On the Thickness of the Lower Green sand Beds of the South East Coast of the Isle of Wight

Abstract

The last time the Green sand beds below the Chalk were the subject of discussion before the Society, great diversity of opinion was expressed concerning the thickness of the group of beds denominated “The Lower Green sand.” To remove all doubt on this point, Dr. Fitton proposed revisiting the south-east coast of the Isle of Wight, and requested my co-operation in determining their thickness. The following vertical section of the strata, seen in the cliffs of the south-east coast of the Isle of Wight, and including the three entire groups, viz:— 1. The Upper Green Sand, 2. The Gault, 3. The Lower Green Sand, was made in company with Dr. Fitton, Mr. Mackeson of Hythe, and the President of our Society, during a visit we made to that coast in July last The horizontal line over which these measurements extended, that is, from Atherfield point to the Cliff on the south of St. Catherine's Down, is about three miles in length. Along nearly the whole of this line, the coast is bounded by mural cliffs, except where slips have taken place (and these are often of considerable extent), and except where “Chines” (as they are called), that is to say, deep precipitous gullies, worn by the action of brooks in the argillaceous sands, open into the sea.