Isotopic events in the Early/Middle Badenian (Miocene) of the Upper Silesia Basin (Central Paratethys)

Middle Miocene foraminifera from the Skawina Formation of the Upper Silesia Basin have been analysed. The stable oxygen and carbon isotope signatures in Globigerinoides quadrilobatus (shallow pelagic), Globigerina bulloides (deeper pelagic) and Uvigerina spp. (benthic) tests show a temporal pattern of changes in the sections studied. The foraminiferal assemblage biozones of the Badenian that were identified earlier, on the basis of taxonomic composition, correspond to changes in the foraminiferal delta O-18 and delta C-13 values. The CPN7/CPN8 transition - as the Moravian/Wielician border - is marked by distinct isotopic events: a delta O-18 increase (IIAB/IIC boundary) followed by a delta C-13 decrease (IIC/IID boundary).