Granite of Aberdeenshire, 31 



district of Scotland, ceases entirely before the meeting of the 

 strata of this class with the primary ridge which forms the 

 southern boundary of the northern mountainous division of this 

 country. A few veins only, are, in some places, found to pe- 

 netrate the primary strata in this direction ; but, after no long 

 course they entirely disappear. 



This slight sketch of the nature and disposition of the stra- 

 tified and superincumbent rocks which occur in the district 

 under review, will be useful in attempting to trace the general 

 extent and continuity of the granite which forms, not only the 

 basis, but the chief visible portion of that tract which is the 

 repository of the phsenomena to be described in this commu- 

 nication. 



The most prominent and conspicuous masses of that rock, 

 are those which form the high mountains of Mar, and which 

 contain the sources of the Dee. In tracing from these moun- 

 tains towards the sea, eastward, the granite is found re-appearing 

 in numerous places ; the interruptions to its continuity being 

 produced by portions, more or less extensive, of the primary 

 strata already described, and, principally, of the gneiss. In 

 this manner it may be traced to Portsoy, and, more or less 

 interruptedly round the coast to Aberdeen. Without a map, it 

 would be impossible to convey any accurate ideas of its geo- 

 graphical position and extent ; but it will be sufficient here to 

 remark, that two irregular lines drawn from Ben Avon to the 

 places just named, will include the principal part of this rock 

 in Aberdeenshire, and all that which it is necessary for the 

 objects of this paper to notice. 



Having formed a geological map of this entire district, I 

 have been enabled to infer, from a comparison of the several 

 apparent portions of the granite, and from the positions and 

 situations of the superincumbent strata, that the continuity of 

 that rock may not only be deduced, but, in many cases, actually 

 traced, in some place or other, in such a manner as to leave 

 no doubt respecting the identity and connexion of the whole. 

 This district must therefore 'be considered as formed of a 



