Against all odds: The survival of Porites corals through the Mediterranean Messinian Salinity Crisis

Despite many reports on the occurrence of reef corals in post-evaporitic Messinian deposits, it is generally assumed that coral reefs disappeared from the Mediterranean region during the Messinian Salinity Crisis. Contradicting this supposition, here we describe coral buildups and associated fossil assemblages that occur in the so-called Terminal Carbonate Complex (TCC) in the Sorbas Basin and Cabo de Gata in SE Spain, and in the Salento Peninsula in SE Italy. In the Sorbas Basin, the TCC conformably overlies the Messinian gypsum and onlaps the basin margins covering an erosion surface on top of pre-evaporitic Messinian coral reefs. This unit is late Messinian in age according to both its planktonic foraminifer assemblages and chronostratigraphic constraints in underlying and overlying units. A late Messinian age has also been proposed for the TCC in Cabo de Gata and Salento. The buildups are constructed by the zooxanthellate coral Porites, with minor Siderastrea in Salento. They formed structures metres to tens of metres wide and decimetres to a few metres high surrounded by bioclastic to oolitic detrital carbonate locally mixed with siliciclastics. Isolated Porites colonies, echinoids, diverse molluscs, coralline and dasycladalean algae occur associated with the buildups in the TCC deposits, in which microbial carbonate domes are also common. The occurrence of coral buildups in the western and central Mediterranean indicates that it is not a local phenomenon but the record of normal marine waters in the post-evaporitic Messinian and the widespread survival of reef corals in the Mediterranean in the late Messinian.