Page:Transactions of the Geological Society, 1st series, vol. 2.djvu/468

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458
Dr. Mac Culloch on Quartz Rock.

Assynt.

Although I have to regret the limited extent of my observations on this district, yet as they tend to illustrate the nature of the rock which forms the subject of this notice, I am unwilling to suppress them. They may at least serve, in conjunction with the remarks which I have made on this rock in other places, to extend its history and connexions, as well as to stimulate future observers possessed of better opportunities, to continue this inquiry, and to assist in determining the composition of that extensive and as yet little known country which constitutes the northern mountainous division of Scotland.

The mountains which form the districts of Coygach and Assynt may be distinguished even from the island of Sky, by their peculiarly smooth and conical outlines, and by the whiteness of their summits, so dazzling in the sunshine, that to a spectator unaware of their composition, they appear as if for ever retaining the snows of winter. Their strong resemblance to the Paps of Jura, both in the even unbroken line which forms their summits, and in the peculiarity of their colour, immediately however, explains their composition and confirms their similarity; for, like those mountains, they are formed of a rock which has here also been called “granular and primitive quartz.” In a distant view they are remarkable too for another peculiarity, which in other situations has been supposed characteristic, of the mountains of this class, and that is, their detached position. The accompanying sketch of the coast, Pl. 32. fig. 2. will better explain than words can, both the singularity of their form and that independence of position which they assume; circumstances which when compared with the irregular outlines and crowded groups of granitic and schistose hills, will strike the most careless observer. The