Tettonica quaternaria nell'area settentrionale iblea (Sicilia sud-orientale)

Abstract

: In the northern Hyblean area (south-eastern Sicily), the most recent tectonic events are associated with faults, folds and thrust faults belonging to two distinct groups of Pliocene-early Pleistocene (?) and early-late Pleistocene age, respectively. In terms of deformation intensity the structures of the first, older group are greater than the Pleistocene structures (second group). The Pliocene structures (first group) controlled the Quaternary paleogeography so that, during early Pleistocene, the northern Hyblean area was adjacent to the Catania-Gela foredeep. To the east, the palaeo-gulf of Augusta was located between Monte Tauro e Gigia. In the Syracuse area this reconstruction is supported by the definition of the Quaternary palaeo-scarps entrenched in the flanks of the Pliocene structures. For both the groups of structures there are uncertainties about the chronological relationships between folds and faults, and in the identification of the structures that have been reactivated by present tectonics. The structures of the Hyblean eastern area, which this study dated back to the Pliocene, are considered in the literature to be associated with the Hyblean-Malta escarpment where the source of the latest large earthquake that struck the area (Dec. 13,1990) would be located.