Syn-orogenic extension in the Peloritani Alpine Thrust Belt (NE Sicily, Italy): Evidence from the Alى Unit

Structural and petrological analyses on the Alى Unit, in the Peloritani Thrust Belt, document the first evidence for Alpine exhumation associated with syn-orogenic extension in this part of the Calabria-Peloritani Arc. The Alى Unit displays ductile structures occurred during three Alpine deformation phases (Da1, Da2, Da3). Da1 and Da3 developed in a contractional context, whereas Da2 was generated in an extensional regime. The present-day tectonic contact between the Alى Unit and the overlying Mandanici Unit is interpreted as a low-angle extensional detachment responsible for the metamorphic break between the two units. Structural overprinting relationships indicate that the development of Da2 structures and related tectonic exhumation occurred during syn-convergence extension, and were followed by further nappe stacking in the Peloritani Belt. To cite this article: R. Somma et al., C. R. Geoscience 337 (2005).