﻿I860.] 



JAMIESON S.W. HIGHLANDS. 



135 



CO 



loch, the strata are also very 

 quartzose with no chlorite- 

 schist ; and the thickest and 

 most persistent bed of lime- 

 stone, lying at the base of 

 this immense quartz-deposit, 

 and ranging from Otter by 

 Barmore to Western Loch 

 Tarbert, is omitted; while 

 the whole district of Knap- 

 dale and Crinan is traversed 

 by great ranges of green- 

 stone, of which no indication 

 is given. The reason, how- 

 ever, why Macculloch omit- 

 ted these greenstones will be 

 afterwards more particularly 

 referred to. 



§ 2. The rocks of the di- 

 strict under consideration 

 seem to have been thrown 

 into a great undulation, whose 

 anticlinal axis extends from 

 the north of Cantyre, through 

 Cowal, by the head of Loch 

 Bidun, on to Loch Eck, while 

 the axis of the synclinal trough 

 seems to lie nearly on the line 

 of Loch Swen. (See the 

 woodcut.) 



Macculloch, in his work 

 on the "Western Isles (vol. ii. 

 p. 288), had remarked that in 

 Cantyre the mica- schist on 

 the eastern shore dips to the 

 E., and on the other side to 

 the W. ; and Sir Roderick 

 Murchison (Quart. Journ. 

 Geol. Soc. vol. vii. p. 169) had 

 noticed a fine anticlinal fold 

 at Loch Eck. These obser- 

 vations led me to expect that 

 I should find a similar phe- 

 nomenon somewhere near the 

 north end of Bute ; and ac- 

 cordingly I went in search of 

 it, and found it, not in Bute 

 itself, but a little to the north 

 of that island, in a high ridge 

 near the Tighnabruich steam- 

 l 2 



