Biostratigraphic and palaeoecological significance of Badenian (Miocene) calcareous nannofossil assemblages of the western Carpathian Foredeep (Skawina Formation, southern Poland)

Calcareous microfossil investigations of the Skawina Formation were performed in the Czeczott Mine pitshaft S-1 borehole, in the western part of the Carpathian Foredeep (near Pszczyna, southern Poland). Based on calcareous nannofossils, the section spans the uppermost NN5 Zone of the uppermost Moravian and lower Wielician substages (upper mid to lower upper Badenian Stage sensu Hohenegger et al. 2014), corresponding to the Langhian/Serravalian boundary interval (Middle Miocene). The calcareous nannofossil assemblages record the transition from relatively warm, eutrophic, outer-shelf conditions to lower nutrient availability and cooler conditions, driven by general climate cooling. This reflects a regional record of the transition from the mid Badenian Climate Transition phase to the late Badenian ‘Icehouse’ phase (cf. Holbourn et al. 2007), as globally recognised in the Middle Miocene. This biostratigraphic framework and inferred palaeoenvironmental changes are consistent with interpretations based on existing foraminifera assemblage data.