The Vallo di Diano and Auletta extensional basins in the southern Apennines (Italy): a simple model for a complex setting

The aim of this paper was to provide a significant case-history concerning the evolution of a segmented system of extensional faults and related basins, investigated by a set of seismic reflection profiles. We investigated two kinematically linked semi-grabens, developed at the hangingwall of two opposite-dipping normal faults: the Vallo di Diano and Auletta basins, located in the southern Apennines, one of the most seismically active regions of the Italian peninsula. Our interpretation suggests that the Pliocene-Quaternary tectonic history consists of a single extensional phase, where the major NW-SE trending normal faults, generating the basins, and the strike-slip and transtensional faults connecting adjacent normal fault segments, simultaneously act, being part of the same extensional system. We also conclude that major normal faults, bordering the basins, should be considered as potential seismogenic sources in the seismic hazard evaluation.