Synsedimentary-tectonic, soft-sediment deformation and volcanism in the rifted Tethyan margin from the Upper Triassic–Middle Jurassic deep-water carbonates in Central Sicily

Abstract

The Pizzo Lupo section (Sicanian Mts, central Sicily) is an Upper Triassic–Lower Jurassic condensed deep-water succession, where the relationships among synsedimentary tectonic, soft-sediment deformations, volcanism and lithological changes reflect the evolution of a rift-basin. The morphostructural setting of the studied basin appears as a gently dipping slopewhere a fault-delimited area (graben to halfgraben) was developed. The instability of the sea floor, related to the seismic shocks, was the cause of the gravity-driven deformational sedimentary structures (slumping, breccia channelized bodies). The partly stratified basaltic rocks,with disorganized and chaotic stratification, suggest the occurrence of a volcanic complex located in neighbouring areas. A regional comparison with the tectono-sedimentary evolution of the pelagic drowning platform succession (i.e. Trapanese domain Auct.), outcropping in adjacent areas, suggests that these different domains were close to each other during the studied period forming a stepped margin platform-to-basin system. The environmental changes, synsedimentary tectonic activity and gravity-driven phenomena were the result of repeated events occurred during a long time interval, spanning from Late Triassic to Early Jurassic.