Late Middle Pleistocene temperate and associated events in lowland England

Abstract

This article examines the interpretation and implications of certain conifer-dominated pollen assemblages recorded in lowland England, at sites glaciated during the Middle Pleistocene Wolstonian Stage. Such assemblages indicate the absence of severely cold-climate during a predominantly cold period and the presence of northern temperate boreal-type forest. The unambiguous stratigraphical position of the sequences provides evidence of climatic change during the late Middle Pleistocene.Nine sequences are considered, six in the English West Midlands, and three in eastern England. Evidence for temperate climate, and at some, subsequent cold-climate (periglacial) conditions is present within deposits pre-dating Wolstonian-age glacial deposits. In the Midlands, Wolston Formation glacial sediments overlie deposits of a pre-existing river system, the Baginton Formation. The latter accumulated during the transition from boreal to subarctic conditions. Evidence is based on sequences at Mathon, Waverley Wood, Brandon, Brooksby, Witham-on-the-Hill, High Lodge and Barnham. Since the Wolstonian glaciation occurred during the Late Wolstonian Substage (= Late Saalian, Marine Isotope Stage [MIS] 6), the Baginton Formation must span the MIS 7/6 boundary.Reinterpretation of the sequences indicates that the temperate continental climate interval, termed here the Waverley Wood temperate event, potentially represents the latter part of MIS 7 (Substages 7a-c, or 7e). This correlation is supported by comparison with sites on the near Continent. The implications of these conclusions are presented.