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The Gulf of Patti and its onshore sector represent one of the most seismically\ud active regions of the Italian Peninsula. Over the period 1984–2014, about 1800 earthquakes\ud with small-to-moderate magnitude and a maximum hypocentral depth of 40 km occurred\ud in this area. Historical catalogues reveal that the same area was affected by several strong\ud earthquakes such as the Mw = 6.1 event in April 1978 and the Mw = 6.2 one in March\ud 1786 which have caused severe damages in the surrounding localities. The main seismotectonic\ud feature affecting this area is represented by a NNW–SSE trending right-lateral\ud strike-slip fault system called ‘‘Aeolian–Tindari–Letojanni’’ (ATLFS) which has been\ud interpreted as a lithospheric transfer zone extending from the Aeolian Islands to the Ionian\ud coast of Sicily. Although the large-scale role of the ATLFS is widely accepted, several\ud issues about its structural architecture (i.e. distribution, attitude and slip of fault segments)\ud and the active deformation pattern are poorly constrained, particularly in the offshore. An\ud integrated analysis of field structural geology with marine geophysical and seismological\ud data has allowed to better understand the structural fabric of the ATLFS which, in the study\ud area, is expressed by two major NW–SE trending, en-echelon arranged fault segments.\ud Minor NNE–SSW oriented extensional structures mainly occur in the overlap region\ud between major faults, forming a dilatational stepover. Most faults display evidence of\ud active deformation and appear to control the main morphobathymetric features. This aspect, together with diffused continental slope instability, must be considered for the\ud revaluation of the seismic and geomorphological hazard of this sector of southern\ud Tyrrhenian Sea

a b s t r a c tIntegrated geological, geodetic and marine geophysical data provide evidence of active deformation in south-western Sicily, in an area spatially coincident with the macroseismic zone of the destructive 1968 Belice earthquake sequence. Even though the sequence represents the strongest seismic event recorded in Western Sicily in historical times, focal solutions provided by different authors are inconclusive on possible faulting mechanism, which ranges from thrusting to transpression, and the seismogenic source is still undefined. Interferometric (DInSAR) observations reveal a differential ground motion on a SW-NE alignment between Campobello di Mazara and Castelvetrano (CCA), located just west of the maximum macroseismic sector. In addition, new GPS campaign-mode data acquired across the CCA alignment documents NW-SE contractional strain accumulation. Morphostructural analysis allowed to associate the alignment detected through geodetic measurements with a topographic offset of Pleistocene marine sediments. The on-land data were complemented by new high-resolution marine geophysical surveys, which indicate recent contraction on the offshore extension of the CCA alignment. The discovery of archaeological remains displaced by a thrust fault associated with the alignment provided the first likely surface evidence of coseismic and/or aseismic deformation related to a seismogenic source in the area. Results of the integrated study supports the contention that oblique thrusting and folding in response to NW-SE oriented contraction is still active. Although we are not able to associate the CCA alignment to the 1968 seismic sequence or to the historical earthquakes that destroyed the ancient Greek city of Selinunte, located on the nearby coastline, our result must be incorporated in the seismic hazard evaluation of this densely populated area of Sicily.