Correlation of Upper Cretaceous Sequences of Eastern Europe Based on Radiolarians

Abstract

Because there was communication of the European peri-Tethyan Ocean with the Boreal and Arctic areas during most of the Late Cretaceous, correlation between them is possible through a planktonic group of microfauna, namely the radiolarians. Worldwide, although there has been considerable progress in research on the Early Cretaceous, Jurassic, and especially Triassic radiolarians, the study of Late Cretaceous radiolarians has been less well advanced. During the last few years, researchers from the Geological Institute, Russian Academy of Sciences, have shown that the Late Cretaceous radiolarians of eastern Europe were taxonomically and morphologically very diverse, and can be successfully used in the study of the biostratigraphy of Upper Cretaceous deposits. The results of a comprehensive analysis show that the following biostratigraphic zonal subdivisions based on radiolarians can be distinguished in several regions of eastern Europe: five subdivisions within the Cenomanian–lower Campanian interval of the Voronezh Anteclise, six within the Cenomanian–lower Campanian interval of the Moscow Syneclise, seven subdivisions within the Cenomanian–Campanian interval of the Crimean–Caucasian area, and nine within the Turonian–Maastrichtian interval of the Ulyanovsk–Saratov Depression. The Turonian Alievium superbum radiolarian zone has a global distribution, whereas the upper Campanian Prunobrachium articulatum radiolarian zone is local and recognized only in eastern Europe. The proposed biostratigraphic subdivisions based on the radiolarians of eastern Europe provide good correlations with the coeval zonal radiolarian units of western Siberia and northeastern Russia. Some radiolarian subdivisions of eastern Europe can be traced into western Europe.KeywordsRadiolarian biostratigraphyZonesEastern EuropeRussia