Udział bentosu i plankton otwornicowego w osadach górnej kredy północno-zachodniej Polski

Abstract

DISTRIBUTION OF BENTHONIC AND PLANKTONIC FORAMlNIFERA IN THE UPPER CRETACEOUS SEDIMENTS OF NW POLANDUpper Cretaceous ecology and palaeogeography in borings from the Polish Lowlands are analysed on foraminiferal studies with reference to recent ecological investigations. The ecological conclusions are based on profile diagrams of the numerical occurrence of benthonic and planktonic foraminifers in the particular beds, on circle diagrams from Upper Cretaceous beds and on diagrams showing the occurrence frequency of the particular families and genera within that whole profile. The greatest depth (over 1500 m.) of the Upper Cretaceous sea occurs in the Turonian. From that time till the Maestrichtian it gradually decreases (50-100 m.) displaying marked variations in depth and horizontal range.