Mollusc assemblages of the Pontian and Dacian deposits from the Topolog-Arge? area (southern Carpathian foredeep - Romania)

A better understanding of Mediterranean-Paratethys water-exchange during the Messinian Salinity Crisis has since long been hampered by the absence of a reliable time frame for the Paratethys. High-resolution magnetostratigraphic studies on the sedimentary sequences of the eastern and southern Carpathian foredeep recently resulted in an accurate chronology for the Mio-Pliocene deposits of the Dacic Basin of Romania. This allowed a straightforward correlation of the Pontian and Dacian stages to the geological time scale, which revived earlier discussions on Mediterranean-Paratethys connectivity. Here, we present Pontian and Dacian mollusc assemblages of the Getic Depression (Topolog-Arge? area, southern Carpathians) of Romania, which are incorporated in a magnetostratigraphic time frame. They indicate that a hiatus - comprising the Early Pontian - is present in the stratigraphic successions, which could be related to a base level drop of the Paratethys water column or to more local tectonic processes. The mollusc assemblages furthermore show a gradual transition at the Pontian/Dacian boundary, which is magnetostratigraphically dated at ∼4.9 Ma. This is significantly later (by more than 400 kyrs) than the Mio-Pliocene boundary in the Mediterranean sequences.