ORIGIN AND EVOLUTION OF THE MESSINIAN BASINS DEVELOPED ON TOP OF THE SICILIAN FOLD AND THRUST BELT

During the Messinian the inherited paleo-topography conditioned the depositional environments of the Mediterranean region, already strongly influenced by the effects of the salinity crisis, mainly in the central region, where seabed at that time is expected to be very uneven and shallower than Western and Eastern Mediterranean. Indeed in this area as from 15 Ma the Sicilian Fold and Thrust Belt (SFTB) was originating, characterized by a multi-stage evolution: two main shortening events generated and developed at different structural levels (shallow- and deep-seated thrusts in thin-skinned thrust-model) and at different time intervals, involving mainly the Meso-Cenozoic carbonate units of the ancient African passive continental margin, followed by a more recent thick-skinned thrusting that involved the Plio-Pleistiocene deposits in the frontal area, as well as the crystalline basement in the internal sector of the chain. Just in the Messinian time interval along the internal sectors of this edifice the transition from shallow to deep seated tectonics was recorded. On top of the SFTB different types of basins originated progressively in response to the shortening wave. Depending on their position and related active processes during the Messinian we can distinguish: intramountain (mainly posttectonic), thrust-top (syn-tectonic), and foreland (pre-tectonic) Messinian basins, with different characters and geometries. Our results are only preliminary and could represent a first approach towards a better understand of the present complex distribution of the different variety of the Messinian sequences. The next step of this study should be the palinspastic restoration of the strongly deformed Messinian successions, in order to reconstruct a more detailed Mediterranean paleogeography