts separated by the Bonsall sill. The western of these, on Bonsall Moor, shows only a small thickness of anticlinally disposed limestone not far below the lower lava. But the eastern tract exhibits some 300 ft. rising eastward in escarpments above the sill on the crest of the saddle. These beds represent the stone of the Hopton Wood Quarries. But- it is here that a considerable thickness of the outcropping limestone has been converted into quartz-rock (see above, p. 20). However, some of the lower strata, containing Cyathophyllum and Syringopora at the north end of this tract, though somewhat hardened by silicification, preserve distinctly the character of the ' Holystone ' as seen in the bottom part of the Hopton Wood Quarries. The highest beds, too, beneath the lava on Masson Hill are unaltered light blue limestones with a giganteid Productus, P. cf . hemisphaericus and Cyathophyllum murchisoni. The Ember Lane agglomerate, situate at Bonsall between the south-eastern spur of the sill and the outcrop of the lower lava, is regarded by Sir A.. Geikie 1 1 Op. cit. p. 151. » Loc. cit. 3 H. H. Arnold-Bemrose, 'The Toadstones of Derbyshire, etc.' Quart. Journ. Geol. Soc, vol. lxiii, 1907, p. 275. 4 ' Ancient Volcanoes of Great Britain,' vol. ii. 1897. pp. 17-18. DETAILS OF BEDS BELOW LOWER LAVA. 29 and Dr. Arnold-Bemrose as probably filling a volcanic \ent. The latter geologist describes 1 the mass as follows : — " The vent is elliptical in area and, extends for a distance of about 1,000 ft. from north-west to south-east, and for about 400 ft. at right angles to that direction. Seen from the opposite side of the valley it makes a distinct feature on the hill-slope." Of the rock itself he states that it " consists of a calcareo-igneous breccia, and is a mixture of limestone-fragments containing fossils (some angular, others more or less rounded), 'and of volcanic lapilli and detritus which are often of a dirty- green or red colour. The proportions of calcareous and igneous material vary considerably. In some parts the rock consists of fragments of limestone, with little volcanic detritus ; while in others it is composed of softer and more com- minuted material enclosing rounded fragments of limestone." 5 On the north side a limestone with lapilli 3 and more or less rounded fragments of similar limestone abuts against agglomerate and the relation of the two rocks to one another is not altogther clear. But it seems evident that the agglomeratic mass transgresses the bedding of the limestone. An examination of fossiliferous limestone-fragments in the agglomerate failed to furnish evidence of derivation from any horizon lower than the strata of the district. The few fossils found include Syringopora cf. geniculate/, and a fragment of a giganteid Productus. These, so far as they go, as well as the limestone matrix in which they are contained, are quite characteristic of the ' Lower Dibunophyllum ' beds, in which the agglomerate lies. Mr. W. J. P. Burton discovered a fragment of wood in the volcanic material of this agglomerate. 4 Dr. Arnold-Bemrose has described a smaller patch of agglomeratic rock at Moor Lane near the south-west margin of the Bonsall sill, with some hesitation as to whether it should be regarded as a vent or a bedded tuff. " It consists of lapilli and small pebbles of fossiliferous limestone cemented by a calcareous paste." 5 The mass is elongated in the direction of the local folding, and lies close to the probable position of the Bonsall Fault. Numerous blocks of similar agglomerate composed of abundant small angular fragments of volcanic rock and limestone with a few larger and somewhat rounded pieces of limestone in a calcareous matrix were found during the surrey in the tip-heap of an old lead- mine south-east of Upper Town, Bonsall, on the north side of Bonsall Dale. 6 This tip is the largest in its immediate neighbourhood and probably derived from the deepest shaft. Its position is on the downthrow side of the Bonsall Fault, on beds above the lower lava. No trace of the agglomerate was found in smaller tip-heaps close at hand. The inference is that it represents either a bedded tuff or, less probably, a contemporaneous vent, which does not reach the present surface of the limestone. On the north-east margin of the Bonsall sill, near Low Farm, is a small area of tuffaceous limestone and tuff, of uncertain relationship to the neighbouring limestone, but without evidence of transgression. We agree with Dr. Arnold-Bemrose 7 in regarding it as probably an interbedded tuff. However, this and the agglomeratic rock, described above, south-east of Upper Town are not seen in association with limestones of the same horizon, the one being in contact with beds considerably below, the other apparently coming from a position above, the lower lava. Quarries have recently been opened in the denuded surface of the Bonsall sill. The Shothouse Spring tuff (see Fig. 3, p. 15), outside this area on the west, has been described by Dr. Arnold-Bemrose, who notes that the overlying limestone is nodular and contains volcanic lapilli up to a horizon at least 18 ft. above the tuff. 8 Lower Lava traced from the south. — South of Hopton Wood and west of the branch-valley a clay-bed, in which at one spot occasional decayed fragments of 1 ' The Toadstones of Derbyshire, etc.,' Quart. Journ. Geol. Soc, vol. lxiii, 1907, p. 263. - Op. cit, p. 264. . 3 H. H. Arnold-Bemrose ' On the Microscopical Structure of the Carboniferous Dolerites and Tuffs of Derbyshire,' Quart. Journ. Geol. Soc, vol. 1, 1894, p. 632. 4 H. H. Arnold-Bemrose, ' The Toadstones of Derbyshire, etc.,' Quart. Journ. Geol. Soc, vol. lxiii, 1907, p. 264. 5 Imc. cit., p. 264. O. B. Wedd in ' Summary of Progress for 1907,' Mem. Geol. Surv., 1908, p. 14. 7 Op. cit., p. 265. e Op. cit.. p. 263. 25276 C 2 30 LOWEE CARBONIFEKOTJS. toadstone were detected, produces a well-marked feature in the limestone on the east side of the hill, but cannot be traced far either southward or westward. We regaid this as the weathered outcrop of the lower lava just before it dies out. The position of the bed, after making allowance for dip and a small intervening fault, is approximately where the lava of the opposite quarries should crop out. The rather small thickness of limestone, much dolomitized, above the clay contains chert, and an abundant fauna of the Floriformis subzone, to judge by the material of walls. The outcrop of the lava at the top of the Hopton Wood Quarries on the east side of the valley is thin, but appears to be pinched by slipping of the overlying limestone and by the effect of a shearing which has driven up jagged edges of the limestone below into the weathered toadstone-clay. But at the Bradhouse Mine not much further east the thickness is recorded as 78 ft. 1 The same lava is faulted down south in a quarry of the Hopton Wood Stone Firms at Middleton. North of the Via Gellia it is mapped as continuing westward for a short distance beyond the hollow, up which the rapidly diminishing Gulf Fault passes. West of this a elay-bed with a red soil produces by its weathering an escarpment in the overlying limestone at a level not much above the outcropping lava on the other side of the fault. The blue limestone just above this clay-bed contains Lithostrotion and a giganteid Productus in abundance. At the mouth of the Via Gellia this toadstone is seen in the bottom of the valley. Beyond the Bonsall Fault it crops out from beneath the tufa-terrace at Matlock Bath, as an inlier exposed by the deep excavation of the Derwent valley. Its outcrop on the lower slope of Matlock Dale and in the foot of High Tor, where it is seen in the crest of the anticline, has been brought about in a similar manner. The main outcrop forms, on the top of Masson Hill, a conspicuous escarpment, diminishing in both directions and giving place north- ward to a clay-flat occupied by the weathered basset of the lava, and flanked by a bare escarpment of the overlying limestone. Further west the toadstone recovers its outcrop-feature for a short distance. In this district even a thick lava is not usually durable enough at its outcrop to produce an escarpment of its own. But on .vlasson Hill the lava occupies a relatively elevated position on the crest of the anticline, while further north- west, where it is degraded to a clay-flat, it has travelled some little distance down the north flank of the saddle. Still further west, b here it partially recovers its escarpment, it has risen again perceptibly in the fold. It is not unlikely that these basic lavas, where arched upwards, have been less affected by the soak of underground water than where they descend to a lower position on the flank of a fold. On Masson Hill it is hot the whole thickness of lava that constitutes the escarpment, the upper and lower parts having disintegrated to clay. A quarry- section sometimes shows large isolated cores of hard dolerite in the middle of a thick bed of soft clay. Limestones above the Lower Lava in the south-west part of the district.— On the south-west side of Middleton Moor, the elevated tract above Middleton, the downward development of the blue cherty type of limestune at the expense of the. pale massive limestones (c) reaches its maximum in this district. At the Hopton Tunner (Sheet 125) on the High Peak Kailway only about 50 ft. of chertless limestone intervenes, between the lower lava and the cherty limestone, 2 which at the neighbouring Intake Quarry yielded several clisiophyllid corals, including Dibuuophyllum muirheadi, with Cyathophijllum regium, Aulo- phyllum aff. pachyendotheaim and Lithostrotion junceum. Less than a mile to the north-east the thickness of the massive pale chertless limestone has increased to about 130 ft. m the Hoptonwood Stone Quarry at Middleton. In the railway- ctrtting-above-the Hopton Incline a highly fossiliferous bed occurs near the top of these chertless limestones at a horizon probably not far below that of the upper lava. It yielded in abundance Oibunophyllum, an undescribed clisiophyllid, Oampophyllum, Gyathophyllum rnurchisoni, the usual species of Lithostrotion and Syrmgopora with a giganteid Productus and other brachiopods, an assemblage characteristic of the Floriformis subzone. ■ A. Strahan iu ' Oarboniferous Limestone, &o. of North Derbyshire,' Mem. Geo!. Sun'., ed. 2, 1887, p. 150. '•"Southern Part of the Derbys'hiro and Nottinghamshire Coalfield' Me-n. Geo'; Skit. 1908, p. 12. ' DETAILS OF BEDS ABOVE LOWEK LAVA. 31 The Gang Vein runs in an eastward direction from the west edge of Middleton moor beyond the outcrop of the limestone south of Cromford. Between Middleton and Bole Hill a north-westerly group of veins (see p. 119) runs for the most part along fault-planes. The southward projection of the limestone outcrop towards Bole Hill shows usually faulted junctions of the chertless limestones above the lower lava with the Limestone Shales, the higher cherty limestones only coming on northward further up the slope. On the southern margin of this projection of the limestone, where it is intersected by the second fault eastward from 'the Gulf (seep. 11), a quarry shows alternations of thin-bedded dark blue limestone and dark shale, evidently the summit of the main limestone, where it begins to pass upwards into shale : these beds, faulted by an east-and-west fault of strong hade against massive pale limestones, contain Cyathaxonia rushiana, C. cornu, Zaphrentis of the ermiskilleni group, Z. costata, Z. disjuncta, and Demiphyllum, together with a small Chonetes in the shale bands, and belong clearly to the Cyathaxonia subzone. On the east side of the north-westerly fault, unfossiliferous Limestone Shales are thrown against massive pale limestone of the Floriformis subzone with Productus antiquatus, P. of the longispinus group and fairly numerous Schizophoria resupinata. A quarry by the side of the High Peak local branch-line to the Middleton quarries, at a point 250 yards west of the junction near Steeplehouse Station, shows an important section in which the two subzones can be differentiated in an exposure of some 23 ft. of blue cherty limestone. The section may be summarized as follows : — Ft. In. ' Thin-bedded blue cherty limestones with very thin shale partings : near base Amplexus condloide* in some abundance, Zaphrentis and Productm latissimus ... ... ... ... ... ... 7 -t Very fossiliferous massive; but laminated, blue cherty limestone : Cyathaxonia rushiana, a densi- phyllid, Caninia aff. cornucopiae, Zaphrentis enniskillenit great abundance of Lonsdalta cf. duplioata, and an occasional Dibunophyllum ; several species of Productus, including giganteid forms and Rhipidomella aff. michelini ■. 5 f Very fossiliferous lighter blue limestone with strong Cvathaxonia or I chert bed at bottom : Lonsdalia cf . duplicata in Floriformis Beds > great abundance, but no forms characteristic of ' i the Cyathaxonia fauna recognised ; giganteid L Producius'; Rhipidomella aff. michelini ... ... 4 f Deep and lighter blue cherty limestone : Dibuno- Floriformis Beds. \ phyllum cf. muirheadi, and other clisiophyllid ( corals, but not very abundant 7 An upward continuation eastward along the railway perhaps does not expose more than 8 ft. of strata above the quarry-section, but evidently nearly reaches the top of the limestone. In view of the amount of lower limestone cropping out above the lower lava there is no reason to believe that the thickness of the Cyathaxonia subzone is greater here than on the north side of Matlock, where ■alone it could be directly estimated. Beyond the outcrop of the cherty limestone, the broad slope rising north- westward between here and the Via Gellia is occupied entirely by the pale massive limestones of the Floriformis subzone. Numerous lead-veins traverse these limestones, for the most part with a general north-westerly trend, though some have an east-and-west direction. The whole slope is dotted with old lead-workings ; but only shows good exposures in the winding valley of Dean Hollow between Middleton and Cromford. The sides of this exhibit a great development of encrinital limestone, near and above the horizon of the upper lava. The cherty beds; coming on again north- eastward, are well exposed in Bdnsall Hollow, near Scarthin Nick, before being thrown up north-eastward by the Bonsall Fault. The limestones throughout the tract just described and on the greater part of Middleton Moor are comparatively free from dolomitization. ; Oyathaxonia Beds. 32 LOWEE CARBONIFEROUS. North of the Via Gellia, tbe beds above the Shothouse-Spring tuff on the western margin of our area require consideration as to their position m the sequence. Stratigraphical and structural conditions postulate that the limestone on Blakelow Hill (see sketch-map, Fig. 3, p. 15), some distance north-east of the Shothouse-Spring tuff, must lie below the lower lava. 1 But it is equally clear that the large tract of limestone some distance south-east of that tuff is above the lower lava of the Via Gellia valley. Between these two tracts of limestone the Bonsall Fault, with southerly downthrow, must intervene (see PI. V, fig. 2). However the Gulf Fault, which has certainly diminished northward, must pass between the beds obviously above the lava and those over- lying the tuff, if this fault continues so far. But it must almost have died out, if, as it seems, the lava crops out west of it. In that case the limestone succeeding the tuff is near the horizon of the lava. And the fossil-evidence shows that it can scarcely lie below the lava, for the scarp overlying the tuff contains a rich fauna of the Floriformis subzone, including Dibunophyllum, Campophyllum, Cyathophyllum murchisoni, Lonsdalia floriformis, Lithostrotion cf . irregulare, L. martini ?, and an abundance of giganteid Productus. Further east the spoil-heaps of old lead-mines on Bonsall Leys in the beds above the same lava furnish a similar fauna, including Dibunophyllum af£. dicki, D. cf. muirheadi, Lithostrotion, Aidophyllum and Syringopora. South of the Bonsall sill at Upper Town, Dr. Arnold-Bemrose and the writer saw debris of weathered vesicular lava in the roadside at a horizon that should be near that of the upper lava, but no positive evidence of outcrop was found. Outliers of the cherty limestone occur some little distance further east, but the extent of cherty rock thereabouts is uncertain. Limestones between the two lavas in the north-east of the district. — Where the upper lava has come in, the beds between the two lavas are best displayed at Matlock Bath, and on the northward slope of the limestone west of Matlock Bridge. At Matlock Bath these beds form a sheer scarp of wide-jointed yellow dolomitic limestone (known as the Romantic Rocks) above the inlier of the lower lava on the west side of the river. The same beds on the east flank of Masson Hill and near Salter Lane, west of Matlock, are not conspicuously dolomitic, but they become strongly dolomitic again westward of Wensley, where bare dip-slopes of yellow dolomite are seen to be full of half-dissolved brachiopods. This limestone, where unaltered, contains a great number of well-preserved fossils. Its lowest beds cropping out in a small escarpment just above the weathered lower lava contain a characteristic fauna of the Floriformis sub- zone, with abundant Dibunophyllum ttirbinatum, including D. matlockense, D. dicki, Diphyphyllum, Lithostrotion of the usual species, Syringopora, giganteid Productus, and other brachiopods. Below Tearsall Farm, beds exposed in an old lead-working midway between the two lavas yielded all the above forms, together with Lonsdalia floriformis, Cyathophyllum regium and Aidophyllum cf. pachyendoth ecum . Upper Lava. — On approaching the outcrop of the upper lava from the south- west, the first undoubted evidence of it was found in the bottom of Bonsall Hollow, in its natural position above the outcrop of the lower lava seen at the mouth of the Via Gellia valley. A little further south-east, beyond the Bonsall Fault (near an old building indicated as Rugshall on the 6-inch map), a small patch of toadstone, 8 cut off on the south-west by the fault, appears to pass under the massive chertless lime- stone on the other side. It doubtless forms a detached part of the upper lava, but presents certain lithological peculiarities in being more or less por- phyritic as well as amygdaloidal. Dr. Arnold-Bemrose supplies a note in which he describes this rock as consisting for the most part of porphyritic fel- spars in a fine ground-mass, but becoming a compact basalt with few porphyritic crystals near its under surface. He states that though this type is unusual, an equally porphyritic type sometimes occurs in the lavas of the northern dis- trict. From a short distance further north the outcrop of the upper lava can ' Dr. Arnold-Bemrose seems to have been led by this to assign the tuff to a horizon some distance below the lava. See 'The Toadstones of Derbyshire, etc.,' Quart. Joum. Geol. Soc., vol. lxiii, 1907, p. 268. 2 See H. H. Arnold-Bemrose, 'The Toadstones, etc.,' Quart. Joum. Geol. Soc. vol. lxiii. 1907, p. 259. " UPPER LAVA AND OVEELYING LIMESTONES. 33 be traced continuously by a shallow clay-bottomed depression in which here and there decayed vesicular lava is found, round the high ground above Matlock Bath and down into the Derwent valley. This outcrop at one point appears to support a small outlier of the higher limestone. It takes in the exposure of Upper Wood, 1 Matlock Bath ; Dr. Arnold-Bemrose states further, of another exposure along this line where it descends into the valley at Mr. Lawton's house, that the rock petrologically resembles that of Rugshall described above. East of the Derwent the vesicular lava cropping out just above the alluvium in the south side of an old lead-adit is certainly the lower, not the upper How, the lead-vein occupying a fault with northerly downthrow. For, at its usual distance above the lower lava, the upper toadstone can be traced in the grounds of Willersley Castle by a belt of red clay-soil with numerous fragments of vesicular lava below an escarpment of chertless limestone. It descends rapidly s mthward from the brow to .the bottom of the valley. North of the cross- fault the higher toadstone crops out beneath the escarpment of the ' Lovers' Walk,' and descends northwards to the Derwent at the 'Jubilee Bridge.' From here it ascends the steep dip-slope of the Heights of Abraham, and thence loops down again into the Derwent valley below High Tor, the face of which it traverses in crossing the anticline, before it descends again to the river on the north flank of the saddle. Thence ascending the western slope of the valley beneath the escarpment of Shining Cliff, it traverses the east flank of Masson Hill and is well exposed in Salter Lane. Its further course can ba traced west- ward as far as the margin of the one-inch map. It is seen in a small pit north of Brightgate, while for the remainder of the distance its outcrop is indicated on the sl'ipe of the limestone by a narrow belt of clay-ground usually free from lead-tips and containing fragments of decayed toadstone. The same lava is present in the shafts of the Millclose Mine further north. The disused shaft south of Cowley Knowl (p. 128) and south-west of Cowley Hall gave the following section 2 : — Ft. Limestone f " Shale with beds of earthy limestone, belonging Shales. \ to the lowest group of the Yoredale Rocks . . . 240 f "Limestone 150 | " Band of deep black clay, without bedding ... 1 Carboniferous f Soft, crumbly, greenish toadstone... 4 to 5 Limestone J ] Solid toadstone, consisting of large with ] " Toadstone etc -> of North Derbyshire,' Mem. Gaol, Sun:, ed. 2, --» ^The Geological Observer,' ed. 2, 1853, p. 560 Tt 'J: U ?^ e u la m a j as reachecl A" *. Pit below the floor of the quarry : H. H. Arnold- p 257 Toadstones of Derbyshire, etc.,' Quart. Journ. Geol. Soc, vol. lxiii, 1907. * T. F. Sibly ' The Faunal Succession in tbe Carboniferous Limestone of the Midland Area, etc. Quart. Journ. Geol. Soc, vol. lxiv, 1908. p. 58. LIMESTONE SHALES AND CRICH INLIES. 35 bedding. A compact bed of Cyathophyllum regium is found in Northern Dale, west of Snitterton, not far below the cherty rock, in much the same position as in the Matlock quarries. Further west there seems again to be a small develop- ment of chert well below the main chert^beds.. Neighbouring Inliers. — Hereabouts the upper surface of the limestone plunges rather steeply under the shales into the valley of the Bridgetown Brook ; in which, close to the margin of the map, the top of the limestone, a dark blue cherty rock, reappears. BrOwn-weathering crinoidal limestone crops up again in the bank of the Derwent near the Millclose Mine, where its relation to the shale is uncertain, The North Darley quarry west of Bridgetown affords an interesting section in a dissected pericline of limestone. The fold has its longer axis trending in a north-easterly direction, with a high dip on the south-east side. In the north wall of the quarry, shale rests upon about 10 ft. of the cherty limestone, the whole of which is missing on the east side, where the shale dips more gently off the pale massive limestone inclined at 60° or more. This local unconformability is similar to that described near Youlgreave by Dr. Sibly. 1 If the shale were stripped off, the periclinal limestone would have a knoll-like appearance. Limestone Shales. — On following the outcrop of the Limestone Shales from the south, blue shales with Posidoniella some distance above the base are seen at a brickpit west of Oromford Moor. They contain thin films of coal. The rail- way-cutting at Cromf ord Station at the south end of the Willersley Tunnel and other adjacent small sections,, where the lowest part of the shales is exposed, show several beds of dark earthy limestone and calcareous shale containing Cyathaxonia,&c. togetheiwithPosidoniella,Posidonomya membranacea '■-, Pterino- pecten papyracens and Glyphioceras philhpsi. But the same horizon at the north end of the tunnel contains no limestone, the change from Carboniferous Lime- stone to Limestone Shales being abrupt. Here the shales for a few inches above the top of the main limestone contain thin coal-films. North of Matlock Bridge the tip-heaps of old lead-shafts exhibit dark shale with a small Chonetes, Martinia glabra and Posidoniella. Further north the Bridgetown Brook west of the limestone inlier exposes several horizons of the shale, often containing Posidoniella and ill-preserved goniatites. Higher up-stream, bands of earthy fossiliferous limestone crop out in the lower shales. Similar limestones and black shales in the bed of the Derwent at Stanton Woodhquse are full of cephalopods (including Glyphioceras phillipsi and Orthoceras) with Pterinopecten papyraceus and Posidoniella. At the brook at Beeley dark-blue shales, presumably near the middle of the series, contain obscure goniatites and Pterinopecten. Con- torted shales of uncertain horizon in the west bank of the Derwent at the stepping-stones showed goniatites and Posidoniella. Crich Inlier. The limestone of the Crich Inlier 3 is brought up as a long narrow periclinal accentuation of a long sinuous anticline (p. 8), and stands out as a con- spicuous hill. The pericline sags down slightly in the middle. On all sides except the west the dips are slight, but on that side, close to the Crich fault, the inclination in the limestone and the shales as proved underground at the Ridgway Sough and the Pearson's Venture Mine becomes so steep as to pass the vertical with the appearance of an eastward dip. J The combined sections ■of several quarries completely expose the limestone from the top downwards for not more than 200 ft. The one important seci ion within the area of Sheet 112 is that of the Crich Stand quarry, in which massive pale limestone _with_two conspicuous ' wayboards ' of day or shale, two or more feet thick, passes up into thin-bedded blue limestone below the cherty beds. The lower of these two shale-beds, cropping out under massive limestone radially jointed in the rounded crest of the anticline, is approximately the lowest bed exposed in the inlier. 1 The Faunal Sucession, etc.,' Quart. Journ. Geol. Soc, vol. Uiv, 1908, p. 63. 2 T. F. Sibly, Op. cit.jp 58. 3 See also 'Southern Part of the Derbyshire and Nottinghamshire Coalfield,' J/em. Geol. * See J. B. Jukes, ' A Popular Sketch of the Geology of Derbyshire,' Analyst, vol. ix 1839, p. 14. 36 LOWEE CAKBONIFEKOUS. The massive pale limestone, less fossiliferous in its lower part, contains in its higher beds the usual fauna of the Floriformis subzone, with Dibunophyllum aff. turbinatum, Lonsdalia floriformis, Lithostrotion cf. irregulare, L. martini, L. porthclci, Syringopora sp., and Produclus giganteus. At the south-east corner of the quarry where the massive white limestone passes up into blue limestone, a bed crowded with Lonsdalia cf . duplicata crops out midway up the quarry wall, and another full of gasteropoda, with ? Euomphalus subpentagonalis, occurs at the top of the section there seen. The cherty limestone is well exposed only outside our area in the southern part of the inlier (Sheet 125), where, of about 60 ft. of cherty rock, it is doubtful whether more than the uppermost 10 ft. should really be assigned to the Cya- thaxonia subzone. The topmost beds of the limestone contain Cyaihaxonia rushiana in some abundance, Zaphrentids, Lithostrotion junceum, Productus giganteus, P. concinnus and P. elegans, also rarely a small Dibunophyllum. Sometimes the limestone underlying a shale-band has a mammillated sur- face with rounded projecting bosses and intervening basin-like depressions, into which the lower laminae of the shale sag down. This affords no proof of con- temporaneous erosion, for conversely the upper laminae of a shale-band some- times arch upwards into solution-cavities along joints. Both phenomena are seen in the higher beds of Hilt's Quarry (Sheet 125). Remarkable variations in the thickness of the toadstone, which does not crop out, have been recorded by J. Alsop, 1 as proved in mining. " A bed of clay, 1 ft. thick, becomes within a short distance 14 ft. thick, and contains large nodules of compact toadstone, while the thick bed of toadstone, actually sunt through at one shaft, diminishes to a thin bed at the other mine." 2 At the Bacchus Pipe on the west margin of the limestone, the toadstone lies at 450 ft., its thickness as proved being 120 ft. In the Old End Mine on the east margin, it lies at 300 ft., and at 180 ft. in the Glory Mine, where it is 57 ft. thick. 3 The only noteworthy exposure of the Limestone Shales shows high-dipping dark blue pyritous shale near the base of the group, with abundant goniatites (Glyphioceras phillipsi, G. reticulatum ?) and Pterinopecten papyraceut, in the brook at Wakebridge. Ashovee Inlier. At Ashover, as at Crich, the limestone crops up periclinally as another elevation on the same long anticlinal saddle. But, unlike the Crich inlier, that of Ashover merely rises as a low elongated dome, intersected by the Amber, in the bottom of a deep and broad valley. The tuff, into which the Amber cuts in the core of the pericline, is exposed at several points in a more or less weathered state. In the Hockley Quany north of the Amber, the upper paH of it is well seen at a kiln below the quarry, in which the base of the cherty limestone is only about 35 ft. higher. Here beds of limestone close above the tuff, and others at West Edge at the north-west end of the inlier, are silicified like the quartz-rock of Bonsall. 4 Nearly the whole of the limestone belongs to the Floriformis subzone. The Cyathaxonia fauna, with Zaphrentis eimiskilleni and Cyathaxonia rushiana, was only found in dark blue thin-bedded limestones and shales forming the passage from the limestone to the Limestone Shales on the crest of the anticline at the south end of the inlier ; and probably descends but little lower. The shales immediately succeeding the limestone are exposed in the brook on the north-east side of West Edge. They are black and dark blue pyritous shales with Glyph ioceras phillipsi, Pterinopecten papyraceus and a Posidonomya. C.B.W. 1 Hep. Brit. Assoc, for 1844, 1845, Trans. Sections, p. 51. 4 A. H. Green & A. Strahan, 'Carboniferous Limestone, etc., of North Derbyshire,' Mem. Geo!. Sum., eel. 2, 1887, p. 154. 3 Op. cit., p. 155. 4 H. H. Arnokl-Bemrose, 'Sketch of the Lower Carboniferous Rocks of Derbyshire,' Proc. Geol. Assoc., xvi, 1899. p. 175. 37 CHAPTER III. UPPER CARBONIFEROUS: MILLSTONE GRIT SERIES. General Account. With the exception of the elevated tract of Carboniferous Lime- stone in the south-west, the Millstone Grit Series occupies all the highest ground in the western part of the district. It produces a rugged and picturesque upland country, traversed along its main strike on the west side by the deep valleys of the Derwent and its tributaries ; but in the direction of its general dip in the north-east by tributaries of the Rother and the Sheaf. The highest and most rugged parts of it form extensive grouse-moors from Beeley north- ward. The structure of the tract, depending as it does upon that of the contiguous Lower Carboniferous rocks, has been sufficiently described in the preceding chapter (p. 8). The general sequence departs but little in its main features from that described in a recent memoir for the neighbouring district on the south. 1 This sequence may be represented as follows : — Rough Rock, Top Grit, or " First Grit " . Shale, variable ft. 100 60 Middle Grit Group Kinderscout Grit Group 2 maximum about 440. 100-150 locally more than up to about ft. ' Thin grit (in the north only) ... up to 30 Shale, with a small coal locally in lower part ... ... approximately 60 Longshaw Grit ... up to 30 Shale about 70 Coal — Chatsworth or Rivelin Grit (=BelperGrit of Sheet 125) 100-250 Shale r Coal Upper or main grit, diminishing greatly north- westward from about 120 Shale, locally about 70 Lower grit, dying out northward, from about ... 70 Shale Grit Group : Shales with comparatively thin grits, very variable : 100 ft., increasing in the north-west to perhaps 400 On Sheet 112 and the Derbyshire part of Sheet 100 the colours introduced on Sheet 125 to differentiate the Middle Grit Group and the Rough Rock from the other Millstone Grits have been retained. But this scheme of colouring is not continued in the Yorkshire portion of Sheet 100, which has not been re- surveyed, and in which, therefore, no change has been made from the original method of colouring. 1 'Southern Part of the Derbyshire and Nottinghamshire Coalfield,' 1908, pp. 27 et seqq. 2 While this group continues the grits that have always been classed as " Kin- derscout Grit " in this and the neighbouring district in the south, it is not certain that it is continuous with the true Kinderscout Grits north of Chatsworth (see p. 39). 38 UPPER CARBONIFEROUS. While the general sequence remains fairly constant, certain lithological changes, in the nature of progressive variation of texture, will be noted below. Moreover considerable variations of thickness take place in the individual grits. Shale Grit Group. The Shale Grits maintain their usual character of fine-grained, rather micaceous and often fissile, yellow and white grits or sand- stones. They do not however bulk largely in the area of Sheets 100 and 112, and north of Chatsworth the westerly tendency of the strike carries them altogether outside our district. In the extreme south of it they have already lost much of their conspicuous development south-east of Wirksworth (Sheet 125), and for several miles northward are quite small and inconspicuous rocks. But at Chatsworth, for the most part outside the one-inch map, they again assume some importance. KlNDERSCOUT GRIT GROUP. Of the Kinderscout Group, the lower grit, while somewhat coarse-grained and even pebbly where it enters Sheet 112 from the south, becomes finer-grained before its outcrop passes over to the east side of the Derwent at Holloway. There, it is quite fine- grained, though still massive and thick ; on the old Survey map it figures as one of the Shale Grits on that side of the river; It cannot be traced with certainty far north of Matlock ; but at Rowsley and elsewhere a fine-grained grit crops out in approxi- mately the same position below the main Kinderscout Grit. The main or upper grit of this group exhibits a gradual, though decided change. Always in the southern district a thick and massive rock, partly coarse-grained and pebbly, it begins first north of Crich to show signs of weakening. A bed of sandy shale appears in the middle, and west of Ashover splits the outcrop into two distinct features, these eventually coming together again further north. But thenceforward the rock becomes mainly finer-grained with rapidly decreasing thickness of' its coarser pebbly beds. The change perhaps does not set in quite so far south on the western outcrop, for at Matlock Bank the rock still contains a considerable proportion of . coarse and pebbly material. But at Stancliff the grit seen is of a finer grain, and quite free from pebbles except in its highest part. The same state of change holds west of the Derwent. In this neighbourhood, too, several small partings of sandy shale make their appearance, one of these producing a distinct effect on the escarpment at Two Dales and continuing for some distance. Thence northward, shaly partings increase in number, while the grit becomes wholly fine-grained. But it still maintains a bold escarp- ment, frequently divided into minor features by the included shaly beds, which towards the bottom of the mass increase in frequency and thickness, so that the grit passes down gradually into shale, without any distinct base. It appears to be the upper part of it only that continues to form a scarp in Chatsworth Park, in the northern part of which this scarp diminishes and becomes almost: MILLSTONE GRIT SERIES. 3ft unrecognizable, though the grit is still seen in the steep south bank of Bar Brook. Beyond this brook the outcrop passes above Baslow as a group of small features, together forming a prominent but indefinite escarpment, which, diminishing northward, soon becomes completely lost under scree from the Chatsworth Grit above. The rock, however, was seen again further on in the pipe- trench of the Derwent Valley Waterworks. At Chatsworth the top of the Kinderscout Grit lies only about 100 ft. below the Chatsworth Grit. On the old Survey map the " Kinderscout Grit " is represented as cut off by an east-and-west fault at Baslow, the grit shown as its continuation north of the supposed fault lying west of the river and apparently at a lower stratigraphical horizon. In the south of the district, as in the northern part of the area of Sheet 125, a coal-seam just above the Kinderscout Grit has been traced northward at intervals as far as Ashover on the eastern and Sydnope on the western outcrop. Middle Grit Group. The Belper Grit of. Sheet 125, which proves to be identical with the Chatsworth Grit of this district and will henceforth be referred to under the latter name, shows, as regards its lateral development an opposite tendency in that it becomes thicker and coarser-grained northward. From its first appearance in the south near Breadsall (Sheet 125) as a comparatively thin fine-grained and flaggy micaceous rock, it maintains, while increasing in thickness and massiveness, a fine-grained character for a long distance northward, with merely an occasional pebble to suggest an approaching change of texture. North-east of Crich a small part of it was seen to have become coarse-grained and pebbly ; but on the whole it remains fine-grained nearly as far as Sydnope ; where its upper part has become a coarse and pebbly grit, though still retaining its finer texture further east. Its lower part on the other hand persists as a fine-textured rock usually passing down by intercalation of shaly beds into the shales below. Sometimes the outcrop splits in this way into two equal features, or throws off at its base a small bed marked by a little feature below the main scarp. From Sydnope northward the upper pebbly portion increases in importance and produces the wall-like escarpment so characteristic of this grit. 1 Before entering Chatsworth Park the fine-grained lower part separates off in a distinct but smaller feature. The upper pebbly member alone forms the rugged brow of Chatsworth Edge, some distance below which fine-grained fissile beds of the lower member appear in water-courses. North of the park blue shale was seen just below the scarp of the upper member ; while at the south end of Baslow Edge a quarry showed some 70 ft. of fine-grained grit or sandstone with several shaly bands in a position immediately below the massive pebbly rock of that edge, beneath which the thicker, fine-grained beds lie concealed under scree from the upper member. 1 A. H. Green, 'Carboniferous Limestone, &c. of North Derbyshire,' Mem. Geol. Sun: ed. 2, 1887, p. 9. . 40 UPPER CARBONIFEROUS. Further north, west of Burbage Moor and mainly outside the area of Sheet 100, these lower beds have a considerable superficial extent, where the upper pebbly grit has been denuded away : but a mile or so to the eastward they have thinned and given place to shale, of which a notable thickness intervenes between their attenuated representative and the escarpment of the upper grit. The ' Coxbench Grit' of the southern area of Sheet 125 diminishes northward and for a long distance is either faulted out at the surface or, when the strata have a steep eastward dip, has its narrow outcrop so concealed between those of the Chatsworth Grit and the Rough Rock, that it cannot be traced into continuity with the out- crop of the Longshaw Grit. But for the greater part of the intervening distance a thin grit is seen to crop between the Chats- worth Grit and the Rough Rock. A somewhat fine-grained grit in this position makes a conspicuous feature at Stonehay Farm, and is doubtless the Longshaw Grit, but it disappears again westward and is perhaps faulted out, before reappearing at Harewood Grange, whence it can be traced almost continously, as a fine-grained rock, as far as the Yorkshire border. A still higher grit seems to come in first below White Edge, where, without being seen in section, it makes a slight feature on the slope. At Longshaw Lodge a thin fine-grained grit has been dug between the Longshaw Grit and the Rough Rock, and it appears to be this grit that caps the rising ground north of Totley Moss (see Fig. 7, p. 56). It is probably the same rock as the fine-grained rather flaggy grit of Whirlow and the old quarries west of Ringinglow across the county border. Rough Rock. The Hough Rock, before entering the district from the south, has taken on a fine-grained character, like that of the Middle Grits in the southern district. On the whole it maintains this character northward beyond Alton ; but east of Beeley Moor, at Stone Edge, where it is still extensively quarried, it has resumed its usual coarser-grained and somewhat pebbly nature. It forms a bold, frequently craggy escarpment from Stone Edge to Slagmill Planta- tion. Along Harland Edge and above Chatsworth it produces two distinct escarpments, which coalesce again before reaching Robin Hood, the double escarpment being doubtless due to the local development of a shaly bed in the middle of the grit ; but this is not exposed. South of Gibbet Moor there is evidence of a small coal-seam overlying the grit. The outcrop of the Rough Rock continues as far as Longshaw Lodge, between which and the Yorkshire boundary it is everywhere cut out by faults, except on BlackaHill. Intercalated Shales. — The shales intercalated between these grit beds vary but little in character and present the usual appearance of Carboniferous Shales. They are for the most part blue in colour, sometimes black and carbonaceous and sometimes more or less sandy. Amongst the shales are occasionally found beds of gannister-like rock and fireclay, not always overlain by a coal-seam. millstone ghit series. 41 Palaeontology. While the various grits often contain ill-preserved plant-remains, including stems and branches of Lepidodendron and Calamites, these were not seen to be so abundant as in the Kinderscout Grit at some localities further south. 1 But it is here, as usually elsewhere, the shales alone that are found to contain animal remains, and these are restricted to certain beds. The mollusca point invariably to marine conditions, though probably not in all cases to the same degree of salinity. In some beds goniatites of more than one species, (including as the commonest species, Glyphioceras bilingue Salt.), Pterinopeeten, and Posidoniella abound, the different forms often occurring separately though closely associated in vertical range ; while in other beds, or in the same beds in other parts of the district, the presence of Lingula in great numbers, either alone or accompanied only by Orbitoidea, probably denotes somewhat different conditions. But the aggregate thickness of shale in which these marine shells have been met with, constitutes a very small proportion of the total thickness of shale in the series. Individual marine beds are seldom more than a couple of feet thick. Consequently these shales afford no proof of exclusively marine deposition, and in this respect they agree with the coal- measures, while perhaps differing from the Limestone Shales of the district. But, as usual in the Midlands, the estuarine or freshwater genera Carbonicola, Anthracomya and Naiadites appear to be completely absent from the Millstone Grit Series. In the adjacent district on the south (Sheet 125) only two horizons of marine fossils were detected, and these only in the northern part of that district ; and no evidence of marine conditions could there be found within the Shale Grit Group, while the highest beds of the Limestone Shales contain goniatites in abundance. 2 On following the Millstone Grit Series northward several more marine horizons were found. In Chatsworth Park a bed containing goniatites (including Glyphioceras bilingue) and Posidoniella, was noted in a position well below the thin remnant of the Kinderscout Grit, but not necessarily below the lower member of that group in the southern district. At Whatstandwell (northern margin of Sheet 125) shales a few feet above the Kinderscout Grit contain Glyphioceras bilingue. 3 On Hathersage Moor (just outside Sheet 100) shales immediately above the Kinderscout Grit of the north are full of goniatites (including apparently a small Gastrioceras) and Pterinopeeten. A bed perhaps a few feet higher south of Grindleford Station contains Glyphioceras. At Whatstandwell again a thin bed crowded with Lingula mytiloides J. Sow. occurs some little distance below the Chatsworth (Belper) Grit. It is not unlikely that this bed is continuous with one containing Glyphioceras bilingue and Posidoniella, perhaps denoting more fully marine conditions, 1 ' Southern Part of the Derbyshire and Nottinghamshire Coalfield,' Mem. Geol. Surv., 1908, p. 29. 1 Op. cit. pp. 25 and 28. 3 Op. cit, p. 30. 42 UPPER CAEBONIFEEOTJS. apparently about the sarne distance below the same grit near the source of the Halldale brook. On Hathersage Moor, too, goniatites are abundant not many feet below the lower fine-grained part of the Chatsworth Grit. In the stream south of Dethick Common is a Lingula-heA. either; above, or in shale below the top of, the Chatsworth Grit. In the upper part of Bar Brook goniatites were found not far above the Chatsworth Grit, and, possibly at the same horizon, goniatites with Pterinopecten some distance below the Longshaw Grit in the grounds of Longshaw Lodge. A few feet above the Longshaw Grit on East Moor, Beeley, and at the same or an adjacent horizon on the Moor above Chatsworth, goniatites and Pterinopecten papyraceus were found. A bed full of Lingula occurs at Plaistow not far below the' Rou°-h Rock, and another with Gastrioceras, Orthoceras and Pterinopecten in the brook at Whitecarr, Brackenfield, lies also probably below that grit ; but its position is uncertain owing to disturbance of the strata. In the banks of the Hipper east of Cathole, goniatites and Pterinopecten occur in black shale about 100 ft. below the Rough Rock. Similar marine beds are known to be of frequent occurrence in the Millstone Grit Series of Yorkshire ; and there is thus reason to suppose that they become more numerous as the series is followed northward through North Derbyshire. If this is really the case, it is in harmony with the results obtained in the Coal Measures.' It was remarked in the memoir describing the neighbouring district on the south, 2 that while no evidence has yet been obtained in Derbyshire of a general change in organic life between the Limestone Shales and the Millstone Grit Series, such as has been obtained in Scotland and in North Staffordshire by Dr. Kidston on the evidence of plant-remains, 3 and in Scotland by Dr. Traquair on that of estuarine fishes 4 , the introduction of the goniatite genus Gastrioceras with the Millstone Grit appears to mark an important molluscan change between Lower and Upper Carboniferous ; while at the same time the Upper suggests a notable restriction of marine, conditions as compared with the Lower Carboniferous. The value of the latter distinction has been diminished, 'but not destroyed, by the discovery of more marine horizons on proceeding northward. Local Details. Lower Grits, from south to north in the Derwent Valley. — In the extreme south of the district, at Long way Bank, a. small coal-seam crops not far below the Chatsworth Grit, and is evidently the seam worked at the Whatstandwell 1 See ' Concealed Coalfield of Yorkshire and Nottinghamshire,' Mem. Geol. Surv., 1913, PI. III. 2 'Southern Part of the Derbyshire, etc/Coalfield,' 1908, pp/9-10. 3 ' On the Various Divisions of British Carboniferous Rocks as determined by their Fossil Flora,' Vice-Pres. Address, Proc. Boy. Soc. Edin., vol. xii, 1893, p. 183r - 'Summary of Progress fox 1903,' Mem. Geol. Surv., 1904, p. 108,. ' The Country around Stoke-upon-Trent,' Mem., Geijl. Surv., ed. 2, 1905, p. 3. 4 ' Ganoid Fishes of the British Carboniferous Bocks,' part i,. Pal. Soc, vol.. xxxi, 1877. ' On the Distribution of Fossil Fish Remains in the Carboniferous Rocks of the Edinburgh District,' Trans. Boy. Soc. Edin., vol. xl., part iii, 1903, p. 687. DETAILS OF MILLSTONE GEITS. 43 Sanitary Pipe Works (Sheet 125), 1 apparently a higher coal than the one usually found in this district just above the Kinderscout Grit. 1 That seam is known to be present at both the western and eastern outcrops of the Kinder- scout Grit at least as far north as Sydnope, beyond which it has not been traced. It was proved in the pipe-trenches of the Derwent Valley Waterworks, under drift, in the hollow of Riber Hill, and again on Matlock Bank, where the general section of the neighbouring beds was as follows :— 2 Ft. , Very coarse-grained pebbly grit with small detrital garnets 8 or 10 Shale, variable, generally not more than 6 Coal 8 in. to 2 Fireclay and shale, locally, up to 2 "Slavin"; fine-grained micaceous flaggy and shaly grit (Kinderscout Grit). The thin bed of coarse-grained grit at the top is remarkable ; for such coarse- grained beds are very seldom developed except in the inner part of thick masses of grit in this district, and even there are seldom so coarse in grain. Detrital garnets have not been detected elsewhere in the district. This grit-bed has been included in the Kinderscout Grit on the map owing to the difficulty of •locating the coal and thin shale in the absence of sections. The narrow crest of Oaker Hill, isolated in the Derwent valley west of Matlock, is partly capped by outlying patches of Shale Grit. The rock worked at the Stancliff Quarries, Darley Dale, and the high-dipping grit low down on the east side of the valley at Rowsley, both appear to be down-faulted masses of the upper Kinderscout Grit. Middle Grits east of the Derwent Valley. — On the north-east side of the Derwent valley, the Southern Crich Fault throws up the Kinderscout Grits of Cromford Moor several hundred feet towards the north-east. At Dethick the detailed sequence is obscured, chiefly owing to the amount of boulder-clay. Here, and northward as far as Rowsley, the synclinal arrange- ment of the grits is readily apparent. The Rough Rock seems to have been completely removed by denudation in the trough of the syncline at Dethick, and the Chatsworth Grit, in two members with a shale-parting, forms the greater part of the surface. A thin coal with underlying fireclay here rests upon the upper and smaller member of this grit. It was exposed at a reservoir about 300 yards north-north-east of Dethick Church. Higher beds represented in the syncline consist of shales with an occasional hard band of gannister-like rock. At the north end of the peat-patch near Jagger's Lot north of Sydnope a cannel-like coal with fireclay was found under thin peat, 3 and evidently repre- sents the seam always present above the Chatsworth Grit in the northern part of the district, but not detected further south except at Dethick. The shales between the Chatsworth and Longshaw Grits are exposed in the deep gully near Stonehay Farm and in Millstone Sick, where a 6-inch coal resting on fireclay is overlain by pale purplish shale. On Beeley Moor, below Harland Edge, occasional old shafts reach the coal overlying the Chatsworth Grit, which seam thenceforth to the Yorkshire border appears always to be present, and has been raised at several localities. This coal and the one above the Longshaw Grit were both worked in the past in the neighbourhood of Robin Hood, as attested by very numerous bell-pits. The Longshaw Grit on White Edge Moor, where it has been quarried,"makes an unusually conspicuous feature. It is this small grit, and the fine-grained rock coming in above it in the north of the district, that occupy the tract elevated between two faults north of Totley Moor, a tract assigned with some hesitation to the Coal Measures on the old Survey map. The small upper grit here prqbably owes its unusual prominence to the absence of the Rough Rock above, which elsewhere dominates its outcrop. The broad valley of Burbage Brook has deeply dissected the plateau of the Chatsworth Grit, and has left numerous outliers of the hard and durable upper 1 See 'Southern Part of the Derbyshire, etc., Coalfield,' Mem. Geol. Surv., 1908, p. 41. 2 From information by Messrs. G. C. Drabble and L. M. Williams, Derwent Valley Water Board. 3 Information by Mr. Barrow, of Sydnope Hall. 25276 D 44 UPPER CARBONIFEROUS. part of that grit in outstanding hillocks above the comparatively soft lower beds. The topmost bed of the coarse and pebbly Ohatsworth Grit is frequently seen in the streams between here and the county boundary to be a compact, though flaggy, fine-grained white or yellowish rock of a type readily recognisable. From Blacka Hill, where a small patch of the Rough Rock is preserved, to the Yorkshire border that rock is wholly cut out at the surface by faults, and the steep rise of the Ohatsworth Grit up to Houndkirk Moor abuts against Coal- measure shales. Along the county boundary near Ringinglow the coal above the Ohatsworth Grit has been mined rather extensively. Its section in the Ringinglow shaft 1 closely represents its character throughout this neighbour- hood, in which the upper and thinner part is the better coal : — Ft. In. Coal 1 Shale 9 Coal ... 2 9 Eastward of here both the Longshaw Grit and the higher grit above described can be recognised : both are seen in succession in and above Limb Brook, where the Longshaw is brought up by a fault. Lower Grits in the anticline at Ashover.— North-west of Ashover two or three fine-grained grits of the Shale Grit group, scarcely seen elsewhere on the east side of the Millstone Grit area, crop out in the stream below Overend. Further north, near Stone Edge and on Harewood Moor, the outcrop of the Kinderscout and Ohatsworth Grits becomes obscure on the ill-drained watershed, for, as is often the case on such watersheds, the want of stream-erosion has left the grit- and shale-outcrops undifferentiated. Rough Rock. — For some miles northward from Crich the Rough Rock, mostly cropping-out with a high eastward dip on the eastward slope down from the anticlinal ridge, makes little show at its outcrop and might be supposed to have diminished in thickness, as it has certainly become finer in grain. But the shaft of the Alf reton Waterworks at Lindways Springs, where the dip is small, proves the contrary in the following section : — Ft. In. Soil ... ■■• 1 Coal ... *. ••■ ■*■ 3 Blue and brown clay with sandstone ' ■' cobbles"... 10 Red and grey grit ... 108 Black shale ... 1 5 This grit is also well exposed a little further north in the road-cutting and in the banks of the lower reservoir of the waterworks. Its outcrop in the neigh- bourhood of Ashover Hay is not easy to define. The stream-section at Whitecarr shows it to have been intensely affected by sharp folding and faulting ; and it is certainly present in a quarry north of Woolley. There it seems to have been brought up again eastward beyond its normal line of strike on the flank of the - main anticline by gentle subsidiary undulation. It is quarried at Alton, where it is still a somewhat fine-grained and homogeneous rock, and can be traced thence northward without difficulty. The Rough Rock in the northern part of the district, like the Ohatsworth Grit throughout, makes a bold escarpment, particularly prominent on Birchen Edge and White Edge (Sheet 100) ; but less regular and wall-like than that of the lower grit. The small patch of Rough Rock preserved on Blacka Hill shows in its upper part a massive rather coarse-grained grit, seen where its faulted junction with the Ooal-measure shales produces a small cascade in crossing the stream. The patch owes its preservation to this and another fault which has let it down to the general level of lower grits. C. B.W. 1 A. H. Green, ' The Yorkshire Coalfield,' Mem. Geol. Surv., 1878, p. 37. 45 CHAPTER IV. UPPER CARBONIFEROUS, Continued: COAL MEASURES. General Characters and Structure. The western margin of the broad sheet of Coal Measures is clearly defined by the outcrop of the Millstone Grits, and the eastern boundary by the bold and conspicuous escarpment of the Magnesian Limestone. On the north, the Coal Measures are continuous with those of South Yorkshire ; and on the south, with those of the southern part of the Derbyshire Coalfield. Lithological Characters. In character, the Coal Measures show a relation to the sequence in South Yorkshire, and to that in the Erewash valley (Sheet 125). Thus the thickly-bedded and somewhat coarse sandstones, conspicuously developed in the upper part of the series east of Rotherham, gradually diminish as they approach the county-border, but though of inferior thickness they are more persistent than in the Erewash valley. Similarly the sandstones in the middle and lower parts, which in the south are fine-grained and of irregular occurrence, slowly assume northward a coarser texture and more massive character so that individual beds can be identified with those of the Yorkshire sequence. Argillaceous rocks form a large and important group. When mixed with sand, as is frequently the case, they are known to the collier as ' stone-binds ' or ' rock-binds ' to distinguish them from the purely argillaceous members called 'binds.' For the beds of unstratified clays and for the seat-earths or underclays of the coals he usually applies the term ' clunch.' Beds of coal occur at intervals, but the thickest (5 to 7 ft.) and most valuable seams lie in the middle part of the sequence, which is also the location of the chief ironstones, termed ' rakes,' extensively worked up to the middle of last century. Sequence. The complete succession is wanting both at the outcrop and in the deeper sinkings in the east, since everywhere the red rocks of the Upper Coal Measures and part of the underlying grey measures were denuded before the deposition of the Permian strata. At Bolsover Castle, where some of the highest grey measures crop out beneath the Magnesian Limestone, the thickness amounts to 4,100 ft. At Maltby (PI. VI, fig. 9), 14 miles north-north- east of Bolsover, where the Upper Coal Measures are present, it is no less than 5,000 ft., while at Oxton (PI. VI, fig. 1), 14 miles south- east of Bolsover, the complete sequence of grey measures does not much exceed 3,000 ft. These are estimated measurements as in no one place have the Coal Measures been penetrated by a shaft or boring ; 25276 D 2 46 UPPER CARBONIFEROUS . but if, as in the following table, the proved thickness in feet of grey measures above the seam of coal known as the Top Hard at Oxton is compared with that above the same seam at Maltby it is seen that the chief increment occurs above this coal. Divisions and Description. Oxton boring and district. Bolsover area. Maltby Colliery and district. UPPER COAL | Hed measure8 without OOal ... MEASURES. ) ( Grey measures, several coals . . . middle coal J Top Hard Coal MEASURES. ) Grey measures, several coals ... ( Silkstone Coal lower coal | G rey measures , some coals ... MEASURES. j J ' Present 1280 1000 1100 Absent. 1550 + 1100 1450 Present. 2250 1100 1650 3380 4100+ 5000 The coal-measure deposits form a continuous series of which one part is not markedly differentiated from another by distinctive lithological characters, while the vertical distribution of the fossils has not been sufficiently worked out to serve as a guide in classification. Since, however, the subdivision of the Coal Measures into the Upper, Middle, and Lower Series, given in the table above, was adopted by Green (' Yorkshire Coalfield,' p. 75) for the con- tiguous district the same classification is retained for the present area. It also has some advantages, for the Silkstone Coal, which was taken by Green as marking the dividing line in Yorkshire between Lower and Middle Coal Measures, can be easily traced throughout the present district and possesses some characters which distinguish it from any other coal. Also, relative to the seams of the Middle Coal Measures, those of the Lower Series are few in number and of far less commercial value ; but this distinction does not hold good either for the southern part of the Derbyshire Coalfield, where the Kilburn Coal, 400 ft. below the Silkstone Coal, is a thick and important seam, or for the northern part of the Yorkshire Coalfield in which the Beeston and Better Bed coals are highly esteemed. So far as the scanty palaeontological evidence admits a comparison, a greater change in the character of the fauna occurs at the horizon of the Top Hard than at the Silkstone Coal. Structure. The Coal Measures occupy a central position in a big synclinal fold which contains the united coalfields of Yorkshire, Derbyshire and Nottinghamshire. The western edge of the fold is exposed in the present area, but its eastern margin is concealed beneath the Mesozoic formations. The axis of the fold trends north and south with a general inclination of the strata to the east ; but several minor folds cross and break the symmetry of the major syncline. Of these, the most important, from its effects on coal- mining, is the conspicuous anticline, usually known as the ' Briming- ton Anticline' which extends from Holmesfield eastward to Unstone where it bends south to continue as a tract of elevated GENERAL STRUCTURE OF THE COALFIELD. 47 a j a —i w a a 02 Gn o CO h a t> in *i o « CO is z, o a CO Z O 3 w CO 2 5"V ground past Brimington to Calow. The uplift is sufficient to bring the top beds of the Lower Coal Measures, here un- productive, to the surface, and thus to introduce a tract of barren ground in the heart of the coalfield ; but the loss to mining is in part compensated for by the double outcrop of the lower and better-class seams of the Middle Coal Measures on the flanks of the anticline. Although, to the south-east of Calow, the fold loses its character of a well- defined anticline and becomes obscured by faulting, it nevertheless continues across the visible coalfield up to the escarpment of the Permian formation west of Skegby. Throughout this dis- tance it can be distinctly traced by means of the underground workings for coal, as well as, though less clearly, by the out- crops of the Coal Measure sandstones. Whether the disturbance extends still farther to the south-east beneath the Triassic rocks has not yet been proved, but the evidence afforded by the borings at Thurgarton and Kelham 1 suggests its extension far beyond the limits of the map (Sheet 112). The central and most conspicuous part of the anticlinal fold thus introduced is" illustrated by the section shown on Plate III., Fig. 1, p. 48. It will be seen that the easterly dip on the east side of the saddle is sharply accentuated, and that it rapidly diminishes from about 20 degrees east of Arkwright Station to somewhat under 4 degrees before the Coal Measures disappear beneath the Magnesian Limestone of Bolsover. It therefore happens that the chief work- able seams of the Middle Coal Measures are within easy mining depths beneath the Permian cover. A complementary synclinal fold with its centre at Sheepbridge occurs to the west of the Brimington anticline between Hasland and a short distance north of 1 ' The Concealed Coalfield of Yorkshire and Nottinghamshire,' Mem. Geoi. JSurv., 1913, p. 39. 48 UPPER CARBONIFEROUS . Barlow Brook, and another to the north around Dronfield where it is clearly denned by the outcropping sandstones above the Silkstone and Deep Hard coals (Fig. 5, p. 47). North of the Dronfield syncline, the anticline trending a little south of east, which brings up the Lower Coal Measures in the districts of Norton and Ridgeway, pitches to the east, so that the lowest strata crop out to the west, where they are deeply trenched by the River Sheaf down to the horizon of the Alton Coal (p. 57). This and the Brimington anticline form the two arms of the horse-shoe-shaped anticline (p. 8) enfolding the Dronfield syncline. The faults crossing the coalfield are neither numerous nor of great magnitude compared with those of the coalfields on the western side of the Pennines. They appertain to two systems : one trending north-west ; and the other north-east. Both are intimately related to the folding, as is conspicuously shown along the line of the Brimington anticline between Tibshelf and Teversal, where the faults coincide with the change in strike of the Coal Measures. The main faults in the neighbourhood of Barlborough, Renishaw and Eckington and the large fault crossing Birley Moor are also in alignment with the Norton-Ridge way anticline. The relative age of the two systems remains uncertain, but that the major part of both the faulting and folding is of pre-Permian age is clearly shown between Hucknall-under-Huthwaite and Teversal where the un- disturbed and unbroken Magnesian Limestone crosses the faulted Brimington anticlinal uplift. Characteristic of the coalfield generally, and in great contrast to other Midland coalfields, the complete absence of boundary-faults may be noted. On the west the Millstone Grits rise at "gentle angles from under the Lower Coal Measures to their outcrop, and the supposed faulted junction between Wheatcroft and Stubbing Edge Hall, along the line of the " Trinity Chapel Fault," 1 has been proved to be an error in the interpretation of the local stratigraphy. 2 Beneath the Magnesian Limestone the Middle Coal Measures also incline gently eastward, and there is no occurrence of the post- Triassic faulting so conspicuously developed on the west side of the Pennine uplift. Palaeontological Characters. — In the list of fossils (Appendix III., pp. 160-7) drawn up by Dr. Moysey the poverty of the flora and fauna of the Lower Coal Measures is at once noticeable, and it will be gathered that in the fuller record from the Middle Coal Measures the localities are chiefly situated in the southern part of the coalfield (Sheet 125). The limited flora and fauna of the Lower Coal Measures may repre- sent an actual barrenness of the strata ; but the more extensive knowledge of the palaeontology of the Middle Coal Measures in the southern part of the coalfield is due to the active work of local geologists in that region, while in the present area 1 'Carboniferous Limestone, etc., of N. Derbyshire,' Mem. Geol. Surv., ed. 2., 1887, p. 84. 2 ' Summary of Progress for 1905,' Mem. Geol. Surv., 1906, pp. 14-18. Geology of N. Derhy Coalfield- . W Ft-g 1. Section, ctcross the Brbrusigtorv AntCc&rve. , ilbu^traltrvg the, Middle Coal Measures. Plcute.HL. ilo^ficvcr 5 E. A LEVEL SEA LEVEL Ti,g. Z. Section, a^cross the Cccrbonxferoivs Limestone, from, MUldose, Mine,, through* BltrJcelow HvU ,~to ike west of Millers Greerv S.l*° E- Shaft Shaft OIJ, Shaft Dole. BXcihoUvr HiU- BotvsojU K JUoor s SorufcLii z*y& MicWZetOTV Mooi- Big7v PecCk,Z-in Thickness (estimated). Ft. Dark shale with ironstone nodules and bed of Carbonicola 1 5 Goal, (probably the Coking or Soft Coal of Yorkshire), about 1 Gannister, worked at Mooredge Mine 3 ft. to 4 Clay H Coarse pebbly grit and finer sandstone 25 Shale with marine bed of dark blue pyritous shale in lower part containing fish-scales, Gastrioceras, Glyphio- ceras and Pterinopecten (cf . Moorwood Moor, p. 54) 60 Fine-grained sandstones with beds of shale 40 Shale with little sandstone 110 At the Mooredge Mine, small faults and a variable easterly dip confuse both sequence and thickness. The coarse grit of Brown Edge, continuing northward in Bole Hill (Fig. 7, p. 56), is seen again capping Lenny Hill beyond Blacka Brook. The marine bed below it is exposed in that brook and on the western flank of Bole Hill. Gastrioceras carbonarium was obtained also from the tip of No. 4 airshaft on the Totley Tunnel, and probably came from this bed,, which should occur in the tunnel near that airshaft. The gannister and coal above the grit have been found in the valley of Blacka Brook by trial-diggings and just above them the bed of Carbonicola crops out by the brook. In that neighbourhood a sandstone upwards of 20 ft. thick, but not recognizable much further south, makes its appearance higher, but still below the Alton Coal, and strikes northward to Whitelow Lane. In the upper part of the valley of Redcar Brook, below Owlet House, goniatites, Pterinopecten and Posidoniella, probably representing the lower marine bed mentioned on p. 50, were obtained from shales presumably above a thick sandstone which crops out earlier in the sequence but higher in the stream, near the road. Higher strata exposed in this valley are difficult to correlate individually with those of the Totley Tunnel (Fig. 7) and the Mooredge Mine, and it seems that they have changed somewhat in the intervening distance. Little- more is seen of them northwards to the county boundary ; but in Limb Brook, about 600 yds. SE. of Whirlow Bridge, black shale with goniatites and Posidoniella occurs above a white fireclay, and probably belongs to the same- marine horizon. The gannister underlying the Alton Coal is now only worked at the Marriott Wood Brickworks, Millhouses ; but was formerly quarried at Dore and Totley. Alton Coal. — No evidence of this coal was detected between Ambergate (Sheet 125) and the village of Wessington ; but owing to the folding between Crich and Brackenfield, its outcrop probably loops round westward in the basin of Moorwood Moor, before bending northward to Wessington. On Wessington G-reen a coal was once dug — apparently a few feet below a thin sandstone cropping out on the Green. Its thickness is not recorded, but the seam is evidently pyritous. Its distance below the Wingfield Flagstones, the marine fossils of its roof -shale and the evidence of a gannister floor show that this is the Alton Seam. From Wessington Green its outcrop can be fixed closely as far as the brook in Ogston Carr, where it has been proved by shallow trial-diggings. The Alton Coal has been somewhat extensively worked by shafts between Littlemoor and 700 yards SE. of Alton village. In the south, near Littlemoor,. the seam has a thickness of 4 ft., which further north has increased to 4 ft. 8 ins. ; it splits up near Alton into two seams — an upper 1 ft. 2 ins., and a lower 1 ft. 8 ins., of good coal, separated by 1 ft. 8 ins. of dirt and batty coal. It is stated 2 that the seam is inclined east at 27° and that it furnished a high- class coke suited for metallurgical purposes. An outlier of a seam, apparently the Alton, was once worked by bell-pits on Gibbet Moor, east of Chatsworth. The main outcrop of the Alton Coal can be 1 Only one bed of Carbonicola is known below the Alton Coal in Derbyshire (' Southern Part of the Derbyshire, etc. Coalfield,' Mem. Geo/. Surv., pp. 73 and 18S) and is likely to be the same bed throughout. It is significant that the only Carbonicola [Antliracosia] bed recorded by Green in the Lower Coal Measures of Yorkshire ('Yorkshire Coalfield,' Mem. Geol. Surv., p. 104) appears to occupy the same position. Cf., also, for North Staffs, 'North Staffordshire Coalfields,' Mem. Geol. Surv., pp. 58, 84-5. ' 2 From information obtained at the Home Office. 56 UPPER CAEBONIFEEOCS. H Z Z & H m J. H O H o a «! a W o ,Q a a O Z o «! z o H O a w as a t3 : -8 IS "8 *s •j r» P ■■i h as z o H 5 4 1 11 Coal 2 1 c 4 9 4 1 6 Where at its best, the Silkstone Coal is bituminous, very pure and is highly prized as a house coal. The smalls yield a coke of excellent quality. At South Wingfield, where it is raised in the Oakerthorpe Colliery, the seam consists of 2 : — -,, _ Ft. In. Tops Dirt Coal Dirt ' Bottom coal Thence northward to Stretton its outcrop can be traced by the old workings. From Stretton northward to the Yorkshire border the outcrop has been traced continuously by means of day-levels, by the extensive old workings in the ironstones directly above the coal, and when these means fail, by the sandstone generally found above the ironstone measures. A good section of the seam, giving its composite character, is exposed in the cutting of the Great Central Railway (Mansfield branch) | mile S.E. of Hadyhill (Plate IV). The seam consists of five bands of coal, from 3 in. to 2 ft. 8 in. thick, separated by shale-beds from 1 ft. to 3 ft. thick. Measures between Silkstone and Tupton Coals. Between" the Silkstone Coal and the next seam above (Tupton or Low Main) there occurs, from South Wingfield to Staveley, a group of variable measures from 150 to 200 ft. in thickness. The most persistently developed are some dark shales with iron- stones, 10 to 70 ft. thick, resting immediately on the Silkstone Coal ; and a sandstone, often coarse grained, and up to 150 ft. thick, which sometimes directly succeeds the Silkstone Coal, but which is usually separated from it by the shales with the Black Shale rakes. The sandstone is occasionally, though rarely, absent. Above it, the Yard Coal occurs in several shaft-sections south of Staveley, and the Tupton Three-quarters Coal invariably ; but north of Staveley, and from there to the Yorkshire border, both these coals are feebly represented. The shales with ironstones correspond to those containing the Claywood ironstone of Yorkshire. Their outcrop is everywhere indicated by old spoil heaps and abandoned pits, both particularly abundant SW. of Chesterfield and around Dronfield. The composition of the band and the position of the ironstones will be seen from the following section taken at the Renishaw pits. Thickness. Ft. In. Hard white rock (Silkstone Rock) 88 Bind and stone bind 13 5 Black shale 2 f Ironstone 1 Black Shale ) Black shale 1 1§ rakes. ) Ironstone 2i (^ Black shale 1 V* 1 Information from Mr. T. Greensmitli. " 2 Information by the Manager, South Wingfield Colliery, ^ Ph c Q ^5 o l>i « a Ph a P a ^ H X J a H 02 o , — . ps < a O z ►3 ►i~ n a a H ^ o ^ a C < a a g o >> a ,_3 a ««; P5 < a Z a z > i-* c o z -a c a z H P Thickness. Ft. In. 2 2 Oi l) 2 4 4 2 1 MIDDLE COAL MEASURES. 65 Ironstone „, , „,, Black shale Black Bhafe^ Ironstone ... rakes-coirf. Bkok shale _ _ Ironstone balls Coal and clunch Silkstone Coal. Exposures at the outcrop are extremely rare, but the group is well displayed in the railway-cutting SE. of Hadyhill. Between South Wingfield and Chesterfield the Silkstone Rock is feebly developed, but it appears as a sandstone from 20 to 50 ft. thick in the pits of the Clay Cross Colliery to the east. This sandstone however may represent the rock that at Barlow lies below the ironstone measures under the Silkstone Rock. At Chesterfield the sandstone swells out, and thence northward to the Yorkshire border it forms a bold and constant feature outlining very clearly the Brimington anticline, the Dronfield syncline, and the Norton-Ridgeway anticline. The rock has been extensively quarried in many places, the most accessible of the excavations being situated around Sheepbridge and Dronfield. Occasionally fl a ggyi highly felspathic, and containing a few thin beds of shale, it is usually a hard somewhat massive sand-rock which yields on weathering a dry, sandy or loamy soil, very unlike the stiff land formed out of the sandstones higher in the sequence. The Yard Coal has not been recognised at the outcrop. The Tupton Three- quarters Coal is also rarely seen, but it is recorded in most shaft-sections. Tupton or Low Main Coal. — This coal is essentially a Derbyshire seam. It furnishes much of the coal in the area to the south (Sheet 125), and extends as a coal of workable thickness to Sheepbridge, on the west side of the Brimington anticline ; but it is reduced to a thickness of 1 ft. 4 in. at the Hartington pits on the east side of the anticline, and is not recognisable in Yorkshire. In pits near the outcrop it ranges between 4 ft. and 5 ft. 6 in. in thickness, and it is not found to deteriorate to the east in the Silverdale pits near Teversal and in the Hardwick pits at Heath. At the Bondsmain Colliery, Temple Normanton, it gives the following section : — Thickness. Ft. In. Top coal 1 5 Clod 1 1 Bottom coal 4 1 It is worked at the Oakerthorpe Colliery, South Wingfield, where it is said to be 4 ft. 4 in. thick, the upper part being a ' best house ' coal, the lower an ' inferior house ' or ' steam ' coal. From South Wingfield to Clay Cross the outcrop of the Tupton Coal has been ascertained partly from day-levels and also by the feature formed by the overlying sandstone. Between Clay Cross and the fault north of Nether Moor the position shown on the map is taken from old plans. East of Wingerworth, old crop-workings define the outcrop ; and west of the fault shown near Grange- wood Farm, it can be traced by levels and old workings into the marl pit of the London Pottery, where the coal, 4 ft. thick, rests on the fireclay used at the pottery. Crossing the Hipper, the Tupton Coal is stated to occur in the grave- yard of St. Thomas's Church ; and by the depths to the coal in several old shafts to the north, the outcrop can be followed into the faulted ground of the Holme Brook Valley. Crossing the belt of faults, the coal, 3 ft. thick, shows in a day-level £ mile SW. of Newbold. It is here succeeded by thin flags. It lies at a depth of 150 ft. in the shaft of the Newbold Colliery, and at 40 ft. in the Monkwood New Colliery two miles further north. In the intervening area, intersected by numerous faults, its outcrop is for the most part obscure ; but where it crops in the bed of Barlow Brook north of Cobnar AVood it seems to be succeeded by thin-bedded sandstone. Measures between Tupton and Deep Hard Goals. — The Tupton Coal is succeeded by a variable group of strata, from 150 ft. to 200 ft. in thickness, consisting ohiefly of shale, but with a local development of fine-grained flaggy sandstones, Thickness Ft. In. ... 15 .. 10 2 6 2 6 1 2 2 6 2 3 2 2 2 2 66 UPPER CARBONIFEROUS . which are most persistently developed south of Olay Cross. One or two coals known as the First and Second Piper coals, between 2 ft. and 4 ft. in thickness, are mentioned in most of the shaft-sections, but they have been worked only to a limited extent. The following section of the highest or First Piper Coal was obtained at the Brockwell Brickworks near the reservoir on the NW. outskirts of Chester- field :— Yellow clay and ironstone nodules . Grey marl and ironstone nodules Black shale (Carbonicola acuta) Black coaly shale Grey marl fcoal Piper Coal-! shale (coal In the valley of Sud Brook, south of Cobnar Wood, an attempt has been made to work this coal at its outcrop. The section of this seam is said to be : — Thickness. Ft. In. Top seam 1 5 Dirt Middle seam Dirt Bottom seam Deep Hard or Parhgale Coal. — Under the name of the Deep Hard Coal a valuable seam occurs throughout the Derbyshire and Nottinghamshire Coalfield, and extends into Yorkshire, where it is called the Parkgate Coal. It is exten- sively worked in the other parts of the coalfield, but remains untouched in the more recently developed areas under the Permian and Triassic formations. It varies considerably in thickness, and usually contains one or more dirt- partings. On the whole, the Deep Hard Coal expands to the north and is at its best to the north of Staveley, where the Tupton or Low Main Coal fails as a workable seam. At the Silverdale pits near Teversal it is 2 ft. 7 in. thick ; at the Hardwick Colliery 3 ft. 8 in. thick ; while at Renishaw the seams consist of 3 ft. 9 in. of coal with a clunch-parting 14 in. thick. It has expanded into 4 ft. 4 in. of coal at Holbrook Colliery, and at the Birley Colliery on the York- shire border into 5 ft. 6 in. of coal. At the old Moorhole Colliery it gave the undermentioned section : — Roof coal Dirt Brights Dirt Brights and Hards Dirt Bottom Brights The pits mentioned, with the exception of those of the Birley Colliery, lie towards the eastern margin of the visible coalfield. The same tendency for the Deep Hard Coal to expand northward is observable over the central and western parts of the coalfield, but it varies considerably in thickness and composition. It is sold for steam, blast-furnace and manufacturing purposes. Some old surface workings 300 yds. NW. of Uf tonfields are probably on this horizon. North of Alfreton Brook a low feature can be traced to Shirland Colliery where the Deep Hard Coal is at a depth of 34 ft. Between Shirland Delves and Shirland Colliery, old surface-workings give the exact outcrop of the coal ; while for over a mile to the north it must lie a little west of the ridge on which stands the village of Shirland. Near Ain Moor indications of crop- workings again occur and a slight rise in the ground probably indicates the presence of the sandstone. Between Ain Moor and Danesmoor the only evidence of the outcrop of the Deep Hard consists of some old bell-pits SE. of Thickness. Ft. In. 9 4 6 2 2 8 2 1 44 MIDDLE COAL MEASURES. 67 the Church. At Clay Cross No. 7 pit, the coal is at a depth of 150 ft., where it consists of a lower bed 3 ft. 8 in thick, separated from an upper bed 9 in. thick by a dirt-bed, 3 ft. thick. It is 15 ft. deep in the No 2 shaft of Clay Cross Colliery. From here to the fault at New Tupton the outcrop shown on the map was obtained from old plans, as far north as Tupton Hall, and then by taking a low feature caused by the sandstone recorded in the adjacent collieries as resting directly on the coal. In the shafts of the Avenue Colliery (No. 9. Clay Cross) the seam gives a section of : — Top coal (dirty) 3 ft. 2 in., Dirt 5 in ; Bottom coal 2 ft. 3 in. and is at the depth of 376 ft. from the surface. The roof consists of flaggy and thick bedded sandstone ('stone binds' and ' grey rock ' of the record). This sandstone crops out to the west at Winger- worth, and throughout the coalfield north of Clay Cross it gives rise to a bold feature, comparable to that formed by the Silkstone Rock. Therefore, though the Deep Hard Coal is not often exposed, its position can be fixed with great accuracy over a very large part of the area. North of Wingerworth the seam receives the name of the Potters Coal and has been extensively worked by numerous pits up to Sheepbridge. 1 Between the Chesterfield trough-faults, the Potters Coal has been raised nearly to its basset near Cutholme. No direct evidence was obtained for the existence of the seam under Chesterfield, but there is little difficulty in identifying the sandstone seen at several places in drains and cellars as the Deep Hard Rock, since it agrees in character with that quarried to the north near Stonegravels, and to the west of Highfield Colliery, Litfclemoor, in which the Potters Coal lies 31 ft. below the Surface, and gives the following section 2 Thicl Ft. mess In. Roof coal 6 Bat ... 3 Smiths coal 74 Dirt ... 1 Hard coal 1 2 Dirt ... 8i Hard coal 1 4 North of Littlemoor, at the Albert (Derbyshire Silkstone or Devonshire) Colliery, the Potters Coal is at a depth of 157 ft. Two or three trial-levels have been opened in the outcrop in Sud Brook, S. of Cobnar Wood, and the coal is being worked beneath the sandstone in this wood. From the southern margin of Sheet 112 to Sheepbridge (Sheet 100) the Deep Hard dips E. of N. West of Chesterfield and Sheepbridge it rises sharply to the east on the flanks of the Holmesfield-Brimington anticline, where it and the sandstone above are clearly exposed in the cutting of the Great Central Railway, south of Hady House, and in that of the Midland Railway below Castle Hill, near Tapton. In the abandoned shafts of the Lockoford pits, I mile to the north, the Potters Coal, recorded as 6 ft. 5 in. thick, was reached at a depth of 158 ft. From here it rises up NE. from the narrow trough under Whittington Moor, and at the Foxley Oaks Colliery it was found at the depth of 70 ft. The outcrop of the overlying sandstone can be traced by its feature from Foxley Oaks to a quarry north of Broomhill Park, 500 yds. SW. of Whittington Church. In the cutting of the Midland Railway to the east, a faulted section of the Coal Measures is exposed, from the horizon of the Deep Hard Rock to the Mickley coals. In the Brushes Colliery the seam gives the following section : — Top coal 2 ft. 6i in. ; Dirt 8 in ; Bottom coal 2 ft. Between Alfreton and Morton the Coal Measures rise to the west, but at Tibshelf they rise at about 20° NE. until it is considered locally that the Deep Hard Coal and rock come to the surface between Tibshelf Wharf and Hardstof t. A somewhat massive sandstone, resting on a coal, crops out at several places near Hardstoft and has been quarried at the Hurst. The region, however, is much faulted and the amount of throw of the faults has not been proved. If the fault of 180 ft. downthrow north, proved in the Silkstone Coal east of Biggin Farm, increases to the south-east, then the coal and sandstone seen near the Hurst belong to a horizon above the rock over the Deep Hard Coal. 1 The depths to the coal are shown on the aix-inch geological maps. ' From plan at Mining Reoords Office. 68 UPPER CARBONIFEROUS. West of Suttonspring Wood the mineral line going N. from Bondsmain Colliery, Temple Normanton, to Calow Colliery, Calow Green, cuts through a coal 6 ft. thick, overlain by a hard flaggy sandstone. It is probably the Deep Hard Coal. The depth to this seam in the shafts of the Bondsmain Colliery is 750 ft. and the rise (15 degrees N.) of the measures would cause it to crop out west of Suttonspring Wood. In the same cutting, 30 yards further N., a coal occurs beneath a hard flaggy sandstone, but owing to the faults crossing Sutton- spring Wood it is not possible to connect this outcrop with that of the Deep Hard on Bolehill. In the tunnel of the Great Central (formerly Lancashire, Derbyshire and East Coast) Railway the Deep Hard Coal is on a level with the rails 240 ft. from the east mouth of the tunnel. On the geological section supplied by the company it is given as 6 ft. thick, succeeded by 24 ft. of shale, and this by a sandstone only 8 ft. thick as compared with that 80 ft. thick above the Deep Hard at Bondsmain Colliery. This attenuation, judged from the absence of any well-marked features, apparently persists north to Staveley Works. North of Bolehill the outcrop, of which the position is corroborated by signs of old surface-workings in West Wood, has been taken from an old plan. In the stream at the north end of West Wood the strata are much disturbed so that it is not safe to consider the coal, 4 ft. thick, seen in the banks of the stream as the Deep Hard ; while between here and the fault crossing Ringwood Park there are no indications of the outcropping coal. It must lie to the east of the park since in the disused Albert Pits, at the SE. corner, the Silkstone Coal lies 324 ft. from the surface. North of the fault, the coal was got in some shallow workings on Hollingwood Common (Sheet 100) bordering the alluvium of the Rother. On the northern margin of the alluvium a coal, 4 ft. thick, crops out in a bluff near the footpath leading E. from Whittington Station. Below it a feature can be traced N. into the railway-cutting where it is seen to be formed by a sandstone resting on a coal. The feature persists N. of the cutting up to an old footrill (day-level), said to be on the Piper Coal, near the road going E. from West Staveley Colliery. This implies that the seam in the river-bluff is the Deep Hard and that the ridge at Handleywood Farm is formed by the overlying sandstone. Between West Staveley Colliery and Springwell Colliery the outcrop of the coal is uncertain. In the wood (Buckley Wood) north of Springwell Colliery, a flaggy sandstone crops out. In the disused Springwell Ironstone Pits, 500 yards NW. and in the direction of full rise (5°) of the measures, the Silkstone Coal is at a depth of 189 ft., which will bring the sandstone into the position of the Deep Hard Rock. To the north-west, around Apperknowle, the sandstone occupies the centre of the Dronfield syncline which it clearly defines and thus gives the outcrop of the coal with considerable accuracy ; while NE. of Springwell Colliery, from Nether Handley to the Yorkshire border, it forms a bold feature which keeps parallel to the outcrop of the Silkstone Rock. Though here again openings on the coal are rare, the position of its outcrop can be readily determined. In the Dronfield syncline and along the western outcrop, the seam has been largely gotten ; but it forms one of the important coals in the Renishaw, Holbrook and Birley collieries, in which it occurs at the depths and of the thickness shown in the following table : — Depth. Thickness. Ft. In. Ft. In. Renishaw 509 3 3 9 Holbrook 591 2 6 4 Birley New Winning 451 11 5 6 Measures between Deep Hard and Deep Soft Coals. A variable group of rocks separates the Deep Hard Coal from the next seam (Deep Soft) above it. In the south-west, around Alfreton, the measures consist chiefly of shales averaging about 60 ft. in thickness ; but with the incoming of the sandstone at Clay Cross they gradually expand northward, until at Birley Colliery the first coal of any consequence is separated from the Deep Hard by nearly 200 ft. of sandstone, sandy shales and shales, the arenaceous sediments being in excess of the purely argillaceous. MIDDLE COAL MEASURES . 69 The rock above the Deep Hard Ooal, of which the outcrop was described in connexion with the coal, changes its character from a flaggy sandstone in the south to a thickly-bedded though ^oft rock around Chesterfield, whence it continues to the Yorkshire border as a somewhat massive but inferior building- stone, formerly much quarried and always forming a bold scarp. Deep Soft Coal. Next to the Silkstone and Top Hard coals this seam furnishes the best house-coal of the area as far north as Staveley, where it begins to deteriorate in quality and thickness until it becomes unrecognisable soon after crossing the Yorkshire border. In the Staveley district it yields a good coke. The seam varies greatly in composition. It consists usually of two coals separated by a dirt-parting, from a few inches to 3 ft. in thickness. The dirt- parting is occasionally though rarely absent, but in the northern area the seam becomes split up into several coals separated by shale or clunch. In the south, at the Morton pits, the seam consists of top coal 1 ft. Oi in. ; dirt 1 ft. 8 in. ; bottom coal 2 ft. 5J in. Further north in No. 4 pits of the Clay Cross Colleries the section gives top coal 1 ft. 7 in. ; dirt 6 in. ; bottom coal 4 ft. At Bondsmain Colliery several partings divide the seam which now presents the following section : — Ft. In. Coal- 1 5 Clod 1 2 Coal... 1 10 Clod 1 Coal... 4 4 It maintains the character of a divided seam to Holbrook Colliery where it is known as the Sitwell or Eckington Soft. The roof coal, here 6 in. thick, is separated by 5 in. of clod from the bottom coal, 4 ft. 1 i in. thick. The Deep Soft appears as a composite seam in the Renishaw area, where it is named the Handley Wood or Eckington Deep Soft. In the shafts of the Birley New Winning, situated over the county border in Yorkshire, the Deep Soft appears to be represented by the two coals, 3 ft. and 1 ft. 1 in. thick, separated by 18 ft. 8 in. of stone bind and rock, at the depth of 239 ft. Measures between Deep Soft and Top Hard Coals. The thickness of this group ranges from 519 ft. at the Langton collieries, Kirkby-in-Pinxton, to 681 ft. at Tibshelf . Between these amounts the measures expand and diminish unequally, so that no general rule can be deduced. Excluding the abnormal development at Tibshelf, the average thickness, calculated from 7 shaft-sections, between Alfreton and Staveley Town works out at 600 ft., which equals the mean between Langton and Tibshelf. Between Alfreton and Staveley several shafts afford sections of the measures. Usually from 3 to 5 coals are recorded, whose position will be gathered from the record of the Williamthorpe Colliery (section No. 3, Appendix I, p. 133). The coals have been worked locally but only to a limited extent. Of these the Ell Coal is a house-coal, formerly worked in conjunction with the Black Bake ironstone, and is said to resemble the Silkstone Coal in quality. Both of the Waterloo coals and the Dunsil are house-coals. North of Staveley there are no pits passing from the Top Hard to the Deep Soft, and little information has been obtained as to the number, thickness and quality of the seams. According to Green, 1 there is only one seam — Swallow Wood or Haigh Moor — 180 ft. below the Barnsley (Top Hard) Coal — of any consequence in the southern portion of the Yorkshire Coalfield. It appears to represent the Waterloo Coal of Derbyshire. The measures between the Deep Soft and Top Hard consist chiefly of shales in the district south of Staveley, with a local development of soft sandstones, irregularly bedded and lenticular. North of Staveley, sandstones become more pronounced. One, above the Deep Soft, can be traced to the Yorkshire border, where it is named the Manor Rock by Green. 2 Above this, around Eckington, a somewhat massive sandstone lies about 150 ft. above the Deep Soft, but it apparently dies out to the north and is unrepresented in South Yorkshire. ' ' Yorkshire Coalfield,' Mem. Geol. Surv., 1878, p. 333. * Op. cit., p. 316. 70 UPPEft CARBONIFEEOUS. Below the Top Hard a sandstone sets in near Eckington and extends northward to Beighton, where it is seen to be continuous with the Woodhouse Rock of Green. 1 In the south the following section was measured at the south entrance of the railway-tunnel east of Cotespark Colliery : — Ft. Yellow shales 3 Flaggy sandstone ... ... ... 6 Grey marls and ironstone nodules 18 Black shales with do. ... ... 3 Grey marl ... ... ... ... li Coal 14 Fireclay ... ... ... ... 2 Grey marl 15 Shale with grit bands 18 Hard grit ... ... ... ... 6 The beds are inclined at 2° to 3° NE., and lie on the eastern flanks of a local anticline, on the crest of which the shafts of the Lower Birchwood Colliery, 600 yards to the 8W., reach the Deep Soft at 175 ft. from the surface. The section therefore lies between the Ell and Waterloo coals. Plant-remains, chiefly stems of C'alamiles, are abundant in the lower shales and grit-bands ; while the ironstone nodules enclose the casts of Carhonicola aquilina. To the west the dip turns over to the NW., and in the workings in the Low Main (Tupton). Coal beneath Cotespark farm it amounts tolinl2(=5°). The dip and a down- throw fault introduce the Top Hard Coal which is 253 ft. deep in the Swanwick Colliery, the seams below occurring at the following depths : Dunsil, 295 ft. ; Waterloo, 410 ft. ; Ell, 780 ft. ; Deep Soft, 886 ft. A clay-pit adjoining the Alfreton Colliery (where the Deep Soft Coal is 458 ft. deep) one mile NW. of Cotespark exposes the Waterloo Coal and associated measures as follows : — Clay Yellow clay and ironstones Grey clay and do Black shale Coal Cannel Coal Fireclay (resting on coal not bottomed) Northward there are no sections until Stonebroom is reached, where a red sandstone has been quarried near the school and to the north ; but we have no data for fixing the position of this rock which is cut off to the east by the fault seen in the brook north of the school. The exceptional red colour, probably due to weathering of iron-salts contained in the sandstone or to the original overlying ironstone measures, appears to be quite local for no mention has been made of red strata in the sinking of the adjacent pits of the Morton Colliery. Between the Morton pits and those of Clay Cross No. 7. a number of sections were observed during the widening of the Midland railway. The beds showed in places signs of disturbance, but as a whole they rise to the north so that the Deep Soft Coal which is 457 ft. from the surface at Morton is only 82 ft. deep at No. 7 pits. North of Doehill Station, at Pilsley Junction, the following section was seen : — Ft. In 3 3 2 10 1 3 10 1 3 ) 1 6 Ft. In Orange sandstone 20 Coal 1 10 Fireclay 2 Yellow sandstone 3 6 Grit 3 Sandy shale 12 The feature formed by the sandstone continues to the northern end of Padley Wood where the rock has been quarried. Op. cit., p. 335. MIDDLE COAL MEASURES. 71 North of Pilsley Junction the cuttings display alternations of thin grits and pale grey shales, with a coal 1 ft. thick separated by shales from a lower coal, 3 ft. 10 in. thick, at the footbridge over the railway to Padley Wood Farm. Beneath the lower coal the following beds rise to the north :- Ft. 27 15 5 25 6 23 4 1 3 Grey sandy shales and grey sandstone Blue sandy shales with ironstone bands Black shales with Carbonicola Grey sandy shales with ironstone nodules .. Black shales, ironstones, Carbonicola Dark blue shales, Lingula, Pterinopecten, goniatites Grey sandstone 8 To No. 7 pit Clay Cross Colliery the cutting shows alternations of black shales containing Carbonicola with pale grey shales and sandy shales. North of No. 7 pit the general dip is NE. at 5° to 6°. In the road-cutting at Park- house Farm, on the south or upthrow side of the fault shown on the map, a coal 5 ft. thick (probably the Deep Soft) with thin partings, overlain by flaggy sandstone, dips E. at 6.° South of Clay Cross Colliery No. 4 pit, where the Deep Soft is again 82 ft. deep, a clay-pit shows ;— Ft. In. White clay Coal Grey shales with ironstone nodules . Sandstone Grey shales with Carbonicola Grey marl To the east a yellow sandstone crops out at North Wingfield and can be traced by its feature to the faulted belt S. of Hagg Hill. A sandstone higher in the sequence appears at Grassmoor and was seen resting on a coal 3 ft. thick in a drain near the mineral line from Grassmoor Colliery. The coal agrees in position with the Dunsil seam of this colliery. In the shafts of the Whitebanks Colliery (abandoned), adjoining the Midland railway E. of Boythorpe church, the Dunston (Deep Soft) Coal is at a depth of 90 ft. The shales exposed in the clay-pit on the east side of the railway are in consequence about 100 ft. above this coal. North of the Chesterfield faults (p. 63) the measures above the Deep Soft Coal appear at the surface between Whittington and Sheepbridge, but they are nowhere well exposed. On the line of the Brimington anticline, beds between the Top Hard and Waterloo Coal are cut through by the Great Central railway between Tibshelf and Stainsby Common where a sag down in the strata introduces the Top Hard Coal of the Williamthorpe syncline. A small area also occurs let in between the Hardstoft and Silverdale faults. The sections are poor and unsatisfactory, and the coals seen cannot be identified with any certainty. The group rises from beneath the Williamthorpe syncline near Temple Normanton and is exposed at intervals along the Great Central railway (Main Line) from Heath to Duckmanton ; but as the cutting crosses the strike obliquely and the beds are highly inclined and faulted a definite sequence cannot be established. An adit on a coal, probably the 1st Waterloo, gives the following section in Muster Brook at the S. corner of Suttonspring Wood. Ft. In. Coal 2 Dirt 6 Coal 2 Dirt 1 Coal 6 The Great Central railway (Chesterfield and Mansfield branch) exposes an almost continuous section 800 yds. long, between the E. end of Duckmanton Tunnel and Arkwright Town Station. 1 1 This section has been described by C. Fox-Strangways : ' Sections along the Lancashire, Derbyshire and Bast Coast Railway between Lincoln and Chesterfield.' Quart, ./own Geol. Soc, vol. liv., 1898, p. 163. 72 UPPER CARBONIFEROUS . Between the Deep Soft Coal which crops in the tunnel-mouth and the Top Hard Coal seen beneath the road-bridge W. of Arkwright Station the beds dip east at 18° to Deepsick lane, and then at 10° to the outcrop of the Top Hard ; which gives a thickness of 550 ft. for the intervening measures. The two coals cropping W. of Deepsick lane are the Bottom Ell and Top Ell, and those seen E. are the 2nd and 1st Waterloo coals. Beneath Deepsick bridge, grey blue shales with ironstone nodules contain some marine shells (list, p. 156). An ironstone bed, above the Ell Coal, is practically made up of Carbonicola aquilina and C. acuta, forming one of the so-called mussel-bands. In the shales over the Deep Soft Coal, Naiadites modiolaris occurs somewhat frequently in ironstone ; while the sandy shales above are rich in plant remains. The absence of massive sandstones may be noted in comparison with their development north of Staveley (p. 69) ; above the shales over the Deep Soft a sandstone 10-15 ft. thick represents the Manor Rock (see below) ; a soft shaly sandstone, 20 ft. thick, about 100 ft. above the Ell Coal, one 30 ft. thick, 70 ft. higher in the sequence, and another 15 ft. thick, 100 ft. above the Waterloo Coal, comprise the chief sandy members in the section. Northward to the Inkersall Fault (p. 74) no information was obtainable either at the surface or underground. At the four-cross roads east of Ringwood Hall, the road to Worksop shows three coals separated by shale-partings with flaggy sandstone above and below. The Deep Soft Coal crops 300 yds. to the west. On the north side of the Rother the position in the sequence of a massive sandstone at Barrowhill Station cannot be precisely determined, except that it lies midway between the outcrop of the Top Hard near the Hartington pits and that of the Deep Soft which was worked by opencast near the by-road leading from Barrowhill to Parkhouse Farm. A flaggy sandstone was formerly quarried south of The Hagge Farm, north of Campbell Colliery, in which the Silkstone is 723 ft. deep. It forms a feature which can be traced at intervals to the north of Red Lodge Farm, and thence a sandstone-outcrop can be followed northward into the fault at Eckington. A coal, probably the Deep Soft (locally called Sitwell or Handley Wood) has been obtained by a level under the sandstone near Marsh Farm. Eastward to Renishaw Park Colliery, where the Deep Soft Coal is 141 ft. deep, the surface is featureless and without exposures. South of Red Lodge numerous mounds extend west for 700 yds. and indicate the sites of old bell pits sunk to the ironstone measures (? Pindar Park Iron- stone). Their linear arrangement at right angles to the strike suggests that they are situated on a fault, probably a continuation of the one near Nether Handley. The absence of massively-bedded sandstones in the south has been previously noted (p. 69). North of Renishaw a sandstone crops out which is 150 ft. above the Deep Soft Coal and 300 ft. above the Deep Hard Coal east of Horn- thorpe's Colliery. In a quarry by the road to Eckington, west of the Hall, it is seen as a massive even-bedded sandstone over 40 ft. thick, and a similar rock has been quarried below Birley and Boiley farms on the west side of the Rother, but it apparently dies out north of Park Hall. In the Renishaw collieries to the south the only mention made of hard rock is a bed 13 ft. thick, 172 ft. above the Handley Wood (Deep Soft) Coal. The occurrence therefore affords a good example of the local and restricted development of a sandstone in the Middle Coal Measures. West of Killamarsh Station, fragments of sandstones turned up by the plough, and a loamy soil, suggest the outcrop of a sandstone in the position of the rock and stone-bind 12 ft. above the Deep Soft Coal of Holbrook Colliery. A steep scarp near the disused Swallows' Colliery, north of Mosbrough, probably indicates the outcrop of this bed, but the existence of a sandstone-bed does not become certain until near the village of Hackenthorpe, where a flaggy rock crops out. Thence there are numerous sections and at Birley Spa a bold feature leads to a quarry, south of Normanton Spring, in a massive sandstone which is undoubtedly the Manor Rock of Green (op. cit., p. 315), who represents it as resting directly on the Heward or Flockton Thick Coal and thus agreeing in position with the white rock and stone bind over the Deep Soft Coal of the Birley New Winning. The next sandstone, except the local rock of Renishaw Hall, crops out and has been quarried near Netherthorpe Station. From the depth to the Top Hard in an old shaft bordering the alluvium of the Rother to the north, it appears to lie about 50 ft. below this coal and is probably the sandstone once quarried further south, north and east of Emmett Carr. It emerges from the alluvium TOP HARD COAL. 73 of the Bother near Field Farm and can be traced thence northwards to the Yorkshire border where it becomes the Woodhouse Rock of Green {op. cit., p. 335). At Beighton, south of the Manor House and at Cliff Wheel, near the bridge over Shire Brook, it is a massive, much-jointed rock extensively quarried in the past. No traces of the underlying S wall wood (Haigh Moor) Coal were found. Top Hard Coal. From its outcrop at Pinxton in the extreme south of Sheet 112 to the Yorkshire border near Beighton, and eastward beyond the limits of the area, the Top Hard maintains an average thickness of 5 ft. At Shireoaks it falls as low as 3 ft. 10 in. but reaches a thickness of 7 ft. 1 in. in the shafts of Glapwell Colliery. Instances of the total absence of the seam due to a ' wash-out ' are rare, but one has been described as extending from the workings of Teversal Colliery, where it is 34 yds. wide, into those of Pleasley. 1 Near the wash-out the coal locally becomes thickened, reaching in one spot in the Teversal workings a thickness of 9 ft. The seam remains constant in character except that, locally, a development of a few inches of cannel occurs at the base or in the middle of the seam, as at Pleasley. Some idea of the composition of the seam will be gathered from the following sections : — Shekwood Colliery. Bolsover Colliery Ft. In. Ft. In. Brights 1 4 Top Softs ... 1 Rifler 9 Hards 1 li Gees 8 Strong Brights... 4 Hards ... 2 Hards 2 n Bottom Soft ... 11 Soft, with pyrites 8 Dirt 3 Cannel or Branch 7 Bottom Coal ... 3 Bottom Softs ... 10 6 2 From these bands a coal suitable for house, gas, steam, and manufacturing purposes can be selected. The ' Hards ' are the most valuable and are used as a converting coal for steel-making. Openings on the Top Hard are extremely rare, and most of the shafts reach the seam at a considerable distance on the dip, so that the actual position of the outcrop cannot be fixed ; but resting on the seam, or occurring a few feet above it, a sandstone, somewhat massive in places but generally of a shaly character, serves as a rough index to the outcrop. Pinxton Church stands on this sandstone which can be traced north to South Normanton which is also situated on it. The coal lies a few feet below, and appears to have been worked by opencast in some fields immediately south of the village. At Blackwell Colliery, Blackwell bridge, the seam lies at a depth of 20 ft. On the opposite side of the valley it is stated to crop out below Hilcote. The sandstone above it can be traced at intervals to Tibshelf where, in the shafts of Tibshelf Colliery, near Newton Station (M.R.), the Top Hard is 105 ft. from the surface. A coal 5 ft. thick, overlain by massive sandstone, comes to day in the railway-cutting north of Tibshelf Station (G.C.R.). Whether this is the Top Hard or a lower seam cannot be stated, since the measures here become highly but irregularly inclined as they rise on the flanks of the extension of the Brimington anticline, until the Waterloo Coal, which is 1 8 ft deep in the Tibshelf Colliery, crops out at Overmoor. In the faulted and folded belt extending from Teversal to Temple Normanton the position of the outcrop remains uncertain. It is possibly the coal seen in the small brook south of Hanley. Further north it is locally stated to have been reached in a, shaft west of the Great Pond, Hardwick Hall. Between Stainsby and Grasshill, Temple Normanton, the Top Hard occupies a shallow synclinal fold, broken by the fault at Stanley. On the upthrow side of the fault the sandstone over the coal appears at Common End and can be traced west into the railway-cutting, where the coal, over 4 ft. thick, crops out. The outcrop of the sandstone cannot be traced farther to the west ; and from the depth to the coal, said to be 340 ft., at the Pewit Colliery close to the Pilsley Extension line where it crosses the road from Williamthorpe to North Wingfield, it would appear that the rock is faulted down. It is however difficult to reconcile the depth to the Top Hard at the Pewit Colliery with that in the Alma pits which are said to reach the Dunsil 1 J. C. B. Hendy, ' Notes on a " Wash-out," found in the Pleasley and Teversall Collieries, Derbyshire and Notts.' Quart. Journ. Geol. Soc, vol. xlvi, 1890, pp. 432-37. 74 UPPER CARBONIFEROUS . Coal at 51 ft. from the surface. North of the Alma Colliery the sandstone above the coal forms a somewhat prominent feature which can be followed to G-rassmoor Station. "Within the western half of its basin the Top Hard Coal occurs at the following depths : — Hardwick Colliery, 186 ft. ; Lings Colliery, 390 ft. ; Willi amthorpe pits, which are at the centre of the trough, 492 ft. ; G-rassmoor Colliery, 179 ft. ; and in an old shaft near Corbriggs, 105 ft. On the downthrow side of the Stanley Fault the Top Hard has not been identified with any certainty. It is possibly the coal formerly worked by opencast beneath a sandstone which forms an outlier at Stainsby, but it may be the coal, with a sandstone above it, seen in the brook near the moat. A sandstone, with a coal below it locally identified as the Top Hard, seen at the fork in the road from Glapwell to Heath, forms a feature which can be traced northward to the brook north of Owlcotes. It is here faulted against shale in which a level has been driven, but apparently without finding any coal, though in an old shaft 300 yds. to the south-westward the Top Hard, rising towards the level, was found at a depth of 81 ft. Since the measures between Heath and Stainsby dip to the west while the Top Hard is at a depth of 872 ft. at Glapwell Colliery, they must turn over to the east between Heath and Doe Lea ; but since there are no signs of an outcrop of the Top Hard in the Doe Lea valley it is possible that the coal may be faulted down by an extension of the fault seen at Owlcotes. On the east side of the Brimington anticline the Top Hard crops out near the railway bridge at Arkwright ' Station, whence it can be traced northward by means of old shallow workings into the fault near Inkersall Green. A shaft at Blue Lodge reached the seam at a depth of 390 ft. North of the fault there are signs of old crop-workings in the fields south of the road to Worksop ; while the overlying sandstone forms a feature fram here to the Rother. The sand- stone emerges from under the alluvium of the Rother near the shafts of the Hartington Colliery, which commence just below the horizon of the Top Hard. Thence to Killamarsh we have no definite information, but the seam is stated to crop out on Barlborough Low Common ; and from the position of the High Hazles Coal at Upperthorpe it is probable that the old workings near Westthorpe are situated on the outcrop. Near the railway at Nether Green a shaft com- mencing in alluvium reached the coal at 42 ft. depth, and the coal is seen in the railway-cutting to the north ; but from here to the county border the outcrop remains concealed under the alluvium of the Rother. Measures above the Top Hard Coal. — These consist of easily weathered rocks, chiefly shales with some subordinate bands of soft shaly felspathic sandstone. They are seldom seen in natural sections, and, except for a few pits opened in the shales for brick-making, artificial excavations are rare. The coals possess small commercial value and, excepting the High Hazles, from 300 to 400 ft. above the Top Hard, are not usually entered in a list of the workable seams, nor are they likely to be raised under existing commercial conditions. At their outcrop the greatest thickness of the measures, amounting to 1550 ft., occurs in the Bolsover district. In shafts sunk to the Top Hard through the Magnesian Limestone the maximum thickness does not exceed 1550 ft., but as in each case the Upper Coal Measures are absent the full thickness is not known. At Steetley Colliery, just beyond the eastern margin of Sheet 100, the shafts penetrated 1591 ft. of Coal Measures above the Top Hard, of which not more than the first 10 ft. can be regarded as Upper Coal Measures. In the south of Sheet 112, surface-exposures are limited to a few isolated sections, to which it is generally impossible to assign a definite position in the sequence. A coal, over 2 ft. thick, exposed in the Dumbles, south of Crow Trees, at a spot 200 yds. NE. of the Great Central main line, is probably the High Hazles, which appears to have been reached in an old shaft in Coalfield Wood. Higher up the dingle, alternations of sandstones and shales crop out, and a coal 2 ft. 6 in. thick, probably the Clowne Coal, appears in a side-stream in Bloomer Wood. The massive sandstone, 20 to 30 ft. thick, on the downthrow side of the fault at Hucknall-under-Huthwaite is an unusual development in this part of the coalfield. Prom the depth (450 ft.) to the Top Hard Coal at New Hucknall Colliery it appears to occupy the position of the sandstone over the Clowne Coal. North of Teversal the arenaceous members and consequently the features to which they give rise become more pronounced. An orange-coloured sandstone, locally regarded as the rock over the High Hazles Coal, can be traced MEASURES ABOVE TOP HAK.D COA1. 75 from Silverhill Colliery into Dovedale Wood where it is sufficiently massive to have been quarried. It has also been excavated under the escarpment at Hardwick, for the construction, in part, of Hardwick Old Hall, and also north of the Great Pond on the downthrow side of the fault shown on the map. On the east side of the Doe Lea valley the Coal Measures form a steep slope, traversed by ridges trending nearly north and south, and consisting of sandstones or sandy shales. The Magnesian Limestone keeps parallel to the highest of these sandstones, thus giving a false impression of strict conformity between two really discordant formations. South of Bolsover a coal, locally named Manor Coal, has been somewhat extensively worked by a level 100 yds. south of the railway-tunnel mouth. It lies 1300 ft. above the Top Hard Coal, and 250 ft. below the base of the Permian, thus giving a thickness of 1550 ft. of Coal Measures over the Top Hard. The railway-cuttings from the tunnel mouth to near Arkwright Station afford a few sections of the measures below the Manor Coal. They consist chiefly of shales but with some beds of sandstone, from 20 to 30 ft. thick, and a few thin coals, one of which, north of Longcourse Farm, is 1 ft. 8 in. thick. The rock above the High Hazles Coal crops out and forms a bold feature from near Arkwright Town to Inkersall. There are no signs of workings on the coal, but the identification of the sandstone with that usually occurring above it is shown by the depth (321 ft.) to the Top Hard in the old shafts near the disused Duckmanton Ironworks adjacent to the loop-line which connects the Bolsover branch line with the main line north of Arkwright Town. The shafts of the abandoned Tow Lane Colliery, Blue Lodge, which are situated on the outcrop of the sandstone, reached the Top Hard at a depth of 390 ft. North of the Inkersall Fault the sandstone over the High Hazles gives riso to a prominent feature which is cut through and the rock exposed by the railway- cutting south of Staveley Town. In the shafts of Ireland's Colliery, } mile to the SB., the High Hazles occurs at a depth of 225 ft. Quarries near Woodthorpe show a thick-bedded sandstone about 30 ft. thick, and below it the High Hazles Coal, 3 ft. thick, crops in the level of the Norbriggs Colliery. Indications of old workings, probably on this seam, occur NW. of Mastin Moor and the coal is exposed in the railway-cutting east of Beighton Fields Priory. In the faulted ground between here and Park Hall some doubt exists as to the outcrop of the High Hazles, and of the position in the sequence of the thin coals seen in the railway -cutting further north. On the upthrow side of the Park Hall Fault, the High Hazles appears in the level of Park Hall Colliery, and thence, by means of old levels or of the over- lying sandstone which has been quarried in several places, the outcrop can be traced north to the county border. The seam reaches a thickness of 4 ft. in a bvel at Upperthorpe and 4 ft. 3in in the shafts of Norwood Colliery (p. 76). Of the measures above the High Hazles Coal little information can be obtained at the surface between Bolsover and Barlborough. The few exposures that occur are indicated on the maps either by a dip-arrow or by a letter Q (= Quarry), while the following shaft-section of the Bolsover Colliery illustrates the general sequence in the south 1 : — Thickness. Depth. Ft. In. Ft. In. Measures 87 'J Coal 1 3 89 Measures 28 - 2 Coal 1 1 118 3£ Measures with three thin coals _. 180 3 Clowne Coal 3 2i 301 9 Measures with two coals 184 1 Coal 2 2 Clunch 3 G Coal 1 492 8 Measures ... 32 10 Coal •j 4 527 10 Measures 01 5i Coal 1 8 590 114 Measures with High Hazles Rock 01 H High Hazles Coal 3 3 G75 4 1 Prom information supplied by Mr. P. P. Honfton. 25276 76 UPPER CARBONIFEROUS . Thickness. Depth. Ft. In. Ft. In. 64 1 4 1 68 2 210 4 2 6 1 3 1 3 283 31 2 2 4 319 4 62 11 1 6 383 9 112 5 3 8 499 10 116 2 10 618 8 Farther .north the sequence, slightly different, is illustrated by the following section of the strata at Oxcroft Colliery 1 :— Measures Clowne Coal Measures , Coal) Dirt V Locally called ' Waterlodge 'Coal Coal J Measures Coal Clunch Coal Measures ... Coal . •■• Measures with High Hazles Rock (3ft. thick) High Hazles Coal ..: Measures 2nd High Hazles Coal North of Barlborough some old excavations in the lower (Coalpit Wood) of the two woods between Pebleygrove and Comberwood are probably on the horizon of the Furnace Coal, in which case the shallow pits in the upper (Newmans) wood will be on the Sough Coal. The Sough Coal was obtained by opencast in the fields west of the mainroad at High Moor. It crops out in the pit's mouth at the Norwood Colliery, of which the shafts proved the Furnace Coal, 2 ft. 5 in. thick at a depth of 58 ft., and the High Hazles at a depth of 255 ft. from the surface. Beneath the Magnesian Limestone the measures above the Top Hard have been pierced by numerous shafts. The record of No. 1 Shaft of the Sherwood Colliery (Appendix I, p. 129) gives the character of the strata, while the position of the named coals and the thickness of others are illustrated by the sections on PI. VI, figs. 2, 3, 4, 5, 7, 8. Considerable variation in the number, thickness and position of . he coals will be observed, and with the exception of the Higli Hazles their character changes from place to place. The High Hazles, though not at present raised, is stated to furnish a first-class house-coal, burning with a cheerful blaze and leaving little ash. The depths to the coals and thickness of the cover in several of the pits is given in the table below : — Name of Colliery. Permian cover. Clowne Coal. High Hazles Coal. Top Hard Coal. Ft. Ft. Ft. Ft. Creswell, 290 ft. O.D. 220 — . — 1328 Kirkby, 538 ft. O.D 172 — . — 1083 Langwith, 265 ft. O.D 210 1003 1262 1610 Pleasley, 500 f t. O.D 154 — — 1543 Sherwood, 390 ft. O.D 252 781 — 1304 Shirebrook, 340 ft. OD 197 1035 1333 1629 Southgate, 430 f t. O.D 107 262 670 980 Steetley (Sheet 101), 217 ft. O.D. 176 1169 1503 1767 Whitwell, 290 ft. O.D 170 293 619 935 W. G-. 1 Abridged from section in Survey Office. 77 CHAPTER V. PERMIAN. General Account. The Permian is represented in the maps under description hy the following divisions : — Middle Marl and Sands. Lower Magnesian Limestone. Basement Beds : Marl with thin limestones, Quicksand and Breccia. The outcrop of the formation occupies the eastern district, stretch- ing continuously southward from the Yorkshire border, -in Sheet 100, to Kirkhy-in-Ashfield, in the south-east of Sheet 112. North of Mansfield Woodhouse the average breadth of the outcrop is about 4 miles, but south of that place it contracts until less than a mile in width. Its rocks have a general easterly clip, averaging about 2°, but false-bedding is so prevalent in the limestone which is the most conspicuous part of the formation that the local dips can rarely be ascertained. Its western margin forms a prominent escarpment from which the ground falls away somewhat irregularly eastward on the dip-slope, the surface in some parts being a smooth plateau and in other parts moundy and broken, according to the variable characters of the limestone. Relation to Coal Measures. Before the lowest Permian strata of the district were deposited the Carboniferous rocks had undergone most of the movements by which, as described in preceding chapters, their present structure is determined, and had been planed down by prolonged erosion to an even surface which cut across their bedding. That they had been dislocated by pre-Permian faulting also, is evident from the fact that there are many important faults known in the Coal Measures which do not affect the Permian rocks, while the displacement in others, in which there has been a renewal of movement, is very much smaller in the Permian than in the Carboniferous. The extent of the unconformity is further indicated by the composition of the Permian Basement Breccia, which contains fragments of chert, limestone and sandstone that appear to have been derived from Lower Carboniferous rocks, along with bits of slate, etc., from still older formations. Owing, however, to the general parallelism of strike in the two formations in this part of Derbyshire, the great break between them is not always, at first sight, evident. Thus, between the county boundary and Glapwell, not only the strike but also the 25276 P 2 78 PERMIAN. dip of the Permian beds closely conforms to that of the Coal Measures, so that the Basement Beds of the newer formation continue along nearly the same horizon of the Coal Measures; and a similar relation holds good near Kirkby-in-Ashfield. But in the intermediate ground, a, marked unconformity is demon- strable ; for the Permian base in the outlier of Whiteborough rests on Measures below the Top Hard Coal, while at Teversal, 2 miles to the north-east, it is on measures G50 ft. above this coal. Further, at Teversal the Coal Measures are inclined to the north-east at 11 degrees, while the dip of the Permian is east-at about 3 degrees. It is noteworthy that the remnant of Permian forming the Whiteborough outlier is the most westerly point at which the formation is now found bordering the coalfield ; and that the watershed between the north-flowing tributaries of the -Don and the south-flowing tributaries of the Derwent runs westward from ■ near the spot where the exposed coalfield is narrowest. Originally, of course, the Permian extended farther westward, and it has persisted longer on this watershed than in the tracts to the north and south where erosion was more pctive. Thickness. There is much variation in the thickness of all the members of the Permian system within the limits of our district. As a whole, the formation expands greatly along the outcrop from south to north; and it is also known, from the sections in deep shafts and borings, to increase eastwards as it sinks beneath the Trias in the country east of our maps. Near Kirkby-in-Ashfield at the southern margin of Sheet 112, the deposits mapped as ' Basement Beds ' consist of the imper- sistent Breccia never exceeding 4 or 5 ft. in thickness, with 15-20 ft. of overlying grey marl and thin limestones which represent the ' Marl Slates.' 1 In the shafts of Sherwood Colliery, Mansfield, the thickness of the Breccia was 8 ft., and of the grey marl series, 88 ft. Farther north, at Clowne, in Sheet 100, the breccia appears to be replaced by a bed of Quicksand, 20 ft. or more in thickness, and the grey marls above it are 15-20 ft. At the Shireoaks Colliery shaft, close to the Yorkshire border just 'outside the eastern edge of Sheet 100, the basal sandrock was ] ft. 8 in. thick, and the marly series, 54 ft. 2 The Magnesia n Limestone, where it enters our district on the south is probably not more than 50 ft. thick. At Sherwood Colliery, its thickness is 142 ft. ; and at Shireoaks Colliery, 103 ft. The Middle Marl and Sands in the south of our district, where they consist mainly of red marl, range in thickness from 10 ft. to 20 ft., but appear to be practically absent from Mansfield northward for "2 or 3 miles. They reappear in stronger force and with sandy intercalations north of the Poulter valley, and are •In the map to the south (Sheet 125), these ' Marl Slates,' on account of their limited outcrop, were not shown separately from the Magnesian Limestone. 2 .T. Lancaster and O. C. Wright, ; On the Sinking of Shireoak Colliery, Worksop,' Quart, down. Genl, Soc, vol. xv. p. 138. GENERAL ACCOUNT OF PERMIAN. 79 probably not less than 60-80 ft. thick in the neighbourhood of Holbeck. The Shireoaks section started below the top of the series, and passed through 45 ft. 8 in. of these beds. Fossils. In the Permian rocks as a whole there is a singular paucity of fossils. None have yet been found in the Middle Marls of our area. They are usually absent also from the main mass of the Magnesian Limestone which, however, occasionally contains obscure casts of shells and, in a sandy bed at Hock Valley Quarry, Mansfield, has yielded some casts of reptilian footprints, some of which are now preserved in the museums of Nottingham and Manchester. These footprints have been described by Mr. G Hickling, who recognizes several distinct forms 1 , the larger being referred to as " Chelichnoid forms." In the thin limestones and their associated marly beds below the main dolomitic limestones, organic remains are not infrequent, though generally ill-preserved. From these beds the following species were collected during the course of the survey, and the specimens are preserved in the Pakeontologieal Department of the Survey. Species. Localities. cf. Astarte tunstallensis King... Railway-cutting -| mile E. of Tever- sal Sta. Bakevellia antiqua (Miinst.) ... ,, ,, ,, W. of New- bound Fm. cf. Gardioinorpha modioli forrnis „ ,, ,, ,, ,, (King) Lima peruviana King ... ... Sherwood Colliery Shaft, Mansfield. cf. I'iciiiDpliorus custatus ,. ,, ,, ,, ; (Brown) and last mentioned Railway- cutting. Schizodus truncates King ... Herrod's Hill, near Hucknall-under- Huthwaite; also doubtful speci- mens from Sherwood Coll. Shaft, and last-mentioned Railway-cut. cf. Sulrmi/a biarmica de Vern. Sherwood Coll. Shaft. Also Schizodus?, crinoidal fragments and plant-remains, from Fackley Hill, near Stantonhill. Origin of the Permian Deposits. The composition and distribution of the Permian deposits indicate that they have been accumulated in a shallow gulf or inland sea. The Breccia and Quicksand at the base of the forma- tion were probably shore-deposits which were afterwards covered by the grey marl and limestone when the sea spread farther west- ward over the subsiding land. The variable character of the Magnesian Limestone, the prevalence of false-bedding and the intercalation of sandy beds show that the sea remained shallow and disturbed by currents in this area throughout the period. The dolomitization of the limestone and the peculiar facies of 1 ' On Footprints from the Permian of Mansfield (Notts.),' Ijmirt Jnnnt, (ieol. Soc, vol. lxii, 1906, pp. 125-31 ; and ' British Permian Footprints,' Mem. and Proe. Manchester Lit. and Phil. Soc, vol. liii, pt. iii, no. 22, 1909. 80 PERMIAN. the scanty fauna point to a concentration of dissolved salts in the waters and suggests that the sea became land-locked and under- went partial desiccation under arid conditions of climate. G. W. L. and J. B. H. Basement Beds. In passing- northward along the Permian escarpment from the southern edge of Sheet 112, we find the first clear exposure of the Basement Beds in the cutting of the Midland Eailway J mile NW. of The Grives. The bottom bed, here seen in a good section resting on Coal Measures, is described by W. T. Avelme 1 as "a calcareous breccia, containing- pebbles of chert, quartz, and sandstone, some of the latter pebbles being red." It is only a few feet thick, and is not continuous, thinning- out southward. The slopes rising above it appear to contain grey clayey beds, which are not, however, clearly exposed. The breccia was also seen in a small pit -| mile SE. of Kirkby- in-Ashfield Church, and in the railway cutting due S. of the church. In the shafts of the Sherwood Colliery, Mansfield, where, as already mentioned, it attained the exceptional thick- ness of 8 ft., the" rock-fragments of the breccia were larger than usual, frequently exceeding 2 inches in diameter. The beds above it at the outcrop in the southern district consist of thin limestones almost free from magnesia, with intercalations of grey mudstone. But the series is very variable and sometimes sandy, as at Fackley Hill, west of Skegby. The limestone bands generally contain poorly-preserved molluscan fossils, and the grey muddy beds yield carbonized bits of plants. The beds are exposed in a road-cutting at Fulwood and in lanes crossing the outlier at Hucknall-under-Huthwaite. The best section of the series in this part of the district is that of the Mid. By. cutting, a mile SW. of Pleasley Station. R. L. S. A partial analysis of rock from one of the limestone bands in this cutting, carried out in the Chemical Laboratory of the Survey, gave the following results : — Residue insol. boiling dil. HC1, ignited ... 1-50 FeO -57 Traces of P.,O r , Al o 3 and Fe.,0 3 -11 CaO ... " ... " " 54-54 MgO -20 Calculating all Fe, Ca and Mg as car- bonates : — Residue (as above) .. 1-50 FeC0 3 •82 CaC0 3 97-32 MgC0 3 •50 Traces of Fe a O a , etc. •11 Total 100-25 Analyst : E. G. Radlet. 1 ' Geology of the Country around Nottingham,' Mem. Oeol. Surv., 2nd ed. 1880, p. 12. PEEMIAN BASEMENT BEDS. 81 Tie grey marly beds appear to occupy the floor of the Medeu valley at least as far east as the Mid. By. Bridge, \ mile NE. of Pleasley, and have caused much slipping of the limestone on both sides of the valley. There are no actual exposures of the clays in the valley, but their position is indicated by the numerous springs issuing from the base of the limestone. The record of the Pleasley Colliery section is difficult to inter- pret, but it mentions a "brown mingled rock," 1 ft. thick, at a depth (from surface) of 154 ft., which suggests the presence of the breccia. If this inference be correct, the Permian base should lie about 40-50 feet below the floor of the Meden valley at Pleasley. The clayey ground at the bottom of the small valley at Stony Houghton, shown as an inlier of Coal Measures on the previous ' Old Series ' map (82 SE.) is probably due to the emergence of the Permian Basement Beds, though there is no exposure, except a foot or two of weathered grey clay at the side of the main road west of the village. Limestones which probably belong to this division are seen in old quarries at and around Stony Houghton, in which traces of shells are abundant, but too ill-preserved for identification. q. W. L. The Basement breccia is seen again at Rowthorn and Glapwell. In the railway-cutting at Rowthorn (Hardwick) Station, the breccia-band is about one foot thick and consists of angular frag- ments of sandstone, limestone (probably Carboniferous Limestone), quartzite, etc., less than an inch in diameter, set in a sandy calcareous matrix. In the road-cutting between Glapwell and Glapwell station the breccia is only 6 inches thick and the angular fragments are smaller than at Rowthorn. Although several other roads intersect the horizon , the breccia is not visible in them, so that the bed is either not continuous or very thin. Fragments of the breccia were noticed on the spoil-heap of one of the air-shafts of the Bolsover Tunnel on the Chesterfield and Lincoln Ry. 1 North of Teversal, the Basement Beds above the breccia, seldom over 30 ft. thick at outcrop, usually rise abruptly above the underlying Coal Measures and form a scarp-face crested by the Magnesian Limestone. Though variable in composition, the lower part consists generally of pale-blue or grey clays furnishing a pale clay-soil indistinguishable from that of the weathered Coal Measure shale, so that the two formations are not separable along the grassed slopes of the escarpment. About 12 ft. of grey clays are seen above the breccia in the railway cutting at Rowthorn. A section revealed in a deep drainage-trench below Hardwick Old Hall showed Magnesian Limestone passing down into about 15 ft. of thin limestones with red marl-partings, and these resting on thin calcareous flags with carbonized plant-remains. The base of the Permian was not 1 The absence of any mention of the breccia in the records of these shaft- sections led Mr. Fox-Strangways to suppose that it did not occur here : see Quart. Journ. Geol. Soc, vol. liv, 1898, p. 161. 82 PEHMIAN. actually exposed, but the grey clays and breccia, if present, could not be more than a foot or two thick, so that the whole of the Basement Beds here are not more than 25 ft. thick. Similar calcareous flags and thin limestones beneath the main Magnesian Limestone are seen in the road-cutting leading from Bolsover to the Great Central Railway Station. W. G. Further north, the clayey series is well exposed in the two rail- way-cuttings at Clowne; also in clay-pits north-west of Barlborough Colliery, and on the west side of Barlborough; and in the pit south of Pebley Pond from which the underlying Quicksand is dug. In the railway-cuttings west of Clowne these beds consist of grey shales and mudstones, both containing plant-fragments, surmounted by thin limestones with shale-partings. Their thick- ness may be from 12 to 18 ft., but their upper limit is somewhat indefinite. ' Quicksand.' — In the neighbourhood of Clowne and thence northward to the Yorkshire border, the base of the Permian takes the form of semi-coherent sands which, as previously mentioned, appear to replace the breccia of the country further south. For the most part the material is a sharp, rather fine-grained, quartz- sand of a pale yellowish colour, sometimes with orange and red patches, and having the consistency of soft sandrock, readily crumbled, but in places indurated with calcite, and occasionally studded with harder rusty brown pellets, about \ inch diameter, cemented by iron oxide. The deposit is frequently cross-bedded and is evidently very variable in thickness, but its outcrop is much obscured by down-creep of the overlying clays. Its junction with these clays is seen in a cutting on the Midland Railway at Clowne and in a large sand-pit south of Pebly Pond ; and its boundary with the underlying Carboniferous rocks may be fixed within a few feet at Barlborough Colliery where the latter consist of red clay. A small outlier of the Quicksand lies immediately SW. of Barlborough Colliery. A cutting of the Great Central Railway has been made at its exact margin so that the Quicksaud is exposed in one bank and Carboniferous red clay in the other. The best sections of the Quicksand are those in two large sand- pits, situated, respectively, S. of Barlborough Colliery and S. of Pebley Pond, which show a thickness of about 20 ft. of sand. In the latter the sand is sufficiently cohesive to be tuuneled from beneath the overlying clays, and to stand firmly in the roofs and walls of the old workings. J. B. H. Lower Magnesian Limestone. Genebal Chabacteks. The Magnesian Limestone shows great variation in all its characters in different parts of its outcrop, so that generalized description is difficult. Where it enters our district, in the south of Sheet 112, the formation consists mainly of pale buff or yellowish dolomite with distinct and fairly regular bedding ; but LOWER MAGNESIAN LIMESTONE. 83 with the expansion of its outcrop and thickness north of Sutton- in-Ashfield, it takes on greater complexity both in composition and structure, being in some portions thin and flaggy, with partings of red marl or clay, and in other, massive, or irregularly cross-bedded, often containing a very considerable admixture of sand. North of the Meden valley, a rough threefold division is generally apparent, the lowest and highest parts of the limestone being composed mainly of flaggy beds with comparatively regular stratification, while the middle portion is characterised by false bedding and the presence of dome-shaped masses of dolomite with obscure stratification. These differences are reflected in the shape of the ground, the upper and lower flaggy beds, by their regular weathering, producing a smooth surface, while the middle beds form moundy irregular country. These sub- divisions are not, however, sharply separable; and they fade out north of Whitwell. In composition the Magnesian Limestone is occasionally almost a pure dolomite, but more frequently it contains calcite in varying proportion, as well as much sand and other impurities. Except in the finer and more compact varieties of the rock, the rhombic crystals of dolomite of which it is mainly composed are apparent to the unaided eye. Partings of red clay are not in- frequent between the beds of dolomite, and become thicker and more numerous in the upper portion as the junction with the Middle Marl Series is approached. The patch of marl shown on the map (Sh. 1.12) at Eosedale Wood, near Scarcliffe, appears to be a thick lenticle intercalated with the limestone. In the neighbourhood of Mansfield the upper part of the Magnesian Limestone becomes increasingly sandy until, in the celebrated red and white building stones of that locality, silica comprises approximately a moiety of the rock. 1 This dolomitio sandstone is quite local, being replaced a little to the north, at Mansfield Woodhouse, by a fine-grained saccharoidal dolomite. In the Pleasley district sandy beds occur among the massive strata forming the central division of Magnesian Limestone, being best seen in the lowest crags of Pleasley Vale, between the mill-pond and Meadow Houses. 1 The following analyses of the Mansfield Sandstones are given in ' Explana- tion of Sheet 82 SE.' Mem. Geol. Surv., 2nd edition. 1879. pp. 10, 12. White Sandstone : — Silica 51-40 Carbonate of Lime ... 2650 Carbonate of Magnesia 17 - 98 Iron, Alumina 1*32 Water and loss 2-80 100- Red Sandstone : — Silica 49-4 Carbonate of Lime ... 26 - 5 Carbonate of Magnesia 16-1 Iron, Alumina 32 Water and loss 4'8 100- 84 1>E&MIAN. It is improbable, however, that the sandy beds form a con- tinuous belt as supposed by Prof. J. P. Blake 1 , and more likely that they occur in lenticles that formed local sand-banks in the Permian sea, as mentioned by Dr. R. L. Sherlock 2 . Sandy beds are likewise met with at Scarcliffe where a specimen yielded 25 per cent, of sandy residue. It is only in the more highly arenaceous varieties, or those in which the grains are large, that the sandy character can be detected in the field, owing mainly to the fact that the sand-grains are usually incorporated within the dolomite-crystals. One of the most striking structural features of the Magnesian Limestone, especially of its middle portion, is the irregularity of its bedding. Even where it possesses a flaggy structure, not only is there often cross-bedding within the individual flags, but the flags themselves are frequently truncated at various angles by cross-bedding with other flags on a larger scale. An excellent section displaying these characters occurs in the railway-cutting immediately east of Scarcliffe Station, described and figured by C. Fox-Strangways 3 . In association with this evidence for strong current-action during the deposition of the limestone, is the curious prevalence, in the middle portion of the limestone, of arched or elongated dome-structure with qua qua-versal dips. These domes are mainly composed of massive dolomite with obscure bedding and cross-becldinn' ; their axes generally strike approximately north- and-south, and they give rise to long hummocky features. They vary in size' and declivity of slope, the latter occasionally ex- ceeding an angle of 20°. That these structures are not the result of folding, but mark an abnormal method of deposition, is in some instances established by the fact that the actual base of the dome is seen resting on horizontal and undisturbed flags, as, for example, in the railway-cutting south of Tipper Langwith 1 - In these mounds the rock is generally of closer grain and more com- pact than usual, and most of the larger quarries of the district are worked in this part of the limestone. In parts where the Magnesian Limestone is of irregular com- position and open texture, it develops a peculiar ' honeycombed ' structure on weathering, as is well shown in Clowne Crags and in the Midland Ey. cuttings between Clowne and Creswell. This type of weathering frequently brings out a pisolitic structure in some of the bands, of which there are conspicuous examples in road-cuttings \ mile NE., and 1 mile S., of Whitwell, and in the large quarries E. of Barlborough. Occasionally the weathered rock shows a brecciform structure, with angular blocks of dolomite embedded in a dolomitic matrix, which is exemplified in many places in Sheet 100, ami strikingly in the scarp at Palterton village. 1 Victoria County History of Nottingham, vol. i, chap, i, p. 190. 2 ' The Relationship of the Permian to the Trias in Nottinghamshire,' Quart. Journ. Oeol. Soc, vol. lxvii, 1911, p. 88. 3 Quart. Journ. Geol. Soc, vol. liv., 1898, p. 161. 4 § mile WNW. of Langwith Junction. "2. s "3 o O Q .a 3 Ed O Z O H W & m « o w g o o LOWER MAGNESIAN LIMESTONE. 85 The beddiug-plaues of the Magnesiaii Limestone, especially in the flaggy portions, commonly exhibit strong ' suture-structure,' by the interlocking of sharp projections on opposing surfaces. Both bedding- and joint-planes are frequently coated with unctuous green clay or shale which often shows slickensides. Solution-cavities and rubble-filled joint-fissures are prevalent in all parts of the Magnesian Limestone, but especially in the massive beds. They are well seen in most of the railway- cuttings and at Creswell Crags (Plate V.) and the crags of Pleasley Vale. The fissures are usually filled with brown earthy loam often mixed with a few pebbles, derived from the Bunter, which have worked down from the surface, sometimes to a depth of 30 or 40 feet. In some eases the joint-fissures are occupied by dolomitic sand and in others by a red marly substance. In rare instances the joints are infilled with fine-textured veins of calcite. Mode of accumulation. — There has been much discussion whether the dolomite was originally deposited as such owing to some peculiarity in the chemical composition of the Permian sea, or whether the rock was at first a normal limestone and after- wards converted by magnesian infiltration. Sedgwick 1 considered that a part of the magnesian earth had been mechanically derived from the dolomitic beds in the Car- boniferous Limestone lying to the west, with subsequent enrich- ment owing to the removal of carbonate of lime in solution. Sorby, in his celebrated address on the microscopic structure of limestones 2 , pointed out that many of the beds in the Mag- nesian Limestone had originally contained normal oolitic grains and shell fragments, but that often the whole rock was so thoroughly crystalline that nearly all trace of its original structure was lost. He concluded that the dolomite had prob- ably a combined organic and chemical origin, being partly a genuine replacement and partly the result of chemical pre- cipitation. The mechanical accumulation of the original material of the dolomite is sufficiently obvious from the nature of its structures already described. That its constituent crystals, however, were secondary to at least some extent is certain, as under the micro- scope they are not only seen to interlock, but they likewise incorporate grains of quartz-sand, and they show no trace of attrition. J. B. H. Details. Mansfield District. — South of Sutton-in-Ashfield (Sheet 112), where the limestone is thin and of fairly uniform character, it is of the Nottingham type, composed of rhombs of dolomite, set in a calcareous cement, and possessing flaggy structures. North of this place, as the limestone becomes thicker, it shows greater diversity, and on approaching Mansfield the red and white dolomitic sandstones make their appearance as already alluded to. The dolomitic sandstone is quite local, being replaced farther north, 1 ' On the Geological Relations and internal Structure of the Magnesian Limestone,' &c, Trans. Geol. Soc. (ser. 2), vol. iii, 1835, p. 123. * ' Anniversary Address of the President,' Quart. Journ. Geol. Soc, vol. xzxv 1879, p. 85. 86 PERMIAN. at tlie Mansfield Woodhouse quarries, by a creamy dolomite, which occurs in knoll-like masses with qua qua-versal dip, forming hills surrounded by flatter land with flaggy dolomite. As far north as the latitude of Mansfield the dolomite has a steady dip at an angle of one or two degrees to the east, and forms comparatively flat country; but after the appearance of the abnormal Mansfield deposits the surface becomes undulating. The Erewash rises at The Grives and flows through large quarries, where the dolomite is excavated for lime and also to some extent for rough building. The Great Central Railway cutting, NW. of the tunnel through the Itobin Hood's Hills, is 950 yds. long and shows the whole of the Mag- nesian Limestone, excepting the basement beds. Near the tunnel the dip is rather more than one degree to the SE., but beyond the junction with the Great Northern Railway the dip becomes less. The rock is of the usual flaggy type, the beds being as much as 2 ft. thick near the bottom of the cutting but splitting into thin flags at the outcrop. Near Kirkby Station there are two quarries, one disused and the other worked for lime. The latter may be described briefly, as typical of numerous small quarries scattered over the outcrop. It is about 15 ft. deep and is in flags of dolomite about 3 ins. thick near the top but becoming thicker downwards. The calcareous cement becomes dissolved on weathering and the small rhombs of dolomite form a sand. The Great Northern Railway runs in a shallow cutting in the limestone, between Kirkby and Sutton, usually showing 3-4 ft. of rock, but at the latter place the cuttings become deeper, and from here to Skegby there is a continuous section of about 20 ft. of limestone. A few hundred yds. S. of Skegby Station, a band, l|-2 ft. thick, having an ill-defined brecciated struc- ture and containing a little barytes, makes its appearance and can be followed for 300 yds. At Baxterhill a quarry, about 20 ft. deep but now being filled up, shows a passage downwards from rather sandy dolomite into a fine-grained ferruginous dolomite resembling a soft sandstone. The insoluble residue from this rock was examined by Mr. H. H. Thomas, who found it to consist mainly of chert, detrital quartz and white mica, with grains of garnet, chlorite, tourmaline, anatase, and zircon. Its horizon is a little above the fossiliferous basement beds. At the pumping station adjoining the branch-railway leading to King's Mill at Sutton, a boring reached a rock described as a mixture of limestone and grit. If this indicates the base of the limestone, as seems probable, the limestone at this locality is 65 ft. thick. The brickyard, 400 yds. NE. of King's Mill, reveals a trough fault, bringing in the Permian Marl. The north branch of the fault is shown in the Midland Railway cutting as a shattered belt of limestone containing barytes, a few crystals of galena, and occasional green specks which may be copper. The road under the railway (Sheepbridge Lane) shows 20 ft. of limestone covered by Permian Marl. The limestone is very sandy owing to the oncoming of the dolomitic sandstone phase. At the Brick Works, £ m. SW. of Mansfield Station, the junction of the Permian Marl with the limestone can be seen. The latter has become a yellowish dolomitic sandstone which is whiter after weathering. The bottom of the quarry is under water, but 25 ft. of rock is visible. Lindley's_ ' White Sandstone ' Quarry, situated i m. S. of Mansfield Station, is in the same stone and is from 30-40 ft. deep. The bedding is very irregular and the rock is composed of short thick lenticular masses from 1-6 ft. thick or even more. The limestone has an undulating top, covered abruptly by Permian Marl. In the town of Mansfield the rock is seen in an old quarry opposite St. Mark's Church and in the banks of the Maun in the Recreation Ground. Between Leeming St. and the Church, 4 ft. of yellow flaggy sandstone dipping to the SE. is to be seen. In the valley of the Maun at Mansfield, E. of the railway, known as Rock Valley, there are large quarries in a red dolomitic sandstone. The quarry described by Sedgwick and Aveline has been built against, and the one now worked is on the opposite, or west, side of the valley." Aveline's surmise — that the red and white sandstones might be the same DETAILS : MANSFIELD DISTRICT. 87 bed 1 is not borne out by the present section, which shows some 30 ft. of yellow limestone above the red sandstone, with a passage between them, while the white sandstone, as already mentioned, is surmounted directly by Permian Marl. It appears therefore that the sandy phase does not continue at a constant horizon. This is confirmed by the evidence of the other quarries in the dolomitic sandstone. At the first milestone on the road to Chesterfield the red sandstone is worked in a quarry 70 ft. deep. The bottom of the quarry (under water when not actually worked) is said to be a bastard limestone, which seems to be the passage-bed of the sand- stone downwards into normal dolomite. At the top of the quarry it passes upwards into yellow sandy dolomite. Ripple-marks were seen on sandstone from a depth of 60 ft. There is a small quarry by the roadside near Debdale Hall, which is 70 ft. deep, and shows a section quite similar to that in Chesterfield Rd. It appears likely, therefore, that the dolomitic sandstone might be met with at an increasing depth (a depth, however, diminished by the rising dip) in the direction of a line drawn from Mans- field towards Pleasley Park. In the country from Pleasley and Penniment Houses eastwards to Mans- field Woodhouse the outcrop is characterised by undtilations which, although irregular, have in general north-westerly axes. On the tops of the ridges it is not uncommon to find limestone ploughed up. Near Mansfield Woodhouse there are numerous exposures of limestone, including large quarries close to the railway station, and others are now being filled in and built upon (e.g., Sherwood St.). The quarries show 20-30 ft. of limestone of the creamy compact type, but less saocharoidal in texture than the rock now quarried a little further north. One of the active quarries, 450 yds. NW,' of the Church, shows about 50 ft. of compact creamy dolomite, often with minute black specks, which are probably manganese. The rock shows a vague lenticular structure, but the absence of distinct bedding-planes is a striking feature. The surfaces are greenish and curiously fretted. A similar quarry, 25-30 ft. dee]), is situated 200 yds. farther N. In both cases the rock forms a hill rising out of the flat of flaggy limestone. The flaggy variety can be seen in an old quarry, 300 yds. NE. of the last mentioned quarry. The creamy dolomite contains curious straight cavities called ' gulls,' about 1 in. wide and 3-4 ft. long, which run through the rock in various directions. An old quarry, J mile NW. of the Milehill Farm, on the road from Mansfield to Pleasley, is in the creamy dolomite, and also shows a domed structure with a .dip increasing from 15 to 30 degrees in all directions. On the south side of Mansfield Woodhouse, close to the Bunter boundary, some remarkable ' concretions,' about the size of marbles and perfectly spherical, were found in the soil. Their surfaces are slightly rough, showing evidence of crystalline structure. These ' concretions ' have not been found in place. A small quarry, 600 yds. WSW. of Park Hall, is in the highest beds of the limestone and shows dolomite intermediate in character between the flaggy and compact types and with an anticlinal structure at the north end, but with comparatively low dips. North of the Meden, 450 yds. SE. of Warsop Park Farm, is a small disused quarry showing 12 ft. of flaggy limestone with a gentle anticlinal axis running NE.-SW. North of the farm a monoclinal fold appears to carry the limestone sharply below the Permian Marl which forms a lower flat on the eastern side. p L g Pleasley District. — In the basin of the River Meden between Pleasley and Sookholme, the Magnesian Limestone is exposed in a series of sections which reveal practically the whole of the formation. The cuttings of the Great Northern branch-railway are well-nigh continuous from near the base of the limestone on the valley-slopes north of Newbound Mill to its top at Shirebrook and Langwith. The Midland Railway-branch has like- wise some long cuttings SW. of Pleasley Station and farther eastward ' Explanation of Quarter Sheet 82 SE.,' Mem. Geol. Suit. 2nd ed. 187H, p. 1 1. 88 PEEMIAN. near Northfield House, as well as another long series on the line between Mansfield Woodhouse and Langwith. The ravine of the Meden is also fringed with high crags in places on both sides between Pleasley and Littlewood ; and there are quarries, road-cuttings, and other artificial excavations in the rock in nearly all parts of the district. The lowest part of the limestone is well seen in old quarries in and around Stony Houghton. It is mostly calcareous or only slightly dolomitic, and occurs in thin irregular beds, frequently nodular, and grey, pinkish, or red in colour, with partings of red shale or clay. These beds are probably equivalent in part to the ' Marl Slates ' of the Kimberley dis- trict in Sheet 125. x Traces of small shells are abundant in some of the grey limestone bands, but are too imperfectly preserved for identification. The character of the beds is illustrated by the following section, visible in an old quarry at Houghton Bassett, immediately west of the farm- steads. All the beds are irregular and lenticular when traced horizontally. A similar section is exposed on the opposite (south) side of the valley at Stony Houghton in another old quarry now converted into cottage- gardens. Section in Old Quarry at Houghton Bassett. it. Irregular flaggy beds of pale buff dolomitic limestone, stained red in places ■•• ••• ■•■ ••• 5 Lenticular and nodular thin flaggy bands of dolomitic limestone, red and greenish mottled, with red marly top containing flat dolomitic concretions ... ... ... abt. 2 Massive lumpy nodular bed, decomposing to brown dolom- itic sand ... ... ... ... ■ • ■ ■■ ■ ... 3 to 5 Thin concretionary flags, red and marly, with partings of marl 1 to 2 Nodular pale pinkish and grey limestone, probably only slightly dolomitized ... ... ... ... ... ■•• +3 17 Thin flaggy red-stained beds, similar to those of the above section, are sparingly exposed along the roadside in Pleasley village, on the left side of the Meden valley ; and again by the road, 100 yds. NE. of Pleasley Church, where they are disturbed through slipping. Above the lower flaggy beds the Magnesian Limestone becomes more massive and irregular in its bedding and more thoroughly dolomitic. In this part it exhibits remarkable cross-bedding, and appears often to have been heaped up in dome-shaped masses with qua, qua-versal dips, so that the true dip of the formation as a whole is rarely distinguishable in isolated sections. The deep cuttings of the Great Northern Railway between Pleasley and Shirebrook reveal n succession of these cross-bedded undulating domes, with intercalated lenses of more flaggy beds which seem often to have been deposited in the hollows between the domes. Occasionally, as in the neighbourhood of the fault NW. of Stuffynwood Hall, there is some doubt whether the undulations are original, or are slight secondary contortions due to later disturbance ; but usually where the sections are clear, their original character is evident. In a few places these dolomites become sandy, and a dolomite of this type was formerly quarried in Pleasley Vale at the foot of the crags at Meadow Houses, where the main bed has a reddish tint. The moundy ground formed by massive irregular beds of the limestone occupies a broad belt west of the Mansfield and Worksop branch of the Midland Railway, stretching to the neighbourhood of Pleasley and Stony Houghton. The rock is extensively quarried both for building-stone and for lime-burning. One of the largest quarries is that of the Pleasley Junction Lime Works, half a mile north of Mansfield Woodhouse Station, where the rock is a massive yellow dolomite, with a rude anticlinal or domed structure, revealed to a depth of 50 or 60 ft. 1 See ' The Country around Nottingham ' ; Explan. of Nottingham District Sheet, .Ifrm Geol. Surv., 1910, p. 26, DETAILS : LANGWITH DISTRICT. 89 The top beds of the Magnesian Limestone are clearly exposed in the Midland railway-cuttings between Mansfield Woodhouse and Langwith, and in a few quarries east of the railway. They are for the most part thinly- bedded and flaggy, with occasional thin partings of red marl, especially in the upper part. They are sometimes cross-bedded, but not to the same extent as the main mass of the limestone beneath them, and they appear to level up and in some cases to abut upon the domes of the lower beds. Their thickness is therefore irregular but probably does not often exceed 20 or 30 feet. The surface loses its hummocky character where these beds set in, and forms a smooth gentle dip-slope, mostly covered with a red clayey soil derived partly from the decomposition of the dolomite and partly from the relics of overlying Permian Marl. G. W. L. Langwith District. — The Midland Railway cuttings between Shirebrook Station and Langwith Junction afford excellent sections of the upper part of the dolomite and its passage into the overlying Middle Permian Marl. Immediately north of Shirebrook Station the dolomite is cream-coloured and flaggy, with occasional greyish-green shaly partings, about J inch thick. This is succeeded by 5-6 ft. of grey shaly dolomite which often assumes a red colour and weathers into red clay-soil like that of the over- lying marls. In the cutting of the Great Central Railway between Shirebrook Station and Warsop Junction the beds show similar relations, but the top of the dolomite here forms a gentle dome and the overlying regular fissile beds strike against the slopes of the dome, giving a misleading appearance of unconformity. Between Langwith Junction and Scarcliffe the same railway traverses the whole of the Lower Magnesian Limestone, and the various cuttings reveal practically the entire sequence from top to bottom. The fissile beds marking the passage from the dolomite to the marl are well seen at Langwith Junction. These are underlain by flaggy and massive dolomite, fairly thick-bedded with strong false-bedding. Towards the footbridge, 700 yds. W. of the station, the upper part of the dolomite is thinner bedded and breaks up into a red subsoil like the passage-beds. A quarter of a mile further to the west there is an arch of false-bedding with dips of 12° east and 10° west. The dome is underlain by flat flaggy dolomite, so that its depositional origin is evident. Still further west, at the last bridge in the cutting, Fox-Strangways noticed a fault bringing down red sandy marl on the west side. 1 This, however, is now concealed by vegetation and talus. In the cutting E. of Scarcliffe Station the false-bedding, as pointed out by the same observer, is of a most pro- nounced type. Near the top of the cutting there are a few feet of red shaly dolomite interposed between dolomite of normal type. On the W. side of the cutting the sandy dolomite previously described (p. 84) is met with, and is further exposed in the road-cutting leading to the village. It is from buff to red in colour and is false-bedded. Another cutting commences to the west of the station. The first beds met with are these red sandy false-bedded dolomites; then follow more regular beds which are likewise sandy and are mainly red but in places streaked with buff, and these have thin partings of shaly dolomite. Below is thin- bedded hackly dolomite, grey to buff in colour, and of fine texture, with ;i dip of about 2° east. These extend to the footbridge, and from thence to the entrance of Bolsover Tunnel there is a gradually descending section. Beyond the footbridge, mottled beds again appear, some of which are more fissile and are evidently near the base of the main limestone, as the lowest beds seen are grey limestones without false-bedding, like those associated with the Lower Permian Marls. In the paper referred to above, Fox- Strangways gives sections of the three ventilating shafts of the tunnel, which show, respectively, from E. to W., 55 ft., 61 ft., and 22 ft. of limestone, the tunnel itself being almost entirely in Coal Measures. 1 ' Sections along the Lancashire, Derbyshire and Rast Coast Ry.. &e.,' Quart. Jonrn. Geol. Soe., vol. liv, 1898, p. 161. 90 PEHMIA2T. In the disused quarries at Limekiln Field, north of Bolsover, the flaggy nature and varying texture of the individual beds of the Magnesian Limestone are well shown. At one place the section, from surface down- wards, is: — Yellow flaggy limestone ... ... • ■ • ■ • ■ 5 ft. Grey flaggy limestone ... ... ... • ■ ■ ■ • • 2 , , Brecciated limestone ... ... ... •■• •■• 3 » Bed limestone with thin red marl-partings ... 5 ,, Various types of the dolomite have been quarried at Shirebrook. About £ mile NW. of the Midland Bailway Station there is u, quarry opened on the upper flaggy dolomite, traversed by a small north-westerly fault. At Garters Lane a quarry shows very solid dolomite of close texture in which there is strong false-bedding at angles from 10° to 15° SW. At Stinting Lane, opposite the Vicarage, a dome is clearly seen in section, and this structure also pervaded the quarries adjoining. Excellent sections of nearly the whole of the Magnesian Limestone are also afforded by the cuttings on the two lines of railway between Langwith Junction and Clowne. Proceeding northwards from Langwith Junction the upper beds of the dolomite are well seen in the two parallel cuttings. The rock is coarsely flaggy and fairly regular, and is gashed by numerous solution-cavities filled with reddish clay. Opposite Upper Langwith a patch of the overlying Middle Marl has been let down by a fault. North of the Poulter, deep cuttings in the dolomite are again met with, the south end of the cutting of the Great Central Bailway showing massive and flaggy beds with very irregular false-bedded structures. About 100 yards further north the cutting reveals a lenticle of red shaly dolomite from 2-6 ft. thick and extending for 90 yds., and this is overlain by dolomite with regular bedding. The shaly dolomite is like that which forms the passage beds into the Permian Marl, but lies in a shallow basin some distance below the top of the Magnesian Limestone. For \ mile further N. the cutting again shows massive false-bedded dolomite, and then the shaly dolomite again appears, from a few inches to a foot in thickness, dividing the massive and irregular dolomite below from the more regularly strati- fied dolomite above. In the cuttings of both railways S. of Creswell Colliery, the dolomite is massive, rudely flaggy, false-bedded, and shows dome-structures. Further north the rock is of the upper flaggy type and passes beneath the Middle Marl and Sands at Creswell. In a small cutting leading from the Midland Bailway to Creswell Colliery, 250 yds. NNE. of the latter, a section shows 5 or 6 ft. of red and grey mottled sandrock, much decomposed, resting on solid massive dolomite and overlain by a thin flaggy dolomite. The latter is rich in calcite, while the mottled sandstone is dolomitic, and was probably originally a calcareous sandstone. Clowne District. — Between Creswell and Clowne the entire sequence of the limestone is seen immediately NW. of Creswell Station (G.C.By.), the cutting shows the junction of the dolomite with the overlying Middle Marl and Sands. On passing further north-west we see, within the dolomite, beds almost precisely recalling the previously described section two miles to the south in which red sbaly dolomite weathering to a red clay is inter- posed between evenly bedded dolomite above and irregular dolomite below. Thus, in the cutting west of Hazelmere Farm a lenticle of this nature extends for 100 yds. with a maximum thickness of about 6 ft. The best sections of the beds below this horizon are along the Midland Bailway in approaching Clowne, which show dolomite mainly of a flaggy type, but distinguished by brecciated and honeycombed structures (.see p. 84). West of Clowne Station the top of the Basement Beds appears at the bottom of the cutting, till displaced by a small fault. Excellent sections of flaggy dolomite are seen in the vertical craws of Markland Grips and Hollinghill Grips between Creswell and Clowne, and in a quarry adjoining the main road, frds mile NE. of Elmton Lodge. In the picturesque Creswell Crags (Plate V.) the dolomite is a compact light yellowish-brown rock, strongly jointed, but without regular bedding. It is exposed in the gorge for a depth of 50 or 60 ft., and, as mentioned by Aveline, the lowest beds are probably not far above the base of the main MIDDLE MAEL AND SANDS. 91 limestone. The Middle Marl series lying to the west owes its position to afault following the course of the valley above Creswell. This fault has a displacement of 130 ft. in the Top Hard Coal ; and in the Permian its throw is nearly equal to the thickness of the Limestone. The celebrated bone-caves and fissures of Creswell Crags will be described in a subsequent chapter ( P . 105). On the Worksop branch of the Midland Railway, the cutting SW. of the tunnel between Whitwell and Creswell shows a faulted junction of the Middle Marl and Sands with the dolomite. The latter rock is of fine tex- ture with very little false-bedding, but some bands contain pisolitic bodies, and others show honeycombed structure. It does not split readily along the bedding planes, and there is a slightly marked curvature extending the length of the cutting, indicating the oncoming of dome-structures. Similar beds occur on the NE. side of the tunnel, but more flaggy types occur at Whitwell Station, while beyond it a cutting shows the flaggy dolomite over- lain for a short space by the Middle Marl. The dolomite is exposed in many natural and artificial sections around Whitwell. In this district it is frequently disintegrated for a depth of a few feet into a fine sand, which, when of a red colour, is difficult to dis- tinguish from the red sands associated with the Middle Marl. At Bake- stone Moor there are two small patches of red sand and clay, separated on the 6-in. map, that represent the weathering of the dolomite. The breaking down of the dolomite into sand is admirably seen in the banks of the road-cutting of Clinthill Lane, immediately south of Whitwell Wood. The flat lands of Whitwell Common and westward as far as Barlborough are mainly covered with dolomite debris of this nature, and the rock is seldom exposed, except in the quarries. It occupies, however, the face Of the escarpment extending north and south from Nitticarhill, and has been extensively quarried at Barlborough, where it is of the irregular hackly and honeycombed type. J. B. H. Middle Marl and Sands. Ceneral Characters. As far south as Mansfield Woodhouse (Sheet 112) in the area under description, the upper boundary of the Lower Mag- nesian Limestone is frequently beyond the eastern limits of the maps, so that the overlying Middle Marl Series is represented by discontinuous projecting portions of the main outcrop, and further to the west by outliers and patches which owe their position to faulting. South of Mansfield Woodhouse, although the eastern boundary of the Permian nearly everywhere lies within Sheet 112, the Middle Marl is either absent, or too thin to be recognisable, for nearly two miles. At Mansfield, however, it reappears and is continuous thence southward to the southern limits of the map. A similar absence of the Marl in the neighbourhood of Market Warsop, an adjacent area falling within Sheet 113, is referred to by the present writer in the memoir explaining that map as evidence of an unconformity 1 between the Trias and Permian, but Dr. Sherlock, who surveyed the Mansfield district, suggests that its absence from the latter area is due to the oncoming of sandy conditions in the Permian and to the conformable passage of the Marl into the overlying Bunter sandstone of the Trias. 2 North of the Poulter valley the Permian Marl is associated with beds of red sand which indeed often preponderate over the 1 ' Geology of the Country around Ollerton,' Mem. Geol. Surv., 1911, p. 15. 8 ' The Relationship of the Permian to the Trias in Nottinghamshire,' Quart. Journ. Geol. Soc, vol. lxvii, 1911, p. 86. 25276 G 92 PERMIAN. clay. Further south, however, there are no such thick beds of sand associated with the clays, but only thin seams of grey and reddish dolomite sandstone. It has been mentioned in the preceding descriptions that there are in many places clear indications of an upward passage from the Lower Magnesian Limestone to the Middle Marl Series. In some cases, however, the transition is locally abrupt. Where sections are wanting, the boundary between the Marl Series and the Magnesian Limestone is difficult to trace, owing to the top beds of the latter yielding a clayey soil resembling that of the Marl. On the other hand, the sandy intercalations of the Marl Series west of Holbeck are not readily distinguishable from parts of the Lower Bunter, except by their association with thick bands of Marl. For these reasons the boundaries shown on the map are in places somewhat uncertain. Further northward, in Yorkshire, and also eastward, where the Marl has been passed through beneath the Bunter in colliery shafts, gypsum is usually found in association with it. This mineral, however, was not observed in any part of the outcrop now described. The maximum thickness of the Marl Series south of Mansfield does not exceed 20 ft. ; but in the Holbeck district it may locally reach 80 ft. The marly portion has been worked extensively for bricks and tiles at several localities mentioned below. When examined microscopically, its chief component is an extremely fine siliceous silt. J. B. H. Details. One of the best sections of the Marl in the southern district is in the cutting on the Great Central Railway, at the west entrance of the tunnel through Robin Hood's Hills. Here the whole thickness of the formation is seen, from the Magnesian Limestone, on which it rests sharply but conformably, to its indefinite upward passage, through lenticles of sandy marl and marly sandrock, into the Bunter. The marl below these sandy lenticles is 13 ft. thick. The section is figured in the memoir on Sheet 125 (' Geology of the S. part of the Derbyshire, etc. Coalfield,' 1908, p. 116). A recently opened brickyard, 600 yds. N. of the cross-roads in East Kirkby, shows the Marl, about 16ft. thick, with some thin intercalations of green sandstone (' skerries '). A band, 6 inches thick, of green ' fuller's earth ' occupies the base of the section. The fault shown on the map near Sutton Junction is visible in the Great Northern Railway cutting; it accounts for the outlier at Sutton-in- Ashfield. Both branches of the trough-fault NE. of King's Mill can be seen in a brickyard situated nearly in the angle of the trough, and the junction with the limestone is here again visible. The marl, containing three bands of greenish sandy marl, is 17 ft. thick, below 2 ft. of clay- soil. The large outlier of Bunter between Skegby and Mansfield exhibits numerous good sections of the Permian Marl around its margin. At Skegby two brickyards show the whole thickness of the marl— about 17 ft. Three other brickyards between that locality and Sutton Forest Side show similar sections. At the cross-roads, f mile NNE. of Sutton Station, some excavations proved 9 ft. of the marl, resting on the dolomite. In the road opposite the schools, 130 yds. SW. of the locality last named, 6J ft. of marly sand was seen resting on marl, and this sand must fall within the Permian Marl, unless it be Bunter introduced by a fault, of which there is no other evidence. There is a disused claypit at the cross-roads a mile SW. of Mans- field, and the road which runs SE. from this point shows the junction of the marl with the limestone. DETAILS OF MIDDLE MARL. 93 At the brickworks i mile SW. of Mansfield Station, about 14 ft. of marl with fine-grained sandstone is seen, resting on sandy Magnesian Limestone, and at this point sandstone greatly predominates over marl. Only 100 yds. to the north, another section, at the same horizon, shows marl of the more normal type. Crossing the Maun valley, the marl is again well exposed above the white dolomitic sandstone at Lindley's Quarry, £ mile S. of Mansfield Station. At the western end of the present workings the marl is of the usual type, but at the eastern end of the same section it has thinned con- siderably and become more sandy, and the ' skerries ' have increased greatly. If this process was carried a little farther it is evident that the marl series would be represented by sandrock and would be indistinguish- able from the Bunter above ; and it is not improbable that this is the true explanation of the apparent absence of the Permian Marl at Mansfield. The marl shown N. of Mansfield Woodhouse extending past Park Hall is part of a large outlier. The only section in it is in a disused brickyard at the S. end of the park. R I S Between Sookholme Bath and Langwith Junction there is an extensive outcrop of the marl dissected by railway-cuttings which show its passage into the Lower Magnesian Limestone. These junction-beds have already been referred to in the description of the limestone. An excellent section of the marl is seen in the cutting immediately S. of Warsop Cottage The marls are mostly red, but in places grey, especially when adjacent to the dolomitic sandstone bands, which are numerous. To the east of Shire- brook the marls occupy a valley, with the Lower Magnesian Limestone rising above them on either side, their position in this trough being due to two faults of contrary throw. The narrow outcrop of marl beneath the Bunter about a mile SE. of Nether Langwith is imperfectly seen ; a small pit on its course shows sandy marl. The faulted outcrop extending from Upper Langwith to the eastern margin of the map is bounded on its S. side by a fault-scarp of the up- lifted limestone at Boon Hills Wood. The faulted junction is seen on the cuttings of the Great Central and Midland railways at the east of Upper Langwith. In this district, the marl is mixed with red sand, as may be seen in the mill-stream in the Poulter valley S. of Nether Langwith, and this condition henceforward becomes increasingly marked northward to the Yorkshire border. The most extensive outcrop of the Marl and Sands in the district is that represented in the NE. corner of Sheet 112, around the village of Holbeck. There is an excellent section of soft red sandstone in the lane leading SW. from Holbeck Woodhouse, just beyond the margin of Sheet 112, which is described in the memoir 1 on the adjoining Sheet 113; the exposures within Sheet 112 are meagre. A shallow cutting in red sand with sub- ordinate marl is seen in the road 250 yds. W. of Hill Top; and red sand and clay are also exposed about 500 yds. SW. of that locality. There is likewise <*• o,t :5,- 1. Surface-soil 3. Cave-earth ; bones and imple- ments Engraved bone at +• 4. Mottled bed, light brownish matrix ; bones and implements 5. Red sand ; bones and quartzite implements ft. in. Fig. 12.— Section of deposits in Church Hole, at 31 ft3 in from Gate (from same). ft. in. 1. Stalagmitic breccia, with charcoal, worked flints, and bones 2. Reddish cave earth, with charcoal frag- ments, layer of ditto, flint implements, bones, and blocks of limestone 3. Lighter cave-earth, with similar remains 1 ft. 8 ins. to 2 4. Mottled cave-earth, more sandy and mottled, with small angular fragments of friable limestone ; quartzite and flint implements, and bones 5. Light-reddish sandy earth ; bones, but no implements 6. White calcareous sand and rock. 1 2 2 3 25276 H 108 SUPERFICIAL DEPOSITS. The surface-soil of both caves yielded a few Romano-British and later relics, with bones of domestic animals, etc. The underlying rave-earth and red sand, in places covered by stalagmitic breccia, contained the bones of Pleistocene mammalia along with rude imple- ments of Palaeolithic type. A few of the implements were of flint, but the majority were of quartzite crudely fashioned, this material being locally plentiful as pebbles in the Bunter Pebble Beds and in the gravels derived from them. Of great interest was the discovery in Robin Hood's Cave of a fragment of a rib-bone with the -outline of the fore-part of a horse rudely engraved upon it. The occurrence of a broken tooth of the extinct ' sabre-tooth tiger' (Machairochis laticlens) in the upper part of the cave-earth of the same gallery (F. of Fig. 10) was likewise remarkable; and in a later exploration of another recess in the same cave Dr. Laing found two mandibles and other remains of a feline which was identified as a species (Felis brevirostris) previously known only from a French Pliocene deposit. In Mother Grundy's Parlour, the most easterly cave on the north side of the valley, Messrs. Mello and Dawkins found that Ihe lowest deposit was probably older than those which they had excavated in the other raves, as it contained the remains of Hippopotamus and Rhinoceros leptorhinvs which were new additions to the Creswell list. The complete section in this cave was as follows : — Thickness. ' a few inches. Surface soil, with burnt bones, charcoal, a few flint chips, etc. 3 ft. Red sandy earth, with bones of reindeer, bison, bear, wolf, fox, hyasna, etc., and a few rudely chipped quartzite pebbles. 6 in. to 3 ft. Red clay ~\ with bones of the leptorhine 1 ft. Ferruginous yellow and j- rhinoceros, hippopotamus, hyaena, red sand ... J and bison ; no implements found. White calcareous sand, no remains. This older deposit was also subsequently found by Dr. Laing in his exploration of an inner recess of Robin Hood's Cave. His description reads as follows:— "At the rear of the Robin Hood cave is a natural tunnel 18 ft. long filled with red sand, which led into a cave 50 ft. long, 30 ft. broad, and 11 to 27 ft. high, silted up to within a short distance of the roof. In a descending series this consisted of unfossiliferous red sand continuous with that m the front cave, where it is the lowest bone-bearing bed; sandy clay, containing rolled pebbles; stiff red clay and yellow ferruginous sand, containing bones and teeth of Hippopotamus major, Rhinoceros leptorhinvs, Bison priscus, Cervus alces, Sus scrofa, Canis lupus, Ursus, Hycena crocuta, Arvicola amphibia. • . . Occupation by man was shown by 'pot boilers,' char- coal, a charred canine of bear, chopped bones, with choppers and scrapers of the rudest Acheulien type. On the floor of the cave, beneath a great block of limestone, a fragment of skull was found, determined by Prof. Boyd Dawkins to be human, and by the side of the stone a fragment of human fibula." 1 1 Rep. British Assoc, for 1889 (Newcastle), pp. 583-4. BUNE CAVES AND FISSUEES. 109 Pleasley Vale. — East of the mining village of Pleasley, the River Meden has excavated a craggy gorge across the Magnesian Limestone similar to that of Creswell, but deeper and longer. Here again, the rock is gashed by fissures, some of. which have yielded bones. There has not, however, been so much systematic exploration in this locality as at Creswell, and the only published accounts which we have been able to find are the short abstract of a paper by Dr. W. H. Ransom recording the occur- rence of Felis lynx ' associated with remains of wolves, deer, pigs, voles and other food-animals ' in a fissure at Pleasley, 1 and some further particulars of the same discovery quoted by Messrs. Dawkins and Sanford. 2 Prom the latter account we learn that this fissure was known as the ' Tew Tree Cave ' and had a total depth of 70 ft. We were unable during the recent survey to identify it with certainty, but it is probably the cavity known locally as ' Digby Hole ' which is situated in the woods on the slope of Pleasley Park nearly 200 yds. N. of the river, in the bend W. of Meadow Houses. On enquiry in the neighbourhood we were informed that bones had also been found in a small cave in the grounds of the house known as Pleasley Vale (at the SW. corner of the Park) and again in a fissure revealed in a cutting of the Midland Ky., on the crest of the valley, 150 yds S. of the lower Mill. The list of Pleasley Vale fossils incorporated in the table on p. Ill, is reprinted from that of Prof. W. Boyd Dawkins. 3 Langwith Bassett, — The latest addition to the known bone- caves of the district is a small cavern on the north bank of the Poulter valley at Upper Langwith, discovered and explored by the Rev. E. H. Mullins. The valley bottom here is 300 ft. above O.D., and the mouth of the cave is about 20 ft. higher, but its floor, where excavated, is only about 10 ft. higher. The side of the valley is not more than 40 ft. high, and the mouth of the cave was hidden by talus which nearly buried the crags of Magnesian Lime- stone. The cave-deposits excavated up to the present time appear from their contents to be somewhat newer than the prin- cipal bone-earths of the Creswell Caves, the extinct Pleistocene animals so abundant there being here scantily represented. Owing to the extreme care with which all the organic contents of the cave have been collected by Mr. Mullins and his co- adjutors, the list of small mammals, birds, etc. is already much fuller than from the previously-mentioned caves. The explora- tion and the determination of the specimens are not yet com- pleted, but Mr. Mullins 4 has kindly sent us a preliminary list, which is incorporated by his permission in the table on p. 111. Age of the Cave-deposits. — There has been wide diversity of opinion respecting the relation of the cave-deposits to the drifts. 1 Rep. British Assoc, for 1866. Trans, of Sees., p. G6. "In 'British Pleistocene Mammalia. Part iii, Felidse,' p. 172. Pal. Soc, vol. xxii. 3 ' On the Distribution of British Post-Glacial Mammals.' Quart. Journ. Geol. Soc, vol. xxv, 1869, p. 195. 4 Since this memoir went to press Mr. Mullins has published a full account of his exploration, with lists of the fauna, mollusca, etc., in ' The Ossiferous Cave at Langwith,' Journ. Derby sh. Archaolog. and Nat. Hist. Soc, vol. xxxv, 1913, pp. 137-158. 25276 H 2 110 SUPERFICIAL DEPOSITS. By some authors the extinct animals are supposed to have lived in the district during a mild interglacial period between two periods of glaciation, while others, have regarded them as belong- ing to Post-glacial times. As previously stated (p. 98), the relation of the patches of Glacial drift to the present topography is such as to prove that the district has undergone prolonged erosion since it was glaciated, and that all the streams were particularly active during the closing stages of the Glacial period when this part of the country was freed from ice. It seems probable that the craggy ravines so common in the Magnesian Limestone country were carved out at this time, and it is unlikely that they would have retained the present steepness of their walls if they had existed from an earlier date. The caves of Creswell and Langwith have their mouths comparatively low down in the sides of the valleys in which they occur, and these openings cannot have existed until the valleys were cut nearly to their present level, which seems to indicate that their tenancy by animals was at a time later than the glaciation. But there is every likelihood that deep fissures had formed in the limestone before the oncoming of the ice-sheets, and that the remains of animals may in some cases have become lodged in these fissures from above, as filled-in cavities are fre- quently revealed in the deep railway-cuttings and quarries of the district, e.g., in the railway-cutting S. of Pleasley Yale. It is quite possible therefore that the formation of the fissure may in some cases have antedated the erosion of the stream-gorge into which it now opens ; hence it may have received part of its contents at an earlier stage. than the rest. The deposits accumu- lated in the caves during and immediately after the excavation of the present valleys should probably be classed as Late-glacial; and to this stage a large portion of the older cave-beds may be assigned ; with, perhaps, here and there in the lowermost recesses, the relics of a stage earlier than the glaciation. Between the Late-glacial and the Post-glacial beds of the caves there is no division possible, as the accumulation of material appears to have been continuous during Palaeolithic times. It is believed that there is an unrepresented interval between the Palosolithic deposits and those of later times in the Creswell caves, but this is a question for the archaeologist rather than for the geologist. The following sentences in which Messrs. Dawkins and Mello summarize their work on the Creswell caves give a graphic picture of the ancient life of the district: — (1) " • • • . at the time the red clay and tide ferruginous sand were being accumulated in Mother Grundy's Parlour by the action of water, the Hippopotamus and leptorhine Rhinoceros, the Hyaena and the Bison haunted the wooded valleys of the basin of the upper Trent, while we may mark the absence of Palaeolithic Man and the Reindeer. Hyaenas were abundant, while Horses were absent. (2) Then followed a time, represented in all the caverns by the red sand, when the Mammoth, Woolly Rhinoceros, Horse, and Reindeer haunted the district round Cresswell Crags, and fell a prey sometimes to the hyaenas, and at others to the hunter, whose FOSSILS OF THE BONE CAVES. Ill implements of quartzite prove him to belong to the same peoples who have left their implements in the river deposits. (3) Lastly we have the Palaeolithic hunter, represented, in the breccia and upper cave-earth of the Bobin-Hood and Church-Hole caves, by flint implements of a higher order, like those found in Solutre (type " Solutrien " of Mortillet), accompanied by imple- ments of bone and antler and the incised figure of a horse, which proves them to have possessed the same artistic faculty of repro- ducing the forms of animals so remarkable in the frequenters of the caves of the South of France, Switzerland, and Belgium." 1 G. W. L. Mammalia prom the Caves. Compiled from the papers mentioned in footnotes on pp. 105-6 and i rom a MS. list of the Langwith fauna supplied by Rev. E. H. Mullins 2 Creswell Caves. 6 4 'o CO .3 8 1* CD P*> > to m a o o a S 2 V E s c3 Arvicola amphibius Linn. Water Yole X _ _ X X Bison prisous Owen Bison ? X X X X X X Bos primigenius Boj. Urus X — — — — X Canis lagopus Linn. Arctic Fox X — — — — X „ lupus Linn. Wolf X X X — X X „ vulpes Linn. Fox X X X X — X X Cervus megaceros Hart. Irish Elk ... X X X „ tarandus Linn. Reindeer X X X X X X X „ elaphus Linn. Red Deer — — — — X X X Elephas primigenius Blum. Mammoth X X X ? Equus caballus Linn. Horse X X X X X X Felis brevirostris Croiz. and Job. — X „ catus Linn. Wild Cat — X — — — ? „ lynx Linn. Lynx — — — — X X „ pardus Linn. Leopard — X „ spelaea Gold/. Lion — X X Grulo luscus Linn. Glutton ... X Hippopotamus major Desm. Hippo- potamus — X — X Hyaena crocuta Erxl. Hyasna X X X X X X X Lepus timidus Linn. Hare X X X — — X Machairodus latidens Owen ... — X Mustela putorius Linn. Polecat — — X — — ? Rhinoceros leptorhinus Owen — X — X „ tichorhinus Luv. Woolly Rhinoceros X X X X X X X Ursus arctos Linn. Brown Bear X X X X — ? X „ ferox Geoffr. Grizzly Bear ... X X X X X In addition the following animals, believed to have been more recently introduced, were also represented in the Creswell Caves : — Dog, marten, badger, stag, roe, shorthorn ox, sheep or goat, and rabbit. . There were likewise human bones and other relics of the later period, besides the stone implements of the earlier man. 1 Quart. Joum. Geol. Snc, vol. xxxv, 1879, p. 733. * The nomenclature of the species found at Creswell is reproduced, without revision, from Rev. J. Magens" Mello's complete list, in Proc. Yorks. Geol. t£ Polytech. Soc, n.s., vol. vii (1880), pp. 2G4-5. 112 SUPERFICIAL DEPOSITS. The Langwith Bassett Cave yielded relics of all the animals just men- tioned, and of the pig or wild boar, otter, weasel, stoat, squirrel, rat, field mouse, vole, common shrew, mole, hedgehog, and small horseshoe bat. 1 Besides these existing animals, Mr. Mullins has also discovered the remains of several northern species no longer inhabiting this country, among which is a single bone (tarsal), believed to be of the Saiga ante- lope, along with three species of lemming (including the Arctic and the Norwegian lemmings), the Siberian vole, and some species or varieties of vole that are probably now extinct. G. W. L. Alluvium. River-terraces such as occur along the lower courses of the Derwent and Don, south and north of our district, are strikingly rare in the present area, and the alluvium shown on the maps lies for the most part on the actual floors of the valleys. In the Coal Measure country this condition may be generally accounted for by the character of the rocks, which form unstable slopes, unfavour- able to the preservation of terraces. But the chief factor appears to have been the previously-mentioned deepening of the valleys nearly to their present level at the close of the Glacial period, and the comparative insignificance of the later erosion (p. 99). G. W. Lv Derwent and tributaries. — The course of the Derwent through the district affords comparatively few examples of old river- terraces. Where such occur, they stand in rather obvious rela- tionship to the degradation of rock-barriers which have impeded the river. Thus, they are found at Beeley and Chatsworth, where they begin immediately above a degraded barrier formed by the Kinderscout Grit faulted down at Rowsley. Thence to the north end of Chatsworth Park discontinuous terraces are seen 2-8 ft. above the modern alluvium ; but on the steep western bank of the river in Chatsworth Park small patches of gravel remain some 20 ft. above that alluvium. The broad alluvial tracts bordering the Derwent where it flows over soft strata are, under modern conditions of artificial drainage, only liable to inundation by the highest floods. For the most part the river flows some eight or ten feet below them. These flats usually consist of silt overlying coarse gravel, which is generally visible in the bank and in the bed of the river. Similar alluvial tracts occur along the course of the Amber and, in relation to the small size of the stream, are of considerable width. The complete absence of older terraces in the Amber valley is noteworthy. Tributaries of the Don. — The alluvium of the upper reaches of Totley Brook but slightly trenches upon the old terrace-gravels of Kedcar Brook (p. 100), which, with a steeper gradient than the present stream, have descended below its bed at the junction of the two valleys. But the Totley Brook alluvium is itself trenched and deserted by the modern stream lower down, where a newer and lower alluvium has been formed on the south side ; for, below the confluence with Redcar Brook the stream-gradient in this reach has since become steeper. 0. B. W. 1 Over thirty species of birds and twenty-eight species of land-shells are also recorded by Mr. Mullins ; see foot-note on page 109. ALLUVIUM AND TUFA. 113 In the coalfield, considerable spreads of fine silty clays, from 3 ft. to as much, as 15 ft. in thickness, extend along the Bother from Chesterfield to the Yorkshire border, near Beighton. The alluvium of the tributaries of the Rother has the same com- position, except in the case of the Hipper between Holymoorside and New Brampton, where it consists of very coarse gravel con- taining large rounded blocks of Millstone Grit. The modern stream deposits a silty detritus only; it is therefore evident that the gravels have been derived from an older deposit. At Holy- moorside a narrow platform, raised about 15 ft. above the present alluvium, although at present devoid of gravel, suggests the existence of an old river-terrace; and it is significant that the platform coincides with the margin of the glacial lake, supposed by Mr. Lower Carter 1 to have extended along the valley of the Hipper. At this point a stream flowing east off the Millstone Grit plateau into the lake would most likely give rise to a delta which, at a later date, may have furnished the material of the gravels along the present Hipper. North of Brimington it will be observed that the Rother turns abruptly to the east and cuts across the hard steeply-inclined Lower Coal Measure sandstones of the Brimington anticline. It has been suggested by Mr. Lower Carter 2 that the Barlow brook originally flowed due east into the Poulter and that the latter stream was afterwards beheaded by the Doe Lea brook. W. G. Calcareous Tufa. In the Carboniferous Limestone area occasional deposits of calcareous tufa have formed; but only one of these attains suffi- ciently large dimensions to be indicated on the 1-inch map. At Matlock Bath such a deposit has produced the broad terrace-like platform on which the Church and the Royal Hotel stand, at the foot of the eroded dip-slope of the limestone on the west side of the river. The lower edge of the tufa, here a white porous deposit doubtless formed around the stems of reeds and other water-plants, has been quarried by the roadside, about 30 ft. above the present level of the river. Its upper surface lies considerably higher. Its deposition is due to the warm springs, before they were confined in artificial channels^. These are thrown out at the surface of the lower lava. At the southern termination of this tufa-terrace the river falls several feet, where its rapids are now controlled by a weir. At this point a fault, bearing a lead-vein, crosses the river with an upthrow to the south, and a bluff of limestone descends to the road and constricts the valley. The rapids doubtless mark the site of a degraded rock barrier, which formerly held up the river above it at a considerably higher level ; and it is probable that the 1 ' Glaciation of the Don and Dearne Valleys,' Proc. Yorks. Geol. Soc, vol. xv, 1906, p. 411. 2 ' Evolution of the Don River system,' ibid., vol. xv, 1906, p. 409. 3 A. H. Green and A. Strahan, ' Carboniferous Limestone, Yoredalo Rocks, and Millstone Grit of North Derbyshire,' Mem. Geol. Surv. 2nd ed., 1887, p. 166. 114 SUPERFICIAL DEPOSITS. tufa-terrace was first formed along the margin of slack-water above this barrier, the degradation of which has left the terrace standing 30-40 ft. above the river 1 . In the Via Gellia, south of Slaley, a small spring thrown out above the toadstone on the brow of the valley trickles down the bare slope of limestone and has produced a tufa deposit of a different appearance. It is a hard compact translucent amber- yellow rock enclosing shells of Helix nemoralis and other land snails. Tufa is said also to have been worked in Bonsall Dale 2 . C. B. W. Peat. In swampy hollows on high ground of the Millstone Grit and Lower Coal Measures more or less extensive deposits of peat occur, while a thin and irregular growth of hill-peat sometimes covers the grit-plateaux. Only the former type is represented by colour on the map. These peaty deposits are found chiefly on the high ground north of Matlock. The most extensive are those of Leash Fen, Big Moor, Totley Moss and the moorlands north of Burbage Rocks on the borders of Derbyshire and Yorkshire. The material necessarily varies greatly in thickness, ranging from a foot or two at the margins of the hollows to probably 20 ft. or more in the deepest spots. The proximity of the coalfield has debarred its exploitation as fuel with rare exceptions on a small scale. C. B. W. 1 See ' Summary of Progress for 1904,' Mem Geol. Surv., 1905, p. 15. 7 ' Carboniferous Limestone, &c. of North Derbyshire,' Mem. Geol. Surv. ed. 2, 1887, p. 166. 115 OHAPTEE VIII. ECONOMIC GEOLOGY 1 Mineral Products : Building Materials : Water Supply : Agriculture : etc. coal. Coal-mining is essentially the most important industry of the district. The numerous seams, their occurrence, quality, and thickness have been fully discussed in Chap. IV., so that it is unnecessary to devote further space to this subject. Several other important industries located in the district, such as iron- manufacture, brick-making, pottery, etc., have arisen mainly from the proximity of coal, cheaply got, or of special composi- tion^ Others, such as the raising of lead-ore and the minerals associated with it, lime-burning, the quarrying of building-stone and road-metal are more or less independent of the coalfield. IRONSTONES. The use of local ironstones has been replaced by imported ores ; but the spoil-heaps of the abandoned shallow workings in the ironstone measures remain to form a characteristic feature in the landscape between Chesterfield and Dronfield, and on the southern outskirts of Sheffield. Ironstones, in the form of nodules and occasional bands, occur throughout the Coal Measures; but the chief concentration of iron was confined to definite horizons in the Middle Coal Measures between the Silkstone Coal and the Top Hard Coal. Ironstone Measures, named ' Baconflitch,' about 70 ft. above the Kilburn Coal, were worked near Alfreton ; but the Honeycroft, Civilly, and Dale Moor ironstones which occur below the Kilburn Coal near Stanton, in the map to the south (Sheet 125), are unrepresented in the present area. The ores consist of rows of ironstone nodules (balls) termed ' rakes,' distributed in shales usually black but occasionally grey. The lowest beds occur above the Silkstone Coal at a height varying from 1 to 30 ft. They are known as the ' Black Shale rakes ' and correspond to the ' Striped rake ' of the southern part of the coalfield (Sheet 125). They were actively worked by 'bell-pits' along the outcrop of the Silkstone Coal, especially at the Hady, Chesterfield, where the rows of nodules are con- centrated in two bands of shale called the ' Top rake ' and 1 The paragraphs without initials have been written or compiled by W. Gibson, partly from notes supplied by the other authors. 116 ECONOMIC GEOLOGY. 44 O H ' Bottom rake ' separated by 12 ft. of unproductive shale. The layers of nodules were known under the following names 1 : — Ft. In. ' Whetstone,' lean or poor measure, not got Shale ' Single balls,' lean Shale ' Double chitter,' lean, brown, rough nodules Shale ' Cheeses,' good measure Shale ' Bearstone,' capped with cone-in cone, lean, rough texture Shale 'Blues,' upper, good and rich, flat nodules Shale ' Blues,' lower Shale ' Old man,' good ; nodules of ten thick Shale ' Old woman,' or sheeting, good ; flat nodules Shale ' Smooth chitter,' a lean measure, brown and rough Shale ' Flampard,' a very rough, granular-structured stone, lean Shale . ••• ' Red measure,' good ; cleavage planes with white coating Shale * Chance measure,' lean Shale ' Dun lining,' lean, black with small crystals of pyrites ... Shale ' ' Dun measure,' good ; thick black nodules Shale ' Over lumps,' good ; cracks coated with white powder ... Shale ' Nether lumps,' good ; cracks coated with white powder Shale ' Overbottoms,' good ... Shale ' Roof measure,' good, rough and black Shale ' Bottom measure,' good Shale Coal smut, 2 ft. 3 in. above the roof coal [Silkstone]. The yield per acre amounted to 4,000-7,000 tons. Over the Tupton Three-Quarters Coal at Clay Cross lies the Three Quarter Balls consisting of 5 courses of ironstone. The ' Dog-tooth rake ' (' Wallis's rake ' at Butterley, Sheet 125), between the Tupton and Piper coals was one of the most im- portant ironstones in the district. The yield amounted to 2,000 tons per acre. The iron-salts appear to have been deposited round the shells of Carbonicola which are very abundant at this horizon. The ' Black rake,' resting on the Ell Coal; and the ' Brown rake,' 1-1 yards above it, both important ores at Butterley, do not appear to have been very extensively worked. The ores belong to the clay-ironstone variety and yield from 22 to 31 per cent of iron. -^ q. •s. a o o m \ 1 1 6 04 1 6 2 3 14 2 1 2 3 1 1 3 1* 2 2 1 6 1 12 24 3 6 3 2 li 3 01 1 6 1 1 2 2 1 1 1 1 6 li 1 6 14 1 6 1 1 6 1 The Iron Ores of Great Britain,' pt. 1. Mem. Geol. Sun:, 1856, pp. 42-3. 38-97 28-27 0-88 1-01 1-09 1-02 0-38 0-33 1-58 13-94 4-62 9-18 30-14 37-61 0-48 0-74 trace trace 0-05 0-04 0-64 0-18 1-02 0-73 0-30 0-92 19-10 6-39 99-25 100-36 31-34 22-98 IRON-OBE AND MINERAL VEINS. 117 The following analyses (I. & II.) of the ' Dog-tooth rake ' iu the Staveley district illustrate their composition. Analyses of Ironstones.' Constituents. I. II- Protoxide of iron ... Peroxide of iron Protoxide of manganese . Alumina Lime Magnesia Carbonic acid Phosphoric acid Sulphuric acid Bisulphide of iron ... Water, hygroscopic ... „ combined Organic matter Insoluble residue Metallic iron .. MINERAL VEINS, &C. From an economic point of view the principal contents of the mineral veins in the Carboniferous Limestone are lead, usually as galena (sulphide), but also as cerussite (carbonate); zinc, as blende (sulphide) and commonly as calamine (carbonate) ; fluorspar ; barytes ; and calc-spar. Copper does not occur within the district as a mineral of economic importance, and silver, found locally in association with galena, is no longer raised. Wad (black oxide of manganese) and yellow and red ochre also occur here and there in the decomposed upper parts of the veins and as deposits in other superficial cavities. The more important vein-products at the present time are lead and fluorspar; and these two are now mined almost alone. As is well known, lead-mining in Derbyshire is of great antiquity, but no longer enjoys the prosperity it once had. Id the last years of the last century and the first year or two of the present it reached its lowest ebb, but since then has experienced temporarily a slight revival. The district falling within the compass of Sheet 112 gives only a glimpse into the industry. The details on the following pages are largely compiled from previous accounts to which reference is given in the footnote 2 . 1 Op. cit., pp. 86, 88. 2 For fuller accounts of the Derbyshire metalliferous mining, see Farey, ' General view of the Agriculture and Minerals of Derbyshire,' vol. i, 1811, pp. 252, et seq. A. H. Stokes, ' Economic Geology of Derbyshire,' Trans. Chesterfield Inst. Alin. Eug., vol. vi, 1878, p. 60; 'Lead and Lead-mining in Derbyshire, ibid., vol. viii, 1880, p. 67 ; vol. ix, 1881, p. 306. A. Strahan in 1 Geology of the Carboniferous Limestone, &c. of North Derbyshire,' Mem. Geol. Surv., ed. 2, 1887, p. 118. C. B. Wedd and G. C. Drabble, 'The Fluorspar Deposits of Derbyshire,' Trans. Inst. ilin. Eng., vol. xxxv, 1908, p. 501. 118 ECONOMIC GEOLOGY. The decline of lead-mining in Derbyshire may be attributed to the fall in the price of lead owing to the competition of foreign ore, the exhaustion of the shallow workings, and the dispro- portionate increase of cost in mining deeper leads due to the expense of unwatering the mines below the level of the Derwent, into which the more important mining areas have long been drained by the old ' soughs.' But since the year 1899 an in- creasing appreciation of the economic properties of fluorspar (which is commonly associated with the lead-ores) began to prevail against the general stagnation of mining in the lead-district, and was accompanied by a slight increase in the price of the metal. In many parts of the Derbyshire lead-districts the miners now have the advantage of raising lead and fluorspar together from the same vein. Moreover, where lead has been mined for many centuries, while the associated fluorspar has, until recently, been regarded as an almost worthless by-product, the old mines naturally contain a considerable quantity of that mineral stored below in the ' gob ' and ready to hand 1 . Further, there are numerous old shafts sunk far below the depth to which the veins are exhausted, so that the initial expense of mining is now minimized. Owing to the restriction of the more valuable mineral deposits to the upper part of the limestone, and the generally gentle dip of the strata, few shafts penetrate as deep as 1,000 ft. The demand for fluorspar is caused by its increasing use as a flux in the manufacture of steel and pig-iron, also in brass- founding and in smelting lead, tin, copper and nickel, and in the reduction of aluminium from bauxite. Besides these, it is put to a variety of other uses, including the production of hydro- fluoric acid. The beautiful purple crystalline variety known as " Blue John," now difficult to obtain and expensive, occurs at Crich, but neither of sufficient size nor in sufficient quantity to be marketable. Barytes (caulk) is used in the manufacture of white paint, but little of this mineral is now raised in the district. Paint-works have long been established in Matlock Dale and the Via Gellia valley. Calc-spar is obtained for the making of gravel-paths, with or without asphalt, and also for garden rockeries. Details. Within that part of the main limestone tract here under description, while there is no considerable portion of it in which lead has not been raised, the old lead-workings are most extensive between Wirksworth (Sheet 112), Middleton, and Oromf ord ; at Bonsall Leys; in the neighbour- hood of the two Matlocks ; at Snitterton and Wensfey ; and beneath the shales north of these villages, where the important Millclose Mine, pro- ducing lead and zinc, is the only mine that has not ceased working in recent years. The inliers of Crich and Ashover are equally rich in lead. On the other hand, fluorspar is found associated with lead in profit- able quantity only at Crich and Ashover, and in the tract extending from ' C. B. Wedd and G. C. Drabble, ' The Fluorspar Deposits of Derbyshire,' Trans. Intt. Ml it. Eng., vol. xxxv, 1908, p. 531. METALLIFEROUS VEINS. 119 Matlock Bridge to Cromford. Silver, mixed with the lead, has been obtained, in sufficient quantity to repay extraction, only at the Ball-Eye Mine, south of Bonsall. 1 In the south of the district the Ratchwood Mine, and Jackson's Mine which has been reopened recently, are both situated on veins parallel to and near the Gulf Fault (p. 11). The Raventor (Rantor) Vein, on the fault which marks the eastern boundary of The Gulf (p. 11), yielded caulk, ochre, iron pyrites, blende, cerussite, and much galena. The Maltsters' Venture Mine is on a parallel vein, 150 yds. to the east, the parallel Dinah's Rake, also rich in caulk, being the same distance further east. " The Wall Close Vein, running nearly south-east, gathers a number of serins from the south under Bole Hill, the principal being the Bage, Walker's Vein, and the Flint Vein. These are worked in the Bage Mine, the shaft of which is 50 fathoms deep . . . The galena . occurs associated with caulk and a little blende, very little fluorspar and some white ore. Towards the north the Wall Close Vein crosses the Gang Vein, and north of this point has lately yielded ochre.-'' On the Gang Vein, ranging east and west (p. 11), the Gang Mine near the east end, on the limestone shales, produced lead in the shales and toadstone as well as in the limestone; with the lead are associated blende, iron pyrites, fluorspar in large cubes (not of economic value), and petro- leum. The Samuel Mine, south-west of Middleton, where the vein is said to have been very rich, and the Bradhouse and Partridge Mines further west, are situated on the same vein. Innumerable old lead-workings cover the limestone-surface east and north of Middleton. Most of the veins have a general north-westerly direction, but a few, the chief of these being the Dragon-eye Vein, trend eastward. Several lead veins run north-westward from Cromford parallel to the Bonsall Fault (p. 11). The Ball-eye Mine on one of these has been men- tioned above as producing silver. Near Cromford Station the Moletrap Rake extending westward from the Moletrap Mine across the Derwent, is the most southerly vein rich in fluorspar in this part of the district. It contains, besides lead, a hard white fluor with blende. The Coalpit Rake and the Great Rake, running respectively along the foot and the summit of the steep slope of the Heights of Abraham (pp. 8 & 34), and thence east- north-east across the Derwent, together with the Side Rake, a branch from these east of the river, produce fluorspar as well as lead. Smith's Mine on the Great Rake above Bonsall works a granular fluorspar below the lower lava. In the Coalpit Rake fluor, associated with calcite in its western range, becomes more abundant eastward under the shale. The Side Rake yielded lead in the toadstone. 3 The Cumberland Mine, situate above Mat- lock Bath and containing calamine, a little copper and some carbonate of iron, Old Nester's Mine, the Dale Mine, and the Knowles or High Loft Mine, all three situate on Masson Hill and connected with the Great Rake, are on pipes rich in fluor as well as lead. Old Nester's Mine, reputedly one of the oldest, produced much lead-ore with calamine and blende. 1 A group of veins ranges through the High Tor mass north-north-west across the Derwent. The Seven Rakes, the most westerly, yielded cala- mine and blende as abundantly as lead-ore, which was worked in the toad- stone (upper lava) as well as in the limestone above and below. A parallel rake further east contains a clear white fluorspar. The most northerly deposit with abundant fluor in this district is that of the Oxclose Pipe and Rake trending east-north-east at Snitterton. 5 Further west a group of small north-westerly veins, thickly massed and once extensively worked half-way between Slaley and Whiteeliffe Farm, with others more wide-spaced for some distance on both sides, yielded lead. A few hereabouts trend east-north-east. Much lead has also been worked in veins traversing the northward slope of the limestone west of Wensley. Millclose Mine. — The following account of the old workings of the Mill- close Mine through the shales north of Wensley into the limestone below 1 A. Strahan, op. cit., p. 125, quoting T. Short, ' History of the Mineral Waters of Derby- shire, Lincolnshire, and Yorkshire,' 1734, p. 73. 2 A. Strahan, op. cit., p. 149-50, from information by Mr. Alsop of Wirksworth. a J. Farey, op. cit.,?. 267, 4 J. Farcy, op. cit., p. 264. 5 C. B. Wedd and G. C. Drabble, r o/>. cit., p. 515. 120 ECONOMIC GEOLOGY. the upper lava is taken from the former Survey Memoir (pp. 146-7), the information being mainly derived from Mr. Greatorex, of Wmster: — " The Millolose Vein, where worked by the ' old men ' on the south side of the valley [of the Bridgetown brook], was composed of a number of parallel veins parted by riders or sometimes running into one vein, with a total width of 140 yards. ' About the year 1743, the Quaker's Company, as it was then called, purchased the Millclose Mine, in the Liberty of Wensley, upon which they not only erected a fire engine to draw water out of the mine, but also built coes . . . . ; they likewise wrought a sough or water gate (without having a vein) into Birchover Lordship, and diverted a brook . . . down such for the purpose of turning a water- wheel, . . . ' (Mander's Mining Glossary). The sough referred to appears to be the Yatestoop sough. " The mine subsequently lay idle for about 100 years, but was reopened in 1859 by the late Mr. Wass. In 1861 ore began to be raised, and since that time up to date the mine has produced 144,341 loads (equal to about 36,085 tons) of lead-ore, with a gross value of between 340,000Z. and 350,000?.. " The working was at first confined to the limestone above the toadstone, except that a, level was driven from the bottom of a shaft, 150 yards south of the brook, southwards as far as the Winster road. The level entered the toadstone a little south of the shaft, and passed through it (the beds dipping northwards) into the limestone below, but no ore was found. The depth to the toadstone at this shaft was about 25 fathoms. " The Millclose Shaft, on the south side of Cowley Knowl, was sunk to about 80 fathoms depth, and a level driven at this depth along the vein to the Warren Car Shaft [now Main Pump Shaft] 580 yards distant." [The section of the Cowley Knowl Shaft is given on p. 33.] " The lode is of very irregular width, the veinstuff mostly semitransparent calcite, mixed with a good deal of chert, of a dull yellowish colour, and differing from the chert of the limestone in being soft and crumbly. The vein is occasionally split up by very large ' riders ' of limestone. Branching from the main vein are chambers or ' pipes,' often very large and almost entirely filled with ore ; these follow in a general way the direction of the bedding. Thin layers of ore and spar also run out between the limestone beds. " The vein on reaching the toadstone is ' pinched ' into a ' leader ' a few inches broad, of white, opaque, imperfectly crystallized calcite, and even this soon thins downwards." The present workings extend further north along a north-north-westerly fault, in the line of which the main level runs at a depth of 147 yards in the Lees Shaft (see p. 33) 280 yds. north of the Main Pump Shaft. Lead is now worked exclusively in a network of veins, chiefly along the west side of the level, in a belt of ground 60-70 yards wide. The Crich inlier is very rich in both lead and fluorspar, the important veins being confined to the northern half of the limestone mass. They range in two general directions, respectively varying between NNE. and ENE., and between NW. and WNW. The chief veins trending NW. are, from north to south, the Hard Bake, the Church Rake, and two parallel rakes south of the last named. The veins roughly at right angles to these are, from north to south, the Glory Vein with its branch the Plaistowfield, and Pearson's Venture on the western margin of the limestone outcrop. Near the junction of this with the Hard Rake are rich pipes, the most important known as the Bacchus. The shafts of the Glory Mine, N. of Crich Stand, have been sunk to 810 ft., and reached the toadstone at 180 ft. The Old End Mine at the E. end of the Glory Vein, and close to the margin of the limestone outcrop, goes down to a depth of 912 ft. In the Pearson's Venture, where the dip is rather high, the toadstone was found at 480 ft., and in the Bacchus Pipe at 450 ft. These veins, still rich in lead for some distance below the toad- stone, become poorer the lower they are followed. 1 All are rich in fluor- spar of good quality above the toadstone, but that mineral is confined almost exclusively to the measures above the toadstone, below which the gangue consists largely of calcite. 2 1 A. Strahan, op. cit., p. 155. ' 2 C. B. Wedd and G. C. Drabble, op. at., p. 516, METALLIFEROUS VEINS. 121 Several mines, including the Bacchus and Pearson's Venture, have been reopened in the last few years. The Ashover irilier contains several veins of which the principal are the Gregory, Overton, Milltown or Fall-hill, and Westedge. The workings are confined entirely to beds above the toadstone, which has not been pene- trated. The Gregory Vein runs nearly due west from the River Amber to the " New Engine Shaft," sunk in the upper beds of the Kinderscout Grit, near Holestone, to a depth of 1,095 ft. Here the vein bends to W. 15° S., and has been worked from under the outcrop of the Chatsworth Grit. The Gregory Vein is joined by the Overton Vein 530 yds. east of the New Engine Shaft, and at the point of intersection proved extraordinarily pro- ductive. From 1758 to 17S3, according to Pilkington,' the mine yielded lead to the value of £105,986, with an average annual production of 1,511 tons. A little antimoniated lead-ore is said to have occurred. 2 The Overton Vein runs E. 35° N. a few yards south of Overton Hall, a number of veins, close and parallel to it, run under the hall and garden. Several small rakes start from both sides of the Gregory Vein, but have not been followed far ; amongst them are the Ravensnest, New Close, Crash Purse and Hard Nab on the south, and the Sanlant and Blaigh Grove on the north. In Starswood (south of the toadstone outcrop) and Fall Hill a set of ten or twelve veins has an average direction of N. 30°-35° W., one of the principal veins being the Stars, Tors, or Blackland Rake, rich in fluorspar. The Great Rake runs through the middle of the wood. The shaft of the Milltown Mine on the Fallhill Vein, containing blende, was 270 ft. deep, and reached the toadstone. The set of veins last 'described is covered by others ranging more nearly east-and-west, the principal being Spencer's Rake. The Townhead Vein, with the same trend, has been worked by a mine about 250 yds. NNW. of Ashover Church. The shaft passed through 60 ft. of shale, 180 ft. of limestone, and touched the toadstone. The West- edge Vein, running about E. 15° S., closely follows the shale boundary. The engine shaft reached the toadstone at about 180 ft., in which, according to Farey, 3 ore was got, and petroleum in geodes in the shale. Fhiorspar is consistently strong in all the larger veins, though associated with a little calcite in some cases. It is being got in the Gregory, Overton, and Fallhill Veins. 4 Drainage Levels and Soughs. — In the south three principal soughs were driven to unwater the lead mines of Wirksworth, Middleton and Cromford. The first, the Hannage Sough, finished about 1740, drains the Ratehwood Mine southward into the Ecclesbourne (Sheet 125). The next driven, the Cromford, drains the Gang and neighbouring mines into the stream from the Via Gellia near Cromford Market Place, and brought down much warm water. The Merebrook Sough, the last of this group, drains from the Merebrook-sough Mine, near Wirksworth, by Bole Hill, into the Derwent opposite Leashaw Farm, a distance of two and a quarter miles. It was begun in 1773, was still driving in 1811, and is said to have cost more than £45,000. The Hillcar Sough drains the mines beyond and under Stanton Moor into the Derwent 1J miles S. of Rowsley. The Yatestoop Sough unwaters the Winster and Elton mines into the Derwent 900 yds. N. of Darley Bridge. At Crich the Fritchley Level drains the Old End Mine on the east side into a brook near Fritchley (Sheet 125) ; the Ridgway Level unwaters the Wakebridge and Cliff Side Mines on the west into the Derwent, 600 yds. above Whatstandwell Bridge. At Ashover the Cockwell, emptying into the Amber above Woolley Bridge, nearly a mile below Cockwell, drains the shallower workings of the Gregory Vein. A branch was driven 800 yds. northward along the east side of Fall Hill to drain the Milltown and Fall-hill Mines, with the intention also of reaching the Townhead Vein. Another branch, driven northwards from the Gregory Vein, unwaters the Overton Mines. i • View of the Present state of Derbyshire, 1789,' p. 128. » J. Farey, op. cit., p. 259. 3 Op. cit., p. 269. J C. B. Wedd and 6. C. Drabble, op. cit., p. 515. 122 ECONOMIC GEOLOGY. BUILDING STONES. The extraction of building-stones forms an important industry, and quarries abound in the areas occupied by the Carboniferous Limestone, Millstone Grits, and Magnesian Limestone. Sand- stones for building were formerly obtained from the Coal Measures, but except in a few cases, quarrying has practically ceased. Besides building-stones, ornamental stones (' Derby- shire Marbles ') are represented in the Carboniferous Limestone, and for fine architectural work by a local sandy bed (Mansfield stone) in the Magnesian Limestone; while stone for construction purposes is yielded in abundance by the Millstone Grits. The different types of building-stone may be considered, ac- cording to their composition, as limestones and sandstones. Limestones. — Many beds of the Carboniferous Limestone are worked, and for varied purposes. At Hopton Wood and Middleton a compact homogeneous limestone of great thickness, mainly below but partly above the lower lava (p. 22), con- stitutes a valuable building-stone, and is extensively quarried. Amongst its architectural uses, it is much employed for interior decoration. Many parts of this and other beds, including the crinoidal limestones, are sawn into slabs and polished. Various shades of blue and brown are obtained in these ' Derbyshire marbles ' ; but red stone does not occur in this district, and black limestone, such as that of Ashford, is not wrought. The Magnesian Limestone has been extensively quarried throughout its entire outcrop and especially in the districts of Mansfield, Shirebrook, Scarcliffe, Bolsover Moor, Clowne, Barl- borough and Whitwell ; while the celebrated Steetley Quarry lies immediately beyond the eastern margin of Sheet 100. The best-known quarry is that situated at Bolsover Moor Plantation, from which the stone for the Houses of Parliament was selected; though apparently this stone was not actually used. The character and colour of the dolomite are given in the account of this formation (p. 82). Sandstones. — Several, but not all, of the Millstone Grits are quarried for building-stone. In the northern half of the district , the Kinderscout Grit, chiefly the upper bed, furnishes most of the stone wrought ; but in the northern half, the Chatsworth or Rivelin Grit is mainly employed. The Rough Rock is now little used except at Alton, where it affords a fine-grained building- stone. The Kinderscout Grit, in the Derwent valley near the southern margin of the district, and the Rough Rock of Stone Edge south of Chesterfield, are in demand for purposes that require a strong freestone, capable of standing great weight and .strain. The Lower Kinderscout Grit, where it is fine-grained, has been quarried as a building-stone at its escarpment east of Cromford Station. The upper rock is wrought on Matlock Bank; and farther north, at Stancliffe, where it is finer-grained, it yields an exceptionally good stone (' Darley Dale Stone '), extensively quarried both for solid masonry and. for decorative purposes. It is also much quarried at the Pilhough Quarries, Stanton Moor, BUILDING-STONES, ETC. 123 on the opposite side of the Derwent valley, just outside the margin of this district, and at Peasunhurst, north-west of Ashover. On the high moorland, from Dethick Common to Beeley Moor, the Chatsworth or Rivelin Grit has been and is still extensively worked for building-stone, kerb-stones, and walling. From Baslow northward, it is the only Millstone Grit that is much wrought within the district. Large quarries in this bed at Grindleford, just outside the western margin of Sheet 100, furnish the bulk of the stone for the Derwent Valley Waterworks. From the Lower Coal Measures, building-stone was obtained before the development of the brick-making trade. At present stone is being raised from the Wingfield Flagstones (p. 58) at Hardwick Wood and Freebirch, west of Chesterfield ; and from the Brincliffe Edge Eock, west of Norton. Considerable quantities of building-stone were formerly ob- tained from the sandstones of the Middle Coal Measures, especially from the Silkstone Rock (p. 64), Deep Hard Rock (p. 68), and Manor Rock in the northern district (Sheet 100) ; but these soft and perishable sandstones are now seldom used either in buildings or for general purposes. The higher sandstones of the Middle Coal Measures, which are still used for buildings in South Yorkshire (Wickersley, Sheet 100), die out or become of inferior Quality before they reach the county border. A rock somewhat difficult to classify occurs as a lenticular bed in the Lower Magnesian Limestone at Mansfield. This is the well-known ' Mansfield Stone ' which is made up of nearly equal proportions of sand and dolomite, the latter forming the cementing material to an original unconsolidated sand. Two varieties are recognised : (1) the ' White Sandstone,' and (2) the ' Red Sandstone.' The white variety is at present obtained in the Lindley and Sills Quarries at the south end of Mansfield. Quarries in the ' Red Sandstone ' occur in Rock Valley, north of the church, and on the Chesterfield Road east of Westfield Lodge, one mile north-west of the town (see pp. 83 and 85-7). GRINDSTONES, &C. Grindstones for Sheffield are prepared from the upper beds of the Kinderscout Grit at Stoneclifi ; and from the Rough Rock at Alton and Stone Edge Plantation. The old industry of supplying millstones for crushing grain, for which the harder and coarser beds of the Millstone Grits were employed, has practically died out, but the increased use of wood fibre in the manufacture of paper has given rise to a kindred industry in the fashioning of pulping-stones. For these, a stone of a finer grain is required, such as the Kinderscout Grit of Stancliffe, Pilhough, and Peasunhurst; and at all these places, as well as other quarries, pulping-stones are now cut. CLAY- WORKING ; BRICKS, ETC., AND GANNISTER. The unstratified clays (olunches) and shales (binds) of the Coal Measurer are extensively used in brick-making throughout 25276 I 124 ECONOMIC GEOLOGY. the district. This industry arises from the abundance of material near railways and canals, or in the vicinity of the rapidly growing mining towns. Many of the colleries also make bricks, not only for their own use but to send out of their immediate neighbourhood. Although suitable clays occur throughout the Coal Measures, it will be found that the majority of the pits are situated on the outcrop of the Middle division. In a previous chapter attention was drawn to the incoming of sandstones in the Middle Coal Measures north of Clay Cross. As a result, buildings and walls of stone, while common over the northern district, especially in the older towns, such as Chesterfield, Dronfield, Mosborough, are comparatively rare in the south. In mentioning the principal bands of clay, we will take their occurrence in upward sequence. Shales overlying the Alton Coal are extensively" dug at the Marriott Wood Brickworks, Millhouses, and at the Mooredge Gannister Mine Brickworks and elsewhere in the northern part of the district. The thick beds of dark grey shale below the Brincliffe Edge Rock (p. 58) at Norton Woodside afford abundant material which is used at the Woodside Brickyard, where the Rock forms a cover, 15 ft. thick, to a mass of shales between 40-50 ft. thick. Further south (Sheet 112), the shales of the Lower Coal Measures, though suitable for brick-making have not been tried, since few villages and no towns are situated on their outcrop, and there is therefore little demand. In the Middle Coal Measures the clays above the Top Hard Coal have been most frequently used ; but at Brockwell, Chesterfield, pits are working shales resting on the Piper Coal ; and between Clay Cross and Chesterfield the clays and shales about 100 ft. above the Deep Soft Coal have been used in several places, though only a few pits are at present in operation. The chief clay-pits which occur at horizons above the Top Hard Coal have been mentioned in connexion with the descrip- tion of these measures (pp. 74-6). The unstratified pale-coloured clays are in most request, though the shale-beds have not been neglected. The Middle Permian Marls are extensively worked for brick- making between Skegby and Mansfield, and to a less extent south of Mansfield, while to the north several disused pits in- dicate a former industry. In order to get the full depth of marl, which ia frequently not more than 13 ft. thick, the excavations commence near their summit so that the pits are mostly situated on the margin of the Bunter. Pot-clay suitable for the manufacture of stoneware occurs below a thin coal (p. 58) above the Alton seam at Upper Loads, west of Holymoorside, where, in a clay-pit south of Loadshead Farm, the following section was obtained: — ft. in. White clay 2 6 Peat 3 Black shale 6 Coal _ 4 Gannister 1 Pot-clay 3 BRICKS, LIME, ROAD-METAL. 125 The clay, after weathering, is carted to Chesterfield. A similar kind of clay occurs below the Tupton Coal and is obtained by open-working at the London Pottery, Chesterfield, and by levels near Grangewood Farm and east of Walton. It is liable to change laterally into a bastard gannister, unsuited for use either as a pot-clay or as a gannister. The underclay of the Forty Yards or Eider Seam (p. 57) is raised as a pot-clay near Millhouses and Beauchief, but it is often replaced by a hard gannister. It has been worked along its outcrop for some miles southward into Derbyshire, and also at Dore. The principal beds of gannister worked are (1) those forming the seat-earth of a small coal, probably equivalent to the Soft Bed Coal of Yorkshire : (2) one under the Alton Coal : and (3) another below the Forty Yards Coal. Of these the bed No. 2 is extensively mined at the Mooredge Gannister Mine, Totley, where the rock is of a pale grey colour with carbonaceous plant- remains and some pyrites. Fire-bricks and all kinds of casings and moulds for steel and chemical works are manufactured from it. LIME AND CEMENT. Black limestones of the Carboniferous Limestone and of the Limestone Shales have been used in the manufacture of cement, but no regular industry has been established for this purpose. The Carboniferous Limestone has been extensively worked for lime in many places, of which at the present day the quarries at Crich Stand are the most active. In the eastern area the Mag- nesian Limestone becomes an important source of lime, and this industry has been continued where formely the stone was chiefly quarried as a building stone. It is said to produce a good ' fat ' quicklime. Mention of the more important excavations has been made in a previous chapter (pp. 85-91). ROAD METAL. The Carboniferous Limestone is used extensively for road- metal, stone for this purpose being principally raised from the beds above the upper lava, including the cherty beds. In the last few years, quarries have also been opened in the ophitic olivine-dolerite of the Bonsall and Ible sills ; three quarries working this dolerite for road-metal in 1909 having extracted 5,759 tons valued at £795*. It is probable that the experiment of using this dolerite would have been tried earlier but for ignorance of the distinction between it and the ordinary toadstones (lavas and tuffs) which are useless for the purpose 2 . C. B. W. 1 Home Office Report for 1909. 8 The dolerite is distinguished by a separate colour on the one-inch map, Sheet 112. 25276 I 2 126 ECONOMIC GEOLOGY. Road-metal is likewise obtained from the harder beds of the Millstone Grit and i'rom the thin gannister-like sandstones of the lower Coal Measures, e.g., at Sleigh Wood, north of Ashbver. South of Mansfield, pebbles from the Bunter Conglomerate are collected and broken for road-metal. SAND AND GRAVEL. Moulding-sand, for which there is necessarily a great local demand, is raised in large quantity from the Lower Mottled Sandstone in the south-east of Sheet 112, and this formation supplies all the sand raised for foundry purposes except for a limited quantity obtained from the Glacial sands of Beighton (p. 104) and from the Quicksands of the Permian. The biggest pit is that of the Mansfield Sand Co. (p. 96) which exhibits a working-face, about i mile long, of which the lower 30 ft. consists of a soft slightly loamy sand suitable for moulding, mixed with a varying proportion of coarser material which, with the rough sands of the Bunter Pebble Beds above, is utilized as a building-sand and for other purposes. In a pit near Sutton Junction (p. 96) the upper beds of the Lower Mottled Sandstone yield moulding-sand ; while at Kirkby Hardwick the lower layers are used. In the northern district the Quicksands at the base of the Permian are a source of building-sand which has been dug in two large sand-pits, one south of Barlborough Colliery and the other south-east of Pebley Pond. Other smaller excavations have been opened at the outcrop in several places. At Red Hill and Creswell the sandy beds of the Middle Permian Marl have also been tried. The Bunter Pebble Beds are dug in several places for the local supply of building-sand, while the pebbly bands are occasionally screened for gravel. Glacial sand and gravel are also quarried at Beighton. WATEE, SUPPLY. In the Carboniferous system, the principal water-bearing formations are the Carboniferous Limestone and the Millstone Grit Series; but the Limestone waters, besides being hard, are in some places liable to contamination, while the springs issuing from the Millstone Grit are inadequate in volume for the supply of large communities. Consequently most of the larger organized supplies of the Carboniferous country are obtained by impound- ing the moorland streams which drain high -lying and almost uninhabited tracts. The great Derwent Valley water-scheme, intended for the service of the Corporations of Derby, Leicester, Nottingham, and Sheffield, by which the waters of the upper Derwent are being impounded, is by far the largest of these undertakings; but its operations lie beyond our area, excepting that its water-mains are carried through the district, and may eventually be tapped for part of the local supply. The towns of Ilkeston and Heanor (in Sheet 125) obtain {heir supply from the old mining drainage-level of Merebrook Sough (p. 121) which draws the water from the Carboniferous Lime- stone and conveys it under Cromford Moor to its discharge into WATER SUPPLY. 127 the Derwent opposite Leashaw Farm. Its volume is reported to be about 15 million gallons a day, emerging at a temperature of 61° P. 1 The Alfreton District (Sheet 112) gathers a public supply from several points on the elevated tract of Millstone Grit between Wheatcroft and Ashover, partly from borings and partly from springs 2 . The Chesterfield Union Waterworks, besides the supply from the Linacre boring (p. 51), impound the surface-waters of several streams from the moorlands between Brampton and Totley Moss in three reservoirs. The Bakewell water-supply is obtained from springs at the edge of the high moorland of Millstone Grit, SE. of Beeley. Middleton-in-Wirksworth is supplied from springs issuing from the limestone above the toadstone; and Bonsall, from similar springs. Matlock Bath utilizes two springs, both from the Kinderscout Grit, one issuing on the east bank of the Derwent at Darley, and the other on Cromford Moor. Matlock has recently supple- mented its supply from springs in the Kinderscout Grit with a reservoir impounding the waters of Bentley Brook, which flow from springs at the base of the Chatsworth Grit. The villages on the elevated tract of Lower Coal Measures rely mainly on streams and springs ftrom the sandstones of these Measures. Many of the mining villages toward the eastern side of the exposed coalfield participate in the organized supplies of Mansfield and other towns, from deep wells in the Bunter situated to the eastward of our area. The supply for the Kirkby- in-Ashfield district is drawn from a well of this kind actually within the map (Sheet 112), at the SB. corner of Nomanshill Wood. The Magnesia n Limestone retains much water in its joints and fissures, but its supply is subject to contamination from the surface. It is tapped in numerous wells for the supply of houses and villages on its outcrop, and throws out strong springs at many points along the escarpment. q t^t j, Mineral and Warm Springs. — Of the Matlock Bath springs Dr. Strahan states 3 : — "The Matlock Spring was first noticed in 1698. Some years afterwards another spring was discovered a quarter of a mile from the first, and a bath was formed. At a still later period a third spring was met with about 400 yards east of the first, but being of a lower tempera- ture was neglected. It was imagined, however, that its water was mixed with that of a cold spring, and in 1786 a level was driven into the hill with the effect of preventing the mixing of the two springs. The total yield of the warm springs is about 60 gallons a minute, the temperature being 68° Fahrenheit, or 69° as observed by Dr. Darwin at the actual source." 1 See ' Geology of the Southern part of the Derbyshire and Notts. Coalfield,' Mem. Geol. Surv., 1908, p. 180. 2 Fuller information respecting the organized supplies of Derbyshire generally will be found in ' Report upon the Water Supplies of Derbyshire,' by Messrs. S. Barwise and J. S. Story (Derbyshire County Council, 1899), to which we are indebted for data in this and following passages. 3 ' The Carboniferous Limestone, &c, of North Derbyshire,' Mem. Geol. Surv., ed. 2, 1887, p. 116. 128 ECONOMIC GEOLOGY. Dr. Darwin, quoted by Pilkington, 1 on examining the sources of two of the springs when opened about 200 yards above their usual exit, found that the upper one issued from cracks in the surface of the toadstone (lower lava) and from underneath a blue marl with pyrites. He found that a dry summer, in which all the cold springs failed or diminished, had no perceptible effect on these warm springs, and on this and other grounds he concluded that the temperature of the warm springs was due to the depth from which the water ascends. It is probable therefore that the warm water comes up along a fault line, like an artesian well, before flowing out along the surface of the toadstone. Warm springs have been noticed also in the Bage and Gang Mines, between Wirksworth and Cromford ; in the Ball Eye Mine, south of Bonsall ; in the Great Rake, Matlock Bath ; and in the underground drainage from Cliffside, on the south-west of the Crich limestone; besides which the water of the Merebrook Sough (p. 121) is warm. It is notice- able that in nearly, if not quite, all these cases the source of warm water is at, or close to, a fault. * C. B. W. AGRICULTURAL GEOLOGY. In the western part of the Carboniferous country much of the land lies too high for profitable cultivation, and as, in addition, the soils over wide tracts are essentially poor, there is much unbroken heathery moorland in this quarter, including most of the higher dip-slopes of the Millstone Grit. A large portion of the Carboniferous Limestone country in the south-west has been rendered dangerous or unsuitable for grazing by the spoil-heaps from the old lead-mines. The outcrops of the Volcanic beds (' toadstones ') furnish a soil of stiffish loam which is tilled at most places where the elevation is not too high. The more open portions of the Derwent valley sustain dairy-farms which are run m association with the grazing of sheep on the uplands. Mixed farming, with grazing predominant, is practised on the Coal Measures, but much of the soil is cold and sterile, and frequent applications of lime are required. The richest agricultural belt of the maps is that of the Mag- nesian Limestone which usually weathers to a brown loamy soil, everywhere cultivated. In some places, more especially toward the eastern boundary of the formation, there are tracts of stiffer red clayey soil like that of the overlying Permian Marl. The superficial clay in such cases appears to be generally the residue of clayey seams that were intercalated with the limestone and is left when the latter disappears in solution, but occasionally it may be the last relics of the once-overlying Marl. The Marl soils themselves have their stiffness ameliorated in the northern part of the outcrop by the interstratified beds of sand, and farther south by the sandy downwash from the Bunter escarpment The Bunter carries light sandy soils, that of the Lower Mottled Sandstone being, however, sufficiently loamy to form excellent tillage, while that of the Pebble Beds is often too ' hungry ' and dry for profitable cultivation, so that, to the eastward of the present maps, there are tracts still remaining waste. G. W. L. ' ' A View of the Present State of Derbyshire.' 1789, p. 256. 129 APPENDIX I. SHAFT-SECTIONS ILLUSTRATING THE COAL MEASURES. 1. Sherwood. Measures above the Top Hard Coax. Section in No. 1 Shaft, Sherwood Colliery, Mansfield. 1 in. map (N.S.) 112. 6 in. map Notts., 22 SE. Abridged from a section communicated by Mr. J. W. Fryar. Height above O.D., 390 ft. f Bed sand Trias ... -J Clay I Hard pressed sand ... , f Bed limestone , I Bed clay Bed, yellow and brown limestone Permian ■{ White and grey sandy limestone Blue limestone ... I Soft blue shales [Schizodus, &c] (_ Breccia or conglomerate... Red and blue shales [Newopteris] and some sand stone Red and grey sandstone Stone bind and sandstone Coal Clunch, stone bind, bind, coal 7 in Coal Bat Bright coal ... ... ... Clunch Bind and stone bind Bright coal Clunch with ironstone Bind and stone bind Bright coal Grey clunch Bind and clunch Bright coal Clunch Bind and clunch... Bright coal Clunch Stone bind and clunch i! ne i b {? d j"n T -n" } Mansfield Marine f Black bind [hard argillaceous > j> j •< limestone] J * ( Coal Bind and some sandstone ... Coal Thickness. Depth. Ft. In. Ft. In. . 4 9 . 1 . 8 3 14 . 15 . 1 6 , 89 10 . 8 9 . 26 11 . 88 3 . 8 252 3 . 16 9 . 33 6 . 17 9 . 2 320 5 . 37 3 . 6 . 7 . 2 8 361 5 . 4 11 . 20 6 . 1 4i 388 24 . 5 2 . 42 10i . 1 9* 438 04 . 6 114 . 22 8 . 1 5 . 10 . 22 2 , 1 8 493 9 9 5 3 60 4 9 1 564 7 . 81 1 , 5 130 SHAFT-SECTIONS OF COAL MEASURES. 1. Sherwood— continued. Olunch and bind (Joal Clunch Bind Coal Stone clunc!i Bind, sandstone, coal 5 in. Streaky grey sandstone ... Strong black bind Coal, Clowne Coal Hard grey clunch Bind and stone bind Coal Clunch Sandstone Bind Coal Bind with ironstone Sandstone and stone bind Dirty coal and bat Clunch Sandstone Strong bind Coal and bat Clunch Bind Coal Clunch Sandstone and bind Coal ...] Clunch V [High Hazles Coal] Coal ...J Stone clunch ... Bind, clunch, stone bind, thin coal Sandstone Bind Coal Grey clunch Sandstone Stone bind Grey bind Grey sandstone ... Stone bind Black bind Clunchy bind Bright co'al} Coombe Coal ... Dark grey clunch Coal, Top Hard Coal Grey clunch Bind Coal Clunch and bind Coal, Dunsil Coal Stone clunch Bind Coal Stone clunch Thickness. Depth. Ft. In. Ft. In. ,.2 3 .12 649 6 . 12 .. 22 104 . Hi 685 4 .62 . 55 5 . 28 . 4 li ,.2 8 781 84 . 2 34 . 19 74' . 1 804 74 . 5 44 . 9 10 . 45 1 . 3 867 11 . 37 9 . 20 7 . 3 2 929 5 . 3 7 . 12 Hi . 6 4 . 94 953 1 . 1 9 . 13 2 .. 2 10 970 10 . 1 ,. 67 9 r 2 9 2 1 8 1043 2 .. 1 6 ,. 82 .. 40 7 ,. 70 2 .. 1 1 1238 6 .. 11 ..8 8 .. 5 11 ..14 ..5 2 .. 27 54 ..10 ..3 8 ( 4 I 1 6 ..3 4 ..6 2 1303 114 ..4 8 .. 23 04 .. 1 6 1333 2 ... 25 1 ..2 8 1360 11 .. 11 11 .. ,6 .. 64 .. 3 54 1377 4 SHAFT-SECTIONS OF COAL MEASURES. 131 2. Maltby. MeASUEES ABOVE THE TOP HaBTJ (BaeNSLEy) GOAL. Section in No. 2 Suaft at the Maltby Main Colliery. 1 in. map (K.S.) 101; 6 in. map Yorks., 291 SW. Abridged from ' Concealed Torts. -Notts. Coalfield,' Mem. Geol. ' ' Surv., 1913;- VV . 98-104. Height above O.D., 25876 ft. ' Made ground and soil- Limestone, blue clay partings Hard limestone Permian ■{ Honey-eombed limestone, gypsum ... Grey limestone I Red and blue marl t Hard grey limestone Red and grey sandstone, some marl (Etruria Marls) Grey bind, ironstone, thin coals, some sandstone ... Coal, 8 in., dirty coai, 4 in. ... Strong clunch ... Grey sandstone, very hard ... ... Grey bind, ironstone-. Coal ... Bind with ironstone; thin coals Very hard sandstone Bind, stone bind, two thin coals Grey sandstone .• t Cannel Coal, clean, bright Dirt Coal, clean, bright -. Bind with ironstone Grey sandstone i Coal ['? Shafton Coal] Clunch ... Grey sandstone Bind, stone bind and 'thin coal Coal Stone clunch ... Hard grey rock Grey bind, bands of rock Grey bind with ironstone (Marine Bed) Coal Clunch Coal Clunch Bind, with sandstone .. Coal Cluneb Stone bind and rock Coal Thickness . Depth Ft. In. Ft. In. 2 2 19 6 76 10 19 40 1 12 2 6 7 176 2 31 7 207 9 146 2 1 354 11 I 38 2 6 5 1 5 401 11 58 10 100 11 561 8 101 4 158 5 821 5 2 2 2 8 824 5 67 5 83 1 1 44 976 34 4 24 105 1 83 1 10 1169 6 1 5 17 10 8 10 11 1207 8 1 8 1209 4 11 9 2 1221 3 3 6 25 4 5 11 135 1 1 7 1392 8 132 SHAFT-SECTIONS OF COAL MEASURES. 2. Maltby — continued. Bind, with ironstone Coal Bind Coal Dirt Coal Bind, ironstone, thin coals ... Coal Chinch, bind Coal Clunch, bind, stone bind G-rey bind Dark greyish-blue shale \ Mansfield Marine Argillaceous limestone / Bed Coal and bat ... Bind, ironstone, stone bind ... Blue bind, ironstone (Marine Bed) Bind, clunch, thin coals Coal, Meltonpield or Wathwood Coal Clunch and bind Thickness. Depth. Ft. In. Ft. In. 73 5 10 33 6 1 8 10 125 6 2 27 10J 1 4 57 74 6 19 04 1 34 125 10 18 8 Coal, bright Dirt ... Coal, bright Dirt ... Coal, bright Dirt ... Coal, hards , Dirt ... Coal, bright 1 - Two Foot Coal J Bind, clunch, thin coals Dark bind with pyrites (Marine Bed) Bastard cannel SaL?! coal ::: } Abdy Coal - ■ Clunch, bind ... Coal, Beamshaw Coal Clunch, bind, thin coals Coal Clunch, bind Bard white sandstone Coal, bright Coal and bat Clunch, bind with ironstone... Coal, bright ... ") Dirt V- Kents Thick Coal Coal, bright ...J Clunch and bind Coal, softs ... } Coal, hards Dirt Coal, bright ... J Clunch and bind Coal, soft Bind and stone bind ... Coal Clod with cank balls ... Coal, Baensley Coal Kents Thick Coal 96 8 2 3 69 4 1 1466 11 1502 11 1630 5 1659 74 1743 7 1818 1 1987 1 2 14 14 1 9 1 64 44 2i 6 8 1 11 3 74 27 2 58 2059 34 2116 1 2146 2204 11 2259 11 8 21 6 31 9 1 5 4 60 1 1 2 04 1 84 2322 11 27 10 4 10 I-} 5f 21 1 1 3 68 11 1 11 6 6* 8 6J 2352 6 2374 10 2445 8 2460 9 SHAFT-SECTIONS OF COAL MEASURES. 133 3. Williamthorpe. Measures between Top Hard Coal and Silkstone Coal. Section at the Williamthorpe Colliery (abridged). 1 in. map (N.S.) 112. 6 in. map, Derby, 30 NE. Height above O.D., 450 ft. approx. Soil and clay Bind, clunch and 3 thin coals Coal Bind, stone bind, rock Coal Stone bind, bind, rock Coal Bind with ironstone, bind, stone bind Strong stone bind Stone bind and rock beds ... Bind with rock and ironstone Dark bind Gees Coal, Top Hard Coal Clunch and stone clunch Rock, stone bind, bind, clunch Coal, Dunsil Coal Bind and stone bind ' Coal, bright .. - 1st Waterloo Coal 2nd Waterloo Coal Dirt Coal, bright Dirt ... Coal ... Bat and coal _ Clunch and bind Sandstone ... Bind Coal, soft „ hard „ soft Dirt Coal, soft Dirt Coal, soft Smutt Clunch Sandstone ... Bind Coal Clunch and bind with ironstone Coal Bind with ironstone Coal, soft Hard band Coal, soft „ hard „ soft Dirt Coal, soft - [? Top Ell Coal] Thickness. Depth. Ft. In. Ft. In 7 7 95 9 1 9 104 6 92 11 2 9 200 2 102 1 1 8 303 11 160 8 5 6 2 1 13 3 2 4 2 4 6 492 5 3 6 68 7 2 2 566 8 39 4 2 24 2 04 1 3 5 611 20 54 42 104 20 3 • 14 1 4 7 3 104 7 1 5 2 699 11 2 2 18 2 12 1 1 733 4 73 1 807 4 51 3 54 14 94 1 3 04 34 860 74 134 SHAFT-SECTIONS OF COAL MEASURES. 3. Williamthorpe— continued. Thickness . Depth. Ft. In. Ft. In. Bat 3i Chinch 2 2 Bind with ironstone .. 48 7 Bright soft coal r l 5 Hard and soft coal 9 Bright soft coal - Ell Coal 6 Dirt 04 Soft bright coal 24 914 7 Bind, stone bind, clunch, ironstone, 3 thin coals 181 3 Coal 1 7 Dirt ) f o 74 Coal 94 Dirt 1 4 Coal 6J Dirt 1 Coal and dirt > [? Deep Soft Coal] ... 9 Coal 3 Dirt 4 Coal 5 Dirt 4 Coal 94 1102 04 Bind with ironstone .. 63 64 Grey rock [Deep Hard Rock] .. 124 5! Soft coal 1 1 Hard open grain coal 1 5 Dirt - Deep Hard Coal -< 2 Soft coal and dirt ... 2 4 Bat and coal ... ; 1 1296 Of Clunch and bind .. 43 li ssisr 1 ;*™*^ I ? 6 3 1340 11 Clunch and ironstone .. 10 2 Coal and dirt 1 3 1352 4 Bind and clunch .. 15 54 Coal and clunch 1 3 Black bind 1 7 Coal 1 1371 74 Bind and clunch, ironstone, 2 thin coals... . 69 7* 9 Coal, Tupton Coal 4 1446 Clunch and bind . 23 74 Soft coal ~| Hard coal m » „ Bat ... 1-Tupton | Coal ... . f o 1 o 9 3 2 Inferior coal J 4 1472 14 Clunch and bind with ironstone .. 100 104 Bright coal ^ 8 Bat ... 4 Bright coal )■ Yard Coal < 1 2 Bat ... 4 Soft coal 5 1575 4 Clunch ... .. 10 5 Rock and stone bind [Silkstone Rock] ... .. 40 5 Bind 2 74 9 Coal, Silkstone Coal 4 1633 64 Clunch, rock, s tone I inc . 40 1 SHAFT-SECTIONS OF COAL MEASURES. 13.5 4. Mickley. Measures between Silkstone Coal and Mickley Thin Coal. Section at the Mickley Colliery. 1 in. map (N.S.) 100. 6 in. map, Derby, 17 NE. Abridged from a section communicated by Mr. A. Riley. Height above O.D., 727 ft. approx. Soil and brickwork Shale, fireclay, ' hard stone ' Soft smutty coal and shale Holing dirt or fireclay Grey stone, very hard Galliard Sandstone rock Grey bind and black shale Mickley Thick Coal or Ten Beds Grey rock or galliard Yellow sand, clay and iron balls ... Gannister stone or rock Cockle shell bind, light Inferior Cannel Coal " Jonnies " Coal [inferior] Hard grey stone Soft dark bind and cockle shells . . . Cannel Coal (rather dull) " Jonnies and Bridey " [bituminous coal] Hard stone ... ... Black shale bind, clod, ironstone binds Mickley Thin Coal Fireclay Rock, grey galliard or gannister ... Other sections illustrating the Coal Measures are given in Plate VI., and Pig. 6, p. 51, the latter including the Linacre and Apperknowle borings which show the remainder of the Lower Coal Measures below the Mickley Thin Coal. Thickness. Depth. Ft. In. Ft. In 19 4 — 13 5 — 1 8 34 5 1 — 6 6 — 3 1 — 25 — "1 8" ■ — :- 6 77 8 10 — 2 — 1 6 — 1 3 — 9£ — 3£ 82 6 9 — 3 4 — 10 — 8 96 4 14 6 — 19 8 — 1 9 132 3 1 8 — 6 139 11 APPENDIX II. Fossils from the Carboniferous Limestone in the Survey Collection. Note. — This list does not include all the species collected by the Survey, but is confined to those of which the nomenclature has been recently revised. Numbers in the Columns refer to the appended List of Localities. Dibunophyllum Zone. g ^ ».2 Genbea and Species. gfo °-S S 0e H S . off- n — . — 20 „ ? or Campophyllum ? [large form ; . 9, 84, 90 characteristic] " Carcinophyllum sp. ... 45 Cladochomis ? 38 Clisiophyllid 49,50 4, 7, 19, 29, 30, 36, 38, 88, 90. 28 „ [group of Clisiophyllum inter- ,«. 71 medium Thomson] ,, sp. nov. ... 62 Clisiophyllum aff. oblongum Thomson — 26 » sp — 48,93 „ sp. nov. 7 Cyathaxonia cornu Mich 20 „ rushiana Vnughan — — 2, 13, 20 28, 94. ,i sp. ... 2,20 Cyathophyllum murchisoni E. & H. 43,76 19,61 57 )) < 49, 78, 79 „ cf. murchisoni 80 _ ., regium Phitt. — 38, 75, 87, 89. — » SP 41, 42, 43, — 28 Densiphyllid 44, 45. 28 " Densiphyllum " charlestonense Thomson... 94 n sp — — 94 FOSSILS OF THE CABBONIFEEOUS LIMESTONE. 137 Genera and Species. Dibunophyllum Zone. sir ffltS- Dibunophyllum dioki (Ihomson) II off- i) „ matlockense Sibly „ muirheadi Nich. & Thom- son ii <# ii ll c/. >i „ turbinatum (M'Coy) ii <#• ii C/- i) „ sp. [near, to D. muirheadi Nich. & Thomson] „ sp. [clD. "0" Vaughan] ... sp. [young form] „ sp. nov. „ sp. nov. ? ii spp Cf. Diphyphyllum concinnum Lonsdale Diphyphyllum lateseptatum M'Coy ,, ? paracida (M'Coy) Cf ? Diphyphyllum sp Lithostrotion irregulare (Phill.) Ii cf. „ junoeum (Flem.) maccovanum E. & H. martini E. tfi H. „ cf. martini Cf. „ martini „ portlocki (Bronn) Lonsdalia cf. duplicata (Mart.) „ floriformis (Flem.) II SP Lophophyllum proprium Sibly ,i a ff- .. ,i sp Michelinia glomerata M Coy Syringopora cf. distans (Fisch. de Wald.) , „ geniculata Phil!. » ? 81 78 43, 44, 46, 49, 59, 80, 81. GO 80 81 47,59 90 62,88 48 38,90 72,88 62 90 10,84 90 19 34 19,68 9, 19,29, 48,87,90. 38 90 87 39 7, 16, 38, 55, 62, 90. 40 33,95 6, 9, 10, 64, 66, 84, 90, 93. 7, 17, 19, 36, 38, 39, 40, 64, 66, 67, 72, 83, 84, 87, 88, 90, 92, 93. 48 19,48 10 63,64 93 11 11,26 52, 61, 86, 87. 48 9 7 19,64 93 28 3 28 28 28 138 FOSSILS OP THE CARBONIFEROUS LIMESTONE. Dibunophyllum-Zone.- Genera and Species Syringopora cf. geniculata reticulata ? Gold/. sp Zaphrentid Zaphrentis costata (M'Coy) ... ? ,, ,, . ... ... ... ... „ off. „ „ disjuncta R, Carr. [pseudo-par- allela stage] „ enniskilleni? E. & H. „ aff. enniskilleni „ omaliusi E. & H. „ sp. [gens of Z. enniskilleni E. & H.] ,, sp. [near to Z. omaliusi E. & H.] ... „ sp. nov. [near to Z. costata (M'Coy)] „ sp. nov. ., SPP • G-ranatocrinus sp. 1 Archaeocidaris sp Bryozoan Fenestellid Tabulipora cf. howesi (Nich.) Ambocoelia? ... Athyris planosulcata (Phill.) ,, sp. nov. ? Brachythyris oblata (/. Sow.) „ planicostata M'Coy „ sp. [planicostate] ■■ S P ? Camarophoria crumena {Mart.) [D av.] ... Ohonetes compressa Sibly ... „ sp. [papilionaceous var.] „ sp. nov.? Daviesiella? Dielasma sp Cf. Martinia glabra (Mart.) Martinia ovalis (Phill.) Productus aculeatus (Mart.) ,, ? „ antiquatus J. Sow. >. p o w a q .a S^_ Productus latissimus /. Sow. _ 28 „ latissimus? 46 19, 53, 57 — .1 >. — — 28 Schellwienella sp , — — 5 Schizophoria resupinata (Mart.) 59 21 — Seminula ambigua? (J. de C. Sow.) — 24 — Cf. „ ambigua — — 94 Spirifer bisulcatus J. de C. Sow — 38 94 „ „ var. — — 2 ? 80 19,39 2,3 ,, cf. bisulcatus — 48, 53, 55 82 „ duplicicosta ? Phill. 59 — — „ integricosta Phill — 23 — ? — 22 — Aviculopecten ? — 39 — Bellerophon? 43 — — Cf. Euomphalus subpentagonalis de Kon. .. — 12 — Euomphalus? 46 — — Euphemus sp — 8 — Loxonema? 43 — — Porcellia cf. mosana de Kon — 92 — Straparollus sp. 44 — — 9 43 — — Cf. Griffithides brevispinus H. Woodw. — 17 — Phillipsia? " 94 25271! K 140 FOSSIL-LOCALITIES IN CARBONIFEROUS LIMESTONE. 7. Crich : Hilt's Quarry : E. side : „ „ N. side : Crich Stand Quarry : SB. corner Localities (Numbered as in the above List). 1. Crich : old quarry E. of Hilt's : SB. corner : top beds of main limestone. 2. „ „ ,, N. end ; W. side : top beds forming dip- slope. 3. „ „ ,, „ „ 3 ft-10 ft. below top. 4. „ „ „ „ „ about 25 ft. below top. 5. „ „ „ „ „ scree representing pro- bably topmost 10 ft. 6. „ ,, „ - below lowest chert at S. end of quarry: approximately 70 ft. below top of lime- stone. 1 f t.-15 ft. above lowest chert. 1 ft.— 15 ft. below lowest chert. 1 ft.— 15 ft. below lowest chert, below Lonsdalia-bed (see p. 36). „ „ Lonsdalia-bed. „ _ „ highest beds full of gasteropods. S. corner of limestone outcrop : small pit on N. side of Gin Lane : top beds of main limestone. „ Hockley Quarry. „ „ about 12 ft. below top of quarry. ,, ,, top beds of quarry. „ quarry in W. end of Hate Wood : cherty bed about 30 ft. from top of quarry. Wirksworth : Stoneycrof t Quarry : S. part above ascending footpath, about 40 ft. below top of quarry. „ incline on High Peak Line, N. of Middle Peak and 50-100 yds. W. of upper road. „ Shaw's Coalhills Quarry (southern quarry) : E. side of M.R. mineral line, 200 yds. S. of High Peak Line, E. side of entrance, W. of north-westerly fault. „ same quarry ; eastern division : massive limestone just below fault-plane bringing in shale. „ fault-cliff-100 yds. N. of same quarry, and S. of Maltster's Venture Mine, . „ cliff in angle of junction of High Peak and Wirksworth mineral lines. „ Coalhills i ii ■•■ ... ... Sigillaria discophora (Kbnig) Kilburn Coal Wingfield Sandstone Kilburn Coal ii ii Silkstone Coal Kilburn Coal Kilburn Coal 180 "ft, above Kilburn '". Kilburn Coal 53 ft. below Kilburn" '.'.'. Kilburn Coal Silkstone Coal 68 ft. below Naughton Coal Wingfield flagstone Kilburn Coal 68 ft. below Naughton Kilburn Coal Q ilkstone Coal Above Belper Lawn Coal 68 ft. below Naughton 32 ft. below Kilburn Kilburn Coal 68 ft. below Naughton Kilburn Coal 44 46 46 46 40 46 23 11 46 46 46 44 25 46 46 25 44 46 33 46 34 46 46 22 46 17 22 40 46 A._£k) V.(h) A. (k) A.7k) V.(i) A.(k) A.(k) A.(k) A.(k) V.(i) G.(P) A. (k) G.(p) V.(h) V.(i) G(P) V.(i) A.(k) A.(k) G (P) A..(k) A.(k) G.(P) Moysey. Vernon. Moysey. ii I! Vernon. Moysey. Moysey. Vernon. Survey. Moysey. Survey. ii Vernon. Survey. Vernon. Moysey. Moysey. Survey. Moysey. Vernon. Moysey. » Survey. Moysey. Mllpp.'m-lls^" *™* " lvcOf0dioide * Sternb. See R. Kidston, "Vegetaux houillers du Hainault,' FOSSILS OF THE LOWEE COAL MEASUEES. 147 Genera and Species. HOBIZON AND LOCAliITT. Refer- ence. Col- lection. CORDAITALES. Artisia approximata (Broyign.) Cordaites sp SEMINA. Rhabdocarpus elongatus Kidston ANIMALIA. Annelida. Spirorbis sp CllUSTACEA. Palseocaris sp. .. Merostomata. Belinurus bellulus (Konig) » sp Cyclussp Aracbnida. Anthracoscorpio sp Kilburn Coal Wingfield flagstones Kilburn Coal Kilburn Coal Kilburn Coal Kilburn Coal •» » Kilburn Coal 46 40 40 46 46 46 46 46 46 A. (k) V.(h) A. (k) M. Moysey. Vernon. Mqysey. Moysey. Moysey. Moysey. » Moysey. 2. FISHES 1 . Elasmobranchi i. Aoanthodes wardi Egert. Kilburn Coal .. 22 G. (p) Survey. „ sp Shales above Alton Coal .. 22 G. (p) n » Roof of Naughton Coal .. 22 tl „ Gyraoanthus formosus Agass Kilburn Coal .. 46 Moysey. Hoplonchus sp Roof of Alton Coal ... .. 6 V. (i) Vernon. Sphenacanthus hybodoides {Egert.') ... Kilburn Coal .. 22 G. (p) Fryar. Teleostomi. ■Coelacanthus elegans Newb 40 ft. above 1st Grit .. 22 G.(p) Survey. jj ,j ... ... 30 ft. below Alton Coal .. 22 J) JJ 5) "• *" Shales above Alton Coal .. 22 1( 1 , Dale Moor Rakes . . . .. 45 S.W.' (q) )J „ Roof of Naughton Coal .. 22 G. (p) ,, 'Elonichthys aitkeni Traq Dale Moor Rakes . . . .. 45 S.W. (q) „ 1 „ binneyi Traq )) )> .. 45 T. (r) Sedgw. Mus. „ sp 30 ft. below Alton Coal .. 22 G. (P) Survey. 50 ft. above Alton Coal .. 22 Megalichthys hibberti Agass Shales above Alton Coal .. 22 !J ;] ., ,, Roof of Naughton Coal .. 22 i) i » j, ... ... Kilburn Coal .. 22 G."(p) Fryar. „ intermedins A. S. Alton Coal .. — V. (i) Vernon. Woodiu. ■Mesolepis wardi Young Dale Moor Rakes ... .. 45 )J 1 Sedgw. Mus. 1 „ microptera Traq. ... ■ )t ■! *•• .. 45 1 „ soalariB Young )J J> .. 45 ?! ,, 'Platysomus tenuistriatus Traq. » 1) .. 45 G. (P) Survey. Rhadinichthys monensis (Egert.) 50 ft. above Alton Coal .. 22 G. (p) » Rhizodopsis sauroides (Will.') 40 ft. above 1st Grit .. 22 )> >i J5 )» ') *•• Dale Moor Rakes ... .. 45 S.W. (q) )) ), Roof of Naughton Coal .. 22 G.(P) j» „ sp 50 ft. above 1st Grit .. 22 J! ,. „ 50 ft. above Alton Coal .. 22 1) )3 1 All those fishes marked with a fig. 1 were identified from complete or nearly complete examples. The others were identified from scales, teeth, &c. 148 FOSSILS OF THE" LOWER COAL MEASURES. 3. FRESH-WATER LAMELLIBRANCHS. Geneka and Species. Horizon and Locality. Repee- ENCE, Col-"" LECTION. Anthracomya laevis, var. scotica Eth. Sbale above Alton Coal ... 22 G. (p) Survey. jun. 30 ft. above Naughton 22 1) ii „ modiolaris {J. de C. Sow.') ii ii ii 20 V.(i) Vernon. Carbonicola acuta (J. Sow.) Shale above Alton Coal 22 (p) Survey. 30 ft. above Naughton 20 V.(i) Vernon. „ var. rhomboidalis Hind ii n ii 22 G.(P) Survey. „ aquilina {J. de C. Sow.)... •i i. ii 20 V.(i) Vernon. Kilburn Coal 25 11 ii " 180 ft. above Kilburn 34 »* ii Silkstone Coal 35 ,1 ii »j n " ii ii ■■■ ••• 27 g.Cp) Survey. „ nucularis Hind 30 ft. above Naughton 22 G.(p) ii Silkatone Coal 35 T.(i) Vernon. " " tl , ii ii ••* ■*■ 27 G. (p) Survey „ robusta (/. de C. Sow.) ... 30 ft. below Alton Coal ... 22 G.(P) Vernon. ; ... Shale above Alton Coal 22 » ii 30 ft. above Naughton Coal 22 *) i ii Kilbuin Coal 25 V.(i) ii ii 180 ft. above Kilburn 34 11 ii Silkstone Coal 35 It ii l' 1! II ■*• ii ii 27 a. ( P ) Survey. „ similis {Brown) ... .„ Kilburn Coal 46 V. (i) Vernon.- ,. turgida {Brown) Silkstone Coal 35 j) ii II I! 11 **■ ■'* n ii 27 G.(p) Survey. Naiadites modiolaris {J. de C. Sow.) ... 30 ft. above Naughton 22 G.(p) n <• Kilburn Coal 46 V.(i) Vernon. ii 180 ft. above Kilburn 84 sp Silkstone Coal 35 11 ii 4. MARINE FOSSILS (EXCLUSIVE OF FISHES). Beachiopoda. Lingula mytiloides J Vernon. Survey. Moysey. Vernon. B. From between the Silkstone and Top Hard Coals. 1. PLANTS AND AETHEOPODS. PLA^TAE. FlLIGALES ET PtERIDOSPEBMEAE. Alethopteris davreuxi Brongn. Below Top Hard Coal 41 A. (k) Moysey. j» ?> *i ■■• Top Hard Coal 12 jj ,, „ decurrens (Artis) Deep Soft Coal 14 — Survey. »' )» n Below Top Hard ... 41 — Moysey. j) » » Top Hard Coal 12 A.(k) „ lonchitica QSchloth.') 210 ft. above Deep Soft Coal 37 J> ., ,, ■ ,, Below Top Hard ... 41 ,, )i i) • ») Top Hard Coal 12 II II M )» 1) ») J) ■" JJ JJ JJ 1) 5 36 H.(d) — Corynepteris ^oralloides ( Gutbier*) . . . Between Ell and Deep Coal. Soft 32 A. 00 Moysey. Ooryne[.teris sternbergi (Mt.~) Between Deep Hard Silkstone Coal. and 4 Survey. Crossotheca sp Below Top Hard Coal 41 A.(k) Moysey. Dactylotheca plumosa (ArtAs) Between Deep Soft and 4 — Survey. ™. Silkstone Coal. j' J? j> •■■ »■• Top Hard Coal 36 H. (d). — Eremopteris moyseyi Arber jj » 12 A.(k) Moysey. Mariopteris dernoncourti Zeiller )) jj ■■■ ... 5 jj ,. lalifolia (Brongn.*) .' Below Top Hard Coal 41 A. 00 jj 'i j) i) *■■ Top Hard Coal ... 5 )» jj *) )j » ••• )? u ••• 16 V.(i) Vernon. „ mnricata (Schloth.') Between Deep Hard Silkstone Coal. and 4 Survey, »I J> »» Between Ell and Deep Coal. Soft 32 A.(k) Moysey. ') )> »t *•• Below Top Hard Coal ... 41 JJ jj n !) sj Top Hard Coal 12 5 36 »J » V )! )* )) r? » H."(d) jj jj j> » >i >» » 31 V.(i) Vernon. » sp Piper Coal 21 — Moysey. » JJ "• ••* ••' •" Between Deep Hard Silkstone Coal. and 4 ~- Survey. Neuropteris gigantea Sternb Below Top Hard Coal ... 28 — Moysey. \i » j; ••• j» jj jj ... 41 A. 00 jj jj )) j< •■• ••■ Top Hard Coal ... 36 H.(d) — )) (J !) ••* •" )> j) ... 31 V.(i) Vernon. „ heteropliylla Brongn. Furnace Coal ... 10 Moysey, » j) »» •• Between Deep Hard Silkstone Coal. and 4 Survey. 150 FOSSILS 01 THE MIDDLE COAL MEASURES. Genera and Species. Horizon and Locality. Refer- Col- ence. IiECTIOK. Neuropteria heterophylla Brongn* Between Ell and Deep Coal. Soft 32 A.(k) Moysey. )) !) J **' Waterloo Coal ... 24 )) J) ■) Below Top Hard Coal ... 41 It » )) J) Top Hard Coal ... 12 ... 5 ... 36 ii r) )j *) » )t •' ji » H.(d) !) )• 11 '! » n *•• ... 16 ... 31 aui 4 V.(i) Vernon. 11 J) J* ., obliqua Brongn Betweed Deep Hard »1 Survey. Silkstone Coal. D jj j) ... ... Waterloo Coal ... 24 Moysey. , ,, j, Below Top Hard Coal ... 41 A. (k) ., ,, ,, Top Hard Coal ... 31 V.(i) Vernon. „ forma impar {Weiss) 1 Between Deep Hard Silkstone Coal. and 4 Survey. Below Top Hard Coal ... 41 — Moysey. ., osmundae (Ariis) )) M jj 41 A. (k) ., pseudo-blissi Pot i) ») )i 41 „ rarinervis Bunb >) » » 41 A. (k) ,, „ Top Hard Coal 12 ,, scheuchzeri Sbffai. Furnace Coal 10 „ tenuifolia (Schloth.) Below Top Hard Coal 41 A.(k) '» )) )» Top Hard Coal 36 H.Cd) — ■* ji •) j* 16 V.£i) Vernon. sp 210 ft. above Deep Soft Coal 37 A. (k) Moysey. )) )) Top Hard Coal ... 36 H. (d) ., (Cyclopteris) trichoman- Between Deep Hard and i Moysey. oides (Brongn.') Silkstone Coal. 1) » >J 1> Waterloo Coal ... 24 — )) » » )) Below Top Hard Coal ... 41 A.(k) ~ , " . » " " Top Hard Coal ... 12 Odontopteris sp )» ?i ... 36 H."(d) Oligooarpia brongniarti Stur Below Top Hard Coal ... 41 A. (k) Moysey, Pecopteris miltoni (Aiiis) Between Deep Hard Silkstone Coal. and 4 Survey. •» )» )i Below Top Hard Coal ... 41 A. (k) Moysey. » ») :? Top Hard Coal ... 5 Rhacophyllum orispum, var. lineare Below Top Hard Coal ... 41 A. (k) ( Gutbier). ■> sp Between Deep Soft Silkstone CoaL and 4 — >! t) M Below Top Hard ... ... 41 Renaultia gracilis (Brongn.') Top Hard Coal ... 12 A.(kj 11 » sp " » Between Deep Hard Silkstone Coal. 5 and 4 — '1 !! Sphenopteris artemisiaef olioides Crepin Top Hard Coal ... 36 H. (d) _ „ dilatata L. 8; M ., fleyuosissima (Stur) ... Between Deep Hard Silkstone Coal. 5 and 4 A. 00 Moysey. Survey. „ furoata Brongn ., H , 4 „ . obtusiloba Brongn. Below Top Hard ... ... 41 ... 41 A.(k) Moysey. D ») n TopHard Coal '.'.' ... 36 H."(d) Jl ii of. sohwerini (Stur) i> *l ... ... 12 Moysey. . „ westphalica (Stur) Between Deep Hard Silkstone Coal. and 4 — Survey. Spiropteris sp. [Neuropteris ?] TJrnatopteris tenella (Brongn.) Below Top Hard Coal " '» >J 41 41 A.Tk) Moysey, _ .,, !' " " Top Hard Coal 12 " Zeillena avoldensis (Slur) Waterloo Coal 24 )1 jj j? » jj Below Top Hard .... 41 A.~k) I See footnote 2, p, 160. FOSSILS OF THE MIDDLE COAL MEASURES. 151 Genera and Species. HoEizox and Locality. Refer- Col- ENCE. lection. Equisetales. Annularia galioides (.■£. 4' H.~) Below Top Hard 41 A. (k) Moysey. » )? M Top Hard Coal 12 I) ii i* » n 36 H. (d) „ radiata (Brongn.') Between Deep nard and 4 Silkstone Goal. Survey. ii n n ••» ••• Below Top Hard Coal ... 41 A. (k) Moysey. ii ii »i Top Hard Coal 36 H.(d) — Asterophyllites charaeformis (Sternb.) Between Deep Hard and 4 Silkstone Coal. Survey. -ii i> ii Between Ell and Deep Soft 32 Coal — Moysey. ii ii n Below Top Hard Coal ... 41 A. (k) lt ii ii ii Top Hard Coal 5 ii M „ equisetiformis Below Top Hard Coal ... 41 ii (Sohloth.). n it ii Top Hard Coal 12 — ii ii ii n 36 H.(d) „ grandis (Sternb.) Below Top Hard 41 Moysey. „ longifolius (Sterai.) ... , 41 A.(k) Calamites oisti Brongn. 210 ft. above Deep Soft Coal 37 If ii it ii ii ... •■• Waterloo Coal 25 ii n ii Below Top Hard 4S 41 M ii ii ii i ii •-• „ cruoiatus (Sterrib.) TopHard Coal 5 ii n „ ramosus Artis Below Top Hard 48 1) Sedgw. Mus. „ suokowi Brongn Between Deep Soft and Ell 32 Coal. Above Deep Soft Coal ... 14 — Moysey. ii ii » — Survey. ii ii ii ■•• ••■ Waterloo Coal 24 Moysey. ii n ii Below Top Hard Coal ... 41 ii •« ii Top Hard Coal 12 A. 00 ii ii ii ■•• ii ii 36 H.(d) „ undulatus Sternb Between Deep Hard and 4 Silkstone Coal. Survey. n ii ii Waterloo Coal 24 — Moysey. ii ii ii Top Hard Coal 5 — ii „ varians Sternb Betw. Eli and Deep Soft ... 32 — ii >, ... ... Below Top Hard 48 A.(k) Sedgw. Mus. „ waldenbergensis Stur Between Ell and Deep Soft 32 Coal. — Moysey. ii sp Between Deep Hard and 4 Silkstone Coal. — Survey. n ii ••• •■■ ■" Between Ell and Deep Soft 32 Coal. A. (k) Moysey. ii ii ■•• ■•• Top Hard Coal 36 H. (d) Calamostachys equisetiformis (Sold.)... Below Top Hard Coal ... 41 - 41 Top Hard Coal 12 A. 00 Moysey. ii S P- ii ii ■•• ■•• )) )) ii Equisctites hemingwayi Kidston Below Top Hard Coal ... 41 JI ii Palaeostachya elongata (JPresV) Top Hard Coal 12 n ,, ettingshauseni Kxdston Piper Coal 21 — „ graoillima Weiss Top Hard Coal 5 A. (k) „ „ pedunculata Will. Between Ell and Deep Soft 32 Coal. ii Paracalamostachys striata Weiss Below Top Hard Coal ... 41 — ii Pinnularia oolumnaris (Artis") Between Deep Hard and 4 SiDxstone Coal. — Survey. ii sp Below Top Hard Coal ... 41 A. (k) Moysey. it ii "• •■■ Top Hard Coal 12 J> ii ii » „ - :..- •-..- 5 Jt 152 FOSSILS OF THE MIDDLE COAL MEASUBES. GENERA AND SPECIES. Horizon and Locality. Refer- ence. Col- lection. Sphenophtllales. * Sphenophyllum cuneifolium (Stemb.) Between Deep Hard and Silkstone Coal. 4 — Survey. n a n Below Top Hard Coal 11 A.(k) Moysey. 3) 11 11 Top Hard Coal 5 -' ., ,i ■ear. ,. ,, 16 V. (i) Vernon. saxif ragaef olium (Stemb.) „ majus Bronn Below Top Hard Coal 41 A. (k) Moysey. Lycopodiales, Asolanus caraptotaenia Wood Below Top Hard 41 A.(k) Moyaey. Bothrodendron minutifolium (Bonlay) Between Deep Hard and Silkstone Coal. 1 Survey. n " ii Below Top Hard Coal 11 A.(k) Moysey. Lepidodendron aculeatum Stemb. Detween Deep Hard and Silkstone Coal. 1 Survey. ii ■* )) '" Top Hard Coal 31 19 37 V.(i) Vernon. )) 3> )) — „ obovatum Stemb. 210 ft. above Deep Soft Coai A.'(k) ii Moysey. ii u ii Waterloo Coal 24 » n )) Top Hard Coal 36 H. (d) ophiurus (Brongn.) ... Between Deep Hard and Silkstone Coal. 4 Survey. •i i 'i -•• Waterloo Coal 24 Moysey. ,i 'i ji Below Top Hard Coal 41 — 51 » ') ii Top Hard Coal 36 H. (d) „ simile Kidston 1 Between Deep Hard and Silkstone Coal. 4 Survey. 11 n ii Waterloo Coal 24 — Moysey. n ii ii ■•• Below Top Hard Coal 41 A. (k) n it ii ii Top Hard Coal 13 ii ii ii >' „ -wortheni Lesq. Below Top Hard Coal 5 41 i ii sp Between Deep Hard and Silkstone Coal. 4 — Survey. ,, ,, Top Hard Coal 36 H. rd) Lepidophloios laricinus Stemb. Between Deep Hard and 4 Survey. *™ Silkstone Coal. ; , sp- Lepidophyllum lancifolium (Lesj.) ... Top Hard Coal 4 16 V. (i) Moysey. Vernon. ,, majus Brongn. Between Deep Hard and Silkstone Coal. 4 Survey. it » i* ■•• Below Top Hard 41 A. (k) Moysey. r ii n Top Hard Coal 12 M ii ii ii 11 )» j) ■•• ■■• 36 H. (d) — „ triangulare Zeiller ... Below Top Hard Coal 41 Moysey. sp )' J! )} 41 A. (k) ■ ii ii Top Hard Coal 12 Lepidostrobus lanceolatus (L. <$• H.)... 1 Top Hard Coal 5 A."(k) ., triangulare (Zeiller) ... Below Top Hard Coal 41 A.(k) ji sp Between Deep Hard and Silkstone Coal. ■ i Survey. )) )» ••• Between Ell and Deep Soft Coals. Waterloo Coal 32 — Moysey. . )» M •'• 24 _ )» J) ••• ■•• ... Below Top Hard Coal 41 A;(k) n 11 11 Top Hard Coal • 12 5 36 4 j» » Sigillaria elegans Brongn n n ••• ii n Between Deep nard and H."(d) n Moysey. Silkstone Coal. „ laevigata Brongn. ... Top Hard Coal 31 V.» Vernon. 1 fice footnote p. 146. FOSSILS OF THE MIDDLE COAL MEASURES. 153 .. — -. - -_. — _.—. - - . - .- . - ^ _ Refer- ence. _. . . . GrENEBA AND SPECIES. Horizon and Locality Col- lection. Sigillaria cf. maraillaris B rongn. Top Hard Coal 36 H. (d) „ ovata Sauveur Between Deep Hard and Silkstone Coal. 4 ~ " Survey. jj )j j) ••• **• Below Top Hard Coal 41 — Moysey. „ rugosa Brongn. Top Hard Coal 19 V.(i) Vernon. „ semipulvinata Kidston Below Top Hard Coal 41 — Moysey. „ cf. tenuis Achep Top Hard Coal 36 H.(d) — „ tessellata Brongn Between Deep Soft and Silkstone Coal. 4 — Survey. Sigillariostrobus sp 1? ii ii X — ii „ ,. Top Hard Coal 12 A.(k) Moysey. Stigmaria ficoides (Sternb.) Universal. COBDAJTALES. ArtiBia approximata (Brongn.') Below Top Hard 41 — Moyaey. Cordaianthus pitcairniae (L. $ B.) ... jj i? 47 A.(k) ii „ ?P Between Deep Hard and Silkstone Coal. 4 Survey. u .; ... ... ... Below Top Hard Coal 41 A.(k) Moysey. Cordaitea borassifolius (Sternb.') Between Ell and Deep Soft Coal. 32 ii 11 i: 11 Below Top Hard Coal 47 41 32 A. (k) ii jl n ij .. principalis ( Germ ) ii ii ii ■■• Between Ell and Deep Soft Coal. Below Top Hard Coal A. (k) ii ii ). j; ,, ... .. 41 )) i. Dorycordaites palmaeformis (Goepp.) Between Ell and Deep Soft Coals. 32 » " Sbmina. Carpolithea wildi Kidston Top Hard Coal 36 H. (d) Rhabdocarpua sp. Waterloo Coal 29 — Moysey. .j )j ... ... ... Below Top Hard Coal 41 A.(k) !) ,f ,, ... ... ... Top Hard Coal 36 H.(d) Trigonocarpus major Newb Dunsil Coal 18 — Moysey. „ parkinsoni Brongn. ... Below Top Hard Coal 41 A. (k) it ••■ Top Hard Coal 36 H. (d) — sp. •■• Between Ell and Deep Soft Coal. 32 Moysey. 11 )1 •*• ■•■• ••• Below Top Hard Coal 41 — >t ,j ,, Top Hard Coal 12 — •j ANIMALIA. Crustacea.. . , Anthrapalaemon sp Furnace Coal 10 — Moysey. u ,; ... ... ... Between Deep Hard and 4 — m Silkstone Coal. - Arthropleura armata Jordan ii ii ii 4 — j? J) 51 11 Below Top Hard Coal 41 — n ., sp. nov »j jj ii 41 — u Estheria sp. jj » ii 41 — 31 Leaia trigonioides Moysey jj jj 41 M. (m) )» Palaeooaris praecursor (B, Woodw.)... JJ 1) 11 ••• — HW.(g) J) „ \ SP- - it ., ... ... ... Top Hard Coal ii ii ••• 12 5 _ j Merostomata. Eurypterus derbiensis B. Woodw. ... Below Top Hard Coal 41 H.W. (f) Moyaey. „ ; moyseyi B. Woodw. ij ii n 41 >! »» » i sp Top Hard Coal 5 M. (m) ij Belinurus'bellulus KSnig Below Top Hard Coal 41 — *) » ii „ Top Hard Coal 12 — )i jj kpenigianns_(ZK Woodw.).., JBelow Top Hard 41 — Survey. 154 FOSSILS OF THE MIDDLE COAL MEASURES. Genera and Species. Horizon and Locality. Refer- ence. Col- lectioh. Belinurus longioaudatus U. W. Between Ell and Deep Soft Coal. Waterloo Coal 32 — Moysey. 29 " ■' » Below Top Hard Coal 41 — 1) „ sp. Between Deep Hard and 4 — )) Silkstone Coals. ... ... ... Below Top Hard Coal 41 — JT ... ... ... Top Hard Coal 12 — 1) Oyclus of. johnsoni H. Woodw. „ ,, ... ... 5 — J) „ sp. Between Deep Hard and 4 — Survey. Silkstone Coal. Below Top Hard Coal 41 — Moyeey. Top Hard Coal 12 — Prestwiehia anthrax (Prestw.~) Below Top Hard Coal 41 — ii „ birtwelli S. Woodw. i« » >) 41 — rt ,. rotundata (_Prestw.~) Between Ell and Deep Soft 32 — >» Waterloo Coal 24 — j» Below Top Hard Coal 41 — Top Hard Coal 5 — IT Mtsiapoda. Buphoberia ferox Salt Betw. EH and Deep Soft ... Coals. 32 — Moysey. Xylobius cf. spinulosus (Scud.) sp Below Top Hard Coal » » » 41 41 Arachnid a. Anthracosiro fritsohi Pocock Between Deep Hard and Silkstone Coal. 4 — Moysey. ,, ,, „ ... Below Top Hard Coal 41 M.(m) I? „ woodwardi Pocock 5) J) )J •" 41 M.(m) „ Eobuthus liolti Pocock Top Hard Coal 12 P.(n) d Eoscorpius carbonarius H. Woodw. ... Horizon unknown 42 H.W. (b) ?Brit. Mua. Geralinura britannica Pocock Below Top Hard Coal 41 P.(n) Moysey. Protolycosa sp >i » n 41 ii Trigonotarbus ? Between Ell and Deep Soft Coal. 32 M. (m) ii Insecta. Archioptylus ingens Scudder ... Horizon unknown 7 S.(c) Brit. Mas. Cryptovenia moyseyi Bolton ... Below Top Hard Coal 41 B.(o) Moysey. Orthocosta splendens Bolton " H )) •■• 41 ii Pteronida plicatula Bolton ... >) 11 11 41 t) ii 2. FISHES. Elasmobranchii. Acanthodes wardi Kr/*n. Ctenacanthus sp. Diplodus gibbosus Agass. Gryracanthus i'ormosus Agass Listracanthus wardi A. 5. Woodw.'' ... Deep Soft and Deep Hard Coals. 298 ft. bel ow Top Hard . . . Deep Soft and Deep Hard Coals. 298 ft. below Top Hard ... 150 ft. above Deep Soft Deep Soft and Deep Hard Coals., 250 ft. above Deep Hard Coal. '•"■;. 39 V (i) 35 » 39 J1 35 38 39 V (0 — — Vernon. Vernon. Moysey. This fish-spine is found exclusively in marine beds. FOSSILS OP THE MIDDLE COAL MEASURES. 155 Genera and Species. Horizon and Locality. Teleostomi. Coelacanthus elegans (Newo.)... Cheirodus granulosus (Young') Eloniohthys egertoni (Egeii.) ... ,l sp '.. Megalichthys hibberti Agass. ... „ „ « SP Platysomus parvulus Will. ii ii ii „ tenuistriatus Traq. Rhadinichthys wardi (Ward')... Rhizodopsis sauroides (Will.') ... ii n n Strepsodus sauroides (Biimey) Jneertae Sedis. (? Egg-Capsules of Fishes.) Fayolia crenulata Moysey „ cf. dentata Zeiller Palaeoxyris carbonaria Sohimpcr ii n ii „ helioteroides (Morris) prendeli Lesq. Vetacapsula johnsoni (Kidston) cooperi 3Iacltic $ Croclter Deep Soft and Deep Hard Coals. 298 ft. below Top Hard . . . Deep Soft and Deep Hard Coals. 298 ft. below Top Hard " ... Below Top Hard Coal Deep Soft and Deep Hard Coals. 298 ft. below Top Hard . . . furnace Coal Deep Soft and Deep Hard Coals. 298 ft. below Top Hard ... About Deep Soft Coal Deep Soft and Deep Hard Coals. 298 ft. below Top Hard " ... Deep Soft and Deep Hard Coals. Below Top Hard Coal TopHard Coal ii ii Between Ell and Deep Soft Coal. Waterloo Coal Dunsil Coal ... Below Top Hard it i' Top Hard Coal Between Ell and Deep Soft Coal. Waterloo Coal Below Top Hard Coal TopHard Coal Between Deep Hard and Silkstone Coals. Between Ell and Deep Soft Coal. Refer- ence. 39 V.(I) 35 )» 39 )) 39 35 41 39 V. (i) 35 10 39 V.(i) 35 23 39 V.(i) 39 35 39 M 49 41 11.(1) 41 )) 12 )» 5 11 32 J* 29 24 »» 18 )J 47 41 JJ 43 )> 12 )» 5 )) 3 32 M.(l) 24 41 M.(l) 41 12 >i 4 32 M.(l) Col- lection. Vernon. Moysey. Vernon. Moysey. Vernon. Moysey. Vernon. Moysey. Survey. ii Moysey. 3. FRESH-WATER ANNELIDS AND LAMELLIBRANCHS. A NNELIDA. Spirorbis sp. 25276 Between Deep Hard and 4 Silkstone Coals. Below Tod Hard Coal ... 41 Top Hard" Coal 12 Moysey. 156 FOSSILS OF THE MIDDLE COAL MEASURES. GrENERA AND SPECIES. Horizon and Locality. Refer- ence. Lamellibbanghiata. Anthracomya modiolaris (J. de C. Sow.) williamsoni (Brown) ... Carbonicola acuta (<7. Sim.) tl „ var. rhomboidalis Mild. „ aquilina (J. de C. Sow.) ... nucularis Hind, robusta (J. de C. Soiv.) similis (Brown) ... subconstricta (/. Sotv.) turgida (Brown) .. Naiadites carinata (./. de C. Sow.) modiolaris (./. de C. Sow.) quadrata (J. de C. Sow.) triangularis (J. de 0. Sow.) Furnace Coal Deep Hard and Deep Soft Coals. 150 ft. above Deep Soft ... 210 ft. above Deep Soft ... Dunsil Coal Top Hard Coal 210 ft. above Deep Soft ... Top Hard Coal Furnace Coal Deep Soft Coal 150 f t. abo ve Deep Soft . . . 210 ft. above Deep Soft ... Dunsil Coal Top Hard Coal Furnace Coal Deep Soft and Deep Hard Coals. 150 ft. above Deep Soft ... Top Hard Coal Furnace Coal Top Hard Coal Deep Soft Coal 210 ft. above Deep Soft ... Furnace Coal 150 ft. above Deep Soft 210 ft. above Deep Soft ... Deep Soft and Deep Hard Coals. Top Hard Coal 150 ft. above Deep Soft ... 210 ft. above Deep Soft ... Dunsil Coal Top Hard Coal 10 39 38 37 26 50 37 50 10 10 10 8 38 37 26 50 10 39 38 50 10 50 8 37 10 38 37 39 50 38 37 26 50 50 50 V. (i) G. (P) V.(i) G. (p) V. (i)! Col- lection. G.(p) Y. (i) Vernon. Survey. Vernon. Survey. Vernon. Survey. Vernon. 4. MARINE FOSSILS (EXCLUSIVE OF FISHES). BliACHIOPOBA. Lingula mytiloides J. Sow. » » » Productus sp. [spines] Lamellibbancbiata. Myalina compressa Hind Nucula gibbosa Mem. Pterinopecten'papyraceus (./. Sow.) SaDguinolites sp. 400 ft. above Deep Hard 15 250 ft. above Deep Hard 13 300 ft. above Deep Hard 14 300 ft. above Deep Hard 14 400 ft. above Deep Hard 15 300 ft. above Deep Hard 14 250 ft. above Deep Hard 13 300 ft. above Deep Hard 14 Survey. Moysey. Survey. Survey. Survey. FOSSILS OF THE MIDDLE COAL MEASURES. 157 Genera and Species. Horizon and Locality. Refer- ence. — Col- lection Gasteropoda. Macroehilina sp Cephalopoda. Gastrioceras sp Orthoceras sp 300 ft. above Deep Hard 14 Coal. 250 ft. above Deep Hard 13 Survey. Moysey. C. From between the Top Hard Coal and Upper Coal Measures. 1. PLANTS AND ARTHROPODS. PLANTAE. FlLICALES ET PTEBIDOSPEBMEAE Neuropteris gigantea Sternb „ obliqua Brongn „ rarinervis Bunb sp Equisetales. Calamites oisti Brongn. „ varians Sternb i< sp Pinnularia sp Lycopodiales. Lepidodendron dichotomum (Sternb.) » I! obovatum Sternb. ophiurus (Brongn.') .. rimosum 1 Sternb. ... simile Kidston Lepidophloios laricinus Sternb. » i» Lepidophyllum lancifolium (Lesq.) ... Lepidostrobus variabilis L. $,• H. Sigillaria cordiformis Kidston „ laevigata Brongn. . „ ovata Sam-eur Stigmaria fiooides (Sternb.') . 25276 80 ft. below High Hazles Coal. High Hazles Coal 80 ft. below High Hazles Coal. » )» ti High Hazles Coal High Hazles Coal ... 80 ft. below High Hazles Coal. High Hazles Coal 80 ft. below High Hazles Coal. High Hazles Coal 80 ft. below High Hazles ... High Hazles Coal 80 ft. below High Hazles Coal. 230 ft. above High Hazles Coal. 80 ft. below High Hazles Coal. High Hazles Coal 260 ft. above High Hazles Coal. » » j) High Hazles Coal 16 L. (u) 16 V. (i) 16 L.(u) 16 16 V. (i) 16 V.(i) 16 » 16 )) 16 L. (u) 16 V. (i) 19 )l 16 )) 19 » 16 L. (u) 16 V. (i) 19 16 L. (u) 16 V. (i) 16 19 )» 16 L.(u) 16 » 16 )) 16 )) 16 V. (i) 19 16 L.(u) 16 )) 16 V. (i) 16 16 L.(u) Survey. Vernon. Survey. Vernon. Vernon. !J !» Survey. Vernon. » i) Survey. Vernon. » Survey Vernon. jj Survey. Vernon. Survey. » Vernon. h 2 158 FOSSILS OF THE MIDDLE COAL MEASURES. Genera and Species. Horizon and Locality. Refer- ence. Col- lection. ANMALIA. Ceustacea. Beyriohia arcuata 1 (Bean) Cytherella sp. [see list of marine fossils ]. Horizon uncertain 16 L. (u) Survey. Mebostowata. Belinurus sp High Hazles Coal 16 V. (i) Vernon. 2. FISHES. Elasmooranchii. Acanthodes wardi Egert. Callopristodus peotinatus (Agass.) Diplodus gibbosus Agass. Listraoanthus wardi A. S. Woodiu. Pleuroplax rankinei (H. $ A.) Teleostomi. Coelaoanthus elegans NewTi. . » )) » » 11 5) )' !) )l Bloniobtliys egertoni (Egert.). Megalichthys hibberti Agass. .. ., sp , Platysomus parvulus Will. » sp Rhizodopsis sauroides ( Will.')., » >t » » » )j » » » Strepsodus sauroides (Binney).. High Hazles Coal ... 630 ft. above Top Hard High Hazles Coal ... 630 ft. above Top Hard High Hazles Coal ... 630 ft. above Top Hard High Hazles Coal ... Clowne Coal 630 ft. above Top Hard High Hazles Coal ... Clowne Coal 630 ft. above Top Hard High Hazles Coal ... Clowne Coal High Hazles Coal ... » )» Clowne Coal 630 ft. above Top Hard High Hazles Coal ... 16 v.co 26 L. (t) 16 L.0U IB 16 V. (i) 26 L.(t) 16 V. (i) 26 L.(t) 16 V. (i) J6 L. (u) 2 V.(i) 26 L. (t) 16 V.(i) 2 )) 26 L.(t) 16 V.(i) 16 L. (u) 16 16 V. (i) 2 16 L. (u) 16 V. (i) 16 L. (n) 2 V.(i) 26 L. (t) 16 v.co Vernon. Survey. Vernon. Survey. Vernon. Survey. Vernon. Survey. Vernon. Survey. Vernon. » Survey. Vernon. Survey. i) Vernon. j) Survey. Vernon. Survey. Vernon. Survey. Vernon. 3. FRESH-WATER LAMELLIBRANCHS. Anthracomya calcifera Hind „ phillipsi (Will.)... „ williamsoni (Brown) Carbonicola acuta (J. Sow.) ... Clowne Coal 290 ft. above High Hazles Coal. Clowne Coal Main Bright Coal High Hazles Coal 210 ft. below High Hazles Coal. 2 V.(i) 16 B.(u) 2 V.(i) 19 16 16 h. (u) Vernon. Survey. Vernon. Survey. FOSSILS OF THE MIDDLE COAL MEASUHES. 159 I Genera and Species. Hobizon and Locality. Refer- ence. Col- lection. Carbonicola aquilina (.7. de C. Sow.') ... „ obtusa Hind „ subconatricta (J. Sow.') ... t) SJ )J *•• „ turgida (Brown) sp Naiadites modiolaris (J. de C. Sow.) ... High Hazlea Coal . Main Bright Coal . High Hazlea Coal . Main Bright Coal . High Hazles Coal . )! )) )» )) Main Bright Coal . . 16 . 16 . 19 . 16 . 16 . 19 . 16 . 16 . 16 . 19 L. (u) V. (i) 9) J) n j) L."(u) V."(i) Survey. Vernon. •j >! t» ») )) Survey. Vernon. 4. MARINE FOSSILS (EXCLUSIVE OF FISHES). Crinoid oolumnala Annelida. Spirorbis sp Bracriopoda. Chonetes lagueasiana de Kim., mut. Hind Inngula mytiloides J. Sow. » » it Orbiouloidea' nitida (Phill.) ... Produotua ep. [spinea] Lauellibranchia ta- Ctenodonta laeviroatrnm ( Portl.) Myalina oompreaaa Hind Nucula gibbosa Flem Nuculana attenuata (Flem.) ... Poaidoniella laevis (Brown) ... „ sulcata Hind Paeudamusium fibrillosum (Salt.) Pterinopecten oarbonariua Hind „ papyraceus (J- Sow.) . Gasteropoda. Euphemua urei (Flem.) Lozonema sp Cephalopoda. Glyphioceras bilinguo 1 {Salt.) phillipsi 1 F. $ C. » sp. Orthooeraa cf. asciculare Brown » S P Pleuronautilus ap. Crustacea. Cytherella sp. 630 ft. above Top Hard ... 26 630 ft. above Top Hard ... 26 630 ft. above Top Hard ... 270 ft. above High Hazlea Coal. 630 ft. above Top Hard ... 270 ft. above High Hazles Coal. 630 ft. above Top Hard ... 630 ft. above Top Hard 630 ft. above Top Hard 630 ft. above Top Hard 630 ft. above Top Hard 26 26 26 26 26 26 26 26 26 26 26 26 26 26 2H 26 26 L. (t) L. (t) L. (t) L 00 L. (t) L. (u) L. (t) L. (11 L. 00 L. (t) Survey. Survey. Survey. Survey. Survey Survey L. (t) Survey 160 FOSSIL-PLANTS OP THE COAL MEASURES. II.— Synoptic Tables showing the Vertical Distribution of the Fossils. 1. plants and arthropods. Geneea and Species. A. M B. 10 11 c. PLANTAB. FlLICALES ET PTERIDOSPERMEAE. Alethopteris davreuxi (Brongn.) ... „ decurrens (Artis) „ lonchitica (Schloth.) ... „ serli (Brongn.) Corynepteris coralloides Gutbier' ... ., sternbergi (Ett.) Crossotheca sp. Dactylotheoa plamosa (Artis) Eremopteris moyseyi Arber... Mariopteris dernoncourti Zeiller ... „ latifolia (Brongn.) „ muricata (Schloth.) ... » sp Neuropteris gigantea Steriib. „ heterophylla Brongn.... ,, obliqua Brongn. ,, „ forma impar (Weiss)*. „ osmundae (Arth) „ pseudo-blissi Pot. „ rarinervis Bunb. „ scheuchzeri Hoffm. ... „ tenuifolia (Schloth.) ... » sp „ (Cyclopteris) tricho- manoides (Brongn). Odontopteris sp Oligocarpia brongniarti Stur Pecopteris miltoni (Artis) ... Rhacophyllum crispum, rar. lineare ( Gutbier). S P- ... Renaultia gracilis (Brongn.) Sphenopteris artemisisefolioides Oripin, 5 6 10 11 11 1 J or description ut this genus, see R. Kidston, " Les Vegetaux houiller du Hainaut Beige," 1909, p.21.. Under this name are included specimens identified by various authors as N. acuminata (Schloth.) rmO. N.impnr (Weiss), see Gothan in Potonie, Abbild. u. Beschreib;ross-Pflanz.-Reste, Lief, iv (1906), No. 68. FOSSIL-PLANTS OF THE COAL MEASURES. 161 Genera and Species. H o tn in Sphenopteris dilatata L. fy II. „ nexuosissima(Star)... „ furoata Brongn. ,, obtusiloba Brongn. ... „ t/. sob. werini ( Star) . . . ,, westphalica (Ster) ... Spiropterissp. [Neuropteris?] Urnatopteris tenella (Brongn.') Zeilleria avoldensis (Stnr) EQUISETALES. Annularia galioides (L. £ II.) „ radiata Brongn Asfcerophyllites charaeforiuis (Stemb.). „ equisetif ormis (Schloth.). „ grandis (Sternb.). ., longifolius (Sternb.). Calamites cisti Brongn ,. „ cruciatus (Sternb.) „ ramosus Artis „ suckowi Brongn. ... „ cf. schutzei (Stur) „ undulatus Stemb. ,, varians Stemb „ waldenbergensis Stur ... „ sp Calamostaohya equisetif ormis (Schl.) „ sp. ... Equisetites hemingwayi Kidston ... Palaeostachya elongata (Presl) ... „ ettingshauseni Kidston „ gracillima Weiss ,, pedunculata Will. ... Paraoalamostacbya striata Weiss ... Pinnularia columnaris (Artis) „ sp Spbenophtl lales. Sphenophyllum cuneifolium (Stemb.) „ cuneifolium, var. saxif ragae folium (Stemb.). „ majus Broun, sp - 3 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 — i 3 10 162 FOSSIL-PLANTS OF THE COAL MEASURES. A. B. c. Geneea and Species. "3 o o 3 o -PI < o 43 a o 43 S3 « o o -a w C3 W ft a) is O u w ft O H o o o CD "3 o o -d u c3 W ft o En 6 >■ o .o A ■d cS « o o en CD N C8 X .a s 4 5 6 7 8 9 10 11 12 Ltcopobiales. Asolanus camptotaenia Wood Sothvodendron minutifolium (Boulay) Lepidodendron aculeatum Sternb.... ,, dichotomum (Sternb.') ., obovatum, Sternb. ... „ ophiurus (Brongn.) „ rimosum 1 Sternb. ... „ simile Kidston, 1 „ wortheni Lesg. » sp Lepidophloios larioinus Sternb. » SP Lepidophyllum intermedium L. % H. „ laneifolium (Lesg.) „ majus Brongn. „ triangulare Zeiller » sp Lepidostrobus lanoeolatus (L. <$• 7/.) „ triangulare {Zeiller) „ variabilis Z. 4'' -HI ... » sp Sigillaria oordiformis Kidston „ discophora (Kbnig) „ elegans Brongn „ laevigata Brongn. „ of. mamillaris Brongn. ... „ ovata Sauveur „ rugosa Brongn ., semipulvinata Kidston ... , of. tenuis Achep „ tessellata Brongn. Sigillariodtrobns sp Stigmuria ficoides (Sternb.) [dis- tributed throughout]. CORDAITALES. Artisia approximata (Brongn.) Cordaianthas pitoairniae (L. 8; B.) .. sp Cordaites borassifolius (Sternb.) ... „ principalis (Germ.) „ sp Dorycordaites palmaeformis ( Goepp.) 1 2 2 3 3 3 3 3 3 — 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 - 7 1 7 8 8 9 9 9 9 10 10 - 10 10 10 10 10 10 10 10 10 10 10 10 10 11 11 11 11 11 11 11 11 J 11 n u n n n 12 12 12 12 12 12 12 12 12 12 12 1 For description of this genus, see E. Kidston, "Les Vegetaux houiller du Hainaut Beige," 1909, p. 21. FOSSILS OF THE COAL MEASTJEES. A. B. c. Genbba and Species. "is O O a o o 43 a Is c3 Kl u a> B. "3 "3 o o a s 3= •t-i M o a o i— ( CD O "3 o o o o a> 43 C8 o 42 H "3 o o o o n CD -3 o O ■a w p. O H o 43 o o 1— < b4 CD 43 <3 ■3 o o •o u w p. o EH o ■a 1 -J 08 o O en o C3 O o o o 43 CS W c3 O O "3 o o H3 u a w -a a C3 Gbnkra and Species. o 43 d i s M o 43 7s O O a 3 33 o 43 CI 73 O ai a o o o a o H o 43 *4 13 o o 43 C8 O O o o o H o O o 7a o O •a u o o crj <3> N a © c "3 m a o 43 1 — 1 3 s 3 ce 02 o 3 CO 43 10 W P. o E-i 11 .a bo a l 2 3 4 5 6 7 8 9 12 Rhadinichthys monensis (Egert.) ... _ 2 s „ wardi (Ward) -j- 7 Rhizodopsis sauroides ( Will.) i 2 1 — — — 7 8 : — ; — 12 » sp i 2 Streptodus sauroides (Binney) 7 12 Inceitae Sedis. (1 Egg. capsules of Fishes.) Fayolia crenulata Moysey „ of. dentata Zeiller 1U Palaeoxyris oarbonaria Sehimper ... 10 11 — „ helicteroides (Morris)... V — 9 ' 10 11 — „ prendeli Zesq — — — — V — 9 10 — — Vetaoapaula johnsoni (Eidston) 10 11 — „ oooperi Maeliie % Crock. 6 V " ~ — 3. FRESH-WATER ANNELIDS AND LAMELLIBRANCHS 2 . Annelida. Spirorbis sp Lamellibbanobiata. Anttiracomya oaloifera Hind „ laevis, var. scotioa Mh. „ modiolaris (J. de C. Sow.) „ phillipsi (Will.) „ williamsoni (Brown) ... Carbonioola acuta (J. Sow.) „ „ var. rhomboidalis Hind. „ aquilina (J', dc C. (Suit).) „ nuoularis .ffiraa! „ obtusa Hind „ ovalis (Mart.) „ robusta (J. de C. Sow.) „ similis (Brown) „ suboonstricta (J. Sow.) „ turgida (Brown) Naiadites carinata (J. de C. Sow.) ... „ modiolaris (J. de C. Sow.) „ quadrata (J. de C. Sow.)... „ triangularis (J. de C. Soto.) 10 10 HI 10 1 See footnote on v. 164. • More attention has been paid, in this district, to the Freshwater Lamellibranchiata than to any other fossils; as it is thought that a more complete knowledge of the distribution of these organisms may be of great value in identifying horizons in the Coal Measures. 166 MARINE FOSSILS OF THE COAL MEASURES. 4. MARINE FOSSILS (EXCLUSIVE OF FISHES) 1 . A. B. c. Genera and Species. O O d O < a -t-> P, |5 3 "3 o o tn p. o H O O *Q >■ 4J.8 O cS >> _o> "o O . — i *0 ■43 (S S ° . © 43 > > U B — h era .B 43 *•§ ^1 2 3 4 5 fi 7 8 9 !io 11 12 13 14 15 Crinoid columnals Spirorbia ap. Braohiopoda. Clionetea laguessiana de Eon., mnt. 9 Hind Lingula mytiloides J. Sow. Orbiouloidea nitida (Phitl.) „ sp. [apines] Spirifer sp. ... Lamellibranobiata. Cfcenodonta laevirostrum (Portl.) Myalina compressa Hind Nucula aequalis J. de C. Sow. ... „ gibbosa Mem „ luciniformie Phill. Nuoulana acuta (J. de Sow.') „ attennata (Mem.) Poaidoniella laevia (Brown) „ minor (Brown) „ sulcata Hind „ 3P Pseudamusium anisotum (Phill.) „ fibrillosum (Salt.) Pterinopecten carbonarius Hind „ papyraceus (J. Sow.) » sp Sanguinolites ap Scaldia carbonaria Hind ScMzodus antiquua Hind » SP Syncyclonema carboniferum Hind 1 1 1 1 1 — — — ~ — 7 7 7 7 7 7 7 — — — — 12 12 12' _ 1 12 12 12 13 13 13 13 13 13 13 13 13 13 13 13 13 13 14 14 14 14 14 14 14 14 14 11 14 14 14 14 14 14 14 14 15 15 15 ? 15 Marine beds in thus district have not as yet been worked out in sufficient detail. Three horizons, r^7i e I^ a i, r L a E2?i te f „ n £, ha I e been p X? T f !d ov -, er wide areas - The flrst oconr s in the roof of the Alton £«+£?! J£! «,- w^r? wherever that ooal occurs. Since it is practically certain that this coal is £2L 1 SL W1, m, th0 Hal > fax Hard Coal of Jorkshire, it is evident that this bed persists over a very large area. The second occurs between 300 and 400 feet above the Deep Hard Coal : it has been found m several exposures, but has not as yet been thoroughly investigated. The third, a very important band, occurs between 600 and 880 feet above the Top Hard Coal. It has been investigated very carefully by Mr W. H. Dyson (s) in the Maltby Colliery sinking near Donoaster? The Zmes ; of ?H„^ el ^ nen t S i, lla y e 4 been * mo . orpo - ratedin tnis list for comparison, which has necessitated a slight alteration in the statement of nonzons in section O, as compared with that of the previous lists. with the CI r00tS 0f the other 0oaIs aie similar) y inoluded along MARINE FOSSILS OF THE COAL MEASURES. 167 ■A. B. C. Genera and Specup. "3 o o o 43 < o 43 a eS S3 a M 1 1 o a .a a « o 43 a o 43 < 2 ■—J C3 O o a 3 "3 o o § GO to o +3 13 W ^3 O o L a o ■S3 "3 o Q u C3 w C. o> O o 43 a o +3 CO 02 o o . — 1 H o t-l C3 W a o> Q -a o o o o n o 8 "3 o o o _o h 0) S w p. o H o 43 o o ^4 0) -§ "3 o o n u ca W a o H s "o o -4 H e3 c3 SB u~ > O G3 CO "o Q Srrt <» ^ « e3 §M 43 [> 3= w c3 CO P*> M 0) 'o O co e3 o >> 5? . — i o o £*g S 3 && .Eh -4. O °1 si* 5 6 7 9 10 11 12 13 14 15 Gasteropoda. Bellerophon sp Euphemus d'orbignyi (Portl.) ... „ urei (Flem.) Loxonema acutum de Kon. „ ashtonense Bolton ... SP Macrochilia a sp Naticopsis sp Straparollus sp Trepospira radians (de Kon.y ... Cefea lopoda. Dimorphoceras gilbertsoni (Pliill.) Ephippioceras clitellarium (J. do Soio.') Gastrioceras carbonarium (v. Buck") „ coronatum F. and C. „ listeri (Mart.) » spp Glyphioceras bilingue (Salt.) ... „ paucilobum (Phill.) „ phillipsi F. and C. „ reticulatum (Phill) » S PP Orthoceras cf. asciculare Brown „ sulcatum Flem. » spp Pleuronautilus costatus Hind ... „ sp Solenocheilus sp Crustacea. Oytherella sp 1 1 1 1 1 1 1 1 1 — — i 1 — — 7 7 7 — " - 12 12 12 12 12 12 12 13 13 ? 7 13 13 13 13 13 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 15 15 15 ' Under name of Iiaphistoma raduim de Kon. in Mr. W. H. Dyson's paper. 168 APPENDIX IV. Selected List of Works on the Geology of the District. 1653. Manlove, E. The Liberties and Customs of the Lead Mines within the Wapentake of Wirksworth, composed in Meeter. London. [Reprinted in 1851 and 1881.] 1789. Pilkington, J. A View of the Present State of Derbyshire. 2 vcls. 8vo. London. [Another Edit, in 1803.] 1809. Martin, W. Petrificata Derbiensia, or Figures and Descriptions of Petrifactions collected in Derbyshire. 4to. Wigan. 1811. Fahey, J. A general View of the Agriculture and Minerals of _D.er.bjt_ _ shire; drawn up for the consideration of the Board of Agricul- ture. 8vo. London. 1822. Contbeaee, Rev. W. D., & W. PhilijIps. Outlines of the Geology of England and Wales. 8vo. London. [Derbyshire Coalfield, Trap-rocks, &c. described.] 1828. Adam, W. The Gem of the Peak, or Matlock Bath and its Vicinity. 8vo. London. [Other Editions in 1840, 1843, 1845, 1851, 1857?] 1834. Hopkins, W. On the Stratification of the Limestone District of Derbyshire. 8vo. [Privately printed.] 1835. Sedgwick, Rev. A. On the Geological Relations and internal Struc- ture of the Magnesian Limestone, and the lower Portions of the New Red Sandstone Series in their Range through Notting- hamshire, Derbyshire, . . .to the Southern Extremity of Northumberland. Trar.s. Geol. Soc, ser. 2, vol. iii., pp. 37-124, and Supplement, pp. 239-240. Abstract, Proc. Geol. Soc, vol. i, no. 7, pp. 63-66 (1834). 1838 & 1839. Jukes, J. B. A Sketch of the Geology of Derbyshire Analyst, vol. viii, pp. 214-238, and vol. ix, pp. 1-32. 1845. Alsop, J. On the Toadstones of Derbyshire. Pep. Brit. Assoc, for 1844; Trans, of Sections, pp. 51-52; and Edin. New Phil. Journ., vol. xxxviii, p. 179. 1851. De la Beche, Sir H. The Geological Observer. 8vo. London. [Derbyshire, pp. 642-644, 781-784, 794, 796.] 2nd Edit, in 1853. Greg, R. P. A Description of Matlockite, a new Oxychloride of Lead. Phil. Mag., ser. 4, vol. ii, p. 120. 1852. Milne-Edwards, H. & J. Haime. A" Monograph of the British Fossil Corals, part iii, Corals from the Permian Formation and the Mountain Limestone. Palazontograph. Soc, vol. vi. 1852 & 1866. Phillips, J. 1-inch Geological Map, Old Series, Quarter- Sheet 81 NE. Geol. Surv. With additions in 1866 by A. H. Green, C. Le Neve Foster & J. R. Dakyns. 1852, 1855 & 1868. Phillips, J., A. C. Ramsay & E. Hull. 1-inch Geological Map, Old Series, Quarter-Sheet 72 NE. Geol. Surv. Editions of 1852 and 1855 with additions in 1868 by A. H. Green. 1852, 1866 & 1867. Phillips, J., & W. W. Smyth. 1-inch Geological Map, Old Series, Quarter-Sheet 81 SE. Geol. Surv. With additions in 1866 and 1867 by A. H. Green and J. R. Dakyns. 1852 & 1866. Smyth, W. W., J. Phillips & A. C. Ramsay. 1-inch Geological Map, Old Series, Quarter-Sheet 82 SW. Geol. Surv. With additions in 1866 by J. R. Dakyns. 1852, 1867 & 1878. Smyth, W. W., J. Phillips & A. C. Ramsay. 1-inch Geological Map, Old Series, Quarter-Sheet 82 NW. Geol. Surv. With additions by A. H. Green, J. C. Ward & J. R. Dakyns in 1867; further additions in 1878 by A. H. Green, J. R, Dakyns, J. C. Ward, R. Russell & T. V. Holmes. BIBLIOGKAPHT. 169 1855 & 1867. Smyth, W. W., A. 0. Ramsay & B. Hull. 1-inch Geol- ogical Map, Old Series, Quarter-Sheet 71 NW, Geol. Surv. With additions in 1867 by A. H. Green & J. R. Dakins. 1858 Aveline, W. T., T. R. Polwhele & A. C. Ramsay. 1-inch Geol- ogical Map, Old Series, Quarter-Sheet 82 SE. Geol. Surv. 1858 & 1879. Aveline, W. T., E. Hull & T. R. Polwhele. 1-inch Geological Map, Old Series, Quarter-Sheet 71 NE. Geol. Surv. With additions in 1878 by W. T. Aveline. 1859. Sorby, H. C. On the Currents present during the Deposition of the Carboniferous and Permian Strata in South Yorkshire and North Derbyshire. Bep. Brit. Assoc, for 1858; Trans, of Sections, p. 108. 1860. Hull, E., W. T. Aveline & A. H. Green. Horizontal Section (Sheet 60, No. 1) across the Carboniferous Limestone near Wirksworth and Crich, the Derbyshire Coalfield by Alfreton Common, &c, and the Magnesian Limestone, &c, to Kirkby Forest. [2nd Edit, in 1868.] Geol. Surv. Lancaster, J., & C. C. Wright. On the Sinking at Shireoak Colliery, Worksop. Quart. Journ. Geol. Soc, vol. xvl pp. 137-145. 1861. Aveline, W. T. Horizontal Section (Sheet 61, No. 2) from Easi of Chesterfield across the Coal Measures to Bolsover, and from thence across the Magnesian Limestone, &c, towards Ollerton. Geol. Surv. 1861, 1875 & 1897. Aveline, W. T., & A. C. Ramsay. 1-inch Geological Map, Old Series, Quarter-Sheet 82 NE. Revised with addi- tions by T. V. Holmes in 1875, and further additions in 1897 by W. Gibson. 1862. Davidson, T. A Monograph of the British Fossil Brachiopoda, part v. The Carboniferous Brachiopoda. Palcrontograph. Soc. See vol. xiv for tabulated localities; also vols, x, xi, xii, xiii (1856-1861). 1866. Phillips, J., & A. H. Green. Horizontal Section (Sheet 18) from Cheshire across the Lower Carboniferous rocks of N. Stafford- shire, the Mountain Limestone and Coalfield of Derbyshire to the Magnesian Limestone near Bolsover. Gen}. Surv. 1867. Hull, E., & A. H. Green. Horizontal Section (Sheet 70) from near Alderley Edge across the New Red Sandstone of the Cheshire Plain, the Millstone Grit and Carboniferous Limestone of Kerridge, Tideswell, &c, to the Coal Measures of Derbyshire. Geol, Surv. 1868. Hull, E., W. T. Aveline & A. H. Green. Horizontal Section (Sheet 60, No. 1) across the Carboniferous Limestone near Wirksworth and Crich, the Derbyshire Coalfield by Alfreton Common, &c, and the Magnesian Limestone, TOP HARD 935 PER Ml A N Bare of Permian/ CLOWNE 2,3 HIGH HAZLES PERMIAN PORN ACE HIGH HAZLES PEP Ml A N /■527£2S3rOP HARD 2+GO JlffansfOelcL' Marine 3eoE MELTON FIELD TWO FOOT ABDY KENTS THICK BARNSLEY Map showing the positions of tfie> Sections attot t*ie rutmben of the Orver-irvchs Maps, JVew Series. Scale, One* Inch/ =10 MUes. □ SHEFFIELD 100 • IS • 7 101 .8 ° •6 8. 13 a • IZ s • CHESTERFIELD " 112 3# z • D »IO □ OLLERTON 113 MANSFIELD 125 '• 126 to MOR TON 1.10 1.10 SIS 561 DEEP HARD PIPER 734 TUPTON YARD SILKSTONE II HARDWICK 813 343 l*7WATERL00 2"? WATERLOO DEEP SOFT DEEP HARD YARD SILKSTONE IZ 30NDSMAIH z6 3BH S94 751 >'.•.'. 921 I *T WATERLOO Zf? WATERLOO TOP ELL BOTTOM ELL DEEP SOFT DEED HARD PIPER /3 Q X CROFT OUNSIL Zf? WATERLOO RENISHAW DEEP SOPT DEEP HARD 514 79B DEEP SOFT DEEP HARD IS 3IRLEY (FLOCKTON) PARKGATE SILKSTONE 732 1 \ SILKSTONE IGS3.I28IM. IS. 7S0 . 4.13. M&lby&Sons.Lith. MIDLAND DISTRICT— conl. SIX-INCH MAPS ON THE SCALE OF 6 INCHES = 1 MILE (1 to 10560). The following six-inch maps are published, and can be bought uncolonred, price Is. 6d. each quarter-sheet, or hand-coloured at the cost of colouring. Derbyshire :— 40 NW, 40 NE (Notts. 32" NE), 40 SW, 40 SE ; 41 NW (Notts. 32 NW), 41 SW (Notts. 32 SW) ; 45 NW, 45 NE, 45 SW, 45 SE ; 46 NW (Notts. 37 NW), 46 SW (Notts. 37 SW) ; 50 NW, 50 NE, 50 SW, 50 SE; 51 NW (Notts. 41 NW), 51 SW (Notts. 41 SW) ; 57 SW (Staffs. 41 SW), 57 SE ; 58 SW (Leic. 9 SW) ; 60 NW (Staffs. 47 s NW), 60 NE (Leic. 15 NE), 60 SW (Leic. 15 SW), 60 SE (Leic. 15 SE) ;. 6i NW (Leic. 16 NW) ; 63 NW (Staffs. 54 NW, Leic. 22 N.W), 63 NE (Leic. 22 NE). Leicestershire :— 9 SW f Derby. 58 SW) ; 15 NE (Derby. 60 NE), 15 SW (Derby. 60 SW), 15"SE (Derby. 60 SE) ; 16 NW, (Derby. 61 NW), 16 NE, SW.SE; 22 NW (Derby. 63 NW, Staffs. 54 NW), 22 NB (Derby. 63 NE), 22 SE ; 23 NW, NE, SW, SE ; 29 NE ; 31 NW, NE, SW, SE ; 37 NW, NE. s Nottinghamshire :— 32 NW (Derby. 41 NW), 32 NE, 32 SW (Derby. 41 SW), 32 SE ; 32" NE (Derby. 40 NE) ; 37 NW (Derby. 46 NW), 37 NE ; 37 SW (Derby. 46 SW), 37 SE ; 41 NW (Derby. 51 NW), 41 NE, 41 SW (Derby. 51SW),-41SE. • . Staffordshire : — 3 SW, SE ; 6 NE, SW, SE ; 7 NW, NE, SW, SE ; 11 NW, NE, SW, SE ; 12 NW, NE, SW, SE ; 13 NW, SW, SE ; 16 NE, SE ; 17 NW, NE, SW, SE ; 18 NW, NE, SW, SE ; 19 NW, NE, SW, SE ; 22 NE ; 23 NW, NE ; 24 .NW, NE ; 41 SW (Derby. 57 SW) ; 47» NW (Derby. 60 NW) ; 54 NW (Derby. 63 NW, Leic: 32 NW). Six-inch maps which are included in the one-inch New Series maps named above, but which do not contain any part of the Leicestershire and South Derby- shire and North Staffordshire Coalfields, are not published, but MS copies have been deposited in the Geological Survey Office, where they can be consulted, or copied, if desired, at the cost of draughtsmanship MIDLAND DISTRICTS-CO^.' MEMOIRS. ■In addition to the Memoirs (Sheet-explanations) mentioned nnd' ^—^ bead of one-inch maps, District Memoirs on the North Staffordshire jP iflid (price 6s.), the Leicestershire and South Derbyshire Coalfield -(prlc* 6s.) and The Concealed Coalfield of Yorkshire and Nottinghamshire (price ^j 6i.) have been published. .■'•;.. ■F' . ■■'{• i , VERTICAL SECTIONS (scale 1 inch = 100 feet) Price, Is. 8d. each. Sheet 86, Sections of Shafts, &c. in the Pottery Coalfield, North Staffordshire ; 1901. Sheet 88, Sections of Shafts, &c. in the Southern part of the Derbyshire and Nottinghamshire Coalfield. For publications relating to other parts of the United Kingdom, reference : should be made to the Catalogue, price 6