The shallow- to deep-water record of the Messinian salinity crisis: new insights from Sicily, Calabria and Apennine basins.

Regional-scale physical-stratigraphic reconstruction of Sicilian basin geological evolution during the Messinian and its comparison with Calabria and Apennines basins, show that the ‘Lower Gypsum’ unit actually comprise in situ and resedimented facies separated in both space and time by the intra-Messinian unconformity. Halite bodies are associated with resedimented gypsum and Calcare di Base in Sicily and Calabria; these deposits are suggested to fully postdate in situ massive selenite deposition which occurred only in small and silled wedge-top and foreland ramp basins of Sicily and Apennine foreland systems while in Calabria they are absent. New data from the Upper Evaporites of Sicily allow cyclostratigraphic considerations suggesting that the resedimented gypsum, carbonate and halite unit formed between 5.6 and 5.55 Ma and records the acme of the Messinian Salinity Crisis during a pan-Mediterranean tectonic phase coupled with sea-level falls at glacials TG14-TG12. This new stratigraphic framework of Sicilian basin, usually considered the best analogue of deep Mediterranean basins, suggests a Messinian scenario with three stages characterized by different primary evaporite associations: selenite in the first and third stages, carbonate, halite and potash salt in the second one associated with hybrid resedimented evaporites. Evaporite precipitation took place only in shallow basins during the first stage and in deep basins in the second and third stages. Our reconstructions suggest that the Ocean connections, even reduced during the second and third stages, likely persisted throughout the Messinian Salinity Crisis.