The Ligurian oceanic successions in southern Italy: The key to decrypting the first orogenic stages of the southern Apennines-Calabria chain system

Abstract

In this paper, we present a review about stratigraphy, petrology, deformation and metamorphism of the oceanic, sedimentary, magmatic and metamorphic successions exposed from northern Calabria to the Campania region (southern Italy), referred to the paleogeographic Southern Ligurian Domain. These successions experienced different tectonic episodes, with those located in the westernmost sector of the Southern Ligurian Domain firstly subducted, reaching high pressure/low temperature metamorphic conditions (Eocene) and subsequently exhumed and exposed (Tortonian). On the contrary, the deep-basin successions located in the easternmost sector (close to the continental Adria margin) were obducted and frontally accreted (Aquitanian-Burdigalian). The tectonic transport for the obducted successions was dominantly to SE (in the present geographic coordinates), whereas new data about tectonic transport directions and vergences of the subducted ophiolites, exposed in northern Calabria, indicate a mean eastward-directed transport during the tectonic exhumation. The petrochemical comparison between the mafic rocks of the Southern Ligurian Domain successions with the corresponding rocks exposed in the Alps, Corsica and northern Apennines, representing the northern sector of the Ligurian Domain, suggests an ocean-continental transition paleotectonic setting for the entire Ligurian Domain. The early orogenic stages of the southern Apennines-northern Calabria system, defined by the subduction of Ligurian lithosphere, were characterised by a complex kinematic evolution of the subduction system, including the migration of the basal and roof decollements upward, downward and toward the foreland within the subduction channel.