STRUCTURAL TRENDS AND PALEOGEOGRAPHY OF THE CENTRAL AND WESTERN SICILY BELT - NEW INSIGHTS

The geology of the Sicilian mainland is summarized by N-S geological s ections. A continuous late Cenozoic orogenic belt through central and western Sicily resulted from a complex deformative history, recorded b y several tectonic events. The deformation mainly involved the sedimen tary cover of the old African continental margin, formed in a large ba sinal area, bordered at its southern margin by a shallow-water carbona te environment attached to Gondwana. The orogenic belt involves a comp lex architecture of thrust systems, of different size, geometry and pa laeogeographical origin. Deformation, which mainly developed in the ea rlier stages of thrusting in the basinal rock assemblages, mainly gave rise to a stack of three different duplex structures, respectively, c omposed of Palaeozoic, Mesozoic-Palaeogene and Neogene strata. Large-s cale clockwise rotation of the thrusts predated transpressional moveme nts in the hinterland during the latest Miocene to Pliocene. High-angl e reverse faults, with lateral components, modified earlier tectonic c ontacts within the allochthons. Contemporaneous southwards-directed im brications affected the external southern areas, progressively incorpo rating foreland and piggyback basins. The stratigraphic relationships of basin-fills to the tectonic structures reveals that reactivation pr ocesses have been active during the last Plio-Pleistocene.