XXXIX. The Geology of Dalry

Abstract

At the bottom of the Carboniferous series, as developed at Dalry, are the lower limestones, separated from the calciferous sandstones by about a thousand feet of volcanic rocks, chiefly porphyrites and trap tuffs. The lower portion of these limestones is well seen at Auchenskeith and Auchenmade, and the upper portion at Auchenskeith, Auchenmade, Low Baidland, Thirdpairt, and near Birkhead, on the Caaf Water. The former is from 15 to 20 feet thick, and is of fair quality for agricultural, building, and furnace purposes; while the latter is from 20 feet thick at Auchenskeith, to 29 feet at Cunningham Baidland, and, in its higher part, flint bands and nodules of a lenticular shape are not unfrequent. In the Dalry district this limestone is all of inferior quality; while in the Beith district its upper portion is of very fair quality. Its total thickness is about 40 feet. The next stratum of importance is the clayband ironstone, separated from the limestone by 27 fathoms of dark shales, in which occur a number of thin bands and balls of ironstone, and two or three beds of sandstone. It crops out along the bases of the hills, and it can be best seen at Giffartland burn, where it is on edge, and at the Pitcon burn, where it dips gently. The clayband seam of ironstone is very regular in thickness all over the district, being seldom less than 11, or more than 14 inches thick, and is now the backbone of the mining industry This 250-word extract was created in the absence of an abstract