Oxygen isotopes of lake marl at Gerzensee and Leysin (Switzerland), covering the Younger Dryas and two minor oscillations, and their correlation to the GRIP ice core

The ratio of oxygen isotopes is a temperature proxy both in precipitation a nd in the calcite of lacustrine sediments. The very similar oxygen-isotope records from Greenland ice cores and European lake sediments during the Las t Glacial Termination suggest that the drastic climatic changes occurred qu asi-simultaneously on an extra-regional, probably hemispheric scale. In ord er to study temporal relations of the different parameters recorded in lake sediments, for example biotic response times to rapid climatic changes, a precise chronology is required. In unlaminated lake sediments there is not yet available a method to provide a high-resolution chronology, especially for periods with radiocarbon plateaux. Alternatively, an indirect time scal e can be constructed by linking the lake stratigraphy with other well-dated climate records. New oxygen-isotope records from Gerzensee and Leysin, wit h an estimated sampling resolution of between 15 and 40 years, match the Gr eenlandic isotope record in many details. Under the assumption that the mai n variations in temperature and thus in oxygen isotopes occurred about simu ltaneously in Greenland and Switzerland, we have assigned a time scale to t he lake sediments of Gerzensee and Leysin by wiggle-matching their stable-i sotope records with those of Greenland ice cores, which are among the best dated climatic archives. We estimate a precision of 20 to 100 years during the Last Glacial Termination. (C) 2000 Elsevier Science B.V. All rights res erved.