LATE CENOZOIC KINEMATICS OF THE CALABRIAN ARC, SOUTHERN ITALY

Based on structural analysis, seismicity, and paleomagnetic data a model is presented for the late Cenozoic kinematics of the southern Italian mountain belt. The model predicts that late Cenozoic deformation of the internal part of the belt involved extension and lateral bending of the mantle and lower crust and that in the upper crust faulting was accompanied by semirigid block rotation. In the external part of the belt thrusting dominated. In the north where the arc joins up with the southern Apennines regional shear was dominantly left lateral and distributed between left-slip along WNW trending cross faults, a component of right-slip on north to NNE trending extensional faults, and counterclockwise rotation of upper crustal blocks, including the basin fill and north to NNE trending basin margin faults. In the southern part of the arc, overall right lateral shear was accommodated by right-slip on WNW trending cross faults, a component of left-slip on NE trending extensional faults, and clockwise rotation of upper crustal blocks, basins, and NE trending faults. These styles of deformation were probably confined to the upper plate of the Tyrrhenian subduction system. They are considered to have been active from the beginning of extension in the Tyrrhenian Basin (circa 11 Ma) and are still active today (based on recent seismicity).