122 MINER ALOGICAL NOTICES. 



it appears that this rock traverses the centre of 

 the great Highland range, in a direction chiefly 

 marked by the course of the Spey, from Portsoy 

 and Buchan-Ness on the north-east, to the Island 

 of Arran on the south-west. On either side of 

 this line, innumerable portions of the great cen- 

 tral mass, — which is nowhere so extensively laid 

 bare, as in the mountains of Cairngouram, — may 

 be traced beneath the superincumbent strata of 

 gneiss, mica- slate, clay-slate, &c. In the direc- 

 tion now mentioned, we find along the lower dis- 

 tricts conglomerate, transition, and floetz-rocks, 

 skirting the clay-slate, which is succeeded by mi- 

 ca-slate and gneiss, as the rocks in general placed 

 contiguous to the granite. 



To the north-west of the granite line, the same 

 relations may be discovered ; so far, at least, as my 

 observation has extended. 



