Correlation of Swedish glacial varves with the Greenland (GRIP) oxygen isotope record

A mean varve thickness curve has been constructed for a part of the Swedish varve chronology from the northwestern Baltic proper. The mean varve thick ness curve has been correlated with the delta(18)O record from the GRIP ice -core using the Younger Dryas-Preboreal climate shift. This climate shift w as defined by pollen analyses. The Scandinavian ice-sheet responded to a wa rming at the end of the Younger Dryas, ca. 10 995 to 10 700 clay-varve yr B P. Warming is recorded as a sequence of increasing mean varve thickness and ice-rafted debris suggesting intense calving of the ice front. The Younger Dryas-Preboreal climatic shift is dated to ca. 10 650 clay-varve yr BP, ab out 40 yr after the final drainage of the Baltic Ice Lake. Both the pollen spectra and a drastic increase in varve thickness reflect this climatic shi ft. A climate deterioration, correlated with the Preboreal oscillation, is dated to ca. 10 440 to 10 320 clay-varve yr BP and coincides with the brack ish water phase of the Yoldia Sea stage. The ages of the climatic oscillati ons at the Younger Dryas-Preboreal transition show an 875 yr discrepancy co mpared with the GRIP record, suggesting a large error in the Swedish varve chronology in the part younger than ca. 10 300 clay-varve yr BP. Copyright (C) 1999 John Wiley & Sons, Ltd.