Un tentativo di analisi integrata della tettonica e sismicità nella zona di cerniera tra Sicilia settentrionale e Basso Tirreno.

Abstract

The Sicilian Magrebides thrust belt geometry, related to a sequence of different tectonic steps (compressional, extensional, transcurrent), from the Late Oligocene, seems to occur through several deformations: the first is characterized by fold associations, clivage and foliation, thrust and compressional fault, which shortened the belt in flat-ramp, duplex, enveloping and breaching geometries. The second tectonic step is related to the activation of low-angle extensional faults, connected to the south Tyrrhenian margin evolution, allowing the northward stretching of the belt and re-orientations and inversions of previous structures. A successive shear tectonics consists in strike-, net- or dip-slip fault systems, which allowed the increasing of the Calabrian Arc bending and identification of an hinge-zone between northern Sicily and southern Tyrrhenian. Several of the Plio-Pleistocene brittle structures are still active and sometimes responsible of the shallow seismicity in northern Sicily and its Tyrrhenian off-shore. A preliminary seismotectonic model for the northern Sicilian Maghrebides has been elaborated by an integrated analysis of both structural and seismic data, which also has identified the main unresolved problems.