Last Interglacial sea-level data points from Northwest Europe

Abstract

Abundant numbers of sites and studies exist in NW Europe that document the geographically and geomorphologically diverse coastal record from the Last Interglacial (Eemian, Ipswichian, Marine Isotope Stage 5e). This paper summarises a database of 146 known Last Interglacial sea-level data points from in and around the North Sea (35 entries in the Netherlands, 10 Belgium, 23 in Germany, 17 in Denmark, 9 in Britain) and the English Channel (24 entries for the British and 25 for the French side, 3 on the Channel Isles) believed to be a representative and fairly complete inventory and assessment from ∼80 published sites. The geographic distribution (∼1500 km SW-NE) across the near field of the Scandinavian and British ice sheets and the attention paid to relative and numeric age control are assets of the NW European database. The research history of Last Interglacial coastal environments and sea level for this area is long, methodically diverse and spread through regional literature in several languages. Our review and database compilation effort drew from the original regional literature and paid particular attention to distinguishing between sea-level index points (SLIPs) and marine and terrestrial limiting points. We also incorporated an updated quantification of background rates of basin subsidence for the central and eastern North Sea region, utilising revised mapping of the base Quaternary, to correct for significant basin subsidence in this depocentre. As a result of subsidence, lagoonal and estuarine Last Interglacial shorelines of the Netherlands and the German Bight are preserved below the surface. In contrast, Last Interglacial shorelines along the English Channel are encountered above modern sea level. This paper describes the dominant sea-level indicators from the region compliant with the WALIS database structure and referenced to original data sources (10.5281/zenodo.6478094, Cohen et al., 2021). The sea-level proxies are mostly obtained from locations with good lithostratigraphic, morphostratigraphic and biostratigraphical constraints. Most continental European sites have chronostratigraphic age control, notably through regional pollen association zones with duration estimates. In all regions, many SLIPs and limiting points have further independent age control from luminescence, uranium series, amino acid racemisation and electron spin resonance dating techniques. Main foreseen usage of this database for the near-field region of the European ice sheets is in glacial isostatic adjustment modelling and fingerprinting Last Interglacial ice sheet melt.