Interpreting gypsarenites in the Rossano Basin (Calabria, Italy): a contribution to the characterization of the Messinian salinity crisis in the Mediterranean

Detrital evaporites and mixed siliciclastic-gypsum arenites are present in theGessi Formation from the Rossano Basin in Calabria, Italy. The detrital origin of thegypsum fragments in the quartzofeldspathic sandstones is revealed by crystal overgrowthsthat outline the shape of former gypsum clasts. The gypsum was subsequentlytransformed into anhydrite at burial conditions. During exhumation, anhydrite washydrated back to gypsum, a gypsum overgrowth rich in F, Na, K, Cl, and Al formedon the original gypsum grains, and the pore spaces were filled with gypsum cement.Detrital modes of Gessi Formation sandstones suggest complex source-basin relationshipsin this area during the Messinian salinity crisis. The clastic deposits are theresult of deep unroofing of the crustal terranes of the Calabrian arc and the reworkingof primary Messinian evaporite facies (selenite). This study indicates that detritalevaporites and mixed siliciclastic-gypsum arenites are more widespread in the Mediterraneanarea than generally described in the literature.