The Vallo di Diano Fault System: New Evidence for an Active Range-Bounding Fault in Southern Italy Using Shallow, High-Resolution Seismic Profiling

摘要: Range-bounding normal faults can presentsignificant challenges for seis- mic exploration. This is the case of fault system bounding Vallo di Diano, largest intermountain basin in southern Apennines seismic belt. Industry reflection profiles define large-scale structure but barely image shallow due to unfavorable topographic and near-surface conditions along foothills eastern range. We present two high-resolution (HR) wide-aperture recorded attheeastern marginof thebasin acrossunreported scarpsthat affect Middle- Late Pleistocene alluvial fans slope debris. The survey aimed at identifying possible recent faulting across these challenging terrains understanding re- lationship between structures master range-bounding depth. Common depth point processing data first-arrival tra- vel-time tomography provide detailed images upper 200-300 m sounding evidence activity previously unknown splays system. These dissect Mesozoic limestone bedrock alluvial-fan sequences, affecting theirdepositionalpattern.VeryhighresolutionVPandreflectivityimagesalsogivehints ofpossiblecoseismicsurfacefaultinginHolocenecolluvia.Theseresultshaverelevant implicationsfortheevaluationoftheseismogenicpotentialoftherange-boundingfault systemandforseismichazardassessmentofthedenselyurbanizedVallodiDianobasin. Online Material: Table acquisition parameters, figures showing schematic stratigraphy Diano basin, restoration dis- placement HR profile, resolution P-velocity tomographic VHR profile.