An ice-moulded surface from the middle pleistocene of the central north sea

摘要

A collection of seismic datasets, including Ultra-High Resolution 2D, High Resolution 2D and Exploration 3D data, have been compared with geotechnical borehole logs, to investigate a Middle to Late Pleistocene sequence within the Central North Sea (CNS). An Elsterian glacial erosion surface is interpreted to be overlain by a series of seismo-stratigraphic formations which can mostly be referenced to the accepted stratigraphie model for the area, though with some significant qualifications. Evidence is shown for the presence of at least three grounded ice-sheets within the Middle-Late Pleistocene of the CNS, including a previously unreported, pre-Weichselian, ice-moulded and lineated surface. The late and post-glacial history of the CNS is re-constructed by reference to borehole lithological data, compared with seismic textures. It is proposed that a seismo-stratigraphic unit at seabed and named in published sources as the late glacial Forth Fm. is much older, with implications for the prediction of geotechnical properties of the unit elsewhere in the region.