Mesozoic tectonics and volcanism of Tethyan rifted continental margins in western Sicily

The paleotectonic and volcanic features of the Jurassic–Cretaceous carbonate successions, outcropping in central-western Sicily, allow us to restore the tectono-sedimentary evolution of a sector of the African continental margin. These successions consist of shallow-to-deep-water Mesozoic deposits that have formed in the carbonate platform-to- pelagic plateau depositional setting of the so-called Trapanese paleogeographic domain. Fieldwork, including structural analyses, has indicated the occurrence of lateral facies changes, resedimented materials, volcanic products (pillow lavas and tuffitic deposits), unconformity surfaces and paleofaults of different trends and age. These data, combined with facies and a physical–stratigraphic analysis, allow one to distinguish between the different tectono-stratigraphic settings. A structural low, filled with thick pillow lavas and reworked deposits, appears bordered by two main structural highs: an articulate carbonate-pelagic platform with a stepped fault margin, and the flank of a structural high, where the volcanoclastic deposits are interlayered with reworked reef materials, suggest the occurrence of a submarine volcano, that evolved into an atoll-type carbonate shelf setting. Tectonic and magmatic events punctuated the sedimentary evolution during the Early Jurassic, Middle–Late Jurassic, Early and Late Cretaceous. The horst and graben structures connected by steeped margins and the occurrence of distinctive types of volcanic products suggest that the study areas could represent a sector of the Jurassic–Cretaceous southern Tethyan passive continental margin, situated at the edge of the continental platform bordering those basinal areas where rifting and possible spreading processes were active during the Mesozoic.