THE PERMIAN FORMATION. 128 



(See Plate VLT.) This breccia is now known to cover an area of over 

 400 square miles beneath Notts and Lincolnshire, and is of some 

 importance as enabling us to fix with certainty the base of the 

 Permian rocks in underground mineral explorations. Sedgwick 

 noticed these beds at Grives Wood, near Kirkby Woodhouse, and 

 subsequently Mr. Aveline described them at that place as consisting of 

 fifteen feet of blue shales and limestones with a thick band of breccia at 

 theirbase. Mr. Aveline also noticed these beds in road cuttings, west of 

 Hucknall Torkard, west of Skegby, and on Fulwood Top, near Sutton- 

 in Ashfield, (a) and mentions the following fossils as having been found 

 in this neighbourhood, viz., Axinus Schlotheimi, A. truncattis, Bakevellia 

 ceratophaga, Pleurophorus costatus, and imperfect plant remains. 

 Though familiar with these beds, neither Sedgwick nor Mr. Aveline 

 appear to have suspected that they were the representatives of the 

 Marl Slates of Durham. Since, however, these rocks have been so 

 well displayed in the railway cuttings at Kimberley, (b) and proved in 

 so many of the collieries of Notts, sunk through the Magnesian Lime- 

 stone, as also in the boring for coal at South Scarle, Lincolnshire, 

 always forming the basement member of the Permians, their true 

 affinities with the Marl Slates of Durham have become apparent. 

 The Marl Slates of Notts, while dying away on the south and west 

 beneath the Magnesian Limestone, display a general tendency to 

 thicken out on the east. On the south border and at several points 

 along the western outcrop of Permians the Lower Magnesian Lime- 

 stone conformably overlaps the Marl Slates, and rests directly on 

 coal measures. At Newcastle, Cinderhill, and New Watnall collieries 

 the Marl Slates are only from 10ft. to 25th. thick. A little further 

 east, at Hucknall Torkard, Bestwood, and Linby collieries, from 50ft. 

 to 60ft. or 70ft. At Bolsover, on the Limestone Escarpment, 33ft., 

 and at Clowne, near to same, 54ft. ; but at Langwith Colliery, which 

 lies two or three miles further east, 130ft. Again at Kiveton Station 

 and North Anston, on the Manchester, Sheffield, and Lincolnshire 

 Railway, the Lower Magnesian Limestone rests directly on red 

 sandstones and grits of coal measure age, but three miles east, at 

 Shireoaks and Steetley, no less that 100 feet of Marl Slates were 

 found beneath the Magnesian Limestone. 



At South Scarle, between Newark and Lincoln, twenty miles 

 east of the Magnesian Limestone Escarpment, nearly 200ft. of these 

 beds were passed through, (c) as will appear from the subjoined 

 section : — 



(a) Geological Survey Memoirs to maps 71 N.E., and 82 S.E. 



lb) On the Permian Rocks of the N.E. of England, (at their south margin,) 

 by E. Wilson, F.G.S., Q.J.G.S., vol. xxxii., p. 533. 



(c) In a boring in search of coal, in 1873, and eventually abandoned without 

 proving that mini 



