Last Interglacial and Devensian deposits of the River Great Ouse at Woolpack Farm, Fenstanton, Cambridgeshire, UK

Abstract

This paper describes Pleistocene fluvial deposits of the River Great Ouse at Woolpack Farm, Fenstanton, Cambridgeshire, UK. These sediments consist of a basal gravel, fossiliferous fluviatile muds, sands and gravels later disturbed and formed into a diamicton, and overlying gravels. The regional climate inferred from palaeobotany, Mollusca, Coleoptera and vertebrates from the diamicton indicates temperate conditions. Coleopteran evidence suggests a mean July temperature of ca. 21°C, 4°C warmer than today in eastern England, and winter temperatures a little colder than at present. Molluscan assemblages indicate a slight brackish influence during deposition of the muds which form the diamicton. The gravel succession is represented by three members which have a broad distribution in the Great Ouse Valley, and which were laid down in a braided river under periglacial conditions. The occurrence of permafrost is indicated by the presence of ice wedge casts in the gravels. The pollen and macrofossil evidence from the diamicton suggests correlation with Ipswichian substage IpII ( Pinus– Quercetum mixtum – Corylus phase). The basal gravel is of pre-Ipswichian age. A Devensian age is proposed for the overlying gravels and their attendant periglacial phenomena.