Positive tectonic inversion of the Western Sicily margin: Geodynamic implications for the central sector of the Africa-Eurasia plate boundary

The offshore western Sicily region is located at the active Africa-Eurasia plate boundary, between the southern Tyrrhenian backarc basin and the Africa continental margin, were tectonics processes makes this sector prone to strong earthquakes and tsunamis. In the area have been documented positive inversion structures due to a contractional reactivation of pre-existing normal faults. However, a detailed geological study of the inversion features addressing the structural inheritance, timing, regional tectonic framework and the geodynamic significance is still absent. The interpretation of a multichannel seismic grid, calibrated by dredges, deep well logs and onshore geology, using dedicated GIS software, reveals a great variability of the inversion tectonics features in terms of degree of deformation, tectonic style, sedimentary thickness and orientation. To address the significate, the origin and the role of the inversion tectonics in the active tectonic frame, have been investigated the structural frame of the area. Indeed, the development of the Quaternary inversion structures occurred within a complex structural pattern of faults characterised by E-W strike-slip faults, folds arranged in an en-échelon pattern, negative flower structures. All the recognized structures are compatible with a dextral wrench zone that developed along the plate boundary offshore western Sicily. In this frame, the pre-existing normal faults represent important crustal discontinuity for the development of the new generated structures, furthermore the inversion structures developed in agreement to the new structural frame growing in correspondence of the tectonic discontinuity. This tectonic frame furnishes new geologic constraints for the Recent geodynamic evolution of a key area of the Central Mediterranean. We attempted to reconstruct the link between the complex tectonic evolution of the upper crust and the development of the subducting slab to unravel the possible triggering factors responsible for these crustal deformations