Sedimente und Ablagerungsmechanismen in instabilen proglaziären Seen (Eisrandstauseen) in Westgrönland

Abstract. Close to Søndre Strømfjord in West Greenland, a number of ice contact lakes with unstable water levels are dammed by the margin of the inland ice. From time to time they drain more or less completely beneath the glacier. Thus, the sediments at the bottom of such dry lake basins can be eliminated in an easy way. 7 lakes of this type, 3 of which were empty in summer 1993, could be investigated in detail by help of a grant of the DFG. The sedimentary infill of the lakes mainly consists of dia miktons, presumably sediments of drift ice. besides of the debris of mass movements, derived from the flanks of the lake basins, deltaic and fluvial deposits play an important role. Fine grained lake sediments, however, which may be expected within a lake close to a glacier, are scarcely to be found. The sedimentary infill of unstable lakes of this type is obviously different from normal glacilacustrine successions. The sedimentary record of fossil lakes of this type, which may have been as common in Pleistocene Europe as in modem Greenland, should be identified easily in the future, due to the investigations presented in this paper.