Further Observations on the Correlation of the Eocene Strata in England, Belgium, and the North of France

Abstract

It is not my intention to reopen the whole question of the position and correlation of the Eocene strata of England and France, but merely to bring again before the Society such portions of them as involve some yet unsettled points of classification and some necessary rectifications of my own work. The synchronism of the Thanet Sands with the Lower Landenian, of the London Clay with the Lower Ypresian, of the Bracklesham Beds with the Calcaire Grossier, and of the Barton Beds with the Grès de Beauchamp is now perfectly well established. But with respect to the exact relation of the Sands of Bracheux and of the Soissonnais to the English Series, of the Oldhaven Beds to the Woolwich Series, and of the Lower and Upper Bagshots to equivalent strata in the Paris Basin, there are still differences of opinion and some open questions. Since'the publication of my early papers on the Eocene strata, the important monographs on the Eocene Mollusca of Edwards* and Searles Wood† in this country, and the last great work of Deshayes‡ in France, have made large additions to the Eocene faunas of the English and French Tertiaries. At the same time, the work of the Geological Survey and others in the London and Hampshire Basins §; of MM. Hébert ∥, Dolfuss ∥, De Mercey ∥, and others in the Paris Basin; of MM. Gosselet ¶, Ortlieb, and Chelloneix ** in the North of France; and of MM. Briart and Cornet M. Dewalque, MM. Rutot, Van