EEMIAN CLIMATIC AND HYDROGRAPHICAL INSTABILITY ON A MARINE SHELF IN NORTHERN DENMARK

Benthic foraminifera and stable isotope data from the last interglacia tion (Eemian, substage 5e) from a borehole at Skagen, Denmark, provide evidence for major environmental and hydrographic changes during this period. During the first millennium of the Eemian, water masses cover ing northern Denmark became gradually warmer. Temperate conditions pre vailed during most of the interglaciation, but these were interrupted by two periods with decreased water temperatures. The first cooling (E vent S-1) was not very distinct at Skagen, but the second (Event S-2), seen in both the foraminiferal and oxygen isotope record, represents a large shift to subarctic conditions. Carbon isotopes indicate a chan ge in ocean circulation during both events. No comparable climate vari ations are seen within the Holocene record at the site. The final cool ing of the water masses associated with the substage 5e/5d boundary oc curred within a few hundred years. These last interglacial climatic ch anges were probably caused by variations in strength and/or position o f the North Atlantic Drift, possibly as a result of varying vigor of t he Atlantic conveyor. In addition, minor variations in the fossil asse mblages also indicate fluctuations in the inflow of Atlantic water to the Skagerrak-Kattegat area during the warm intervals of substage 5e. (C) 1997 University of Washington.