On the River-courses of England and Wales

Abstract

In the following paper I propose to show the origin of many of the principal rivers of England and Wales—that is to say, what are the special geological causes the operation of which led them to flow in the general directions they now take. I am not aware that any attempt has heretofore been made to do this on a large scale, though I have already done something on the subject with regard to the rivers of the Weald, in which line of argument I was afterwards followed by Mr. Foster and Mr. Topley. I shall begin the subject by a rapid summary of certain physical changes that affected the English Secondary and Eocene strata, long before the Severn (leaving the mountains of Wales) took its present southern and south-western course along the eastern side of the palæozoic rocks that border that old land. About the close of the Oolitic epoch the strata of these formations were raised above the sea, and remained a long time out of water; and during that period those atmospheric influences that produced the sediments of the great Purbeck and Wealden delta were slowly wearing away and lowering the land, and reducing it to the state of a broad undulating plain. At this time the Oolitic strata (till abutted on the mountain country now forming Wales and parts of the adjacent counties. They also completely covered the Mendip Hills, and passed westwards as far as the hilly ground of Devonshire, running out between Wales and