s OF THE GEOLOGICAL STJEYEY OP GREAT BRITAIN AND OF THE MUSEUM OF PRACTICAL GEOLOGY. THE GEOLOGY OF THE LEICESTERSHIRE COAL-FIELD AND OF THE COUNTRY AROUND ASHBY-DE-LA-ZOUCH. BY EDWARD HULL, B.A., F.G.S. rUBLISHED DT ORDER OF TUE LORDS COMMISSIONERS OF HER MAJESTY'S TBEASUBT. LONDON: FEINTED FOR HER MAJESTY'S STATIONERY OFFICE. PUBLISHED BY LONGMAN, GREEN, LONGMAN, AND ROBERTS. 1860. 579. LIBRARY I UNIVERSITY OF V CALIFORNIA ] EARTH SCIENCES LIBRARY s 6 O I o o o a M H MEMOIRS OF THE GEOLOGICAL STJRYEt OF GREAT BRITAIN AND OF THE MUSEUM OF PRACTICAL. GEOLOGY. THE GEOLOGY OF THE LEICESTERSHIRE COAL-FIELD AND OF THE COUNTRY AROUND ASHBY-DE-LA-ZOUCH. BY EDWARD HULL, B.A., F.G.S. PUBLISHED BY ORDER OP THE LOR2)S COMSflSgil ONERS' Ol v HEX 'MAJESTY'S TREASURY. LONDON: PRINTED FOR HER MAJESTY'S STATIONERY OFFICE. PUBLISHED BY LONGMAN, GREEN, LONGMAN, AND ROBERTS. 1860. 570. [2,246. 1,000. -10/60.] Swot PREFACE. BEFORE commencing the following observations, it is with pleasure I record the assistance received in carrying out the Geological Survey in the district of Ashby-de-la- Zouch. A ild first, my thanks are due to the Rev. W. H. Coleman, who for several years had been an accurate observer, and had tabulated a large amount of statistical information concerning the geology of the neighbourhood. Mr. Coleman, in the handsomest manner, placed the whole at my disposal, and also rendered me much per- sonal assistance ; and it is but due to my friend to state that he had mastered the geological structure of the greater portion of the area included in the following remarks, before the Government Surveyors commenced their labours. I have also to record the readiness with which, in the great majority of cases, the proprietors or agents of the collieries allowed me to inspect the plans and sections, and, when necessary, visit the mines. Amongst these I may specially mention Mr. Woodhouse, of Oversea!; Mr. Edward Green, of Charnwood Lodge; and Mr. John Browne, formerly assistant to Mr. Woodhouse. The ser- vices of many other gentlemen are acknowledged in the foot-notes in their proper places. I have also had occasion frequently to refer to Mam- mat t's " Geological Facts," a work of which, considering the state of geological science at the time it was pub- lished (1831), it is impossible to speak too highly. 325142 A 3 * o o f> *> :V * ^V>' * The following Maps and Sections of the Geological Survey illustrate the Leicestershire Coal-field, and are referred to in the following pages : Geological Maps, 63 N.W. and 71 S.W. Price 2s. 6d. each. Horizontal Sections, Sheets 46, 48, 49, 52. Price 5s. each. Sheet 46. From the Trent, near Repton, to Bardon Hill, crossing the New Red Sandstone, the Coleorton coal-field by Whitwick and Swannington collieries, and the Carboniferous Limestone, near Ticknall. Sheet 48. From the Warwickshire coal-field across the Trias of Gopsall Park, by Heather Mill, Coalville, and Charnwood Forest to Wysall, near Loughborough. Sheet 49, No. 2. From the Warwickshire coal-field to Chellaston Hill, crossing the Moira coal-field by Donnisthorpe and Moira. Sheet 52, No. 1. From the Trent at Newton Solney to Swep- stone, crossing the Moira coal-field by Newall, Gresley, Moira, and Measham Hall. No. 2, from west to east, by Linton, Ashby Woulds, Coleorton Common, Grace Dieu, and the northern edge of Charnwood Forest. Vertical Sections, Sheets 19, 20. Price 3s. 6d. each, plotted to a scale of 40 feet to 1 inch, (copperplate.) Sheet 19, Coleorton District. 1. Bagworth colliery ; 2. Ibstock colliery ; 3 and 4. Snibston colliery ; 5. Whitwick colliery ; 6. Heather colliery ; 7. New Swadlincote colliery ; 8. Pegg's Green colliery ; 9. Coleorton colliery ; 10. Lount colliery ; 11. Heath End colliery ; 12. Boring at Rough Heath; 13. Clay Pit, Woodville ; with an explanati9n of local mineral terms. Sheet 20, Moira district. 1. Donnisthorpe colliery ; 2. New Oak- thorpe colliery ; 3, 4, .5. Moira colliery ; 6. Woodville colliery ; 7. Granville colliery ; 8. Boring at Old Swadlincote colliery ; 9. Arthcote colliery; 10. Whitehouse colliery; 11. Gresley Common colliery; 12. Gresley Wood colliery; 13. New Stanton colliery. CONTENTS. CHAPTER I. PAGE Physical Geography - 9 CHAPTER II. Geological Formations. Rocks of Charnwood Forest. Cambrian Slates and Porphyry - - 1 1 CHAPTER III. Carboniferous Limestone. Fossils from Breedori. Limestone Shale. Grace Dieu Limestone - 13 CHAPTER IV. Millstone Grit. Section at Stanton Harold. Beds at Castle Donnington - - 17 CHAPTER V. Coal-Measures. Nature of Strata. Underclays with Stigmaria. Thickness of Coal-Measures in Leicestershire. Lower Coal- Measures - 19 , CHAPTER VI. Coal-seams of Moira District - 22 CHAPTER VII. Coal-seams of Coleorton District - 36 CHAPTER VIII. Faults of Moira District - - 47 CHAPTER IX. Faults of Coleorton District - 52 CHAPTER X. Rock-faults of Coleorton - 53 CHAPTER XI. Upper Coal-Measures with Sternbergia - - 56 CHAPTER XII. Permian Formation - - 57 A 4 8 CONTENTS. CHAPTER XIII. PAGE New Red Sandstone. Bunter Sandstone. Waterstones or Lower Keuper Sandstone. Red Marl - - - 60 CHAPTER XIV. Trap Rocks. Bed of Whinstone at Whitwick - - 64 CHAPTER XV. Abortive Borings and Sinkings for Coal - 66 CHAPTER XVI. Salt Water in the Main Coal of Moira - - 67 CHAPTER XVII. Post-Pliocene or Drift - - 67 CHAPTER XVIII. General Conclusions, &c. - 68 Index. Geological Map. THE GEOLOGY OF LEICESTERSHIRE. CHAPTER I. PHYSICAL GEOGRAPHY. BEFORE proceeding to describe the geological structure of the Ashby-de-la-Zouch coal-field and the surrounding districts, it will be necessary to give a rapid sketch of its chief physical features, these being, in effect, the result of the geological structure, modelled into form and feature by the agency of the sea when it formerly inundated the British Islands. The Ashby-de-la-Zouch coal-field will form the more imme- diate subject of the following Memoir, but observations will also be extended over the area embraced by the Trent, the Soar, Charnwood Forest, and the confines of the districts occupied by the Keuper Marls of the New Red Sandstone. Were a plane surface caused to extend over this area, and rest upon the higher portions, it would be found to touch these points of contact at nearly the same level as far as the confines of Charnwood Forest. The elevation of this plane would be about 450 feet above the sea, the intervening low grounds being scooped out in the form of basins and valleys. The higher grounds always present a flat tabulated appearance, which is particularly remarkable in the case of the high district extending from Pistern Hill to Smisby, and from Stanton Harold to Wilson. This is caused by the horizontally of the strata of which they are formed. In other cases such as those of the limestone hills of Breedon and Breedon Cloud, the flatness of the upper surface can only be accounted for on the supposition, that they have formed for a long time the bed of the ancient glacial sea ; and it is remarkable how these masses of hard rock have formed barriers to the action of the sea on the district on their eastern sides during the elevation of the land ; for while the ground to the westward is considerably lower, that to the eastward remains on a level with the upper surfaces of the Breedon Hills. Above this comparatively level district, the hills of Charnwood Forest rise abruptly to a height of 200 or 300 feet, presenting in their rugged and sharp outlines a striking contrast to the scenery of the surrounding country, and endeavouring to assert their stratigraphical relationship to the Welsh highlands by similarity 10 GEOLOGY OF LEICESTERSHIRE. of physical feature. The highest points of Charnwood Forest are the summits of Bardon and Beacon Hills, each of which reach an elevation of about 850 feet above the sea, and about 700 feet above the level of the Soar at Leicester.* From Bardon Hill a line of watershed extends along the ridge to the Derby road at Green Hill, thence through Coalville, Coleorton, Pistern Hill, Woodville, and along the Burton Road to Bretby. The lowest grounds are the alluvial plains of the Trent, Derwent, and Soar. All rivers which flow through comparatively level regions form along their courses areas with level surfaces, bounded on one or both sides either by cliffs, steep banks, or gentle slopes, depending on the nature of the strata, and the resulting physical features of the districts. These flat, low-lying plains have a breadth generally proportional to the magnitude of the stream, and are liable to be flooded when the waters are much swollen. The banks which enclose the plains mark the limits beyond which the river never penetrates. The plains are overspread by the detritus of the strata composing the regions along the course of the river, which on being deposited in the river valleys is denominated " allu- vium," and is composed of sands, clays, and gravels, amongst which are imbedded remains of the fauna and flora of the coun- tries through which the rivers flow. A large area of the northern portion of our district is over- spread by alluvium, and towards the junction of the Trent with the Derwent, the breadth of their united alluvial surfaces is nearly four miles. One remarkable feature presented by the plain of the Trent must not be left unnoticed. We occasionally find in the neigh- bourhood of this river two terraces, of different elevations, and of which that next the river is the lower. The higher terrace is about 20 feet above the lower; and as they are both alluvial surfaces, we may, perhaps, account for their existence on the supposition that the river formerly ran at a higher level than at present. In many localities the upper terrace has been subsequently swept away, and when this is the case the alluvial plain presents an uniformly level surface between its extreme limits. Both terraces are well defined at Weston. The lower extends from the base of the picturesque cliffs which are washed by the Trent, along the north side of Donnington Park, across to the bank of the canal, from whence the higher terrace extends to the village of Weston. They are also very marked in Elvaston Park. The dividing terrace traverses the park from east to west, the higher being about 12 feet above the lower. * Geology of Charnwood Forest, by J. B. Jukes, Esq., in the History of Charn- wood Forest, by T. E. Porter, Esq. GEOLOGICAL FORMATIONS. 11 CHAPTER II. GEOLOGICAL FORMATIONS. THE district contains a large variety of formations, which, arranged in their order of super-imposition, are as follows : Post-pliocene, or Drift - - Sand and gravel, with boulders. f 1. Red Marl, with gypsum and f Keuper - < Upper Keuper Sandstone. INCW Red Sandstone I ^ Lower Keuper Sandstone . or Irias. [Bunter - Conglomerate Beds. Permian Rocks - Lower Permian Sandstone, Marls, and Breccia. {Coal-measures. Millstone Grit. TT T Cil 1 "\7" J 1 T 1 Upper Limestone Shale or loredale Kocks. Carboniferous Limestone. Cambrian Rocks - Slates, Breccias, Metamorphic Rocks, and Porphyries. Trap Rocks - - Granite, Syenite, Greenstone. Cambrian Rocks of Charnwood Forest. This isolated tract of slates, porphyries, and other igneous rocks partly owes its appearance at the surface to a large fault, by which they have been upheaved along the north-eastern side. It is completely surrounded by the uppermost Triassic strata, which wrap around the flanks of the ancient rocks and ramify far up into the valleys. The rocks of this miniature mountain range form in their out- line a striking contrast to the hills of more recent formations by which they are surrounded. These latter are for the most part tabulated, and planed off along their upper surfaces, as is strikingly exemplified even in the case of the hard limestone bosses of Breedon ; but the rocks of Charnwood Forest form either knowls or serried ridges, which stand out in relief when viewed from the north-west. In the absence of organic remains, these rocks have been referred by Professor Sedgwick and Mr. Jukes to the Cambrian period, amongst other reasons, from their resemblance to the rocks of this age in Wales. They have been described in detail by Mr. Jukes,* and the geological survey of the range has been executed by my colleague Mr. H. H. Howell. The general structure of the Forest-rocks is that of an anti- clinal, first pointed out by Professor Sedgwick, and shown on Mr. Ho well's section across the forest.f This axis runs in a slightly curved line from Whitehorse Wood, through Iveshead Lodge, along the little valley called Longdale, to Holgate Lodge. * Geology of Charnwood Forest, appended to Mr. Porter's History of Charnwood Forest. To this work I must refer the reader for details. | Horizontal Sections of the Geological Survey, Sheets 48 and 52. 12 GEOLOGY OF LEICESTERSHIRE. Along the line itself the beds are nearly vertical, and from either side they dip to the south-west and north-east at high angles. As it is beyond the object of this Memoir to enter largely into details regarding the districts beyond the limits of the Ashby coal-field, it will be sufficient to give a short description of the Forest-rocks along a line which crosses them transversely, and which presents nearly the whole series of beds in succession. This line is nearly in the direction of Mr, Howell's section, and stretches from New Cliff Plantation, south of Sheepshead to Peldar Tor, near Whitwick. The quarry at Moorley Hill exposes to view a coarse-grained greyish slate, imperfectly cleaved and traversed by three systems of joints, recorded by Mr. Jukes.* Joint A. - - N. 24 E. - - Perpendicular. Joint B. - North - Ditto. Joint C. - N. 80 W Ditto. The dip is north-east at 35, and the cleavage at right angles to this. The anticlinal axis passes a few yards to the west of this quarry, where the beds are vertical, so that these are the lowest rocks brought to view along this line of section. Crossing the axis, we find the beds as far as Upper Black Brook, consisting of bluish purple and green slates, of a coarse character, alternating with fine grits, and dipping towards the south-west at angles varying from 35 (St. Ives' Head) to 55 (Black Brook). At this point the beds pass under red marls of the Keuper series. A line of isolated crags, ranging south-east from Thringstone to Charley, marks the base of a series of bedded porphyries. These plutonic rocks are not eruptive, that is, injected after the deposition of the slates, but are of an age contemporaneous with the Cambrian rocks themselves, and like the great sheets of fel- spathic lava of North Wales, have been poured out on the bed of the ocean, and have assumed the stratified arrangement of the aqueous rocks with which they are associated. This bedded form may be clearly observed at Kite Hill, and at Peldar Tor. (See Frontispiece.) At the base of the porphyry there occur some beds of slaty felspathic ash, which become more indurated upwards, and finally pass into the hard massive porphyry of which the rocks of the Hanging Stones, Kite Hill, High Cadinan, and High Sharply are composed. The same series of rocks continue to Peldar Tor,f and rise in masses as rugged and bleak as any to be found on the highest summits of Wales or Cumberland. These rocks consist generally of dark greenish felspar, with distinct crystals of pale felspar and sub-crystalline glassy quartz disseminated throughout. Sometimes the felspar crystals are of * Geol. Charnwood Forest, p. 10. f The " Tor," a pyramid of rocks above the road, is 660 feet high, according to Mr. Coleman's measurement with the aneroid; but north-east of this there are portions of the hill which reach a height of nearly 700 feet. The name " Pedlar Tor" of the Ordnance Map is incorrect. GEOLOGICAL FORMATIONS. 13 large size, two inches in length. The clip is south-west generally, and the cleavage clip in the opposite direction north-east at about 80. The strike of the beds and of the cleavage planes nearly coincide. Mr. Jukes remarks that bands of slate are intertangled with the porphyry, and much indurated. The porphyry itself is overlaid by beds of ashy slate, which are visible between Green Hill and Pelclar Tor. Bar don Hill. In 1854-5 the component rocks of Bardon Hill were only visible near the summit, and there they assume the aspect of greenstone, apparently erupted through the slates.* In 1860 1 visited the hill again, in company with Mr. Coleman. New quarries have been opened on the north side, in which the rock is finely exposed to view. At the entrance to the lower quarry felspathic ash with a slaty structure may be observed dipping under and passing upwards into felspar porphyry, which also exhibits a somewhat bedded aspect. Ascending the hill, we reach a second quarry, and here it be- comes evident the mass is similar to some varieties of bedded porphyry, which form the ridge above Whitwick. It consists of dark blue and green felspar, with crystals of hornblende, felspar, and quartz. There are also bands of epidote and veins of white quartz, in which small quantities of green carbonate of copper may be observed. It therefore seems not improbable that the rock of Bardon Hill belongs to the porphyritic series, but has been dis- connected by a large fault ranging from north-east to south-west, the existence of which I had long since inferred on other grounds. There are great variations in the rocks of Bardon Hill, and hand specimens might be obtained of nearly every gradation from ashy slate to syenite, through the varieties of felspar, porphyry, and greenstone. A small boss of greenstone appears in some old quarries in a field north of Bardon station, but it is difficult to say whether it belongs to the period of Forest-rocks or to a later date. The rocks of Stanton Field, Cliff Hill, Markfield Knowl, and Groby are of a different character. These masses are generally in the form of bosses or knowls, composed of crystalline syenite, in which the minerals, quartz, felspar, and hornblende are distinct, and combine to produce a rock of great durability and beauty. CHAPTER III. CARBONIFEROUS LIMESTONE. THIS formation reaches the surface in eight isolated areas, namely, Ticknall, Calke Park, Dimmingsdale, Breedon Hill, Breedon Cloud, Barrow Hill, Osgathorpe, and Grace Dieu. At Breedon Hill and Breedon Cloud we are presented with beds lower down in the Limestone formation than those of the * The survey of Charnwood Forest, as already stated, was executed by Mr. If. H. Ilowell, with the assistance of Prof. Ramsay. 14 GEOLOGY OF LEICESTERSHIRE. remaining localities; at Ticknall, Calke, Dimmingsdale, and Grace Dieu the highest beds occur ; and the strata of Barrow Hill and Osgathorpe are probably intermediate. The strata of the two Breedon Hills are almost identical with each other in lithological character, as they also probably are in stratical position. They are composed of magnesian limestone or dolomite, exceedingly hard, brittle, full of cavities, and traversed by joints. The colour of the rock is generally yellowish-brown, but frequently tinged red by the presence of peroxide of iron, and the structure is frequently sub-crystalline. The beds of the two hills plunge at angles varying from 40 to 80 to the westward, the great amount of inclination being due to the proximity of the axis of disturbance which traverses Charnwood Forest, as also to a fault of later date, which passes along the eastern edge of the limestone between Wilson and Osgathorpe. The stratification at Breedon Hill may be observed with greater precision at some distance, where the whole can be taken in at a glance ; but care is to be exercised in discriminating between the beds and the joints, which are frequently very deceptive. The stone is extensively quarried, threatening some years hence to make a considerable alteration in the original form of the hills. It is carried on tramways to the Leicester and Burton Railway and Canal. It is, however, unsuited for architectural purposes, being full of irregular cavities. The fossils generally occur in casts, and in some specimens of Spirifer the internal spiral processes are beautifully preserved in calcareous spar.* The following list of fossils is furnished from the collection of Mr. A. H. Green, of Ashby, and by Mr. J. W. Salter, from the specimens obtained by the Fossil- Collector of the Geological Survey : Fossils from Carboniferous Limestone, Breedon. Orthoceras giganteus - A shell. Bellerophon opertus - Do. Trochus - - Cast. Euomphalus Dionysii Do. E. tabulatus - - Do. Acroculia spirata - Do. Macrocheilus - Do. Spirifer duplicicosta - Do. S. subconica - Do. S. papilionacea - Do. Cyrtina septosa^ - - Do. Athyris (small species) Do. Syringopora gcniculata (?) Zaphrentis cylindrica The small round knoll, which from its appearance has obtained the name of " Barrow Hill," is formed of limestone formerly * Some of these are in the cabinet of M. Huish, Esq., of Castle Donnington. f This is Spirifer of Phillips. It is almost like Pentamerus in the development of its large internal plates. J. W. Salter. CARljOXTFEUOUS LIMESTONE. 15 quarried. At Osgathorpe the limestone, which is very impure, is interstratified with shale, and full of joints. In one of the quarries the red marl is seen resting upon it, the base being a limestone-breccia, irregularly bedded and from 2 to 3 feet thick. On the opposite side of the western quarry the beds are probably broken off by the fault already alluded to. At Grace Dieu the vertical walls of the old quarry afford an admirable opportunity for studying the stratification and mineral composition of the rocks in which they have been excavated. The higher beds arc interstratified with shales, and are doubtless con- temporaneous with those in similar positions in the Ticknall and Dimmingsdale sections. It is extremely doubtful, however, whether any great mass corresponding to the Breedon rocks actually exists beneath the Grace Dieu series. The proximity of the Charnwood Forest rocks, upon which the limestone rests, and around which it was deposited tinconformably, renders such a supposition improbable. The limestone of Grace Dieu varies from a pure bluish-grey carbpnate of lime to a light yellow or brown dolomite, and in general it is highly argillaceous. In some places the beds are com- posed of spherical concretions, resembling conglomerate, while in others there occur cavities 2 or 3 feet wide and deep, filled with white, red, and blotched marl, now considerably indurated. SKETCH FROM GRACE DIEU QUARRY, SOUTH SIDE. Fig. 1. a Limestone breccia in a base of red sandy marl (Keuper). b Interstratified limestones and shales. c Bed of concretionary limestone. d Massive limestone, with eroded cavities filled with marl. The limestones and shales are surmounted by brecciated strata of Triassic age, which rest upon them unconformably, the former dipping to the northward at angles varying from 10 to 6, while the breccia is horizontal. Fossils are very scarce at Grace Dieu and Osgathorpe. The three limestone areas of Ticknall, Calke, and Dimmings- dale, are brought to the surface through the combined agency of a great fault and of a series of gentle rolls. They form the highest beds of the Carboniferous Limestone, and are surmounted by shales. The western extremities of the rolls or anticlinals terminate against the boundary fault of the coal-field, the down- throw of which is consequently on the west side. At Tick- 16 GEOLOGY OP LEICESTERSHIRE. nail the throw of the fault is a minimum, and it increases in amount towards Whitwick, higher strata of the Coal-measures being brought down in succession against the older rocks in that direction. This will be evident from an inspection of the map where it will be seen that the coal-crops terminate successively against the fault from Dimmingsdale to Whitwick, while on the upcast side the same strata occur at both places. The Ticknall limestone is surmounted by from 30 to 40 feet of blue, black, and purple shale, with occasional sandstones, con- taining beds of limestone towards the base. The upper beds of the limestone are also interstratified with shales, so that there is evidently a gradual passage from the calcareous to the argillaceous deposits.* The Ticknall limestone is generally "very fossiliferous, some beds being composed principally of encrinital fragments and Brachiopoda. List of Fossils from the Carboniferous Limestone, Ticknall. P. gig ante a. P. antiquata. P. hcmisphcerica. Tercbratula acuminata. GASTEROPODA. Euomphalus catillus. E. carmatus. ZOOPIIYTA. Cyathophillum basaltiformc / Syringopora geniculata. Calamopora tumida. Retepora. CEPHALOPODA. Bellerophon tenuifasciata. BRACHIOPODA. Spirifer linguifera. S. glaber. S. rotundata. S. expansa, S. rhomboid&a. S. scmicircularis. S. bisulcata. Producta scabricula. P. depressa. P. Martini. P. resupinata. At Calke Park copper ore was formerly obtained in a quarry situated a few hundred yards west of the Hall. At Ticknall and Dimmingsdale, the limestone is worked in caverns, and at the latter the rock is highly metalliferous. In one of the veins, the following minerals were obtained ; copper pyrites, galena, calcareous spar, sparry iron-ore, blende, and bitumen. Mr. Bauerman, of the Geological Survey, called my attention to the curious fact, that most or all of the lodes in Dimmingsdale are formed of a quartzose conglomerate or breccia, and that the galena principally occurs in ribs at each side of walls of the lode, while crystals of the remaining minerals are formed in the druses of the veinstone. The ore is extracted in what is technically called " pipe-work," being followed by means of small horizontal galleries or pipes. f * A very unusual instance of current-bedding is presented to view at the south side of the quarry east of the village. There -we may see a series of interstratified lime- stones and shales, with a very regular dip to the eastward for a distance of about 50 yards, resting upon and surmounted by beds which are almost horizontal. Phenomena of this kind are common in sandstone and oolitic limestones, but, I believe, rather exceptional amongst strata of this formation. t Geol. Cham. Forest, p. 16. CARBONIFEROUS LIMESTONE. 17 All the limestones are ultimately surmounted by shale, which is occasionally very thin, specially in Calke Park. The shale varies in colour from black to purple or red, the latter being prin- cipally characteristic of these beds at Ticknall. Some black shales were found in a deep drain, excavated in a field north of Worth- ington. They there gave origin to a spring at their junction with New Red Sandstone. Along the borders of the shires of Derby and Stafford the Upper Limestone Shale attains a much greater development than in the localities in question, falling little short of 2,000 feet. Its thinning out in the direction of Charnwood Forest, taken in connexion with the debased character of the Grace Dieu Limestone, leads to 'the conclusion, long since arrived at by Mr. Jukes, that this lower portion of the Carboniferous series here approaches its original limits, formed of the ancient Cambrian Kocks, which were land during the earlier Carboniferous period. CHAPTER, IV. MILLSTONE GRIT. RESTING upon the Limestone shale, and forming the founda- tion for the Coal-measures, there occurs a series of grits, sand- stones, and conglomerates, with shales, which, on account of the fitness of some of the beds for millstones, has been designated Mill- stone Grit. The grit forms the higher grounds around the lime- stone valleys of Ticknall, Calke, and Dimmingsdale, and produces an elevated ridge along the line of fault, rising on the upcast side above the western area occupied by Coal-measures, as is repre- sented in the accompanying section (Fig. 2). Fig. 2. SECTION ACROSS STANTON HAROLD AND HEATH END. S.W. N EL. STANTON P A R. K . HEftTH 1 ,EMD r COLLIERY, !L P O N D B. Limestone shale. C. Millstone grit. E. New Ked Sandstone. The lower bed is generally a conglomerate, the pebbles being white or coloured quartz, sometimes three inches in diameter, ferru- ginous concretionary nodules, red jasper, and pieces of slate. The middle beds consist of coarse yellow, brown, or red grit, which yield large blocks either for millstones, troughs, or building pur- poses, at Stanton, Melbourne, and Repton Kocks. The mass of the stone is formed of siliceous particles, cemented by felspar, and 18 GEOLOGY OF LEICESTEBSHIRE. occasionally both these components assume a distinct form, and produce a rock such as might be supposed to have been derived from the detritus of granite. This is the appearance of the grit in a quarry at the north side of the village of Stanton. In a quarry in Calke Park, near the Melbourne Road, a remarkable con- glomerate belonging to this formation may be seen, surmounted by more compact beds with plants, as Sigillaria, Lepidodendron, &c. The highest beds of this formation are composed of fine-grained, thin-bedded grits, interstratified with shales, and presenting a variety of colouring from white to purple, through various shades of yellow and pink. These strata are well exposed in a quarry west of the village of Stanton-by-bridge. The dip is north-east, at 7, and the ridge which the grit here produces marks a line of fault which can be traced to Repton Rocks, and having a downthrow on the west side, brings successively the New Red Sandstone, Permian, and Coal-measures, in contact with this formation. North-west of Castle Donnington a section is opened in certain strata, which are probably referrible to the Millstone Grit. The section occurs in the lane leading to Cavendish Bridge. The strata consist of yellow, white, and blue shale, alternating with thin-bedded grits and rusty ironstone in bands or concretions. The dip is towards the south-east, and the beds are surmounted by the New Red Sandstone, which forms the banks of the alluvial plain in the neighbourhood. If these strata do not form a part of the Millstone Grit, they at least belong to the lower portion of the Coal-measures, and their appearance at the surface gives us a knowledge of the strata which underlie the New Red Sandstone in that neighbourhood. It renders it improbable that productive Coal-measures have set in between Donnington and Melbourne, and as there are at least 500 feet of unproductive measures resting on the Millstone Grit, it is improbable that coal-seams occur any- where under the area occupied by the Trias included between Charnwood Forest on the south, the Trent on the north, the line joining the limestone areas on the west, and the Soar on the east. At the north end of Thringstone, in the lane leading to the mill, Millstone Grit makes its appearance, rising from under newer deposits, which probably allow of its occupying a very limited superficial area. It consists of coarse purple grit, with quartz pebbles. It was first observed by the Rev. W. H. Coleman, of Ashby, whose attention was attracted to the spot by numerous blocks of the grit built into the walls around. In a narrow lane to the west of this a section is exposed in different beds, consisting of thin- bedded grits and shales, with a westerly dip ; these are probably above the former. In many localities Coal-measure plants, generally silicified, are found in considerable quantities in this formation. This is par- ticularly the case in the district between Cheadle and the Potteries in Staffordshire. COAL-MEASURES. 19 CHAPTER V. COAL-MEASURES. WE have now to enter upon the consideration of the next series of strata, as it occurs in our district, one which is economically the most important, as supplying our stores of mineral fuel and iron- ore. The beds which combine to make up the Coal-measures are very variable in mineral character, and their nature can best be under- stood by reference to the pit sections.* They consist of various interstratifications of sandstones, clays, shales, and coal-seams. The sandstones are generally fine-grained, and of the colours of white, yellow, brown, and sometimes purple, and are known as " freestone," "poststone," and when in the state of a sandy ironstone, " cank." The clays are often in the state of " fire-clay/' and are able to resist intense heat. These clays are used for making " fire-bricks" for furnaces, and " saggers/' or pans for holding china-ware when undergoing the process of " baking " in the furnace. " Clunch," (< clot/' and " rammily earth," are names for the more common clays, and a very favourite term is " bind," which, perhaps, is rather synonymous with the word " shale/' intended to denominate clay in a laminated state. There are also bituminous or black shales, and impure coal-seams termed "bat" and " sulphur," the latter term referring to seams impregnated with iron pyrites, which on burning give off sulphurous acid and sulphur fumes. In the clays, seams or nodules of iron-ore, in the state of argil- laceous carbonate of iron, frequently occur. The ore is called " clay ironstone," and is seldom found thicker than 5 inches for each layer; but in some measures the seams are frequently repeated, being separated from each other by beds of shale. In the Ashby coal-field, iron-stone is not at present either mined or smelted. The coal-beds in particular districts are all known under distinct names, given them on account of their qualities, thickness, the name of the first discoverer, or from the caprice of the miners. Thus we have the " Main coal/' always the principal seam of the district ; the " Cannel coal," the " Four-foot coal," the " Jack Dennis" and "Dickey Gobbler" coals. It will be observed on referring to the vertical sections that the coal-seams invariably rest on floors of clay, and wherever oppor- tunities for observation have been afforded, it has been found that the clay-floor is penetrated by carbonized fibres trending down- wards from the bottom of the coal. They are generally very thin, often mere threads, but are occasionally several inches in diameter. They are known to be rootlets of various plants. -f * See Vertical Sections of the Geol. Survey, Sheets 19, 20. f See a series of carefully executed lithographs of the flora of the Moira coal-field in the late Mr. Mamraatt's " Geological Facts." B 2 20 GEOLOGY OF LEICESTERSHIKE. Amongst the most remarkable is a rootlet called Stigmaria ficoides, formerly supposed to be an aquatic plant, but since shown by Mr. Binney, of Manchester, to be the root of Sigillaria. The persistency of these roots penetrating a bed of clay or earth below the coal has afforded us the means of arriving at more definite con- clusions with reference to the origin of that mineral. These cloy- Jloors must have formed the soil on which the plants composing the coal had formerly grown. In the district of Ashby the coal-beds are generally evenly stratified, retaining their thickness with great persistency over extensive areas, and are seldom mixed with earthy or sandy matter. The total thickness of measures known in the Leicestershire coal-field is at least 2,500 feet, and that part of the series contain- ing the principal coal-beds is situated at about the centre. Towards the base, from 800 to 1,000 feet of unproductive measures occur, through which trials in search of coal have been made, hitherto unsuccessfully. It is uncertain whether we have in this neighbourhood repre- sentatives of a series of beds which in other districts form the " Upper Coal-measures." In the coal-fields of Staffordshire, these measures attain a thickness of one thousand feet, and produce only thin worthless coal-beds.* Here, the highest measures are pierced by the pits of Moira and Gresley Common on one side of the coal- field, and on the other by the Wbitwick and Bagworth shafts ; but in none of these do we find the series of deep purple marls, with interstratified sandstones, which occur in the former localities. If these beds were ever deposited over this district, they have since been swept away ; or perhaps they may be repre- sented by certain local gritty sandstones, to be hereafter described, which present some slight evidences of unconformity to the measures on which they rest.f The Ashby-de-la-Zouch coal-field may be divided into two portions, that of Coleorton on the east, and of Moira on the west. It is difficult to identify the coal-seams in both these districts ; and as they are separated from one another by an interval of lower unproductive measures, no opportunity is afforded of connecting them together by means of the outcrops of the coal-seams. The productive areas are situated at the western and eastern extremities. On the former side, the continuation of the coals is broken off by a great fault, passing through Woodville and Willesley, and throw- ing up on the east side lower measures; while on the latter there is a general dip to the eastward, and the coal-seams basset in succession as we cross the country from St. George's church to Coleorton Farm Town, where a great fault throws out all the coals below the Upper Lount seam.J * See Hor. Sec., Geol. Survey, Sheet 55. f See page 56. J Mr. Coleraan informs me that this fault was struck in coal-workings at " Par- son's Meadow." LOWER COAL-MEASURES. 21 LOWER COAL-MEASURES. The Pistern Hill Coal-seam. These are two or three thin coal-seams worked by shafts sunk through the New Red Sandstone, which lies horizontally upon the summit of the hill. These coals have been proved to dip towards the south, and their outcrop may be traced by a series of old workings along the northern borders of South Wood ; on approach- ing Heath End they are thrown down by a large fault, which brings in the Heath End coals. Beyond the outcrop of the Pistern Hill coals none have ever been proved, and a shaft sunk 557 feet at White Hollows failed to reach any seam of greater thickness than 20 inches ; we may therefore place the Pistern Hill coals at the base of all the workable seams. Coal was formerly worked in a gin-pit a little south of Smisby church, not many yards from the surface ; a seam probably the same, but thinner, crops in the brickyard, east of the village, and it is to be supposed that this coal represents that of Pistern Hill. A coal-seam has been reached in the well of the Ashby work-house, which may be a continuation of the Smisby seam. The difficulty of tracing the Pistern Hill coals is insuperable owing to want of continuous workings, but the line now indicated in all pro- bability approximates to their outcrop, and hence we have a geological horizon beyond which no coal-seams thicker than a few inches have ever been found. Though the sections in the Moira and Coleorton districts cannot be identified, yet it is highly probable that the productive measures of each occupy the same general position irr the series ; in other words, that the representatives of the Coleorton coals are not underneath those of Moira. This is the opinion of Mr. Jukes, who even goes so far as to suggest that the Main coal in both districts is one and the same bed.* We might also attempt to identify the Heath End seams with the " Rafferee " and its associated " Four-foot" coal, and these latter with the " Stockings" and " Eureka " coals, and hence argue that below these last no useful seam exists. All such speculations, however, are exceed- ingly unsatisfactory, and would only tend to diminish that enterprise in exploring unknown regions of the strata, which in the case of the Eureka coal has been attended with so much success. From the depth of 50 feet f beneath this seam there lies buried a vast series of measures hitherto untouched by the boring rod, and though there are grounds for supposing that this series is composed of unproductive beds, yet it is to actual experiment we must look for any degree of certainty. This, however, cannot be said of the district lying to the eastward of the great Boothorpe fault. Any attempt in search of useful coal below the outcrop of the Pistern Hill, and Smisby coal, can only be attended with disappointment. * Gcol. Cham. Forest, p. 17. f Messrs. Nadin reached a coal of 1 foot thick at a depth of 15 yards below the Eureka; and the same seam was found by Mr. AVilliamson at 22 yards from the Eureka in Lord Chesterfield's new pit near Bretby Park. f 22 GEOLOGY OF LEICESTERSHIRE. CHAPTER VI. COAL-SEAMS. MOIKA DISTRICT. Bottom or " Eureka Coal" While Messrs. Robinson and Fore- man were engaged in sinking a sump-shaft at the bottom of their Swadlincote pit, they proposed penetrating a few yards deeper than was necessary for their object into strata hitherto unexplored in that district, and the result was the discovery of a highly valuable coal-seam. Their example was soon followed by Messrs. Nadin at the New Stanton or Hawfield colliery. Having reached the necessary depth, they were dissappointed in not discovering the expected coal; but upon continuing to sink 15 yards further, they reached a thin seam one foot in thickness, with a roof of black shale (" Rattle Jack "), thus differing in several particulars from the "Eureka" of Messrs. Robinson and Foreman, the roof of which is " Stony bind" ten feet thick. It was evidently a lower seam than that they were in search of; and supposing it possible that the Eureka might have been cut out by a rock fault in the position of the shaft, they commenced to drive a horizontal heading at the proper depth, and at three yards from the shaft the first traces of the missing seam were discovered. From this point it gradually increased in thickness, till at eight yards from the shaft, it reached five feet, which is one foot more than at Swad- lincote old colliery. (See Vertical Section, Sheet 20.) This seam, however, had already been proved under Moira as far back as the year 1833, by means of a boring below the Main coal at Newfield pit. The section was kindly furnished by Mr. Woodhouse, for the details of which I refer to Sheet 20 of the vertical sections. In the boring, the following coal-seams were ascertained below the Main coal : FT. IN. 1. Toad Coal - - 3 6 2. Slate Coal (Little Woodfield) - 3 8 3. Coal (Woodfield) - - 6 4. Coal (Stockings) - - - - 8 5. Coal (Eureka) - - - - 5 26 2 The qualities of these seams are thus described, but from the evidence of a boring, such particulars must necessarily be im- perfect : No. 3. FT Top part dicey - -2 Mingy - -2 Rather dicey - 1 Soft - - - 1 No. 4. Dicey Mingy Dicey Soft No. 5 is described as being " mingy and spiry." Above No. 3 there occurs a series of valuable ironstone -measures. CJOAL-SEAMS. MOIRA DISTRICT. 23 The absence of the Eureka coal in Hawfield colliery shaft is produced by a " rock fault " or " saddle/' The coal has been swept away and its place filled in by drifted matter. Where it attains its full thickness its roof is formed of sandstone, remarkable for containing roots and stems of trees sometimes 15 feet long, lying horizontally and partially imbedded in the coal itself. These have evidently been drifted and spread over the coal-bed when in a pulpy state by the waters which deposited the sandy sediment now forming the roof. At Swadlincote and Hawfield the roof of the Eureka coal is stony bind, or fine argillaceous sandstone. This would also be the case at Moira but for the intervention of a thin band of " dark bind " or clay four inches thick. At all these localities, however, the floor is composed of the usual underclay, either as " clunch," " rammily earth," or " fire-clay/' The Eureka coal has lately been found at its outcrop along the Burton Boad, near Bretby Park ;* and a pit, the property of Lord Chesterfield, has been opened, which reaches the coal at 20 yards, though only about 50 yards from the outcrop. The sec- tion found in this shaft throws much light on a portion of the coal-field hitherto very obscure. At the mouth of the pit the Stockings coal reaches the surface, where it becomes mixed with a deposit of Boulder clay and sand, which forms a deep covering to the high grounds of the neighbourhood, and is cut through by the Burton Road near Brislingcote. The floor of the Eureka seam is fire-clay, and the roof stony bind, or argillaceous sand- stone. Its thickness varies from 4 ft. 8 in. up to 5 feet, and it is of the usual good quality, though soft, being so near the basset. The strata here dip to the south-west, at 16 inches in the yard (24), a high angle, but fully accounted for by the proximity of the great boundary fault which passes by Bretby Park gate. The inferior thin seam, found in Hawfield colliery, is also present here. Its thickness is only ] 6 inches, at 22 yards from the base of the Eurekaf coal-seam. The quality of this coal-seam (Eureka) is everywhere said to be excellent. It produces a bright flame with little ash, and pos- sesses nearly throughout that structure of its parts known as " dicey/' by which is understood that it breaks up into sub-cubical fragments resembling dice, of glossy, bituminous coal. As this seam appears to extend to Moira, and doubtless much further south, and even to thicken out in that direction,! it will furnish a most valuable supply after the Main coal shall have been worked out. * A person of the nariie of Williamson, lately ground bailiff of the colliery, appears to have been the first to identify this coal as the Eureka at its outcrop, the smut having been previously taken for that of the Woodfield coal. j- My friend Mr. Coleman furnishes the following note : " A still lower seam has been found in the well of the engine-house some 40 yards below the last 16-inch scam, and f[ yard thick. The * Anglesea coal' must be lower still. The ' Three- quarter ' coal crops out half a mile to the north-east close up to the Great Fault." t See Horizontal Section (Sheet 52), and ante, p. 22. 24? GEOLOGY OF LEICESTERSHIRE. Stockings Coal. This seam, the next in ascending order to the Eureka, produces a coal of impure and earthy nature, though occasionally reaching a thickness of nine feet. So inferior is its quality that the attempt to bring it into the market has been several times abandoned. This may have arisen from the abundant sup- ply of fuel of a superior description, as the market value of most commodities is comparative. It was once got to some extent in the old pits near Brislingcote and at Gearies Lane, where the beds were found dipping rapidly from the boundary fault already alluded to. The Stockings coal is mentioned as attaining a thickness of eight feet under Moira colliery, and in terms which would augur more favourably for its quality in that direction. It is quite possible it may improve towards the south and west, according to the manner of several other coal-seams, of which the " Over" and " Nether main " coals are well-known examples. It has been suggested by my friend Mr. Coleman that the if Rafferee coal " on the upcast side of the great Boothorpe fault is identical with the Stockings coal on the other ; and there are several points, with regard to thickness, quality, &c., favourable to the supposition. By means of this probable identity we can calculate the amount of throw or dislocation produced by the fault, which at Woodville would amount to about 1,100 feet! If these two coal-seams are not the same the throw must be much greater, as there is no other seam known on the downcast side of the fault to which the Rafferee coal can be referred. Woodfield Coal. The thickness of this seam averages 5 feet. The only place where it is mined at present is at Woodfield col- liery near Newall, from which it derives its name. I have been favoured by Mr. N. Nadin with the section of the Newfield pit, which is sufficiently short to be inserted here. SECTION AT WOODFIELD COLLIERY. YDS. Black earth 20 Nether coal - 3 Rammily earth (under-clay) - 35 Shale - 4 Rammily earth (fire-clay) - 34 Coal (Woodfield) 2 98 This seam, which is of inferior quality, containing a rather large per-centage of ash, was once extensively worked all over the northern portion of the coal-field, between its own outcrop and that of the Nether (Main) coal. Many old banks are to be seen over this district, and it is probable that very little of the coal remains unexhausted.* The upper part of the seam, to a depth of 12 or 14 inches, is cannel. * For much general information concerning this district I am indebted to Messrs. N. and J. Nadin, of Stapenhill, as also to Mr. Robinson, of Swadlincote, and Mr. Bodemau, of White House, Newall. COA.L-SEAMS. MOI11A DISTRICT. 25 A new pit has been opened between Brislingcote and the Bur- ton road. The upper portion of the shaft passes through New Red Sandstone (Waterstones) to a depth of 13 yards, and the coal is reached at 50 yards. It is 5 feet thick, and it has been fol- lowed to its junction with the marls and sandstones of the " Red formation/' which appear to rest upon or against it unconform- ably ; and it is said that a bed of gypsum was found dovetailing with the coal-seam. The boundary of the New lied Sandstone is a fault, proved farther south, at the village of Stanton. From these data the position of the beds in this neighbourhood would appear to be as represented in the annexed section. SECTION THROUGH BRISLINGCOTE COAL-PIT. i. 3. BRISUNGCOTE PIT N. R. SANDS. AND MARL. COAL-MEASURES. -r Fault. a. Woodfield coal. b. Stockings coal. c. Eureka coal. x. Anglesea coal. Scale 530 feet to 1 inch. I was formerly of opinion that the Woodfield Coal of the north was the same as the Slate coal of the south of our district. Mr. Coleman, of Ashby, however, thinks differently, and holds that the " Toad " coal of Measham and Oakthorpe is identical with the "Little Woodfield" seam of Newall, and that the "Slate coal " of the south passes into black shale, or thins out north- wards. In the former case the lowest seam pierced in the Moira boring would be lower than the Eureka, in the latter it would be identical with it. The determination of the point is interesting and important, as involving the known existence or the contrary of a considerable bed of coal ; at present, I do not think we have sufficient data for arriving at a conclusion.* The Slate Coal has been worked to some extent around Oak- thorpe and Measham. It is described as a good burning coal, and, consequently, undeserving of its disparaging name. It varies from 3 feet 8 inches to 4 feet thick. The following table is intended to represent the number and thickness of the coal-beds at the northern and southern part of the district, under the supposition that the " Little Woodfield " * The northern outcrop of the Woodfield coal has been traced on the map from information derived from Mr. N. Nadin, and from several old miners of the neigh- bourhood. It is 12 yards below Thorntree Farm. The outcrop is also known between the old collieries near Brislingcote, and the New Eureka coal-pit, by the side of the Burton road. It had also been found in a field west of Brislingcote Farm, and farther south, near Newall Park. 26 GEOLOGY OF LEICESTERSHIRE. and " Toad " coals are identical, and reckoning from the base of the main seam, NEWALL. MoiRA. Feet. Feet. Name of Seam, &c. From To Name of beam, &c. From To Nether Main coal 5 9 "Nether Main coal 3* 7 Various measures 40 50 Various measures 31 7 _ Little Woodfield coal 31 4 Toad coal 3 6 _ f Various measures - ~| Various measures 135 145 < Slate coal - 3 8 V 148 _ 1 Various measures - J Woodfield coal 5 6 Coal - 6 _ Various measures 48 71 Various measures 29 _ Stockings coal 54 9 Coal - 8 _ Various measures 60 75 Various measures 45 _ Eureka coal 4 5 Coal 5 _ Various measures 431 Various measures 6 As the Slate coal bassets both at the north and south sides of the coal-field, and as there is also reason to conclude that the strata along the western boundary dip towards the centre, we obtain an idea of the general form of the coal-field. It is evi- dently not a true basin, but a basin smashed in two by the great Boothorpe fault. Various other fractures also traverse the basin, and destroy all symmetry of outline. The Slate seam is the loAvest hitherto worked in the district of Measham, and whatever be the extent of area of the Main coal in that direction, that of the Slate seam must be greater ; and in con- junction with the underlying Woodfield, Stockings, and Eureka seams, will form a most valuable repository of mineral fuel for future consumption. Mr. Colemaii considers that at Stanton colliery this seam is represented by a bed of bituminous claystone 4 feet thick, and probably in some measure an ironstone. The surfaces of the laminae are spotted with light-brown impressions of shells of the genus Anthracosia ( Unio), and of a small crustacean called Cypris or Cythere, of a species hitherto unknown.* These produce an appearance which may have given rise to the name of the bed, which, indeed, is very like a celebrated bed of ironstone in the Pottery district of Staffordshire. Little Woodfield Coal. The outcrop of this seam is exposed to view in a brick-yard close to the side of the lane leading from Newall to Bretby Park Lodge. As a coal it is of little value, and I am not aware that it is or has been worked for consumption. Toad Coal The position of this seam from Moira southwards is from 30 to 50 feet below the Nether Main coal, and it is from 3 to 4 feet thick. Discovered by Henry Green, Esq , of Ashby-de-la-Zouch. COAL-SEAMS. MOIHA DISTRICT. 27 Main Coal. This seam, as its name implies, is the most impor- tant in the district, and is worked in all the collieries from its northern basset to Oakthorpe. It has lately been reached in the New Willesley Basin colliery. In all the northern portion of the coal-field it consists of two beds, the " Over" and " Nether/' separated by strata which gradually thin out southwards, thus throwing the two seams into one. Both parts, however, are capable of being distinguished, and are known as "Over" and " Nether" throughout the whole extent of the coal-field. At the Old Stanton collieries the measures which separate the Over and Nether seams attain their maximum thickness of 60 feet, as will be seen by the following section. SECTION AT STANTON OLD COLLIERY. Name of Stratum. Feet. Feet. New Red Conglomerate - 45 45 Coal-measures 33 78 Over coal 6 84 Various measures 60 144 Nether coal 6 150 At New Stanton colliery the intervening measures are only 15 inches thick; at White House colliery, 2 feet; at Gresley Wood colliery, 9 inches; and from Moira colliery southward the Over and Nether coals form one undivided bed, averaging 14 feet in thickness. The floor of the Nether coal is uniformly a stratum of clay, or fire-clay, which led Mr. Mammatt to infer if that an immense flat " was originally covered with the substance of this fire-clay " many feet thick, and that upon this flat there took place a uni- " form growth of vegetation." * The thickness of the Over and Nether seams is very nearly equal, ranging from 5 feet to 7 feet each ; but it is a remark- able fact, that while in the southern half of the coal-field, from Moira to Measham, the Over coal is superior in quality to the Nether ; the reverse is the case in the neighbourhood of Newall, towards their northern bassets. The consequence is, that dif- ferent parts of the Main coal are got in each district ; while at Church Gresley colliery, situated in the centre of the area, where both the Over and Nether seams are of medium quality, the whole thickness of 15 feet is extracted. That any portion of this valuable coal-bed should be neglected is much to be regretted. But, as I am informed by Mr. Wood- house, there is at Moira colliery a difference in the market value of the " over " and " nether " portions of two shillings and upwards per ton. This depreciation amounts to an actual pro- * " Geological Facts," p. 74. Mr. Mammatt proceeds to speculate concerning the alternations of coal and lire-clay, in a manner which, however ingenious, appears incompatible with the views stated in the above extract. GEOLOGY OF LEICESTERSHIRE. hibition. Those portions of the Main coal now left exposed to the atmosphere will certainly deteriorate, and cannot at a future period be got as economically or with as much safety as at the present time. At Church Gresley Colliery the whole thickness of the Main coal is extracted, and it is to be hoped that this plan will be pursued more extensively for the future. To those interested in the subject I would earnestly recommend the peru- sal of the valuable observations of Mr. Warington Smyth on the plans adopted in the South Staffordshire coal-field for getting the whole thickness of the 10-yard coal;* a work of much greater difficulty than would be necessary in the Ashby coal-field. | The Main coal has been divided into a series of subdivisions, known to the miners, and named according to texture, purity, and fracture. Mr. Mammatt asserts them to be constant over the area included between " the southern and western bassetings of " the Main coal to a depth of 1,000 feet on its northern side," that is, as far north as Gresley Wood and Swadlincote.J DIVISIONS OF THE MAIN COAL. No. Name. Explanation. Feet. In. 1 Roof coal - Spires, dark slaty structure 11 2 Stone coal - Spire and dice mixed 1 7 3 Dicey Breaking into cubes or parallelepipeds - 5 4 Grisley Small cubes, with pyrites 5 5 Spires As No. 1 - 11 6 Dicey As No. 3 7 7 Hard Seam - As No. 1 , but more compact H 8 Dicey As No. 3 44 9 Slating As No. 7 1 10 Holing As No. 3, but not so compact 1 11 Scalps Dice, with two seams of spires - 6 12 Grounds Dice, with spires mixed, very stout 11 13 Undergrounds As No. 1 4 14 Roof coal - Dice 2 2 15 Hard Seam - Spires, compact - 1 16 Soft Seam - Dice 4 17 Hard Brown Spires, compact - 1 18 Hard mixed - Spires (and dice ?), compact 6 19 Holing Dice, tender 1 2 20 Jods Spires 1 Total 14 5 The roof of the Main coal is generally a thin bed of fire-clay called " tow," upon which there rests a coal-seam, the " Second Rider coal/' from 6 inches to 4 feet in thickness. In the case of the Bath pit (Moira) the tow is absent, and the Rider, here 4 * Records of the School of Mines, vol. i. part 2, p. 339. Longman. f Mr. Woodhouse informs me that the Nether coal is left at Moira colliery in such a state as to be capable of being raised, should the price of coal authorize it. | These subdivisions must be considerably modified by the changes in the thick- ness of the Main coal, amounting to 4 feet. " Smut " is the soft black carbonaceous matter into which a bed of coal decom- poses at the outcrop. COAL-SEAMS. MOIRA DISTRICT. 29 feet thick, rests immediately on the Main coal, producing a solid bed nearly 18 feet in thickness. The Over coal has been almost exhausted under Measham Field, from Oakthorpe eastward nearly to Gallows Lane, as also north- ward and eastward of Donnisthorpe. The Nether coal remains, for the most part, undisturbed, though considered by no means of inferior quality. At Oakthorpe the Main coal bassets,* but is thrown in again by an east and west fault, which crosses the country on the south side of the village. The smut may be seen in a garden close to the turnpike on the Measham and Moira road ; and the cellar of the Gate Inn at Oakthorpe is said to be excavated in the Main coal. I was unable to verify this statement personally, as the landlord informed me that the coal was covered up. Near both these places the Slate coal was worked by means of pits which did not pass through the Main coal, which places it beyond doubt that the coal-crops in question are those of the Main coal.f About 80 years since Oakthorpe Hill was on fire all along the basset, and the combustion continued for several weeks, defying all attempts to extinguish it. The depth of the Main coal over Measham field varied from 20 to 25 yards, and the beds were found nearly horizontal, the clip being slightly towards the south and west. There was formerly a pit to the Main coal at 25 yards, between the farm and the river Mease, about 200 yards from the Swepstone Road, on the side opposite Measham Hall. The coal was worked as far south as the brook and there left. According to Mr. Mammatt, the Main coal bassets at or near this point. This statement is confirmed by recent borings, though the actual exposure of the coal is concealed under Permian Breccia. There is also a probable southern basset, but for the supposition that there is a western basset in this neighbourhood there is no evidence whatever ; on the contrary, all the evidence goes to prove that the Main coal deepens in those directions. It is true this seam reaches the surface at Oakthorpe, but it is thrown in again by a fault of considerable magnitude, of the existence of which Mr. Mammatt does not appear to have been aware. On the downthrow side of this fault there was a boring made not many months since, when it was found that the 4-foot coal was 50 yards deep. Now the 4-foot coal is about 60 yards above the Main coal, and hence south-west of Oakthorpe the main coal ought to be 110 yards deep. As far as the evidence goes the Main coal may spread for miles west and south-west of Measham. As the boring to which I have alluded is of great interest, and as there appears to be no doubt about its accuracy, I give the details. The position was on the west side of the lane leading * From Mammatt's " Geological Facts." f Most of my information about the old workings in this neighbourhood was derived from an intelligent old miner, Samuel Dennis, alias Cornet. (Sam. Dennis died in 1857, aged 85 years.) so GEOLOGY OF LEICESTERSHIRE. from Oakthorpe village into the Burton road, and about 150 yards south of the canal. MR. PIDDOCK'S BORING, OAKTHORPE.* Name of Stratum. Feet. In. Name of Stratum. Feet. In. Soil - 2 Brought forward 84 6 Sandy clay 4 Fire-clay 1 6 Brown rock - 3 Grey rocky shale 34 Rocky shale - 3 Mixed shale and coal 2 Brown rock - 2 2 coal 9 Yellow rock - 5 Dark shale and coal - 1 3 Dark shale 1 Grey rocky shale 2 Grey rock 6 Blue shale - 7 Blue shale Dark rocky shale Grey rock 19 35 2 {Coal 1 Little or f Parting I Four-foot 4 Coal J coal. [ 3 1 5 2 10 Dark shale 6 Dark fire-clay 2 6 1 Coal 2 Rocky shale - 1 6 Carried forward 84 6 Total - 143 4 Though the parting near the centre of the coal (No. 3) in the above section appears to identify it with the Little or Four-foot coal, and though some of the measures above, as " mixed shale and coal " are very similar to those of Mr. Mammatt's section, yet it is to be regretted that the boring was not continued down to the Main coal, or at least to the intervening bed of Cannel, so as to leave no room for doubt as regards the existence of the Main coal underneath this portion of the country. The northern bassetings of the Over and Nether coals was traced on the map from the following data : The Nether is 4 yards deep in the well of Newall Park ; it was also obtained along with the basset of the Little Wooclfield coal, south of Hills Close Farm, in an open work. The Over coal-crop is seen in the lane-cutting south-west of Thorntree,f and the Nether in a clay-pit near Woodfield colliery. Its basset north of Newall, where it forms with the Over coal a solid seam with a small parting of shale, is known to the miners, if East of the Moira main fault there is no basset for any of the coals below the Little coal, those lower down being broken off by the Boothorpe fault before arriving at the surface. The following is the mode of excavating the Main coal adopted in the Hastings and Grey pit, Moira : Scarcely one-half of the Main coal is got, the portion worked being 6 feet in the Over-coal, leaving a roof one foot thick, and a * The Section was kindly procured for me by the Rev. W. H. Coleman, of Ashby- de-la-Zouch. f " Thorntree " in the Ordnance Map is an error for " Rowan Tree," i.e. Moun- tain Ash. % These details I obtained principally from Messrs. Nadin and a miner, Francis Dent, of Newall. For these particulars I am indebted to John Brown, Esq., who kindly accom- panied me over the Hastings and Grey colliery ; and to the details in the " Geological Facts." COAL-SEAMS. MOIRA DISTRICT. 31 floor of the Nether seam, which is said to be a good coal, though inferior to the upper part. At about the centre of the portion worked there occurs a soft seam, 8 inches in thickness. This is " holed " or excavated as far as a man can, with effect, use a mandril or pick, that is about 3 feet. When about 20 feet has been holed wedges are inserted in the roof, about a foot underneath the "tow." The wedges, which are long and thin, are driven up by hammers with long shanks. The mass is thus detached and cleared away, then the wedges are inserted at the floor, and the lower part of the coal is forced upwards, by the same process and with the same results. Only large blocks are sent up the shaft, and were the refuse and small slack allowed to remain exposed to the air of the mine, spontaneous combustion would ensue. To prevent so dangerous an occurrence the following means are employed : When the blocks of coal have been carried away, and the refuse swept out of the workings or "gobbins," two walls or " brettices" are formed, by laying crossways several tiers of oak stems, 3 feet long by 6 inches thick, and reaching from the floor to the roof. The walls are carried forward \vith the proper interval for a passage between, generally 6 feet. Inside each brettice a wall of plastic clay called "wax," brought down from the surface, is formed progressively with the brettice, and is firmly squeezed under the roof, so as to render the gobbin air-tight, The gobbin is then filled in with the refuse slack, and the brettice and clay wall are carried onwards as the excavations proceed ; this part of the work being accomplished by men specially appointed to the task in the evening. This mode of working the coal produces a waste of (including the roof) one-third of the portion of the Main coal which is excavated, and thus of the entire seam only about one-fourth is made use of. The following diagram is intended to represent a cross section of a heading newly completed in the Hastings and Grey colliery, Moira. SECTION THROUGH MAIN COAL. Fig. 4. T Tow, or clay roof of Main coal. H Open passage. B Brettice wall. W Wax, or clay wall. G Gobbins, or waste filled with refuse slack. 32 GEOLOGY OF LEICESTERSHIRE. In some places the roof settles considerably, and the pressure becomes so great that the balks of timber are crushed to nearly half their former thickness. This pressure is often occasioned, Mr. Brown informed me, more from the presence of faults than from the weight of the superincumbent strata. It has been already observed that in the northern portion of the Moira coal-field, the Main coal is divided by the intercalation of various measures, attaining at Stanton colliery a thickness of 60 feet. In order to account for these phenomena, we may suppose that after the growth of vegetation, probably in the form of peat, which now constitutes the lower half or nether seam, a slight subsidence of the country occurred, the amount of which was greatest in a north-west direction, and causing the submer- sion of a portion of the area to a depth greater than 10 fathoms. Over the mass of vegetable matter under water, sands and clays were tranquilly deposited to the upper surface of the water, and a new growth of vegetation commenced, now composing the over seam of the Main coal. Cannel Coal. The next seam above the Main coal of which any use has been made is one which though thin is very constant, both in mineral character and thickness throughout the whole extent of the coal-field, from its northern to its southern basset- ings. It is No. 354 of Mr. Mammatt's pit sections. Its average thickness is 3 feet, though it sometimes reaches 4 feet. The greater portion is cannel, which always forms the upper side, the lower being common coal of variable thickness. I have never heard of its having been got, except by one miner on a small scale many years back, who by some means or other, became a losing party by the transaction. Little or Four-foot Coal. This is the most important seam above the Main coal ; it varies in thickness from 4 to 5 J feet. The roof is strong bind, with an occasional parting of tow or clay, while the floor is clunch. In the section of the Rawdon pit there occurs a parting of fire- clay 1 foot thick, near the bottom of the seam, which in the Hastings and Grey pit section is replaced by black bass. It is No. 335 of Mr. Mammatt's sections, who gives the following sub- divisions of the seam. FT. IN. 1 . Dicey coal, with a seam of spire one inch - 1 8 2. Hard spire coal * -19 3. Soft dicey coal - 5 4. Soft fire-clay - 5 5. Soft dicey coal - 6 Total - -49 The basset of the Little coal was found in laying the founda- tions of the bridge of the Burton road, near Stanton. It occurs 10 yards below Hawfield Farm, and crops out along the southern side of Newall, till it terminates against the main fault. It also COAL-SEAMS. MOIRA DISTRICT. 33 occurs close to the surface, between the Potteries and Spring Wood, south of Bretby Park, being proved in the old pits in that neighbourhood.* The southern basset was laid down on the map from information on the spot,f and from Mr. Mammatt's hori- zontal sections. In the New Willesley Basin pit, near Oakthorpe, the Little coal was found to be 39 yards from the surface. It is 4 feet thick, without any parting near the base, and the roof is " strong blue rock/'J Block Coal t otherwise known as ef Jack Dennis " or " Watson" around Swadlincote. This is No. 271 of Mr. Mammatt's sections, and is a seam varying in thickness from 3^ to 4 feet. It invariably occupies a position underneath a thick stratum of bind containing several seams of ironstone. The northern outcrop may be viewed in the cutting of the tramway leading from Gresley Wood colliery to the main line of railway, where it strikes against a small fault. It is also exposed to view in a clay pit north of Mr. Bodeman's new colliery, Swadlincote; on the Moira side of the coal-field Dennis coal bassets north of the New Willesley Basin pit, as it has not been touched in the shaft. On the west side of the Moira main fault it is cut off at " the stone wall fault." My friend Mr. Coleman informs me that it was formerly worked to a small extent at Sale's Spring pit. As far as I am aware, this seam has not been got to any extent. It is generally of a friable and jointed nature, and in the sinkings is usually found charged with water. Dickey Gobbler, so called from the miner by whom it was first worked. It occurs at the mouth of the pit at White House, Newall, and within a few feet of that of Gresley Wood colliery. It is No. 222 of Mr. Mammatt's sections, and ranges in thickness from 3 to 4^ feet. Bands of ironstone are common in the clays which overlie the Dickey Gobbler. The coal is of medium quality, resting on a floor of strong clay, with ironstone nodules. Ell Coal. This is the highest seam which has been worked in the Moira coal-field. Its thickness, as its name implies, is generally a yard and a quarter. It has been extensively got under Gresley Common, and to some extent on the east side of Ashley Woulds. A new pit has been sunk on Gresley Common, south from the " Church pit," a section of which has been forwarded to me by Mr. Coleman, from Mr. Healy. The object was to work the Ell coal, which was found to be 4 feet thick at a depth of 82 feet from the surface. In the shaft of the Grenville colliery its depth is 72 * These particulars I learned from an intelligent miner, Francis Dent, of Newall. t Furnished by Samuel Dennis, alias Cornet, of Measham. j The section was kindly given me by Mr. Whithead, bailiff. Since writing the above this colliery has passed into the hands of the Marquis of Hastings (1860). On reaching the Main and Little coals the inflow of water from the old workings was so great as to necessitate the erection of the largest Cornish engine in this district. The diameter of the cylinder is 84 inches, and it was manufactured at the works of the Burton-on-Trent Iron Foundry, 34 GEOLOGY OF LEICESTERSHIRE. feet, with a thickness of 3 feet 1 1 inches, with three beds of potter's clay, at the following depths from the surface : Depth. Thickness. No. 1 - 35 ft. - 4 ft. (grey). No. 2 - 65 - 8 (grey and black). No. 3 - 66 - 4 (grey and good).* It bassets in the wood, north of the Granville colliery and west- ward of Woodville, till it is broken off against a fault having a downthrow on the south. Three yards above the Ell coal there occurs a valuable bed of fire-clay, well adapted for making saggers. This clay is worked by means of gin pits on Gresley Common, and in open works south-west of Woodville. f In a series of borings, in a position about 500 yards south of Woodville, and on the west or downcast side of the Great Boothorpe fault, which were undertaken by Mr. Joyce for the purpose of proving the depth of the Ell coal, and for a copy of which I am indebted to Mr. Coleman, the smut of a coal 8 feet thick, ^heretofore unknown, was ascertained, close to the surface, and in a position about 85 feet above the Ell coal. This is all that is at present known about this seam, which appears to be the highest of which we have any knowledge. Besides the coal-seams here particularized, there are several others of minor importance, the history and statistics of which are unknown, and of the value of which little account is taken, owing to the present abundant supply now obtained principally from the Main coal. They are kept in reserve for future use ; and their value will be augmented in proportion as the supply from other sources fails. RAFFEKEE COAL, WOODVILLE. On the upcast side of the great Boothorpe fault there occur around Woodville two coal-seams, separated by about 8 or 10 yards of measures, and chiefly valuable for the potter's clay with which they are associated, The uppermost of these seams is called " Rafferee coal/' and is chiefly remarkable for the inconstancy of its character. In some places it attains a thickness of 10 feet, and at a short distance is not more than 2 or 3 feet thick ; this will be seen by the following sections, at a distance of little more than a quarter of a mile from each other. Messrs. Hough and Grey's Pit. Waterloo Pit. YDS. FT. YDS. FT. Measures - . . 19 . _ - 14 Rafferee cdal _ . 9 . _ - 3 Measures with pot-clay 8 - - 11 Coal - - - 3 - - - 4 Clay - Pot-clay - 2 * See Vertical Section, Sheet 19, Granville colliery. f " Saggers " are pans used in pottery works, in which are placed the finer kinds of ware when placed in the " ovens " to be " baked." COAL-SEAMS. MOIRA DISTRICT. 35 The basset of these coals occurs near the east end of the village, but they are repeated again by a fault passing through the Waterloo pit, and a few yards east of Butt House, and the two sections given above are on opposite sides of the fault. At Block- fordby the outcrop of the 4-foot coal is exposed in an open work i OUTCROP OF THE FOUR-FOOT COAL AT BLOCKFORDBY. Fig. 5. A Loose breccia in matrix of marl. B Purple marl forming base of New Red Sandstone. C Sandy shale. D Coal 3 feet thick. E Pot-clay, with rootlets stretching from the coal. in a field north of the village. The bed forms a little basin, or rather basin with a portion of the side flattened out. The basset of the Rafferee was proved some years since in a deep trench at the west end of the village near the brook ; the smut was 9 feet thick.* Further south than this there are no data for tracing the crop of the Rafferee coal ; but a higher bed, or at least an' appa- rently higher bed, makes its appearance in this neighbourhood. It was formerly worked by the landlord of the " Blue Bell," Black- fordby, in a shallow pit close to the Boothorpe road; its thickness was described to be 3^ feet, the coal good in quality, and the beds dipping rapidly to the west. After a few tons had been got the works were drowned out. If all these particulars are correct, this coal could not be the seam underneath the Rafferee, as the latter did not appear in the shaft. I conclude, therefore, that it is a higher seam, and probably continuous with the coal formerly worked at Sweet Hill Oak. At these pits the coal was 30 or 40 yards deep, and 4J feet thick. The pits were worked by a blind collier some forty years ago.f The outcrop of a coal-seam (pro- bably the same seam) was laid bare in the railway cutting south of Sweet Hill Oak ; it is there 4 feet thick, and was excavated and burnt during the formation of the line. The section is now almost entirely concealed. It is not improbable that the Rafferee coal is the same as the " Stockings " seam of Moira. Both are of inferior quality ; both rest on clay from 2 to 3 feet in thickness ; and in both cases a bed * On the authority of John Orme, of Woodville, a native of Blackfordby. f From information obtained from John Orme, of Woodville, and Samuel Dennis, alias Cornet, of Measham. c 2 36 GEOLOGY OF LEICESTERSHIRE. of good coal of nearly equal thickness is found underneath,, at depths by no means very dissimilar. In order to render the comparison more obvious, the two following sections are placed in juxta- position : SWADLINCOTE SECTION. WOODVILLE SECTION. Woodfield coal - Measures - Stockings coal - Clunch - Measures - Eureka coal Clunch FT. IN. 5 48 5 2 3 61 4 FT. IN. Probable coal seam 4 6 Measures (more than) 42 Rafferee coal - from 9 to 3 Clay and Measures - - 33 Coal - 4 Pot-clay - - 2 It will be admitted that, making due allowance for changes consequent on the interval, more than a mile between the two sections, there is a strong similarity ; and should it ultimately prove to be the case that the Rafferee is the Stockings coal, and the underlying 4-foot coal the Eureka seam, it will be sufficient to deter from attempts to reach a good coal below the Eureka, ns it will in that case form the lowest bed of the productive Coal- measures.* This event will also throw light on the magnitude of the Boothorpe fault. The Ell and Rafferee seams are at about the same depth from the surface on each side of this fault at Woodville; and on the supposition of the "Rafferee" being iden- tical with the Stockings, the amount of throw at the south side of Woodville will be equal to the depth of the Stockings below the Ell coal nearly, i.e., 800 feet. CHAPTER VII. COLEOBTON DISTRICT. LEAVING Moira, and commencing our course to the eastward towards Coleorton, we make a diagonal section of the coal-pro- ducing district, with which it will be well to become acquainted, in order to the proper understanding of the relationship subsisting between its eastern and western portions. After crossing the " 120 yard " fault, which traverses the strata not far from the east side of the village of Moira, we arrive at the Hastings and Grey pits, where the Main coal is worked at a depth of about 120 yards deeper than in the Bath pit, on the shallow side of the fault. Here the beds are almost horizontal, being at the centre of the trough formed by the strata between the northern and southern bassetings. Continuing our course along the railway, we find, on passing under the bridge of the Willesley Road, the strata rising rapidly to the eastward, first at angles of about 10, but increasing in amount * Except, perhaps, the the " Eureka." Anglesea seam," which Mr. Coleman considers as below COAL-SEAMS. COLEORTON DISTRICT. 37 till, at a distance of 200 yards from the bridge, they stand in a vertical position, and are broken and dislocated in a very remark- able manner. We have, in fact, arrived at the position of the great Boothorpe fault, by far the greatest dislocation on this side of the Ashby coal-field ; and in crossing we pass at once from a thick series of coal-producing measures into another almost unproductive, and far down in the coal formation. As we proceed eastward the beds, with two or three coal crops, are found still rising to the east, but at angles which lessen as we recede from the Boothorpe fault. This westerly dip is constant till we have passed half a mile beyond Ashby-de la-Zouch, where we arrive at the axis of the " Ashby Anticlinal" east of which the beds roll over and dip towards the east ; and as we proceed towards Coleorton we pass in succession the outcrop of a series of coal-seams, which, though representing generally those of the Moira district, are not strictly comparable. The New Red Sandstone overspreads the southern half of the Coleorton coal-field, and the upper portion of the Whitwick, Snibston, Ibstock, and Bagworth shafts pass through the red marls and white sandstones of this formation. The strata incline at a very small angle to the south-east ; and underneath, the Coal- measures preserve a steady dip to the eastward at angles from 4 to 6, and consequently the coal-seams rise and basset against the under surface of the newer and unconformable beds of the New Red Sandstone. Tbe'direction of the dip at the northern extremity of the Coleorton field changes by a quarter of a circle, and the coal-crops form a series of concentric curves, which are abruptly terminated towards the east by the great fault which forms the boundary line of the coal-field. As the Coal-measures approach the position of the boundary fault, they are found to rise very rapidly, so as to become almost vertical in the space of a few hundred feet ; this produces a synclinal, the axis of which passes at a short distance east of Peggs Green colliery, through the new Swannington shaft, and a quarter of a mile east of Whitwick colliery. In company with the son of Mr. W. Stenson, jun., I explored a heading which had been driven in a direction 20 north of east, to a distance of nearly half a mile from the shaft of Whitwick colliery.* Upon reaching the position of the synclinal axis, we commenced ascend- ing along the floor of the coal, at first gradually but at a rapidly increasing inclination, till the heading finally passed into a nearly vertical shaft, which had been driven upwards with much diffi- culty at an angle of .about 80 ; we measured the interval between the shaft and the place where the coal-seam was hori- zontal, and found the distance only 60 yards. East of the new Swannington shaft the rise of the strata is even more rapid, and its effect is to render the coals unworkable east of the pit ; the dip is north-east, at 3 inches in the yard, but at 80 yards east of the shaft the coal commences to rise into a vertical position almost * See Horizontal Section, Sheet 48. 38 GEOLOGY OF LEICESTERSHIRE. instantaneously.* At about 100 yards from the pit the beds are probably vertical, between which and the boundary fault there is room for 600 feet of strata, so that were a deep cutting to be opened, we would probably find all the beds, as far as the base of the Lount coals, rising vertically to the surface in succession. With the exception of the main or boundary fault of the Cole- orton coal-field, and another which branches from it at Heath End, there are no dislocations of importance in this district. The absence of faults, properly so called, is however, fully counter- balanced by those irregularities in the stratification known as u rock-faults ;"f to these I shall refer hereafter, proceeding at once to the consideration of the principal seams of coal, commencing with the lowest. Heath End Coals. These constitute, as far as has been hitherto determined, the lowest workable seams of the Coleorton coal-field. Their outcrop occurs at the entrance to Dimmingsdale, and the seams are broken off against the boundary fault to the north-east of the Heath End pits on the one side, and by a large branch fault, which ranges along the west side of Rough Heath, on the other. The following is a section of the coal-seams which were worked at Heath End colliery 4 HEATH END SECTION. FT. IN. 1. Bind (shale) - 10 2. Stone - 4 3. Bind - 2 ? 4. Coal - 4 5. Stony bind 1 6 Coal / Coa1 ' 2 feet \ Q O ll \Cannel, 7 feet/ In some places the 4-feet coal rests immediately upon the thick coal, so as to form a solid seam 13 feet in thickness. The outcrop is now visible (1860), but though the cannel is somewhat anthra- citic so near the surface, there is reason to infer that its quality improves on the deep, and should this prove to be the case, it will form a seam of great value under the Coleorton district. At Heath End the dip is southward, and it is terminated both to the east and west, by large upcast faults. The probable depth of the Heath End coals below the Coleorton main seam is shown in Horizontal Section No. 1, Sheet 46. * For these particulars I am indebted to Mr. Houldsworth, manager of the New Swannington colliery. f Miners, and those who ought to be better acquainted with the subject are con- stantly confounding the two kinds of phenomena here referred to. The distinction is essential. Faults are breaks in the strata, accompanied by a vertical displacement ; rock-faults are banks of sand or clay which replace in a coal-seam parts previously carried away. This section was kindly furnished by the Rev. W. II. Coleman. COLEORTON COAL-FIELD. COAL-SEAMS. 39 Lount Coals. Roaster (No. 1).* This is a thin seam, averaging only 2 feet in thickness, but of excellent quality. It has been got to a small extent at Lount. The position of the outcrop of this and the higher seams I obtained from the information of an intelligent miner, who had worked in all the pits, which are numerous between Lount colliery and Lount wood. I was informed by Mr. Houldsworth, of Swannington colliery, that the " Roaster " was found in the cellar of Stanton Hall. The late Earl Ferrers had caused a coal to be laid open alongside the lane leading from Lount to Stanton Hall, in a position one hundred yards north of the brook. The dip was found to be north, and a few yards further towards the deep of the coal, a pit was sunk for the purpose of proving its quality, when it was found that the seam had dis- appeared, hence there would appear to be a roll-over of the beds, accompanied by a fault; and this coal may be the Roaster described as being under Stanton Hall. Nether Coal (No. 2). This seam is 70 yards deep at Lount pits, and its thickness 4J feet. Middle Coal (No. 3). This seam at Lount is 4J feet thick, and the same at Lount Wood and Coleorton Moor. Its outcrop is exposed to view in an open work at the east side of the Ashby and Nottingham road, near Lount Wood, where it is laid open for the potters' clay, on which it rests. This clay is full of rootlets (Stigmaria ficoides), which run downwards from the bottom of the coal. OUTCROP OF THE MIDDLE LOUNT COAL, NEAR LOUNT WOOD. Fig. 6. A Yellow Drift clay. B Blue shale, with ironstone nodules, 7 feet. C Middle Lount coal, 4 feet 6 inches. D Grey under-clay, with Stigmaria rootlets, &c. This seam together with the Nether, and to a small extent the Roaster, has been almost worked out over this district, near the outcrop. Old pits and banks are numerous over and around Lount and Smoile Woods. * The numbers after each coal refer to the Vertical Sections of the Geological Survey, Sheet 19. 40 GEOLOGY OF LEICESTERSHIRE. The Middle coal is generally divided by a band of ironstone about a foot from the top, and the upper part is occasionally cannel. Second Lount Coal (No. 4) is 3 feet thick and of medium quality. The Upper Lount or Smoile Coal (No. 5) is 3 feet thick at Lount, and nearly 4 feet at Coleorton Moor ; this, together with the Middle and Nether seams is, I understand an inferior coal, and at present in but little request. The basset of the Lount seams preserves, in all probability, a continuous course southward to the west side of the village of Heather, but is concealed beneath the New Red Sandstone. Near this village there were formerly some coal-pits, and four seams of coal were pierced through, which presented the following section : SECTION OF HEATHER PIT.* No. Name of Stratum. Feet. In. Feet. In. 1 Blue bind, &e. - 36 36 2 Sandstone 13 49 3 Blue bind 39 78 4 Coal 6 6 84 6 5 Blue bind 3 87 6 6 Coal 6 93 6 7 Rocky bind and chinch. - 42 135 6 8 Coal 4 139 6 9 Blue bind 8 147 6 10 Coal .3 ft. 9 in.") 11 12 Shales 2 3 \ Main coal of Ibstock - Coal 4 9 J 10 9 158 3 13 Tire-clay - 3 161 3 14 Rocky blue bind - 117 278 3 It is probable that Nos. 4, 6, 8, represent the Lount Upper, Second, and Middle coals, in which case No. 10 would represent the Nether, and No. 12 the Roaster, or Nos. 10 and 12 conjointly may represent the Nether coal of Lount, and the Roaster be absent. At Heather colliery, Nos. 4, 6, and 8 were found to be of very inferior qualities, whilst Nos. 10 and 12 were good. These two last seams are considered to unite farther to the east- ward, and form the bottom coal of Ibstock and Bagworth, 8-J feet in thickness. I am informed by Mr. Price that the measures at Heather form a synclinal trough, and that the higher coal beds basset both east and west of Heather colliery. The lower seams were (I understand) worked westward to this basset under the New Red Sandstone, but it is improbable that they crop in the opposite direction. The following section probably represents very closely the position of the strata; it is drawn through Heather and Ibstock collieries. The strata have been proved un- Furnished by the Rev. W. H. Coleman of Asbby. COLKORTON COAL-FIELD. MAIN COAL. productive 117 feet below Heather colliery. Section, Sheet 48.) Main Coal ( No. 7 ) . This seam, also known as the Coleorton coal, is the principal seam of the dis- trict, and is got in all the deep pits, from Pegg's Green colliery southwards. Its average thick- ness is 6 feet, but on approaching a rock-fault south of Whitwick colliery, it reaches 12 feet, caused principally by partings of the rock dovetailing with it. The outcrop of this seam is close to Lount toll-gate, and runs along the west side of Smoile Wood, where it was formerly excavated in open ^ works. In this direction the seam S was found to exceed its average thickness by 2 or 3 feet, and tra- 8 dition records that it was on fire H along the outcrop at Lount Wood as far back as the commence- Q ment of the 15th century. It 3 was also got in a similar manner # ^ along the hill-side west of Rough 5 Park, and I understand it bassets 3 ft under the New Red Sandstone at y Coleorton Hall. In a " spinney " on the hill-top south of Coleorton o rectory, the Main coal was for- merly worked at a depth of 60 ^ yards, with about 20 yards of 2 New Red Sandstone a- top. It o was followed westward to a large & fault under Parson's Meadow, and was there 36 yards deep. This fault is considered, with great probability, by Mr. Coleman, to range all along the western side of the Coleorton coal-field, throwing out all the valuable coal-seams on the west side. It is probably a continuation of the large Heath End fault already described as terminating the Heath End coal along the west side of Rough Heath. This fracture was pro- duced prior to the deposition of the New Red Sandstone, and consequently does not appear at the surface. (See Horizontal 5-^1 z o r HI fc urn J j o 42 GEOLOGY OF LEICESTERSHIRE. There is a similarity between the measures which accompany the two seams in the Ibstock and New Snibston sections, as well as in the thickness of the coal-seams themselves, due allowance being made for changes in thickness, consequent on the interval between them. SECTION AT NEW SNIBSTON PIT. N PIT. SECTION AT IBSTOCK I 'IT. FT. IX. 10 37 5 Stony bind White sandstone FT. 9 8 IN. 4 4 9 Strong Stony bind 8 6 5 4 6 Coal (top coal worked) - Clunch - 5 3 1. Strong blue bind. 2. Grey metal stone 3. Blue bind i 4. Black stone j 5. Main coal - 6. Fire-clay - To my friend Mr. Coleman I am indebted for a copy of a very interesting boring made on the land of L. Fosbrooke, Esq., in 1830. The spot is between a pond and two cottages half a mile north of Hugglescote. It only reached as far downwards as the seam called Battle Jack, which is about 33 yards above the Main coal. The measures correspond very closely with those in No. 2 pit, Snibston colliery, and the following are the coal-seams passed through : Thickness. Depth. FT. IN. 1. Stone Smut coal - 2. Swannington coal 3. Soft or Three-quarter coal 4. Slate-coal Eider - 5. Slate coal 6. Yard coal - 7. Rattle Jack coal - FT. IN. 4 3 8 1 11 11 3 254 280 325 363 387 433 465 9 4 6 5 11 11 9 There is evidently a large area of useful Coal-measures over- spread by the New Red Sandstone as yet undisturbed, and extending from a line joining Coleorton to Heather, and eastward to the boundary fault of the coal-field, which will afford an almost unlimited supply after the Main coal, has been exhausted. To the southward a similar area extends from the western basset of the Heather coals (which will probably continue to Market Bosworth), eastward to the confines of Charnwood Forest. West of this little coal is to be expected until we arrive at the deep side of the Boothorpe fault, which probably continues its course for several miles in a S.S.E. direction from Willesley, throwing up productive Coal-measures on the west side. From the basset between Lount colliery and Coleorton Hall, and eastward to the north side of Pegg's Green colliery, the Main coal is said to be exhausted ; and, indeed, the numerous old pits and banks which abound over this area bear witness to the fact. Over this tract there is probably not an acre of undisturbed ground. The easterly dip of the strata must, therefore, cause the accumulation of water in these old mines in the direction of COLEOETON COAL-FIELD. MAIN COAL. 43 Pegg's Green, and the greatest precautions are found necessary in order to prevent the flooding of the present mines by the bursting of these reservoirs. At Pegg's Green colliery, before a heading is driven in the direction of these old collieries, a boring rod of 1 2 feet in length is inserted through the Main coal in a horizontal direction, in order to prove the solidity of the seam to that distance. On one of many occasions the old mines were tapped, and upon the withdrawal of the boring rod the water gushed forth with great impetuosity ; a plug was immediately inserted in the orifice, and it required the strength of two men to hold it in, while a third with a sledge hammer drove it home. As the hydrostatic pressure is proportional to the depth alone, there must evidently be a large accumulation of water for a considerable distance in the direction of the basset in order to produce a depth proportional to the pressure indicated upon this occasion. The following section showing the quality of the Main coal throughout its thickness was furnished by Mr. Houldsworth, of Swannington New Colliery. MAIN COAL, COLEORTON. FT. IN. 1. Bright coarse coal - 9 2. Fine grained - - 1 3. Very bright - - 2 4. Coarse bright - - 9 5. Bronzed spire - - 1J 6. Coarse bright -04 7. Spire - - 1 8. Close-grained bench - - 1 7 9. Top spire - - 1 10. Tod - - - 9 11. Bottom spire - - 1 12. Dice - - 3J 13. Floor coal - - 1 6 Total - 7 6 The Main coal is overlaid by several feet of strong argillaceous sandstone, which at Pegg's Green, Coleorton Moor, and Whit- wick collieries rests directly on the coal, while at Snibston and New Swannington collieries a stratum of bind from 2 to 5 feet thick intervenes. The value of a solid and hard roof is great, as otherwise 12 inches or so of the coal-seam must be allowed to remain a-top ; but sometimes the sandstone roof is found to soften and give away after long exposure to the air ; and where inter- laced with partings of coal is liable to break off unexpectedly. Sulphurous Coal (No. 8). This is a thick seam, with partings of shale, but unfortunately so charged with "sulphur" (iron pyrites) as to be almost valueless, and from the quantity of sul- phuous acid produced during combustion is called the " stinking coal." Rattle Jack Coal (No. 9). From 2 feet to 3 feet thick. Yard Coal (No. 10). From 2^ feet to 3 feet thick. 44 GEOLOGY OF LEICESTERSHIRE. Slate Coal (No. 11). This seam, as its name implies,, is of inferior quality, and like " the 4-foot coal " of Moira, which it is possible it may represent, is generally parted near the base by a thin stratum of shale, from 3 inches to 3 feet thick. Its average thickness is from 4J to 5 feet. It was formerly got to a con- siderable extent around Coleorton, and is probably well nigh exhausted. A thin seam, " the Slate Coal Rider," generally accompanies the Slate coal, separated by from 8 to 12 yards of measures, and is more valuable as indicating the position of the seam, than on account of its intrinsic worth. The following Table shows the composition of the Slate coal at Swannington.* SLATE COAL. 1. Average quality coal - 2. Black stone 3. Fire-clay (uncertain) - 4. Coal ----- 5. Blue bind 6. Coal - Total - 8 9 The outcrop occurs alongside the brook, which runs by the east side of The Paddock, where some sixty years ago the coal was extracted in an open work.f Soft Coal (No. 13). Also known as (: the Three-quarter Goal/' is a thin seam varying from 1 to 2^ feet thick. Swannington Coal (No. 14). This seam, I am informed, is of good quality, and in olden time was extensively worked. In sinking the shafts of the Coleorton and Swannington new col- lieries, it was found to have been worked out, as the " gobbins " alone remained. The outcrop may be viewed at the junction of the incline, with the main tramway at Orton Quarter Mars. The thickness of the seam varies from 2|feet to upwards of 4^ feet. Stone Smut (No. 15), and Stone Smut Rider (No. 16). These are average coals, and were formerly got at Whitwick colliery before the existence of the Main coal was ascertained. The Stone Smut Rider averages 3 J feet ; the Stone Smut 4J feet ; and between the two there is an interval of 45 feet of measures. In sinking the New Swannington shaft these two seams, together with the Swannington, were found to have been exhausted. From the number of old pits north of Swannington, it is probable that these seams have been entirely worked out over the district. Mr. Houldsworth pointed out to me no fewer than thirteen old banks, within sight of the engine-house of the New Swannington colliery. The basset of the Stone Smut occurs at the north side of the * Furnished by Mr. W. Walker, jun., Coleorton. f According to the account of an old collier, Grandsir, of Coleorton. COLEORTON COAL-FIELD. SLATE COAL. o O M 5 % tunnel close by the California pit. The Stone Smut Eider bassets the south side of the tunnel, is close to the mouth of the shaft of the New Coleorton colliery, and was cut through in the tunnel at its northern out- crop, where its thickness was found to be 3^ feet. One-foot Coal This is a seam which occurs near the mouth of the shaft at New Swannington colliery, and its basset was marked out for me by Mr. Houldsworth. As the strata are thrown up very suddenly, east of the pit mouth, this and probably a few of the lower seams do not come in actual contact with the Coleorton boundary fault. The One-foot seam, toge- ther with several higher, but thin coals were found in the Whit wick and old Snibston shafts ; and, consequently, the beds through which they pass are the highest with which we are acquainted in the country. It is not im- probable that we have now reached a position in the coal formation at or near the top of the productive series, and are now on the confines of the upper unproductive Coal- measures, which, though at- taining a thickness of from 600 to 1,000 feet in Staf- fordshire, are not represented in the Ashby-de-la-Zouch coal-field, having either been swept away by the waters of an ancient sea, or covered over by the New Red Sand- stone in a district further south than has been explored by the boring rod of the miners.* cc O * Tor full details of the coal series at the collieries of the Coleorton district, see Vertical Section, Sheet 19. GEOLOGY OF LEICESTERSHIRE. FAULTS. MOIRA COAL-FIELD. 47 CHAPTER VIII. FAULTS. MOIRA COAL-FIELD. THERE are few physical phenomena to be met with in a coal-field calculated to excite greater interest in our minds than the lines of dislocation, or faults, which traverse it, often in great numbers, and the effect of which is to produce vertical displacements in its strata. On crossing a fault we often pass at a step from a district, it may be, rich in mineral produce to one utterly barren ; or we leave behind an area of country where some valuable coal-seam lies within easy distance of the surface, and enter upon another where the same bed of coal has been plunged to a greater depth by several hundred feet, and where the difficulties and expense of obtaining it are greatly increased. There are four principal faults producing important changes in the structure of the Ashby coal-field. Their general direction lies N.N.W. ; this is parallel to the axis of elevation of the Charn- wood Forest rocks, and- proves a connexion between the forces which produced these phenomena. The faults to which we allude are the " Main " or " 100 yard fault " of Moira ; the Boothorpe fault, the Heath End fault, and the " Main " or Coleorton boundary fault. We now proceed to trace the first of these from its northern to its southern termination. Moira Main Fault This line of fracture traverses the coal- field from the south side of Decoy Wood to Oakthorpe, in a direc- tion of N. 20 W. The downcast is on the east side, and amounts to 120 yards at Newall, 100 yards at Moira, and 80 yards near Oakthorpe. Its position has been proved at the lodge, Bretby Park, from the smashed and tilted character of the strata in that locality.* The fault was also proved at the old collieries on the hill side north of Newall, the Block coal having been worked at one side on a level, with the Woodfield on the other, f It has likewise been struck in the shafts of White House collieries,J and was found in the excavations for the railway at Swadlincote station. Its position was ascertained in some old pits at the north side of Swadlincote village as far as Gresley Common, where it splits into two arms, one of which extends to Castle Gresley, and the other southward along the Wooden Box branch line of rail- way,! crossing the main line near the east end of the tunnel, and the sum of the downthrows being nearly equal to the throw of the main line of fracture. It is not probable that the line of the fault is continuous with either of these arms for any great distance in a southerly direction from their point of junction. At the east side of Ashby Woulds there is a line of unproved ground, along which * According to Mr. Nadin, of New Stanton colliery, j- From information obtained from Francis Dent, of Newall. j According to Mr. Bodeman, who led me to understand that the fault splits into two portions for some yards. From plans in Mr. Woodhousc's office. II Ibid. 48 GEOLOGY OF LEICESTERSHIRE. I suppose the fault to run till it reaches the eastern end of the reservoir, where it has again been proved by actual experiment. From this it extends along the east side of the Hartshorn Road, coal having been worked on its downcast side,* and it was again proved near William Hough's farm, west of Moira village.! Farther south than this the extension of the Main fault appears involved in mystery. Of the old workings no records have been kept, and the fault, which at Moira collieries is a great reality, suddenly becomes a matter of considerable uncertainty. I believe, however, that by the help of information obtained from Samuel Dennis, of Measham, an intelligent old miner, well acquainted with all the old coal-pits of the neighbourhood, I have succeeded in tracing the main fault for some distance farther south. It appears that many years ago the Main coal was got in collieries between Willesley and Oakthorpe. There were two pits alongside the lane joining these villages, one on the site of Mr. Merriman's house, another within a quarter of a mile of Willesley Park. Both of the shafts were exactly the same depth, so that the lane is parallel to the line of strike or level, the clip being north. Another pit, however, was sunk to the Main coal much nearer the Moira Road, and not far from Oakthorpe, on the same line of level as the former, and the depth was found to be 20 yards. It is therefore evident that a fault 80 yards downthrow on the east passes between Merriman's house and the Moira Road, which, as it is in the direct line, is doubtless a continuation of the main fault. Much farther south than this it probably does not extend, as there is a cross fault extending from Oakthorpe to Gallowslane, against which it appears finally to terminate. The branch faults are numerous, though generally of small amount. The following is a brief account of them, derived either from information of coal-miners or from plans of workings : A fault crosses by Woodfield colliery with a downthrow of 16 yards on the north. The fault which runs under Newall Church and the other in a parallel line through Hawfield farm were marked out by Messrs. Nadin, who described the Main coal as having been worked along their faces. Another, a knowledge of which I de- rived from the same source, passes due east through the shaft of the New Stanton colliery, having a downthrow of 16 yards on the south. The position of the Church Gresley faults have been proved in the colliery, and were marked out for me by Mr. Walters, the bailiff, and Mr. Nadin informed me that in the Old Stanton collieries the Main coal was worked westward to a fault which is doubtless that marked on the map, and which passing N.IST.W. through Overseal, brings the Red Marl down on the west side against lower beds of the New Red Sandstone. From the Hastings and Grey pit (Moira) a heading was driven * From plans in Mr. Woodhouse's office. f From the account of Mr. Hugh, landlord of the Moira Inn, who asserts that the Block coal is thrown near the surface of the west side. FAULTS. MOIRA COAL-FIELD. 49 due south for one-third of a mile, crossing several minor faults with " tip-throws " on the south side. Two small faults pass between the two shafts, which it is not possible to represent on the ordnance map.* At Willcsley old pits, two faults were struck, of which there are no particulars preserved. Mr. Green, of Charnwood Lodge, thinks that there is a fault with a down- throw of 100 yards running due east and west across the south .side of Moira. This, I think, is a point of much uncertainty. The Main coal has been worked as far west as the lane leading south from the toll-gate, east side of Overseal, and no fault was struck. Half-a-mile further to the north the same coal was worked up to a fault which was traced for a distance of 80 yards, its direc- tion is N.N.E., but the amount and side of the downthrow are not known. A fault, ranging from the east end of the reservoir to the railway, is marked in the plans in Mr. Woodhouse's office, but there are no details concerning the throw. There are also two small faults west of the Bath pit, the directions of which were marked out by the bailiff. Mr. Woodhouse informs me that the boundary of the New Red Sandstone at Gresley railway station is a fault which has lately been struck in a heading driven from Moira colliery. Stone Wall. This fault traverses Donnisthorpe Field in a direction E.N.E., with a downcast of 100 yards on the north side. It was proved on both sides in the old mines of Donnisthorpe Field, and is marked in Mr. Mammatt's section (C to D), where it crosses the canal embankment south of Moira. In ,that locality the throw is from 120 to 140 yards. It probably terminates on the east side against the Main Fault of Moira, and is lost under the New Red Sandstone in the opposite direction, t Oakthorpe Fault. By this name I mean to designate a line of dislocation, of the existence of which as proved by actual experi- ment, I can find no record, but of which there is not the less certainty, if the information received from several sources con- cerning the depth of the Main coal in the old pits is to be relied upon.f The fault appears to range east and west, passing a few hundred yards south of the village of Oakthorpe, where, as has been already stated, the Main coal crops out, and where there have been pits into the Slate coal which did not pass through the Main seam. On the south side of the fault the Main coal is thrown in again, and at the south-west side of Oakthorpe the downthrow must be about 110 yards.J The following section, drawn nearly along the Moira Road from the turnpike gate east of Oakthorpe to the Measham and Ashby Road, will explain the nature of the evidence by which the position and amount of this fault has been determined. * From information afforded by John Brown, Esq. t For the information concerning the old pits and faults in this neighbourhood, I am chiefly indebted to Samuel Dennis, alias Cornet, of Measham. t See p. 29. D 50 GEOLOGY OF LEICESTERSHIRE. In the Slate coal pit marked in the section the Main coal was passed through at a depth of 15 yards from the surface. The " Over " coal, or upper part of the Main seam, was found to have been wrought out, and only the " gobbins " remained ; but near the shaft a fine pillar of the Over seam was found standing as a support to the roof, and was speedily demolished by the miners. I was informed by an old miner at Measham, that a fault runs along the north side of the village having a down- throw on the north side of 25 yards ; Dennis, however, had no knowledge of it, but as the Main coal is very near the surface under that part of the village, its existence is not improbable. Boothorpe Fault:* This line of dis- location, though unknown to the miners, and consequently not distinguished by a title, has produced the most important ! changes in the position of the Coal- measures and the mineral value of the western and central areas of the Ashby coal-field. It forms a boundary wall be- i tween a district of vast mineral value on the west, and one of an opposite character on the east. The first evidence we get of the exist- ence of this fault is the disturbed nature 1 of the beds in the old pits south of the potteries near Bretby Park. I was for- tunate enough to fall in with Francis Dent, of Newall, who had formerly worked in all the old collieries of the district, and in the accuracy of whose statements I place the utmost confidence. From him I learned that a fault had actually been struck close to the turnpike road near Spring Wood. It cut out the coal, and he considered it as passing under the potteries and joining the Main fault near Bretby Park Lodge. He also affirmed that the coal-seams were found pitching at high angles as they approached the position of the fault, and that it was the general opinion of all the old miners that some great dislocation existed along the line already indicated. From the information afforded by Mr. Ely, ground bailiff of the Granville colliery, I was enabled to trace approximately its * I have adopted this name from the Kev. W. H. Coleman, who had made himself acquainted with its position previous to my arrival in the country. FAULTS. MOIRA COAL-FIELD. 51 position in the neighbourhood of Round Wood. Mr. Ely also marked out a small branch fault which gradually dies out 200 yards south-east of the Granville shaft. From the plans I ob- tained the position of a cross fault striking from White House colliery to the north end of Midway House ; the downcast is on on the south side, but the amount is unknown. At Woodville the measures have been proved unproductive to a depth of at least 200 yards*, above which there are two or three coal-seams, accompanied by potters' clay, the whole of which are unknown in the Moira coal-field on the deep side of the fault, unless, as has been surmised, they represent the Woodfield, Stockings, and Eureka coals. These seams, one of which is called the Rafferee coal, have already been described,! and the position of the Boothorpe fault can be fixed upon with considerable accuracy south of Woodville, as there is the Ell coal on the deep side, and the Rafferee coal on the shallow side of the fault. The fault passes close along the east side of the village of Boothorpe, producing a probable, though uncertain, dislocation in the New Red Sandstone. At Sweet Hill Oak, its position must be close to the old pits, in which, some 60 years ago, the Rafferee or one of its associated coal-beds was worked. It thence con- tinues its course, crossing the Burton railway at the Willesley cutting, at a position 180 yards east of the bridge of Willesley lane. Here, during the excavations the beds were found to be tremendously smashed; and though covered over at present, I was enabled to observe a small section a few yards west of the fault where the shales were lying at an inclination of 35. The dip gradually lessens as we recede from the Boothorpe fault, and at the entrance to the cutting on the Ashby side, the dip is only from 8 to 10. Further south we find no sections, and the fault becomes lost under the New Red Sandstone, which it does not appear to affect, having, in fact, been produced at a period antecedent to the deposition of that formation. I shall presently endeavour to explain why, though this is the case, these faults in some places appear to form its boundary lines. The Boothorpe fault appears to pass close under Willesley Church, and a little east of Gallows Lane turnpike ; the Main coal having formerly been won within a short distance of this position, and also along the west side of Willesley Park. The strata were found to rise rapidly to the east, the strike having changed by a quarter of a circle from its normal direction, which is due east and west. These phenomena are all to be accounted for by the proximity of the Boothorpe fault.} To trace this line of dislocation farther south is necessarily impossible, the country being overspread by the New Red Sandstone ; but it is probable that it continues its course for several miles in the same general * See page 66. t See pages 35-6. See Mammatt's " Geol. Facts," the information in which was corroborated by Cornet, of Measham, who had formerly worked in these old pits. D 2 52 GEOLOGY OF LEICESTERSHIRE. direction, throwing out all the productive measures along the east or upcast side ; and the proximity of this fault will explain the reason for the basset (under the New Red Sandstone) of the Main coal in Swepstone Brook, as the fault appears uniformly to have produced in the Coal-measures a rapid inclination to the westward, all along its course. Heath End Fault. For a knowledge of the existence of this fault I am indebted to Mr. Coleman. Commencing at the north, it appears to branch out of the boundary fault, at the edge of Calke Park. It has been proved to throw out the Heath End Cannel coal, near the west side of Rough Heath, and its proximity is indicated by a strong spring of water, which rises from a bore- hole about 150 feet from the surface, along the side of the road. It is remarkable that three weeks after this spring commenced to flow the well of Ashby workhouse dried up. In the brook at the south end of Rough Heath the strata are much disturbed, and the fault probably continues southward by the west side of Lount Wood, and was again struck in the workings of the Main coal at Parson's Meadow, Coleorton. Its further extension southward under the New Red Sandstone is no doubt considerable. It thus appears that the Coleorton coal-field lies between two large faults, which throw out the coal-beds both on the east and west sides. CHAPTER IX. COLEORTON BOUNDARY FAULT. IT is no uncommon circumstance to find the coal-producing districts of our country walled in, as it were, by faults. The Shropshire coal-field is bounded on its east and west sides by walls of Permian and New Red Sandstone , and the South Stafford shire coal-field is similarly circumstanced. But while in these instances the areas of the Coal-formation have been vertically elevated to a level with the newer formations, the Ashby coal-field has been limited along its eastern side by a process the reverse of this. Here the coal-field has either been caused to sink, or the older formations been upheaved from below, and the line which marks the juxtaposition of the two series of strata is known as the Main or Boundary Fault. This line of dislocation commences at Ticknall, and traverses the country in a straight line in a south-easterly direction to the eastern extremity of Bardon Hill. The amount of throw is a minimum at Ticknall, where the Mountain Limestone Shale on the one side is brought up against the Millstone Grit on the other, and becomes a maximum east of Whitwick Colliery, where the Millstone Grit and Charnwoo J. Porest rocks are brought up against strata about 2,200 feet above these formations. This is con- sequently the amount of throw here, and this amount diminishes in proportion as we proceed towards Ticknall, as will be evident COLEORTON BOUNDARY FAULT. 53 from the manner in which the coal-crops are broken off in succession against the fault. The following calculation gives us the downthrow at Whitwick colliery, where it is nearly a maximum : FEET. Depth from the base of New Red Sandstone to the Main coal - - 700 from the Main coal to the Nether Lount '/.. f.imv ,>i' Fault. (ambrian Age) ,^'t'fflitt. Dip of Str,it