ON SIMILARITIES AND DIFFERENCES BETWEEN FORAMINIFER ASSEMBLAGES OF THE PALEOGENE IN POLAND AND EUROPEAN PART OF THE USSR

Abstract

Paleogene foraminifer assemblages of the Polish Lowlands and European part of the USSR were found to be highly similar. The similarities are primarily marked in Lower Paleocene and Upper Eocene microfaunas. This is especially the case of the Boreal Province but the similarities are also visible in Lower Paieocene (Dano·Momian) foraminifer assemblages of the Meridional Province (K. Pożaryska, J. Szczechura, 1968; J. Szczechura. K. Pożaryska, 1976), also known as the Transitional Province (V. Scheibnerova, 1971). The deposits yielding common foraminifer elements are also similar in lithology. In the Early Paleocene, fades of marly glauconitic sands was predominating in the Boreal Province, and facies of calcareous and marly deposits or organodetrital limestones known as "tuffeau" –I n the Meridional (Transitional) Province. In comparisons of Paleogene foraminifer microfaunas of the Polish Lowlands and European part of the USSR, attention was mainly paid to assemblages reported from well-known regions, including the Black Sea and Donets depressions, Crimea, as well as Byelorussia and Lithuania. In the Polish Lowlands, marine Upper Paleocene and Lower Eocene deposits are lacking and the Middle Eocene is represented by some relics only. A rich assemblage of species common for the areas of Poland and USSR is known from the Upper Eocene. However, this is only the case of the Boreal Province as the majority of warm-water species are confined to the Fore-Sudetic Monocline only, being completely unknown from eastern and northern Poland. This is presumably the result of existence of the Pomeranian-Kujavian anticlinorium, uplifted at that time and acting as effective barrier for faunal migrations. Differences between Oligocene foraminifer assemblages of Poland and the USSR are very high. They may be explained by existence of hypothetical Mazury - Mazowsze barrier, separating West-European Ruppelian sea and Ukrainian Maikop Basin.