The micromorphology of Last Glacial Maximum sediments in the Southern North Sea

The terrestrial ice limits of the Last Glacial Maximum ice sheets are well understood, but areas submerged during postglacial sea level rise have proved more difficult to accurately map. Fine grained diamicts in the Southern North Sea have been variously interpreted as glacial, glacioaqueous or periglacial in origin, implying different sedimentary environments. This has resulted in contrasting opinions regarding the position of the last ice sheets in this area. Micromorphology is presented as a useful technique to aid the analysis of such sediments, using systematic description of the physical characteristics of the sediments related to an interpreted seismic stratigraphy. Results indicate that the British ice sheet deposited glaciomarine sediments during an early advance, and then advanced over an extensive part of the Southern North Sea as terrestrial ice.