TECTONIC HISTORY OF THE SUBMERGED MAGHREBIAN CHAIN FROM THE SOUTHERN TYRRHENIAN SEA TO THE PELAGIAN FORELAND

A description is given here of the structure and tectonic evolution of the submerged NW-SE trending Alpine belt extending from the Sardinia Channel across the Sicily Straits to the Pelagian Sea. This mainly res ults from re-interpretation of the existing seismic network. In the Si cily Straits the crust comprises an allocthonous belt composed of Tert iary flysch-type thrust slices stacked in an imbricate wedge. The wedg e is composed of Mesozoic basin and platform carbonates thrusts derive d by deformation of the old Sicilian continental margin. Lower Miocene to Lower Pleistocene foredeep deposits (terrigenous and elastic carbo nates) filled progressively onlapping foreland basins during regional compression. In the southern Sicily offshore the deformation spanned e arly Miocene to early Pleistocene time. The structural evolution of th e Gela foredeep shows the kinematics and timing of emplacement of the 'Gela Thrust System', that is believed to be the present-day thrust fr ont of the Sicilian accretionary wedge. In the Sicily Channel, the Pli o-Pleistocene tectono-sedimentary history of the Lampedusa-Linosa sect or reveals evidence of middle Pliocene extensional tectonics, and indi cates a rift mechanism for formation of the Sicily Channel. This event was followed by inversion tectonics and strong vertical tectonics in the late Pleistocene.