﻿I860.] 



NICOL N.W. HIGHLANDS. 



103 



a N.W. strike. Where it meets the red sandstone the surface is 

 very rugged and uneven, and the beds above are often, as noticed on 

 the Grairloch, a coarse angular breccia. The red sandstone dips 15°, 

 to S. 33° E. In the mountain, east of Sleugach, and separated from 

 it by a deep ravine, the red sandstone is covered by the quartzite, 

 which continues along the summit of the ridge to Glen Laggan. 

 The red sandstone, however, forms the foot of the hill to the head 

 of the loch; but further up a great mass of igneous rock (s) (a fine- 

 grained syenite, or rather diorite) forms the base of the hill, covered 

 by broken masses of quartzite and limestone. In the valley of the 

 Laggan the limestone (cl) has been quarried in several places, dip- 

 ping to E. 20° S., but much altered by the diorite (s), which forms 

 a wide mass, running for several miles along the valley. The other 

 side of the valley consists of grey granitic gneiss (a), in some places 

 more quartzose, in others fine-grained and micaceous, and dipping 

 15°-30°, to E. 30°-40° S. In the low ground, however, near the 

 mouth of the glen, grey granitic gneiss occurs, dipping at 60°-70°, to 

 E. 45° N., and thus with a true N.W. strike, though on the east 

 side of the fault and of the quartzite*. In this place, though the 

 formations are only separated by a deep and narrow valley, yet the 

 quartzite is nowhere seen dipping below the gneiss on the east, nor 

 the gneiss resting on the quartzite on the west. 



In the low ground near Kinloch Ewe, the gneiss is seen in the 

 bed of the river near the inn, dipping 10° to S. 45° E., and about a 

 quarter of a mile west the red sandstone forms some low rounded 

 knolls. The intervening space is thickly covered by detritus ; but, 

 from the dip of the beds, the red sandstone here is probably in con- 

 tact with the eastern gneiss, the limestone and quartzite having 

 been entirely denuded. The quartzite, sloping down from Ben Ey, 

 covers the red sandstone on the south, but at the foot of Loch Clair 

 is again thrown out, so that the eastern gneiss and red sandstone are 

 brought into contact. The same relation also appears to occur in 

 the wild country towards Loch Carron. Anyhow we find in this 

 region that the limestone, forming the upper portion of the quartzite 

 series, only occurs in rare fragments, where left behind in the de- 

 nuding process, so that the phenomena are quite opposed to any 

 theory of continuous upward succession. 



In regard to the relation of the quartzite and red sandstone in 

 this region, they seem to be generally conformable to each other. I 

 infer this, rather from the view of the two formations as exposed in 

 the mural precipices of the mountains, than from direct observation 

 on the beds. This general parallelism is very marked in Leagach, 

 one of the loftiest mountains on the west coast, and, as the appear- 

 ance is the same whether the hill is looked at from the north or 

 south, can hardly be a mere optical effect. In Ben Ey (a mountain 

 nearly as high, but more picturesque), the same parallelism appears., 

 and is the more striking from both the red sandstone and quartzite 



* It may thus be regarded as the other side of the anticlinal to the beds seen 

 under the red sandstone of Sleugach. 



