The evolution of the Late Badenian calcareous nannofossils assemblages as an reflexion of the palaeoenvironmental changes of the Vienna Basin (Devínska Nová Ves – clay pit, Slovakia)

This paper discusses the results of high resolution study of the Late Badenian calcareous nannofossils from the Studienka Formation of the Vienna Basin, locality Devínska Nová Ves – clay pit (section DNV 1). Results are based on quantitative data of nannofossil assemblages from the sixty nine samples of the studied profile. The age of sediments was determined as Late Badenian and correlated with NN6 – Discoaster exilis Zone. Abundance of the species Holodiscolithus macroporus was noticed, quantified and interpreted for the first time. Abundance patterns indicate: (1) nearshore environment with nutrient supply (prevailing of small Reticulofenestra over Coccolithus pelagicus); (2) cooling trend (by abundance of Holodiscolithus macroporus, Coccolithus pelagicus; low abundance of sphenoliths and rare discoasterids); (3) eutrophy (local enrichment of species Helicosphaera and Syracosphaera pulchra); (4) salinity decrease (higher number of Braarudosphaera bigelowii bigelowii, B. bigelowii parvula, Micrantholithus flos and M. vesper); (5) higher turbulence of palaeoenvironment (locally higher abundance of helicospherids); (6) signal of higher erosion rate (local increase of reworked nannofossils). Cluster analysis according to ecological demands was performed on the assemblage data. Four groups related to different temperature and trophic conditions have been distinguished.