The effects of a meso-Alpine collision event on the tectono-metamorphic evolution of the peloritani mountain belt (Eastern sicily, southern Italy)

Abstract

The Pcloritani Mountains, in the southern part of the Calabrian Terranes, southern Italy, have been classically interpreted as the product of the Palcogcnc brittle deformation of the European continental back-stop of the Ncotethyan subduction complex. This reconstruction conflicts with the occurrence of an Alpine metamorphic overprint that aficctcd portions of both the Variscan meta- morphic units and part of the Mesozoic sedimentary covers of the mountain belt. New field data, integrated with pettugiuphic, mlciu-And niesu-siiui'tuial analyses and siiaiigraphic investigation of the syn-Tectonic terrigenous covers, well constrain a Paleogene collision event along the Africa-Nubia convergent margin that caused the exhumation of the Alpine metamorphic units of the Peloritani Mountains. The syn-collisional exhumation was associated with shearing along two major Africa- verging crustal thrusts arising from the positive tectonic inversion of the former European palaeomar- gin. Early tectonic motions occurred within the mountain belts and produced the exhumation of the external portions of the edifice. Later tectonic motions occurred along the sole-Thrust of the entire edifice and caused the definitive exhumation of the entire mountain belt. The whole crustal thrusting lasted for a period of c. 10 Ma, during the entire Oligocene. The definitive southwestward emplacement of the Peloritani Mountain Belt onto the Neotethyan accretionary wedge was followed by two Late Oligocene - Early Miocene NW-SE-oriented right lateral shear zones, replacing the previous crustal thrust. These two strike-slip belts are interpreted as the surface expression of the deep-seated suture zone between the colliding Africa and Europe continental crusts.