On the Succession of Rocks in the Northern Highlands, from the oldest Gneiss, through strata of Cambrian Lower Silurian age, to the Old Red Sandstone inclusive

Abstract

Abstract This memoir comprised a general sketch of the succession of the stratified rock-masses occupying the northernmost counties of Scotland (Sutherland, Caithness, and Ross), as determined by former observations of Prof. Sedgwick and the author, and of Macculloch, Jameson, Cunningham, Miller, and Nicol, and by the recent discoveries of Mr. C. Peach. In the commencement. Sir Roderick, having referred to the long-held opinion that the great mountainous masses of red conglomerate and sandstone of the west coast were detached portions of the Old Red Sandstone, alluded to Mr. C. Peach9s discovery (in 1854) of organic remains in the limestone of Durness, which led the author to revisit the Highlands (accompanied by Prof. Nicol), when having found still more fossils, he expressed his conviction (at the British Association, Glasgow Meeting, 1854) that the quartzites of Sutherland and their subordinate limestones were of Lower Silurian age; and was strengthened in the opinion (which he had already published) that large portions of the crystalline rocks of the Highlands would prove to he the equivalents of the Lower Silurian deposits in the South of Scotland.