GNGTS 2015 - Atti del 34° Convegno Nazionale

GNGTS 2015 S essione 1.1 27 part of the Mesozoic Malta Escarpment and borders a series of eye-shaped half-grabens, which are infilled by up to 800 m thick syn-tectonic deposits, suggesting the long lived activity (~ 330 kyr; Bianca et al., 1999) of the fault. The southernmost extensional features of the region are located along the southeastern margin of the Hyblean Plateau (Avola and Rosolini-Ispica faults, f in Fig. 1). These faults replaced an Early Pleistocene contractional belt (Catalano et al. , 2007) and accommodated the huge Late Quaternary tectonic uplift of the Hyblean Plateau (Catalano et al. , 2010). South-eastern Sicily . In south-eastern Sicily, the Western Fault and the Avola-Rosolini- Ispica faults border the eastern portion of the Hyblean Plateau (Siracusa Domain; SD in Fig. 2) that represents an uplifted mobile crustal block of theAfrican Foreland. The tectonic boundaries of the Siracusa Domain consist of inverted tectonics that drove the Late Quaternary (< 850 kyr) motion of the crustal block. The western boundary of the Siracusa Domain is represented by a left-lateral shear zone, inherited from a previous dextral fault (Scicli Line; Ghisetti and Vezzani, 1982). The north-western margin of the mobile block consists of a NNW-verging thrust and fold belt that extends to the north, as far as the southern margin of Mt. Etna. These contractional features derived from the positive tectonic inversion of NE-oriented extensional basins (Simeto Graben and Scordia-Lentini Graben; Fig. 2), that originated in the 1.5-0.9 Ma time interval (Pedley et al. , 2001), at the peak of the impressive emission of tholeiitic to alkaline volcanic products in the region. Fig. 1 – Age and distribution of active extensional fault in southern Calabria and eastern Sicily.