Tectonic Structure of the Latian-Campanian Shelf (Tyrrhenian Sea)

Four seismo-stratigraphic units separated by regional unconformities have been recognized on multichannel seismic reflection sestions of the Latian-Campanian shelf, calibrated with well data. The two upper units belong to the neoautochthonous Upper-Neogene-Quaternary cycle (Upper Miocene - Lower Pliocene, Plio-Quaternary), the intermediate unit belongs to the Tertiary allochthonous successions and their associated flysch units, the deepest unit to the Meso-Cenozoic carbonates. During the Miocene tectogenesis the carbonates and the allochthon underwent conspicuous tangential movements which generated typical compressive structures (reverse faults, overthrusts and thrust-sheets), mainly N - and Ne - verging, sometimes coupled with coeval low angle normal faults. The origin of the structures, described in the text, seems due to differential tangential tectonics cause by gravitational gliding, which affected the Meso-Cenozoic carbonate plates and the overlying Tertiary allochthonous successions. This kind of movement is insufficient in explaining the involvement of the crystalline-metamorphic basement, for it could represent a late stage of the tectogenesis due to the uplift of a wide Tyrrhenian area identifiable in the present-day slope