PALEOMAGNETIC EVIDENCE FOR A PLEISTOCENE CLOCKWISE ROTATION OF THE CALABRO-PELORITAN BLOCK (SOUTHERN ITALY)

A paleomagnetic study of marine marls of (Early) Pliocene age and clays of Late Pliocene to middle Pleistocene age from sites along the Ionian coast (Spartivento basin and Catanzaro depression of Calabria) and from sites along the Tyrrhenian coast of both Calabria and Sicily was carried out to determine the amount and timing of tectonic rotation of the underlying Calabro-Peloritan block. The magnetisations of the Lower Pliocene Trubi marls have maximum blocking temperatures indicating the presence of magnetite. These Lower Pliocene sediments as well as the younger Upper Pliocene-Lower Pleistocene clays of this area reveal consistent clockwise rotations of 10-20-degrees. There is evidence for a uniform 15-degrees clockwise rotation of the entire Calabro-Peloritan block during the middle Pleistocene. This is opposite in sense of rotation to the earlier established 23-degrees counterclockwise rotations for the Southern Apennines, but the timing is the same: between 0.7 and 0.2 Ma. The tectonic rotations occur 1 Myr after the major phases of extension in the southeastern part of the Tyrrhenian basin, but simultaneously with the onset of major uplift of the block.