Sea-level changes, river activity, soil development and glaciation around the western margins of the southern North Sea Basin during the Early and early Middle Pleistocene: evidence from Pakefield, Suffolk, UK

摘要

This paper outlines evidence from Pakefield (northern Suffolk), eastern England, for sea-level changes, river activity, soil development and glaciation during the late Early and early Middle Pleistocene (MIS 20-12) within the western margins of the southern North Sea Basin. During this time period, the area consisted of a low-lying coastal plain and a shallow offshore shelf. The area was drained by major river systems including the Thames and Bytham. Changes in sea-level caused several major transgressive-regressive cycles across this low-relief region, and these changes are identified by the stratigraphic relationship between shallow marine (Wroxharn Crag Formation), fluvial (Cromer Forest-bed and Bytham formations) and glacial (Happisburgh and Lowestoft formations) sediments. Two separate glaciations are recognised-the Happisburgh (MIS 16) and Anglian (MIS 12) glaciations, and these are separated by a high sea level represented by a new member of the Wroxharn Crag Formation, and several phases of river aggradation and incision. The principal driving mechanism behind sea-level changes and river terrace development within the region during this time period is solar insolation operating over 100-kyr eccentricity cycles. This effect is achieved by the impact of cold climate processes upon coastal, river and glacial systems and these climatically forced processes obscure the neotectonic drivers that operated over this period of time. (c) British Geological Survey/Natural Environment Research Council copyright 2005. Reproduced with the permission of BGS/NERC. Published by John Wiley & Sons, Ltd.