ROZWÓJ LITOFACJALNY PÓŻNEJ KREDY NIŻU POLSKIEGO

Abstract

LITHOFACIES EVOLUTION OF THE LATE CRETACEOUS BASIN IN THE POLISH LOWLANDSAbstract. The report is a general overview of the author’s many-year studies on the Late Cretaceous stratigraphy, lithology and paleogeography of the Polish Lowlands. Six lithofacies maps are presented for individual transgressive-regressive cycles in the Late Cretaceous of the Polish Basin: K3-II–K3-III (Early–early Late Cenomanian), K3-IV (latest Cenomanian–Middle Turonian), K4-I (Late Turonian–Coniacian), K4-II (Santonian–earliest Campanian), K4-III (late Early Campanian–earliest Maastrichtian), K4-IV–K4-V (late Early–Late Maastrichtian). The maps were constructed using qualitative lithofacies reconstructions with the dominant lithofacies component and accessory components indicated. Nine lithofacies types, corresponding to specific sedimentary environments and depositional systems, have been identified within the Upper Cretaceous succession of the Polish Lowlands: chalk, carbonate, carbonate-siliceous, marl, claystone-marl, mudstone (siltstone)-marl, mudstone-sandstone-marl, sandy-carbonate and sandstone lithofacies. The present version of the maps is based on an integrated analysis of drilling materials, mainly wireline logs. Lithology and stratigraphy in some boreholes were verified and reinterpreted by the author. In particular, special emphasis was laid on analysing hardgrounds, sedimentary breaks and any signs of sedimentarycyclicity. It enabled logical correlations between corresponding lithological complexes, which were previously incorrectly correlated. General succession of lithofacies in the basin is characterised, remarks on its subsidence and bathymetry are presented and a brief discussion of the problem of Late Cretaceous tectonic inversion of the Mid-Polish Trough is given. The report also presents the history of lithofacies evolution in the Late Cretaceous basin.