﻿♦ 



I860.] NICOL N.W. HIGHLANDS. 105 



having been tilted over towards the line of fault on the east, as shown 

 in the sketch* fig. 12. 



Fig. 12. — Section of Ben Ey and Leagach. Seen from the north. 



e. Quartzite. b. Red sandstone. 



Loch Torridon and Loch Garron. — Immediately south of Loch 

 Maree and the Gairloch lies the wild unfrequented district of Loch 

 Torridon. On the shores of this most magnificent sea-loch, and in 

 the lofty mountains that surround it on every side, there is some of 

 the grandest scenery in Scotland, and at the same time some of the 

 most instructive geological sections. The whole structure of the 

 mountains is clearly exposed in the naked precipitous walls of rock, 

 built up, layer above layer, in the most majestic piles of masonry. 

 How geologists could traverse this region, and yet believe that the 

 great Red Sandstone formation of Applecross and the West Highlands 

 was superior to the quartzite, is hard to understand ; and yet this 

 was regarded as an established fact up to the publication of my paper 

 on the N.W. Highlands in 1856. 



The lowest formation is, as usual, the gneiss, well seen on the 

 narrows near Sheildag, where, its dip is N.E., and commonly at a 

 considerable angle. It rises to a height of 2000 to 3000 feet in Ben 

 Ailigin and the Gairloch mountains, but is in most places hidden by 

 the red sandstone. On the lower loch the red sandstone generally 

 dips west at 8° or 10°, but often higher near the outer headlands. 

 In many places it seems almost horizontal, as in the lofty moun- 

 tain of Leagach, where it is covered apparently in conformable 

 superposition by the white quartzite. On the upper Loch Torridon 

 the dip changes to the east, and then retains this direction through- 

 out. As shown in the section (fig. 13) of the mountains east of 

 Loch Torridon, it is still overlain by the quartzite. In this most 

 remarkable section, the red sandstone, always dipping to the east, 

 and covered by its capping of quartzite, is again and again brought up 

 by faults ; and this not only on the summits of distinct moivntains, 

 but no less than five times in a single continuous ridge. Had only 

 a surface-view been exposed, as each fragment of quartzite seems to 

 dip below the next one of red sandstone, it might have been supposed 

 that the rocks alternated with each other ; but no such mistake can 

 be made in this place, as the true structure of the mountain, to a 

 depth of some hundred feet, is clearly exhibited in the vertical escarp- 



* This rough sketch, taken from the plateau on the north, shows only about 

 half the true elevation. 



