The Upper Cretaceous carbonate-dominated sequences of the Polish Lowlands

Abstract

Four depositional systems have been distinguished basing on borehole data in the Late Cretaceous sedimentary basin of the Polish Lowlands: (1) pelagic carbonates system containing (a) limestone-opoka facies and (b) chalk facies, (2) pelagic clastics system, (3) siliciclastic shelf system, and (4) submarine fan system. The material collected from the Polish Lowlands and its interpretation was subsequently compared with the data from the marginal parts of the Late Cretaceous basin. All the data derived from both boreholes and outcrops have been compiled and the correlation of trends and geological events occurring in various areas of the basin gives a more complete picture of the Late Cretaceous sedimentary cyclicity. As a result of these investigations, two major cycles (K3 and K4) have been recognized. They are related to panregional tectonic events. Nine lower-order sedimentary cycles have been distinguished within them. Since the Early Palaeocene sedimentation is intimately connected with the Late Cretaceous basin, it has been necessary to include the youngest, Early Palaeocene cycle (Pc-I) terminating the Zech-stein-Mesozoic evolution of the basin.