PERMIAN. 215 



In South Yorkshire the Permian beds admit of the following 

 divisions :' — 



Upper Marls ) 

 and Sandstones, } West of Doncaster. 50 feet, 

 with Gypsum. ; 

 •r^ ,, . -, Brotherton Limestone (thin yellow or grey flaggy limestones) 



"K ■ '= I and Red Marl and Gypsum of Brotherton, Knottingley, 



,r. , 1 H ^ I Womersley, Hexthorpe, Wadworth, Tickhill, etc. 30 



^ '■-' to 120 feet. 



Middle Marls \ 

 and Sandstones, [ (Local) North of the Wharfe. 30 to 50 feet, 

 with Gypsum. .) 



}" Small-grained Dolomite" (irregularly bedded) of Vale of 

 Went, Lound Hill, Cusworth, Levit Hagg, Roche Abbey, 

 Warmsworth near Doncaster ; and in the picturesque 

 crags of the Don, west of Doncaster. 200 feet. 



T nT • \ Pontefract, Wentbridge, Hampole, Enisall, Brodsworth, Conis- 



Lower Magnesian , 1 at- 1 1 1 • r- 1 i, n u j 1 



T • ^ ^ l borousih, Micklebrnig, Crakehall quarry near Bedale. 



Lmiestone. | , „r^t '^ ' •' 



} 120 feet. 



Marl Slates. Kippax, Glass Houghton. 5 to 15 feet. 



Quicksand. Harthill, etc. 20 feet. 



The Lower Magnesian Limestone (100 feet) is well exposed at 

 Creswell Crags, in Derbyshire. The Quicksand, which consists of 

 yellow incoherent sand and sand-rock, appears in places to be 

 formed by decomposition of the sandy and gritty beds of the 

 Magnesian Limestone that occur above it.^ It occurs in Durham, 

 and southwards to Harthill near Worksop. (See Fig. 28, p. 183.) 



The greater part of the ' Lower New Red Sandstone,' which 

 Conybeare first suggested to be the equivalent of the ' Rothliegende,' 

 and which has been grouped as Permian, is now considered to be 

 stained Carboniferous rocks. These rocks include the Plumpton 

 (or Plompton) and Spofforth Grits, near Knaresborough, some- 

 times known as the Knaresborough Grits ; and the Pontefract rock 

 of William Smith. ^ Hence the " Pomfret (Pontefract) series," 

 of old writers, embraces rocks belonging to two systems. (See 

 p. 208.) 



Prof. Hull has suggested that the Lower Permian series of the 

 western and central parts of England may be arranged under two 

 distinct types of strata, of which those at Enville in Shropshire, and 

 the sandstone of CoUyhurst, near Manchester, may be considered 

 as representative beds. To the Salopian type he would refer 

 the whole of the Permian rocks as they occur in Shropshire, 

 Staffordshire, and Warwickshire ; and to the Lancashire type, the 

 rocks of this formation as they occur at Stockport in Cheshire, and 



1 J. W. Kirkby, Q.J. xvii. 287, 298. See also A. H. Green, G. Mag. 1S72, 

 p. 99 ; and E. Wilson, Midland Naturalist, iv. 122. 



- C. F. Strangways, (Jeol. Harrogate (Geol. Surv.). The term Quicksand is 

 applied to a loose and shifting or ' running ' sand. 



» J. C. Ward, Q.J. xxv. 291 ; Explan. Sheet 93 S.W. (Geol. Surv.) ; E. 

 Wilson, Midland Naturalist, iv. 97. 



