Rise and fall of the Paratethys Sea during the Messinian Salinity Crisis

Extremely thick evaporite units were deposited during the so-called Messinian Salinity Crisis (MSC: 5.96–5.33 Ma) in a deep Mediterranean basin that was progressively disconnected from the Atlantic Ocean. A crucial, but still poorly understood component in Messinian evaporite models is the connectivity between Mediterranean and Paratethys, i.e. the former Black Sea domain. Inadequate stratigraphic correlations and insufficient age control for Paratethys sediments have so far hampered a thorough understanding of hydrological fluxes and paleoenvironmental changes. Here, we present a new chronology for the Eastern Paratethys by integrating biostratigraphic and paleomagnetic data from Mio–Pliocene sedimentary successions of Romania and Russia. We show that a major flooding event from the Mediterranean surged the Paratethys basins at the Maeotian–Pontian boundary, 6.04 million years ago. This indicates that sea level in both Mediterranean and Paratethys was high at the beginning of the MSC. We argue in favor of changes in Paratethys–Mediterranean connectivity to initiate the MSC in combination with elusive tectonic processes in the Gibraltar arc. A subsequent fall of Paratethyan water level closely coincides to the Mediterranean isolation-event, corresponding in age to the glacial cycles TG12–14 (5.60–5.50 Myr). In the latest Messinian, a major climate change towards more humid conditions produced a positive hydrological balance and likely a transgression in the Paratethys, although our stratigraphic resolution cannot exclude a possible relation to the Pliocene flooding of the Mediterranean here.