LATE-GLACIAL STABLE-ISOTOPE RECORD, RADIOCARBON STRATIGRAPHY, POLLEN AND MOLLUSK ANALYSES FROM THE GEISELTAL AREA, CENTRAL GERMANY

Combined investigations of isotopes, pollen, and mollusc shells were c arried out on a Late Glacial limnic high-resolution sediment sequence from the Geiseltal open-cast mine in Central Germany. The data confirm the division of the Late Glacial biozones into two colder (Older and Younger Dryas) and two,warmer periods (Bolling, Allerod), which have a lready been established for the Central and Northern German area. Radi ocarbon data, mainly based on wood material, cover a time span between c. 10800 BP and 12760 BP, indicating a mean sedimentation rate of c. 2 mm/yr. The stable isotope data (delta(18)O, delta(13)C) reflect the transition periods between the climatic phases as changes in relative air humidity (transition from dry, cold to warmer, more humid conditio ns). The dominance of evaporation effects, however, is superimposed on any temperature signal throughout the profile. Repeated conversions o f the hydrologic regime (silting-up phases, lake-level variations) cha racterize the specific history of the lake development.