Palinologiczne i diatomologiczne badania osadów interglacjału mazowieckiego z odsłonięcia w kopalni Bełchatów

Abstract

Pollen and diatom analysis of the Mazovian Interglacial deposits from the open-cast mine “Bełchatów” (Central Poland).Summary. The thickness of Pleistocene deposits in the Kleszczów Graben reach 300 m. Data from these deposits are important for stratigraphic schemes of the Pleistocene of Poland. However, up to now the Mazovian Interglacial deposits were recognized from boreholes only, not from the exposures in the open-cast mine and they comprise incomplete interglacial successions. The present analysis of organic deposits from closed depression exposed on the escarpment of the mine, reveals almost the full pollen succession of the Mazovian Interglacial. The succession started with dominance of birch forest followed by birch-pine and afterwards birch-pine forest with increasing share of alder, spruce and thermophilous trees that led to development of mixed forest which corresponded to climatic interglacial optimum. First there were forests with share of yew which later were replaced by hornbeam and fir. The fir-hornbeam phase closed the climatic optimum. The distinctly colder pine phase following fir-hornbeam phase ended the interglacial succesion of plants in Folwark 93K site. On the basis of changes in diatom composition and relative (percentage) diatom frequency in this site it was determined that the fossil lake sediments represent the diatom succession of the Mazovian Interglacial. The diatom succession from Folwark has been divided into 7 local diatom assemblage zones (LDAZ Fd 1–Fd7). These zones represent four stages of paleolake development and correspond to the local and regional pollen assemblage zones of the Mazovian Interglacial. The Mazovian Interglacial age of the organic deposits from the site Folwark 93K implies the revision of the stratigraphical position of some lithostratigraphic units from the Middle Pleistocene in the Kleszczów Graben. The obtained results indicate also that at least some intensive deformations of the Lower Pleistocene deposits were completed before the Mazovian Interglacial.