New Insights on the Role of the Strike-Slip Tectonics in the Late Miocene-Quaternary Evolution of Sicily

Understanding the influence of the Late Miocene-Quaternary opening of the Tyrrhenian Basin on the evolution of the external sectors of the Africa paleo-margin in Sicily, actually, represents a hard challenge, even though several, and contrasting, models have been proposed in the last decades. One open problem refers to localizing the main regional scale tectonic lineaments of Sicily that accommodated the hundreds of kilometers of lateral displacement, due to the Tyrrhenian Basin opening. In the present work, we present the results rising from a detailed field mapping carried out in relevant vast areas of central Sicily. These data enabled to reconstruct a Neogene-Quarternary kinematic evolutionary model of the collision belt of Sicily. We analyzed the northern tectonic margin of the Caltanissetta Through, which represents a structural depression hosting a thick allochthonous tectonic wedge, on which lay different unconformable thrust-top basin deposits. In more details, our study aims to reconstruct the tectono-sedimentary Late Tortonian-to-Quaternary evolution of this tectonic wedge, revealing that regional E-W-trending dextral shear zones deform and cut the NE-oriented, SE-verging, thrust-and-fold belt. The strike-slip tectonics thus controlled the deposition of different sedimentary cycles on the thrust-top basins and governed the tectonic inversion of the external sectors of the Africa paleo-margin.