Abstrakt
The LSVE tephra is one of the most important chronological markers in European lacustrine varved sedimentary archives that resides close to the onset of the YD. The timing of this at least Europe-wide event, based on carbonatite U-Th zircon isochron age (12,900 cal.
B.P.) and lake varve age (12,880 cal. B.P.), is within the error range of the YD onset provided by Cheng et al. (12,870 +- 30cal.
B.P.). Results of our recent multiproxy study of a sedimentary archive in the Central European paleolake Stará Jímka suggest that the first drop in δ(18)O originated from a previous warmer climate in combination with a long-term climate repercussion following the LSVE.
The subsequent major continuous decrease of δ(18)O indicates the actual YD onset, as a reaction to an extraterrestrial impact event (ETIE) revealed by the Pt anomaly along with the occurrence of microspherules and nanodiamonds. The lag estimated by Cheng et al. of approx. 50 y between their proposed YD onset and the Pt anomaly is within our error range of a approx.70-y lag found in the sediment of the Stará Jímka paleolake between the accumulation of LSVE tephra and magnetic impact microspherules that indicate an ETIE.