On the Lower Silurian Rocks of the South-east of Cumberland and the North-east of Westmoreland

Abstract

1. Introduction .—The district to which this memoir has reference consists of a narrow band of country on the western side of the Pennine Chain, possessing external features which indicate a difference in mineral nature from the rocks which form those Pennine escarpments, and also from those which, in Cumberland and Westmoreland, usually lie on their western side. The area occupied by this narrow band of Lower Silurian rocks extends in length about fourteen miles in a N.N.W. and S.S.E. direction; and it has a varying breadth from a very narrow strip to about a mile and a half, the average width being about a mile. Its northern limit is in the township of Melmerby, in Cumberland, and its most southern point is in that of Hilton, in Westmoreland, this narrow band of Lower Silurian Rocks running from Melmerby through Ousby and Kirkland in Cumberland, and through Milburn, Knock, Dufton, Murton, and Hilton in Westmoreland. The northern boundaries of this Lower Silurian area are the rocks which usually form the base of the Pennine escarpment, namely, the Upper Old Red Sandstone and the Melmerby Scar Limestone—the base of the Carboniferous formation in the north of England. The boundary on the W.S.W. side is more varied: the more southern portion, being the Great Pennine Fault, which brings the Lower Silurian Rocks and the Upper Permian Sandstones in contact, is very regular; but the more northern portion has a very irregular outline, and consists of Upper Old Red Sandstone and Lower Carboniferous Rocks