New insights on the Adria plate geodynamics from the northern Adriatic perspective

The interpretation of approximately 1300 km of multichannel seismic data, acquired in the northern Adriatic Sea, revealed that the Apennine foredeep in the northern Adriatic does not show any evidence of tilting since Early Pliocene, suggesting that slab retreat cannot be the geodynamic driving force for the northern Adriatic subsidence and for the northern Apennine kinematic since that time. Moreover, the presence of two fault systems that developed since the Pliocene indicates that the northern Adriatic underwent intraplate deformation during the Plio-Pleistocene. These considerations suggest that, since Early Pliocene, subduction below the northern Apennine ceased, and that the Adria Plate movements were mainly driven by the kinematics of the adjacent plates, particularly by the Nubia-Europe convergence. At present, on the basis of the foredeep setting, four distinct sectors can be recognized in the Adriatic foreland: Po Plain, northern, central and southern Adriatic, separated by major tectonic lineaments. The northern Adriatic differs from the two adjoining sectors because its foredeep deposits are still well preserved. In the Po Plain in fact, the Adriatic foredeep is almost totally incorporated into the Alpine and Apennine chains while in the central Adriatic, it is affected by a considerable intraplate deformation (e.g. the Mid Adriatic Ridge). In this framework, the northern Adriatic region may be regarded as a triangular shaped sector indented below the Southern Alps to the north and the northern Dinarides to the north-east and bounded to the west by the Schio-Vicenza fault system and to the south-east by the Kvarner fault.