OF THE GRAMPIANS. 459 



ed, I am perfectly aware ; but all of these which 

 have as yet come to my knowledge, appear to me 

 to be vague, theoretical, and unsatisfactory. 



This species of rounded conglomerate in Scot- 

 land, is by no means peculiar to the south front of 

 the Grampians ; it is found in various other situa- 

 tions. In Argyleshire, near the former site of an- 

 cient Beregonium, I have observed a vast accu- 

 mulation of it, which stretches to Gban, upon the 

 western coast, and there covers a considerable di- 

 strict of country. But the conglomerate at Oban 

 differs much in its position from that of the 

 Grampians At Oban it is almost horizontal, and 

 only shews undulation where it has been deposited 

 upon unequal ground. The rounded materials 

 combined in the mass, are of the same species of 

 stones as those which compose the conglomerate of 

 the Grampians : they both consist of masses of the 

 older formations, which, from their hardness, have 

 been enabled to withstand the severe and long at- 

 trition which they must have been subjected to 

 before they were deposited in their present situa- 

 tions. The rounded masses at Oban are much 

 larger than those of the Grampians. 



The cementing mass of the conglomerate at 

 Oban is also different from that of the Grampians. 

 At Oban, this cement has the appearance of a 

 blackish-grey indurated mud, which is composed 

 of argil, fine-grained sand, black oxide of iron, 



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