62 



Physical Geology. The geographical feature just pointed out, 

 of high ground in the East and low ground in the West, is the 

 accompaniment and the result of a change in the geological 

 character of the two areas; the high ground being formed of 

 Skiddaw Slate and the Volcanic rocks of Borrowdale, and the low 

 ground of rocks of Carboniferous and of Permian age. 



Within the area occupied by the Skiddaw Slate and the volcanic 

 rocks, that is, among the mountains, there occur, at different 

 places, patches of rocks of various kinds, each presenting characters 

 so peculiar, that once they have become thoroughly known, they 

 may be recognised anywhere. Boulders of these rocks are of 

 frequent occurrence in the drifts hereafter to be described. (The 

 positions of the rocks were indicated in the author's paper on 

 " The Distribution of Boulders," &c. See Transactions, Part V., 

 and they are shewn on Fig. 1 1 herewith. 



The Carboniferous and Permian rocks occurring in the lower 

 ground are developed as below : — 



PERMIANS. 



Prevailing Colour of Rock. 



1 St. Bees Sandstone - - - . red 



2 Magnesian Limestone C'^°3=^,riy^^'1 grey 



3 Breccia red 



CARBONIFEROUS ROCKS. 



1 Coal Measures / '^^itehaven Sandstone reddish grey 



( Lower Coal Measures bluish grey & black 



2 Millstone Grit reddish grey 



3 Carboniferous Limestone - - . grey 



The St. Bees Sandstone, the Permian Breccia, and the White- 

 haven Sandstone, being harder rocks than those forming the bulk 

 of the Coal Measures, frequently occupy higher ground and form 

 the ridges separating valleys, whilst the softer Coal Measures 

 appear in the sides and bottom of valleys. 



The general dip of the Carboniferous and Permian rocks is 

 toward the sea, its direction varying, but being everywhere nearly 

 normal to the line separating the higher from the lower ground. 



