A new chronostratigraphic and palaeoenvironmental framework for the end of the Messinian salinity crisis in the Sorbas Basin (Betic Cordillera, southern Spain)

Abstract

New palaeontologic, sedimentologic, and Sr isotope data allow to reconstruct a high‐resolution chronostratigraphic and palaeoenvironmental framework of the continental‐marine transition at the Miocene–Pliocene boundary in the Sorbas Basin (Betic Cordillera, South‐eastern Spain). The presence of Reticulofenestra zancleana , Ceratolithus acutus , and R . pseudoumbilicus in a marine horizon sharply overlying the continental deposits of the Zorreras Member indicates that the Messinian salinity crisis ended in the Sorbas Basin synchronously with the other Mediterranean basins at the base of the Zanclean, within the MNN12a biozone. Our results suggest that the Zanclean flooding turned the Sorbas Basin into a shallow bay with limited exchange with the main Mediterranean basin, probably through narrow seaways connecting also the Almeria, Nijar, and Vera basins. Our results do not confirm previous hypotheses envisaging an older age for the return to fully marine conditions in the Sorbas Basin and is in a good agreement with the reconstructions suggesting that the Zorreras Mb. continental deposits are the local time‐equivalent of the latest Messinian Lago‐Mare phase during the last stage of the salinity crisis.