﻿PROCEEDINGS OP THE GEOLOGICAL SOCIETY. 



[Dec. 5, 



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the granitic gneiss intermixed with 

 syenite-veins is seen stretching away 

 to the east, below the quartzite-heds 

 of Ben Uie and Ben Uarran, and con- 

 tinuous with the gneiss of central 

 Sutherland. Nothing can be more 

 striking than the contrast between the 

 dark -grey gneiss and hornblende-rocks 

 forming the north-east base of these 

 mountains and the almost horizontal 

 beds of brilliant white quartzite, which 

 rest upon them for miles. 



Assynt.— The structure of the Assynt 

 region is represented in the next sec- 

 tion (fig. 8), extending from Queenaig 

 on the west to the south-east declivities 

 of Ben More. The middle of the sec- 

 tion shows the strata as seen on the 

 north shore of Loch Assynt and in 

 Stronchrubie ; but in the background 

 I have sketched-in the northern range 

 of mountains, connecting Queenaig and 

 Ben More, showing the continuity of 

 the quartzite round the whole lime- 

 stone-plateau. 



The first formation, on the west, is 

 the gneiss (a) intermixed with veins of 

 granite and syenite. It is covered by 

 red sandstone (b), beautifully seen in 

 the western declivities of Queenaig, 

 an d r this by the quartzite (c 1 ) sloping 

 down from the summit of the mountain 

 in vast, almost unbroken sheets. As 

 well seen in Skiag Bum, the dip is 

 about 10°, and thus probably uncon- 

 formable to the red sandstone below, 

 though the great fardts intersecting 

 the mountains and the protrusion of 

 igneous rocks render this fact less 

 certain than I formerly thought. Above 

 it come the fucoid-beds (c 2 ), and over 

 them the limestone (d), forming the 

 whole low ground north of Loch 

 Assynt, from Skiag Bridge by Stronch- 

 rubie to the foot of the Ben More 

 mountains. This limestone is the 

 highest bed in the series, being every- 

 where troughed by the quartzite. As 

 this fact is of great importance, and 

 as it has been affirmed that an upper 



