MILLSTONE GRIT. 169 



of at least 400 feet. In Swaledale the series embraces coarse 

 gritstones, shales, sandstones, and coal, having a thickness of 500 

 feet. At Wensleydale the series is very similar in character, but is 

 less in thickness. At Penyghent the remnant of the series left on 

 the summit is less than 200 feet thick. Other outliers occur at 

 Whernside and Penyghent. (See Fig. 25, p. 160.) 



In Northumberland, as Prof. Lebour observes, the place where 

 the Millstone Grit should be undoubtedly exists, but the grits 

 themselves are sadly deficient, both in character and in thickness. 

 Shales, shaly sandstones, and sandy shales, with a few beds of 

 sandstone, seldom coarser in grain than many beds in the Coal- 

 measures, and not nearly so coarse nor so thick as some of the 

 grits of the limestone series below — these, in considerable spreads 

 between the Derwent and the Tyne, and in a narrow band from the 

 latter river to the sea near Warkworth, are the component parts of 

 the Northumbrian Millstone Grit.^ The beds are also to be seen 

 in the Wansbeck valley, at Mitford, near Morpeth. 



In West Yorkshire the Millstone Grit occupies much of the 

 country around Pateley Bridge, Ilkley, and Keighley, to the west 

 of Harrogate, Bingley, and Halifax. Thence it stretches south- 

 wards to the Peak in Derbyshire, and the country west of 

 Sheffield. 



The following divisions of the Millstone Grit in parts of Mid- and South- 

 Yorkshire and Derbyshire have been determined by tlie Geological Survey : ' — 



Feet. 

 Upper f Rough Rock (First or Topmost Grit), coarse felspathic grit 50 to 20a 

 ■ Grits. ( Shales (impersistent) . ...... 



Flags [Haslingden Flags (Second Grit)], fine-grained sand- 

 stones and shales ....... 60 to lOO 



M'ddl 1 Shales and Coal [Brooksbottom Series] . . . • 75 to 150 



P .. < Grits and Shales (Third or Roaches Grit), massive grit- 



stone, forming bold mural escarpments in places . 100 to 300 

 Shales and sandstones [Sabden Valley shales (1500 to 



2000 feet)] . 300 to 500 



i Kinder Scout Grit (Fourth Grit), coarse and often con- 

 glomeratic grit and flagstone ..... 500 to 1000 

 Shales. . . . . ) ,0 /-/- \ 



Shale Grit or Yoredale Gritj * ' ^^^^ P" ^^^'^ 



The several divisions are, however, not always represented, and they are subject 

 to great changes in thickness. 



The name Kinder Scout Grit was proposed by Professors E. Hull and A. H. 

 Green ; the rock forms the high table-land of Kinder Scout, in the Peak country, 

 where the disintegration of the quartzose conglomerate yields numbers of white 

 quartz pebbles. 



The Kinder Scout Grit forms the Rowtor and Cratcliff rocks near Bakewell, the 



^ G. A. Lebour, Proc. N. of Eng. Inst, of Mining Engineers, vol. xxv. ; 

 Geology of Northumberland, p. 30. 



~ Geology of the Yorkshire Coal-field (Geol. Surv.), by A. H. Green and others ; 

 E. Hull and A. H. Green, Q. J. xx. 249 ; also Geology of Stockport, etc. (Geol. 

 Survey), p. 12. 



