SD1

The release of meltwater from the margins of the Late Quaternary Fennoscandian ice sheets resulted in complex networks of (now buried) Pleistocene tunnel-valleys that extend beneath large parts of the North Sea and the adjacent northern European lowlands. Deeply incised (100-500 m) into mostly Neogene sediment strata, they form a dominant architectural element of the North Sea sedimentary basin and are a primary cause of small scale lithological heterogeneities. Offshore mapping based on seismic surveys is far from complete, but has provided evidence of multiple generations of buried valleys, inferred to record at least three successive cycles of continental glaciation and interglacial marine transgression. The largest known buried valleys lie in and adjacent to the southern North Sea and have been tentatively correlated to the mid-Pleistocene Elsterian glaciation. The recent discovery by MARUM scientists of a so far unknown major E-W trending buried valley in the SE North Sea poses new multi-disciplinary questions with regard to the ages of cross-cutting features, their infill architecture and lithology, the orientations and dynamics of former ice margins, the number and nature of interglacial marine transgressions and the mitigation of geotechnical risks. The latter is of economic importance as lithological heterogeneities in shelf sediments induced by such valleys, common features also in other formerly glaciated regions, have recently gained attention in offshore wind park planning as potential geotechnical risks.

Depth contour of the base of the recently discovered E-W trending buried valley in the German Bight.

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