4 Major Quaternary Glaciations: Extent, Timing, and Global Synchronism (Posters)

THE LAST GLACIAL MAXIMUM AND DEGLACIATION OF THE KRKONOSE MOUNTAINS, CZECH REPUBLIC: EVIDENCE OF ASYNCHRONAEITY WITH THE SCANDIAVIAN ICE SHEET?

Paper number: 4-2
Program: Technical Sessions
Time: 1:30 PM – 4:30 PM

Authors

Abstract

The nature and timing of the LGM and subsequent environmental changes during the Last Termination in Central Europe is poorly understood, with no high-resolution, well-dated sequences yet interpreted. The location of the Krkonose (Giant) Mountains of the Czech Republic/Polish borders is highly significant, lying in the corridor between the Scandinavian ice sheet and the Alpine ice field, and the first significant mountain belt beyond the limits of the Scandinavian ice sheet during the LGM. Thus, the Krkonose may preserve a unique record of glaciation and palaeoclimate for this period, reflecting climate changes that are perhaps out of phase with the broader NW European transition.

This study reports the findings of a range of investigations in the Upa valley, Krkonose Mountains. Geomorphological mapping identifies a sequence of moraine belts in the upper valley, and a suite of erosional terraces in the middle and lower valley, thought to reflect cycles of erosion and glaciation subsequent to the mid- Quaternary. Lithofacies analysis of sediment exposures in the vicinity of Svoboda nad Upou suggest that Late Quaternary glaciation of the Krkonose mountains was more extensive than previously considered. Palaeoecological analysis of cores extracted from bogs lying between moraines, as well as a site beyond the moraines provides the first detailed paleo-environmental reconstruction for this region for the period of the LGM and last Termination, supported by AMS radiocarbon dating.

The nature and chronology of LGM glaciation in the Krkonose is compared to that of the Scandinavian ice sheet. Evidence for asynchronaiety of glaciation and environmental change in the Krkonose are compared to other studies from areas beyond the major ice sheets to evaluate the significance of such phasing. We by evaluating the evidence from the Krkonose and nearby regions in the context of regional climatic patterns during, and subsequent to the LGM.