Lake basin development in the Endinger Bruch area (Vorpommern, NE Germany) during the Late Pleistocene and Early Holocene

摘要

This study focuses on the Lateglacial sedimentation and morphodynamics of a river-fed palaeo-lake basin (12 km(2)) situated in a flat to slightly undulating till plain of the Weichselian Mecklenburg Advance. Geological mapping in combination with sedimentological, biostratigraphical, geoarchaeological and geochronological data enables conclusions on the sedimentary character of single periods, on the process of dead-ice melting and on the palaeohydrology. During the Late Pleniglacial, in the course of areal deglaciation, glaclofluvial and glaciolacustrine sediments were deposited. An accelerated melting of buried dead-ice was recorded for the time-span Oldest Dryas-Bolling. The majority of profiles show that the sedimentation process started with silicate gyttlas and organic-silicate gyttjas in the Bolling. During the Older Dryas, silicate gyttjas and fluvial sands were deposited, indicating a local differentiation of the sedimentation. The sediments of the Allerod, e. g. organic gyttja, calcareous gyttja and peat, point to a lacustrine environment without any fluvial influence. The final dead-ice melting is dated to the Allerod-Younger Dryas transition. Fluvio-lacustrine sands of the Younger Dryas, partly in the form of coarse-grained sands containing stones and blocks, indicate a hydrological event. A sudden outflow of a basin above the Endinger Bruch could have been this event. Widespread lacustrine sediments of the Preboreal and Boreal allow the reconstruction of a palaco-lake landscape. The filling-up of the larger lake areas by means of peat formation started in the early Atlantic. For the study area, a summarizing curve of the lake-level development is presented.