Paleomagnetism of Jurassic to Miocene sediments from the Apenninic carbonate platform (southern Apennines, Italy): evidence for a 60° counterclockwise Miocene rotation

Abstract

The tectonic evolution of the Apennine belt/southern Tyrrhenian Sea system is addressed through a paleomagnetic study of Lias to Langhian sediments from the Apenninic carbonate platform (southern Apennines, Italy). Reliable paleomagnetic data gathered from 21 sites document a regional-scale post-Langhian 80° counterclockwise (CCW) rotation. Since previous studies of the Plio–Pleistocene clays spread over the orogen had shown a ∼20°CCW rotation, we conclude that the southern Apennines rotated by 60° during Middle–Late Miocene. Our data provide evidence that the southeastward drift of Calabrian block (and synchronous spreading of the southern Tyrrhenian Sea) induced ‘saloon door’ like deformation of the southern Apennines and Sicily, which underwent similar magnitude (although opposite in sign) orogenic rotations. A paleomagnetically derived paleogeographic reconstruction shows that at 15 Ma (Late Langhian) the Alpine–Apennine belt collided with a NNE-oriented carbonate platform corridor surrounded by oceanic basins. We speculate that both the end of the Corsica–Sardinia rotation and the eastward jump of the locus of back-arc extension (from the Liguro-Provençal to the Tyrrhenian Sea) may have been consequences of this event.