On the Nature, Correlation, and Mode of Accumulation of the Drift Deposits of the West Riding of Yorkshire; with remarks on the Origin of Escarpments, Valleys, and Outlet Gorges, and an Appendix on the Cliffs of Plumpton, Brimham, Goredale, and Malham

Abstract

[ For Plate and Explanation see Close of this Paper. ] For the last six months I have been devoting almost undivided attention to the classification and correlation of the drifts of the West Riding, between York and Settle in one direction, and between Ripon and Barnsley in another. I started with the idea, which subsequent observations have confirmed, that it is only by a comparison of the characteristics of the drifts on plains with those in valleys and on hill sides that we can arrive at correct notions of the mode of their accumulation. CLASSIFICATION AND DESCRIPTION OF THE DRIFTS OF THE WEST RIDING. 1. Greyish-blue and Variegated Boulder-Clay. —So far as I can ascertain, it is to the late Mr. Teale, of Leeds, that we are indebted for the discovery of two lower boulder clays, the blue and the yellow. He found patches of blue clay at New Wortley, Nether Green, Woodhouse Moor, Adel, and Yeadon Colliery, at various levels, and at Adwalton at a height of about 600 feet above the sea. At nearly all these places he found the blue clay overlain by the yellow clay. I have traced the existence of blue clay up the valleys of the Aire and Wharfe, and on the plain of Craven, where it is extensively developed. At lower levels, to the south-east and north of Leeds, it exists only in patches. In the north-west part of the West Riding, where it lies near to, or on the carboniferous limestone, the stones ...