Evidence of Upper Pleistocene-Holocene tectonic activity along the Longhere-Fadalto-Cadola line (eastern Southern Alps, NE Italy)

We made paleoseismological investigations on the eastern part of the Bassano-Valdobbiadene Thrust Auct., i.e. the left lateral Longhere-Fadalto-Cadola transpressive fault. The study area lies at the Pliocene-Quaternary front of the eastern Southern Alps, a S-SE verging active thrust-and-fold belt characterized by moderate to high seismic hazard and risk, where some historical earthquakes registered Mw ≥ 6. The Bassano-Valdobbiadene Thrust Auct. extends with NE-SW trending at the base of the Venetian Prealps, where the Jurassic-Cretaceous carbonate succession overthrusts the Palaeozoic Turbidites and Miocene Molasse. In the framework of the National Seismic Microzonation Project, we carried out a paleoseismological study following preliminary morphotectonic and geophysical investigations, to assess the recent activity and capability of Longhere-Fadalto-Cadola transpressive fault. The paleoseismological trenches, dug on upper Pleistocene-Holocene sediments, reveal clear evidences of recent tectonic activity, possibly related to the 1873 Alpago earthquake (Imax X MCS, Mw 6.3).