Generation and Disruption of Subducted Lithosphere in the Central-Western Mediterranean Region and Time-Space Distribution of Magmatic Activity Since the Late Miocene

Abstract

The long migration of the Balearic Arc (Alpine-Apennine and Alpine-Maghrebian belts) in the Early-Middle Miocene caused the formation of a subducted lithospheric edifice in the western and central Mediterranean regions. Then, since the Late Miocene, this slab was almost completely disrupted, only maintaining a narrow and deformed remnant beneath the southernmost Tyrrhenian basin. This work describes a tentative reconstruction of the tectonic processes that caused the formation of major tears and breakoffs in the original slabs and the consequent disruption of the subducted lithosphere. In particular, it is suggested that this relatively fast process was produced by the collision between the Anatolian-Aegean system and the continental Adriatic domain, which triggered a number of extrusion processes. Possible connections between the proposed tectonic evolution and the spatio-temporal distribution and geochemical signatures of magmatic activity are then discussed. It is supposed that such activity has been mainly conditioned by the occurrence of transtensional tectonics in the wake of escaping orogenic wedges.