GEODYNAMIC AND SEISMOLOGICAL MODELLING OF THE CENTRAL-WESTERN MEDITERRANEAN MID-LATE CENOZOIC DYNAMICS AND STRUCTURE.

The Central-Western Mediterranean is one of the most complex tectonic settings on Earth. The articulate lithospheric structure currently observed in the region is the result of manifold tectonic processes that have occurred since the Mid-Late Cenozoic. Despite its shallow tectonic evolution has been relatively well constrained by a wealth of geological and geophysical data, several uncertainties persist about the recent mantle dynamics and the mechanisms that led to the present-day surface morphology and deep slab geometry. This Thesis attempt to reproduce the recent large-scale evolution of the Central-Western Mediterranean and the associated strain-induced upper mantle fabrics and seismic anisotropy adopting a strategy that combines geodynamic and seismological numerical modelling techniques. We explore a wide range of models and evaluate the modelling results by comparing seismological synthetics and the predicted tectonic evolution with geophysical and geological observations. The good correlation between modelled and observed slab morphology and seismic anisotropy patterns poses new important constraints on the tectonic evolution of the study area, explaining the major tectonic events proposed in the literature (e.g., the rotation of the Sardinian-Corsican block and the opening of back-arc basins related to the retreat of the Ionian trench, the lateral tearing and breakoff of oceanic slabs, etc..) that have contributed to shaping the Central-Western Mediterranean. The research activities demonstrate that this methodology can capture to a first order the overall evolution and the current geological scenario of the study region, thus representing a powerful tool to investigate mantle dynamics. Furthermore, geodynamic models were exploited to test the capabilities and limitations of P- and S-waves anisotropic inversions, showing that inverting for seismic anisotropy allows to avoid notable imaging artefacts and, consequently, errors in the interpretation of the tomographic results.