©eologg. 353 



it also has suffered very violent treatment from the subter- 

 ranean forces ; and these displacements are especially obvious 

 where it crosses the valleys; for instances, Winandermere 

 and the vale of the Kent. 



Brathay Flags. — Superimposed again upon the Lime- 

 stone is a group of similar course and extent called Coniston, 

 or Brathay Flags, which consists mainly of a dark, almost 

 black, stone easily worked into flags. The manner in which 

 the line of cleavage in most of these rocks runs across the 

 line of deposit is well demonstrated in this flagstone, and 

 may be studied to advantage in the roadside wall on the 

 high-way from Ambleside to Coniston, as it passes through 

 the enclosures above Brathay, where these lines are seen 

 very plainly as well as divisions running parallel to the line 

 of deposit, and containing brilliant incrustations of Iron 

 Pyrites, which appear upon the edges of the stones used in 

 building the wall. The rock also preserves a few remains 

 of organic life. Remarkable displacements of these two 

 formations, and sometimes of the next, are exhibited as in 

 Low Furness, Ravonstonedale, and the vicinity of Ingleton. 



Coniston Grit. — Upon the Flagstone rests, in its turn, 

 a formation called Coniston Grit, or Hard Grit, a coarse, 

 hard, tenacious stone, whose structure has enabled it to resist 

 the disturbing forces more successfully than most of its 

 neighbours. A similar rock occurs on Howgill Fells and in 

 the country at Sedbergh, towards Kirkby Lonsdale. It has 

 also been hoisted up by enormous disruptions of the car- 

 boniferous strata, so as to form the summits of Ingleborough 

 and other hills in that direction. 



Ireleth Slate. — The Coniston Grit forms the base of 

 the third great system of Slate Rock, called Ireleth, now 



Y 



