II.—Geology and Petrology of the Intrusions of the Kilsyth-Croy District, Dumbartonshire

The group of intrusions of which this paper treats is a part of a series of intrusive rocks piercing the Carboniferous starta of the Midland Valley of Scotland. As a rule, they have forced their way into the Carboniferous Limestone Series in layers roughly parallel to the stratification. At the surface they stand out as rough, craggy hills, often of considerable elevation, rising abruptly out of the plain of the Carboniferous sediments, and frequently ending off in a vertical escarpment of bare rock. They generally confront, at a distance of 1 or 2 miles, the terraced escarpments of Lower Carboniferous lavas, which bound the Midland Valley on the north, west, and south-west.