ALBERT

Description: Organic-walled dinoflagellate cysts from Eocene-Oligocene transitional deposits have been studied in a section at Leluchow, Flysch Carpathians, Poland. The Eocene-Oligocene boundary, as based on dinoflagellate cyst distribution, is placed in the upper part of the Leluchow Marl Member. The main biostratigraphic events associated with this boundary interval are the highest occurrence of Areosphaeridium michoudii and Areosphaeridium diktyoplokum, and the lowest occurrence of Wetzeliella gochtii. Distinct changes in dinoflagellate cyst assemblages and palynofacies across the Eocene-Oligocene boundary at Leluchow imply a drop in relative sea-level within the Carpathian flysch basin that might correlate with a major eustatic fall during the earliest Oligocene. A drop in sea surface temperature is recognized prior to the Eocene-Oligocene boundary, and evidence is presented for an increase in nutrient level and decrease in salinity within the photic zone during the earliest Oligocene.