Freshening of the Mediterranean Salt Giant: controversies and certainties around the terminal (Upper Gypsum and Lago-Mare) phases of the Messinian Salinity Crisis

The late Miocene evolution of the Mediterranean Basin is characterized by major changes in connectivity, climate and tectonic activity resulting unprecedented environmental ecological disruptions. During Messinian Salinity Crisis (MSC, 5.97-5.33 Ma) this culminated most scenarios first precipitation gypsum around margins (Stage 1, 5.97-5.60 subsequently > 2 km halite on basin floor, which formed so-called Salt Giant 2, 5.60-5.55 Ma). final MSC Stage 3, however, was a "low-salinity crisis", when second calcium-sulfate unit (Upper Gypsum; substage 3.1, 5.55-5.42 showing (bio)geochemical evidence substantial brine dilution brackish biota-bearing terrigenous sediments (substage 3.2 or Lago-Mare phase, 5.42-5.33 deposited that received relatively large amounts riverine Paratethys-derived low-salinity waters. transition from hypersaline evaporitic (halite) to facies implies change Mediterranean’s hydrological regime. However, even after nearly 50 years research, causes modalities are poorly understood original scientific debate between largely isolated (partly) desiccated fully connected filled still vibrant. Here we present comprehensive overview brings together (chrono)stratigraphic, sedimentological, paleontological, geochemical seismic data all over Mediterranean. We summarize paleoenvironmental, paleohydrological paleoconnectivity arose cross-disciplinary dataset discuss arguments favour against each scenario.