143Nd/144Nd and 87Sr/86Sr isotopic records coupled with foraminiferal δ18O and δ13C reveals dynamic oceanographic settings following the Middle Miocene (Badenian) salinity crisis in Central Europe

Abstract

The Middle Miocene salinity crisis in Central Europe and the Middle East is an example of a profound environmental transition in marine ecosystems resulting from the complex interplay of climatic and palaeoceanographic changes during the Middle Miocene. In this study, we use a combination of multi-proxy methods to reconstruct the environmental dynamics in Central Europe, right after the evaporitic depositional period, utilising material from two cores, Babczyn 2 and Cieszanów 1, located in the Polish part of the Carpathian Foredeep. From this perspective, understanding the environmental response to such changes is particularly relevant in the context of the unique palaeogeographic setting of Central Europe during the Middle Miocene, together with the final stage of existence of the Paratethys marine system, and the associated faunal turnaround known as the Badenian-Sarmatian extinction event. This study identifies and characterises a post-evaporitic phase marked by alternating different palaeoenvironments as reflected by the response of the various geochemical proxies, namely ¹⁴³Nd/¹⁴⁴Nd, ⁸⁷Sr/⁸⁶Sr, or by foraminiferal δ¹⁸O and δ¹³C. In general, periods of active communication, or at least exchange of water masses between neighbouring basins, alternated with periods of isolation, reflecting local and global triggering factors, all linked to three individual connectivity events.