Shear zones and metamorphic signature of subducted continental crust as tracers of the evolution of the Corsica/Northern Apennine orogenic system

the paper focuses on new data conerning the deformation and metamorphic history of continental margins of the Mesozoic Ligurian Tethys. In the Tenda massif (NE Corsica), a slice of European-Iberan continental margin, contractional shea zones show P/LT metamorphic assemblages and top-to-the-west kinematics. These shear zones are overprinted by greenschist facies exhumation-related structures showing top-to-the-SW sense of transport and then top-to-the-NE extensional shearing. The presence of HP/LT metamorphism, together with the kinematics of syncontractional shear zones, supports the classic view of Cretaceous-Eocene east-wergent "alpine subduction" during the early evolution of the Corsica belt. By tacking into account structural and metamoprhic data on Tuscan continental margin belong to the other side (Adria margin) of the former Mesozoic Ligurian ocean, we ascribe the Corsica/Northern Apennine system to a polyciclic orogen