Kilometric sea level changes during the Messinian salinity crisis caused by river erosion and climate

Abstract

The Messinian salinity crisis (MSC) was a short period of isolation of the Mediterranean Sea that caused the precipitation of a million cubic kilometers of salt. The puzzling sedimentary record that formed after this deposition yields conflicting values of the extent of desiccation. Estimations range from a full exposure of most of the Mediterranean seafloor based on shallow fossil fauna found in the abyss to a nearly full Mediterranean scenario as suggested by similar, fresher-water deposits ubiquitous along the coastline: the so-called Lago-Mare formation. Using a landscape evolution model of the drawdown stage constrained with paleoclimate and sediment budgets, we show that the propagation of an erosional wave into the surrounding continents added a gradual sea level rise superimposed on the climatic oscillations of the Mediterranean. This retrogressive river incision along the spillways of the Paratethys and the Pannonian basins also explains the Mediterranean transition to fresher-water conditions during the last stage of the MSC.