Paleomagnetism of the Hyblean Plateau, Sicily: A review of the existing data set and new evidence from the Scicli-Ragusa Fault System

Several paleomagnetic data from the Hyblean Plateau of SE Sicily pointed out that the plateau did not undergo any significant rotation with respect to Africa (Schult, 1973; Barberi et al., 1974; Gregor et al., 1975; Grasso et al., 1983). However, Besse et al. (1984) suggested a counterclockwise rotation of about 15° of the Hyblean Plateau with respect to Africa acquired during the Pliocene-Pleistocene rifting of the Pelagian Block in the Strait of Sicily. Additionally, the Hyblean Plateau is dissected by an important tectonically active dextral strike-slip zone, the Scicli-Ragusa Fault System (SRFS), but the possibility that strike-slip tectonics yielded block rotations was never taken into account. We re-evaluated the existing paleomagnetic data set from the Hyblean Plateau using updated paleo-poles from Africa (Torsvik et al., 2008) and, to explore block rotation pattern along the SRFS, we paleomagnetically sampled 13 sites (133 samples). Measurements were carried out in the shielded room of the paleomagnetic laboratory of the INGV (Roma), using a 2G Enterprises DC-superconducting quantum interference device cryogenic magnetometer. The entire data set confirmed that the Hyblean Plateau did not rotate with respect to Africa and that no significant rotation was induced by the rifting in the Strait of Sicily. The data from the northern sector of the SRFS, showed that blocks within 10 km from the fault are not significantly rotated. Therefore, the SRFS did not induce significant rotations around vertical-axis, and the horizontal displacement along this tectonic feature has to be considered less than 3 Km.