COMPLEX INVESTIGATIONS OF QUATERNARY ICE- DAMMED LAKE EVOLUTION IN CENTRAL GERMANY

Geological-sedimentological (grain size; micromorphology, varve correl ation) and geochemical (stable isotopes: O-18/O-16, C-13/C-12) investi gations with ice-dammed lake sediments of the Dehlitz-Leipzig varved c lay enable to elucidate in detail the palaeosedimentologic and palaeoc limatic conditions in the surrounding of the Elsterian Scandinavian in land-ice sheet a relatively short time before its maximum extension in Central Europe took place. For the space of lime between formation of the ice-dammed glacial lake and its run-over by Scandinavian inland-i ce sheet the obtained results allow to distinguish at least Four evolu tionary phases. Regarding the palaeosedimentologic relations in the ic e-dammed glacial lake these four phases are characterized bg differenc es in the dynamics of sediment input, suspension density within the wa ter body and existence/absence of stagnation events with syngenetic fo rmation of carbonates under anoxic conditions. During the formation of glacial varves the obtained data seem to support the existence of sma ll seasonal differences which can be due to very cold, long winter- an d short, cool summer periods. In this way the time of the first Elster ian glacial maximum, reflected by the varved clays, can be classified as a typical glacial climatic period.