Paleomagnetism of the Peloritan Terrane (NE Sicily): From Greater Iberia to the Neo Apennine-Maghrebide Arc

Abstract

Calabria and the Peloritan Mts. of NE Sicily are exotic terranes predominantly formed by Hercynian rocks interrupting the Meso-Cenozoic sediments exposed along Apennine-Maghrebide chains. Dual-polarity pre-tilting magnetization direction retrieved from 5 Jurassic, 5 upper Cretaceous-Eocene, and 4 upper Oligocene sedimentary sites from external-intermediate Peloritan nappes yield 99° ± 12°, 131° ± 15°, and 138° ± 12° (respectively) clockwise (CW) rotations with respect to Europe. Upper Cretaceous-Oligocene values are similar to the ∼130° CW late Miocene-Early Pleistocene rotation previously documented on internal Maghrebian nappes of W Sicily. Jurassic data imply a ∼30° Early Cretaceous counterclockwise (CCW) rotation, similar for sign, magnitude, and timing to Iberia rotation, proving that the Peloritan crust was part of Greater Iberia before its <30 Ma fragmentation and dispersal. Furthermore, 20 Jurassic-Oligocene sites yield post-tilting overprint direction (later rotated up to 60° CW) that was acquired synchronous to late Miocene-Pleistocene rotation. The Peloritan rotation is completely different from the 160° post-late Jurassic CCW rotation documented on NE Calabria, and demonstrates that the two terranes underwent independent drift histories. Lack of a Sardinian rotation fingerprint (90° CCW between 30 and 15 Ma) suggests that the Peloritan terrane lied S of the Calabria-Sardinia CCW rotating system, at the non-rotational apex of an Oligocene-early Miocene “Paleo Apennine-Maghrebide Arc.” The Peloritan terrane was stacked onto the African margin and incorporated in the Maghrebian chain in mid Burdigalian (18–17 Ma). Afterward, it formed the S limb of the “Neo Apennine-Maghrebide Arc,” and was passively carried on top of CW rotating Maghrebide nappes during late Miocene-Early Pleistocene (12–1 Ma).