Late Younger Dryas to Holocene palaeoenvironments of the southern Kattegat, Scandinavia

Abstract

Palaeoenvironmental changes since the late Younger Dryas are reconstructed in the southern Kattegat (Scandinavia) and provide a basis for correlating the whole of the North Sea-Skagerrak- Kattegat-Baltic region. The foraminiferal content of seven piston and three vibrocores were analysed. Radiocarbon dates were obtained from four of the cores. Relatively warm water masses occurred in the shallow areas of the Kattegat during the late Younger Dryas and early Preboreal, while cold, arctic/ subarctic water masses occurred in deeper parts of the Kattegat and Skagerrak. Full interglacial temperature conditions developed in the southern Kattegat at 9600 BP. A sea-level rise is recorded at 9600-8200 BP, a period during which the Skagerrak-Kattegat area experienced a gradual warming. A change in sedimentological and environmental conditions occurred in the southern Kattegat at around 8000 BP, reflecting the opening of a connection to the Baltic and corresponding hydrographic changes. The modem general circulation pattern of the area was established after this event. A further rise in sea level is recorded after 8000 BP. A mid-Holocene alteration in hydrographic and sedimentation pattern in the area is marked by the reappearance of Nonionellina labradorica in the southern Kattegat. This alteration, previously dated to 4000 BP, is redated to 5500 BP and is interpreted as reflecting the well- defined late-Atlantic cooling of the North Atlantic region resulting in changed inflow/outflow pattern of water masses in the Kattegat.