268 



PROCEEDINGS OF THE GEOLOGICAL SOCLEXr. 



[Feb. 



one of the islands in Loch Awe, at the foot of Cruachan, exhibits the 

 mica-slates in a perfectly vertical position. Loch Awe seems to 

 have been an area of subsidence ; and the gorge of the Brander Pass 

 lies along the line of a great fracture connected with the subter- 

 ranean movements which brought up the granites of Ben Cruachan. 



Pig. 2. — Section across the Brander Pass. 



Gorge of the Awe, or Brander Pass. 



Loch Awe. 

 A. Mica -schists. 



Island of Freuchlin. 

 Slates perpendicvdar. 



Granite of Ben Cruachan. 



That fracture and dislocation of the strata have taken place is cer- 

 tain. It is for the erosionists to prove that this fracture and dislo- 

 cation was without influence in causing the " deep gorge" through 

 which Loch Awe finds its exit to the sea. It is for them to prove 

 that the time when the subterranean movement took place was not 

 also the time when the Brander Pass was formed. I might mul- 

 tiply instances of the same kind without number. 



Here I should- observe, as an important fact, that although Mr. 

 Geikie speaks of the Highland mountains being tossed into folds, or 

 wave-like plications, I know of no instance in which the same beds 

 are literally folded so as to bend over the top of a mountain and fold 

 down into the valley beneath. In all cases the beds which rise to 

 the summit of the mountains are there broken, and present more or 

 less rugged escarpments, in the direction towards which the undu- 

 lation appears to have proceeded. In short, they are, as Mr. Geikie 

 says, very hke waves ; but then they are waves which have broken 

 at the top — not the waves of a heavy ground- swell, but rather the 

 waves of a sea vexed by the meeting of wind and tide. This is as 

 we should certainly expect if wave-Kke movements were ever pro- 

 pagated under a surface occupied by rocks already hardened and 

 consolidated, as these mica-slates appear to have been when the 

 subterranean movement affected them. 



I shall now direct attention to another specific case in which 

 Mr. Geikie has omitted all mention of the principal facts connected 

 with the geological structure of the country. He takes the trans- 



