LITHOLOGICAL OBSERVATIONS, §tC. 39^ 



breadth, and presents those scattered groupes of 

 islands, which render its appearance so extremely 

 beautiful and picturesque. The portion of its 

 neighbourhood which I examined, begins on the 

 east side, about two miles south of Row Ar- 

 dennan, and terminates at the north-west extre- 

 mity of the base of Ben-Lomond, opposite to 

 Tarbet : On the south side, it reaches from Tar- 

 bet to the head of the Leven. In this district, 

 the rocks which occur along the margin of Loch- 

 Lomond on both sides, form a regular and com- 

 plete series, from the older mica- slate, to the 

 newer species of grey-wacke ; including several 

 subordinate beds and minerals, and followed by 

 different sandstone formations, which compose the 

 lower country, on the banks of the Leven, to- 

 wards Dunbarton. 



Before proceeding to describe the particular lo- 

 calities and relations of these rocks, it is proper to 

 notice, that the general structure of the country 

 in this quarter corresponds to what is found 

 throughout the v/ho!e of the Highlands, where 

 mica-slate is the prevailing rock. The moun- 

 tains and hollows appear to be formed by the ir- 

 regular effects of decomposition and waste on the 

 mass of alpine strata, which runs in the direction 

 of N. E. and S. W. Thus, at the summit, and 

 along the sides and base of Ben-Lomond, the 

 strata of mica- slate are distinctly observed crop- 

 ping out in the usual direction, and in a position 



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