Late Glacial to Holocene environmental development near an oil-producing platform in the Danish North Sea

The Late Quaternary North Sea basin represents a highly dynamic shelf system, altered by glaciations, deglaciations, and the recent Early Holocene marine transgression. However, detailed studies on the timing of the marine transgression and the paleoenvironmental development of the Danish North Sea are lacking. In this article, we present a Late Glacial–Holocene paleoenvironmental reconstruction of the central North Sea using multiproxy data from three sediment cores. As a novel approach, integrated benthic faunal analyses were applied, including both bivalves and benthic foraminifera, supported by radiocarbon dating, macrofossils, lithology, sediment geochemistry (X-ray fluorescence (XRF) core scans), and sub-bottom profiler data. By focusing on sites located near an oil-producing platform, an overarching goal is to investigate the response of the benthic fauna to anthropogenic activities. The results show age offsets between radiocarbon dates performed on benthic foraminifera and bivalves, possibly driven by contamination of younger carbon, sediment reworking, and changing marine reservoir ages, highlighting a dynamic depositional environment. During the Younger Dryas, the macrofossils reveal the presence of a lake situated in a tundra landscape. This was followed by marine transgression of the area at c. 10 cal ka BP, where the benthic foraminifera point to cold water conditions. Starting from c. 8.3 cal ka BP, increasing sedimentation rates and incursion of warmer water masses, is related to the isolation of Dogger Bank in the central North Sea and the opening of the English Channel. A transition toward colder and more unstable conditions is captured in the cores, presumably related to the 8.2 ka cold event. The cores record a depositional break between c. 8 cal ka BP and 2 cal ka BP, reflecting a highly dynamic depositional environment on the eastern Dogger Bank. The recent development is associated with a top layer containing benthic indices of anthropogenic impact under fully marine conditions. Our study reveals key transitions in the postglacial evolution of the North Sea.