Mesozoic and Paleogene megabreccias in Southern Sicily: New data on the Triassic Paleomargin of the Siculo-Tunisian platform

Abstract

Mesozoic and Paleogene clastic carbonates in deep-water successions outcropping in the Sicani mountains (central southern Sicily) represent debris-flow and turbidite deposits accumulated in slope/base-of-slope sectors of the Sicanian Basin, a Permian to Miocene deep-water sedimentary domain of Sicily. Reef-derived carbonates of late Triassic age are frequently found among the clastic elements of these deposits, in association with other shallow and deep-water Mesozoic carbonates. The provide us with new data on the stratigraphic setting of a platform paleomargin now buried beneath the Sicilian thrust and fold belt. This paleomargin bounded the wide middle and upper Triassic carbonate platform which is now known in the subsurface of the Southern Sicilian thrust and fold belt. This paleomargin bounded the wide middle and upper Triassic carbonate platform which is now known in the subsurface of the Southern Sicilian mainland and offshore in the Pelagian Platform, from the Malta escarpment to the Sciacca and Trapani areas through the Hyblean Plateau. The hinge zones between this platform domain and the Sicanian basin were particularly affected by the paleostresses related to the Mesozoic and Paleogene evolution of the Southwestern Tethys. The sedimentary successions of these areas recorded repeated episodes of progradation, aggradation, backstepping, uplift and erosion of the platform-basin system, under eustatic and tectonic forcing.