Stratigraphy and age of two postglacial sediment cores from the Baltic Sea

Abstract

Abstract Two sediment cores, one from the Bornholm Basin and the other from the Landsort Trench were investigated. For the Bornholm Basin, the diatom data were complemented by an initial pollen dating for this area. The diatom and pollen records of the Landsort core resulted in the assumption that the whole core consisted of Litorina and post-Litorina clays. For the first time 14C-accelerator datings of five sediment levels from the Baltic could be complemented by the dating of a fishbone found in the core. This confirmed the biostratigraphic determinations and gave a high tentative sedimentation rate of 1.3 mm/year, tentative because there were roughly constant ages for sediments between 8.80 m and 6.30 m core depth. The composition of the diatom flora yielded indications both for a Litorina transgression phase in the lowermost part of the accumulation of 2.50 m sediment and for a local redeposition. Upwelling gas has been observed in echosoundings close to the Landsort core, so a trap effect might have ...