Marine and terrestrial environmental change during the MIS 5–4 transition (southern North Sea area)

Abstract

The Late Pleistocene Marine Isotope Stage (MIS) 5 – MIS 4 transition (at ca. 75 ka) is globally known to correspond to a period of strong cooling and sea-level lowering. Terrestrial records indicate the transition had a large impact on terrestrial environments, but the impact on coastal and shallow-marine areas is poorly documented due to a lack of well-dated, continuous archives caused by erosion during succeeding glacial lowstands. The extensive offshore deposits of the Brown Bank Formation in the southern North Sea yield a valuable record of this transition in a shallow-marine environment. We show that the southern North Sea experienced subarctic marine conditions with a high input of terrestrial material during the MIS 5–4 transition. These continued marine conditions, which have not been described earlier for northwestern Europe, show that sea level remained relatively high, and lagged cooling on land inferred from lipid-biomarker palaeothermometry. The time-lag between terrestrial cooling and sea-level fall created a sediment preservation window during the onset of MIS 4 in a shallow-marine environment. Our record captures changes in both the terrestrial and shallow-marine environments, and allows for linking terrestrial and marine records of the MIS 5–4 transition in NW Europe.