BE-10 RECORDS OF SEDIMENT CORES FROM HIGH NORTHERN LATITUDES - IMPLICATIONS FOR ENVIRONMENTAL AND CLIMATIC CHANGES

The Be-10 records of four sediment cores forming a transect from the Norwegian Sea at 70-degrees-N (core 23059) via the Fram Strait (core 23235) to the Arctic Ocean at 86-degrees-N (cores 1533 and 1524) were measured at a high depth resolution. Although the material in all the cores was controlled by different sedimentological regimes, the Be-10 records of these cores were superimposed by glacial/interglacial changes in the sedimentary environment. Core sections with high Be-10 concentrations (> 1.10(9) at/g) are related to interglacial stages and core sections with low Be-10 concentrations (< 0.5 . 10(9) at/g) are related to glacial stages. Climatic transitions (e.g., Termination II, 5/6) are marked by drastic changes in the Be-10 concentrations of up to one order of magnitude. The average Be-10 concentrations for each climatic stage show an inverse relationship to their corresponding sedimentation rates, indicating that the Be-10 records are the result of dilution with more or less terrigenous ice-rafted material. However, there are strong changes in the Be-10 fluxes (e.g., Termination II) into the sediments which may also account for the observed oscillations. Most likely, both processes affected the Be-10 records equally, amplifying the contrast between lower (glacials) and higher (interglacials) Be-10 concentrations. The sharp contrast of high and low Be-10 concentrations at climatic stage boundaries are an independent proxy for climatic and sedimentary change in the Nordic Seas and can be applied for stratigraphic dating (Be-10 stratigraphy) of sediment cores from the northern North Atlantic and the Arctic Ocean.