From Alpine syn-orogenic deformation to late-orogenic clockwise rotations in the Calabria-Peloritani Arc (NE Sicily, southern Italy)

The Peloritani Mountains belong to the Calabria-Peloritani Arc. This sector of the Alpine Chain is characterized by a thrust pile made up of Variscan and/ or Mesozoic-Cenozoic successions, capped in angular unconformity by post-orogenic Miocene onwards covers. These thrust units are denoted, from top to bottom: Aspromonte, Mela, Mandanici-Piraino, Alì-Montagnareale, Fondachelli and LongiTaormina Units. Alpine deformation started in the latest Oligocene-earliest Aquitanian time-span with the onset of metamorphism. Alpine metamorphism was characterized by two metamorphic events. The first metamorphic event occurred in a contractional deformation phase, whereas the second one presumably took place during syn-orogenic extension. Alpine metamorphism affected exclusively the Aspromonte, Mandanici-Piraino and Alì.Montagnareale Units. The stacking of the Peloritani units was post-metamorphic and occurred after the earliest Aquitanian as indicated by the age of the syn-orogenic deposits involved in the thrust pile. The collision between the Peloritani Mountains thrust stack (Internal units deriving from the Mesomediterranean microplate) and the Maghrebian units (External units deriving from the Africa plate) started in the late Burdigalian. During the late Langhian-early Serravallian, out-of-sequence thrusts affected the northern region of the Peloritani Mountains, whereas significant rotations, responsible for peculiar “Z-shaped” patterns in plan view and due to an E-W trending transpression, affected during the early Serravallian the thrusts of the southern edge of the Peloritani Mountains. Two geological itineraries are proposed to present geological structures developed during different stages of the Alpine metamorphism and tectonics of the Peloritani Mountains. Itineraries are located in the Messina area extending along the Sicilian Ionian side from Alì to Taormina, as key sites for understanding the complex tectonics of this sector of the Alpine chain.