THE LAST GLACIATION OF THE NORTH SEA BASIN

Despite a long history of investigation, critical issues regarding the Last Glacial Maximum in Northwest Europe remain unresolved. One of these refers to the extent, timing and dynamics of Late Weichselian glaciation of the North Sea, and whether the British and Scandinavian ice sheets were confluent at any time during this period, or whether glacimarine environments existed between two separate ice sheets.

This study presents the results of seismic, sedimentological and micromorphological evidence, used to reconstruct the depositional history of regionally extensive seismic units across the North Sea Basin. Micromorphology is suggested to provide an effective means of discriminating between subglacial and glacimarine sediments from cored samples.

Two major episodes of extensive glaciation of the North Sea Basin are identified from this study, and the dynamics of glaciation are inferred. During OI stage 4, extensive glaciation of the North Sea occurred, during the ‘Ferder Glacial Episode’, when Scotland and Scandinavian ice sheets extended to the continental shelf margin. Subsequent glaciation is identified during the Late Weichselian, when at least two phases occurred. After 30¹⁴kaBP, confluent ice sheets covered the central North Sea, during the Cape Shore Event, corresponding to the suggested Last Glacial Maximum in NW Europe. Subsequent to 22¹⁴kaBP, both ice sheets retreated, interrupted at approximately 18¹⁴CkaBP by a short period of ice sheet advance, mainly relating to surging of the eastern part of the British ice sheet.

This poster discusses the processes and environments associated with each glacial episode, providing clear indications of the style of glacial and glacimarine processes operating in this region throughout the Weichselian. Brief analysis of potential external trigger mechanisms for rapid glaciation suggests a correlation between Heinrich events H3-H1 and advance of the British ice sheet, although current chronostratigraphic data is poor for much of the region.