The Sangatte raised beach and the age of the opening of the strait of Dover

Abstract

This study is a pedological and mineralogical diagnosis of the loamy cover deposits of the Sangatte raised beach (Strait of Dover), presently at almost 10 m N.G.F.4, to determine their chronostratigraphy. The analytical data are compared with those obtained for the Cagny-la-Garenne (Somme, Picardie) section, which is considered a stratotype for Middle Pleistocene loesses of Northern France. Our results support the notion that formation of the Sangatte raised beach can be attributed to a high sea level of the Middle Pleistocene. This provides further evidence on the paleogeographical evolution of the Southern North Sea Basin during the latter half of the Middle Pleistocene. It confirms the previous assumption of an early opening of the Strait of Dover in the Middle Pleistocene. Furthermore, it demonstrates that the loesses with high green hornblende and garnet content, that were previously supposed to be restricted to the Weichselian, were already deposited during the Saalian.