The history of Quaternary sedimentation in the UK sector of the North Sea Basin

Abstract
Reconnaissance seismic and sampling surveys have shown that up to 500 m of Lower and early Middle Pleistocene deltaic sediments are preserved in the UK sector of the North Sea. The distributions of delta-related facies record the progressive expansion of peripheral delta systems northwards across the southern North Sea during the early Pleistocene. A late Middle Pleistocene unconformity is present throughout the UK sector, and sedimentation above the unconformity was dominated by glacial erosional and depositional processes. A complex system of deeply incised valleys was eroded during each of three regional Middle and Upper Pleistocene glaciations and the valleys have been filled or partially filled by glaciolacustrine or glaciomarine and interglacial marine sediments. The valleys of the earliest (Elsterian) glaciation are up to 400 m deep in the southern North Sea. The Saalian and Weichselian valleys are commonly more than 100 m deep, they are eroded through their contemporary tills nearshore but occur well beyond the limits of these tills offshore. The origins of these valleys are attributed to a combination of fluvial, subglacial and periglacial processes