Paleo-environment and radiocarbon calibration as derived from Lateglacial/Early Holocene tree-ring chronologies

We present an overview of the extended Hohenheim oak chronology (HOC) and t he dendrochronologically dated Preboreal pine tree-ring chronology (PPC). B oth provide an absolute, annual time frame of the Holocene, extending into the Younger Dryas (YD) back to 11,919 BP. Two floating pine and larch chron ologies are C-14 dated, covering large parts of the Lateglacial. Dendro-eco logical parameters, such as ring width and stable isotope variation are use d to infer past environmental conditions. C-14 analyses on decadal sections provide a high-precision, high-resolution data set for calibration of the radiocarbon time scale. Based on a marked change in ring-width and growth p attern, the YD termination is clearly identified in the German pine chronol ogy. Its absolute age of 11,570 BP appears synchronous, within the errors o f the respective chronologies, to related signals in the Greenland ice core s (GRIP, GISP2) and in lacustrine varve sequences. The C-14 age of the Laac her-See tephra (LST) is determined from a series of decadal tree-ring sampl es to 11,063 +/- 12 C-14 BP; the calibrated range is 13,010-13,200 cal BP. The climatic impact of the LST is reflected in the growth pattern of our tr ee ring chronologies. (C) 2000 Elsevier Science Ltd and INQUA. All rights r eserved.