Stanisław Geroch

Upper cretaceous abyssal claystones in the North Atlantic and Western Tethys: current status of biostratigraphical correlation using agglutinated foraminifers and palaeoceanographic events

Abstract The biostratigraphic correlation scheme of Upper Cretaceous multicoloured claystones in the Polish Romanian. External Carpathians using agglutinated deep-water foraminifers can be extended to onshore localities in the Gibraltar Arch area (Morocco, Spain) and DSDP/ODP sites in the North Atlantic. In all studied areas, taxonomic turnovers in deep-water agglutinated foraminifers are observed at the Cenomanian-Turonian boundary and in the early/middle Campanian. Additionally, a remarkable decrease in abundance and diversity of benthic agglutinated foraminifers is observed at the same levels in continuous sections of North Atlantic DSDP sites. These datum levels correspond to inter-regional and time-constant palaeoceanographic events, and may facilitate the direct correlation of the biozonation of agglutinated foraminifers to the standard geomagnetic polarity time scale.

The Oldest Assemblages of Agglutinated Foraminifers of the Polish Flysch Carpathians

The oldest assemblages of agglutinated foraminifers of the Polish Flysch Carpathians occur in the marly shale intercalations of the Cieszyn Limestones (Upper Tithonian-Berriasian). The assemblages are comprised of primitive forms such as astrorhizids and ammodiscids and advanced ones such as trochamminids and verneuilinids. Fifteen genera and 19 species have been recognized. Most of these have been found in the Atlantic and Indian Ocean DSDP sites, proving the ubiquitous character of the Early Cretaceous arenaceous foraminiferal faunas. The accompanying calcareous foraminifers, mostly nodosariids, are interpreted as partly redeposited, connected with turbidites.

The use of deep-water agglutinated Foraminifera in correlating Lower Cretaceous pelagic and flysch sequences : current status and prospects for the future

Abstract Deep-water agglutinated Foraminifera (DWAF) display potential for correlating pelagic (calcareous and non-calcareous) and flysch environments. This is illustrated by an example from Sites 765 and 261 on the Argo Abyssal Plain. A working zonation based on DWAF has been developed for Lower Cretaceous flysch sequences of the Polish Carpathians, but this zonal scheme has not been tested in other areas of the Tethys. No zonation has yet been developed for abyssal oceanic DWAF. The challenge for the future, under the auspices of Project 262, is to test the existing zonation in other regions and develop a widely applicable biochronology for integration into a general Tethyan biochronological correlation scheme.