The south-western side of the Calabrian Arc (Peloritani Mountains): geological, structural and AMS evidence for passive clockwise rotations.

Geological and structural investigations have been integrated with the results of a study of anisotropy of magnetic susceptibility (AMS) carried out along the south-western side of the Calabrian Arc (NE Sicily; Lat.: 37°50’–38°00’N; Long. 14°57’–15°19’E). The results of this research suggest the occurrence of middle–upper Miocene passive clockwise rotations about a vertical axis. These rotations, superposed on pre-existing (Aquitanian) thrust and fold structures of the Calabrian Arc, have been identified by mapping of rotated (in plan view) regional traces of thrusts, beds, stretching lineations, fold axes and magnetic lineations evidenced by the AMS technique. The driving mechanism responsible for the origin of the recorded rotations could be sought in the geodynamic processes associated with WNW-dipping subduction and development of the Tyrrhenian Basin–Calabrian Arc–Apennines back-arc Basin–accretionary wedge system. According to previous models provided for this area, the southern margin of the mentioned arc-shaped system would be affected by clockwise rotations and by dextral transpression. Our results are consistent with the latter models, suggesting that middle–upper Miocene kilometre-scale clockwise rotations and folding occurred in northern Sicily as a result of dextral transpression along an E–W trend south of parallel 38°N.