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PROCEEDINGS OP THE GEOLOGICAL SOCIETY. 



[Feb. 6, 



From the summit of the hill the 

 quartz-rock plunges down the north- 

 eastern side towards the valley of Loch 

 Clare ; but the Cambrian again comes 

 in, owing to the intervention of other 

 faults. Crossing along the ridge to 

 the next hill to the south, we meet 

 with other examples of the apparent 

 interbedding of quartz-rock and red 

 sandstone. There is a gorge or bealloch 

 (of which we could not ascertain the 

 name, and it is nameless on the maps) 

 on this ridge, having a stream on the 

 east side, which descends into Loch 

 Coulan, and another on the west, that 

 falls into the valley of the Torridon 

 Water. Following the line of the glen 

 on the south-east side, we are pre- 

 sented with one of the most striking 

 natural sections anywhere to be seen 

 in the North- western Highlands. The 

 alternations of red sandstone and 

 white quartz-rock are repeated again ; 

 but here, in place of merely an out- 

 crop-line along the strike, we have a 

 magnificent transverse section several 

 hundred feet deep, along the southern 

 side of a wild glen. The contrasting 

 tints of the two rocks give the decli- 

 vity all the appearance of a vast dia- 

 gram ; and no diagram could repre- 

 sent the dislocations in a more im- 

 pressive manner. The subjoined figure 

 (fig. 13) was copied while we walked 

 down the glen, and represents, as nearly 

 as may be, the actual relations of the 

 rocks. We may add, that the same 

 dislocations cross to the north side ; 

 but the greater amount of debris on 

 that side makes them less easily trace- 

 able. They undoubtedly run both 

 north and south of the glen ; and 

 these mountains have thus the sin- 

 gular aspect of alternating cliffs of 

 snowy whiteness and sombre brown. 

 We could mark the arrangement on 

 the hills a short way north of the 

 Dingwall road at Loch Doule, a di- 

 stance of fully ten miles from Ben 

 Eay, where similar dislocations were 



