Page:Quarterly Journal of the Geological Society of London, vol. 28.djvu/182

148 PROCEEDINGS OF THE GEOLOGICAL SOCIETY, [Feb. 7, 1. Further Notes on the Geology of the neighbourhood of Malaga. By M. D. M. d'Orueta. Communicated by the President.

[Abstract*.]

In this paper, which is a continuation of a former note laid before the Society (see Q. J. G. S. xxvii. p. 109) the author commenced by stating that his former opinion as to the Jurassic age of the rocks of Autequera is fully borne out by later researches upon their fossils. They apparently belong to the Portlandian series. The author made considerable additions to his description of the Torcal, near the foot of which he has found a sandstone containing abundance of Gryphoea virgula and Ostrea deltoidea. This he regards as equivalent to the Kimmeridge Clay. In the Torcal he has also found a soft, white, calcareous deposit, overlying the limestones of supposed Portlandian age, and containing a fossil which he identifies with the Tithonian Terebratula diphya. The author discussed the peculiar forms assumed by the rocks of the Torcal under denudation, which he supposed to be due originally to the upheaval caused by the rising of a great mass of greenstone, portions of which are visible at the surface on both sides of the range.

2. On the RIVER-COURSES of England and Wales. By Prof. Andrew C. Ramsay, LL.D., F.R.S., V.P.G.S.

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 palaeozoic 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 still abutted on the mountain country now forming Wales and parts of the adjacent counties. They also completely covered the Mendip Hills, and


 * The publication of this paper is deferred.