Multi-temporal tectonic evolution of Capo Granitola and Sciacca foreland transcurrent faults (Sicily channel)

Joint analysis of high-penetration multi-channel and high-resolution single-channel seismic reflection profiles,
calibrated by deep well boreholes, allowed a detailed reconstruction of the Late Miocene to Recent tectonic
history of the Capo Granitola and Sciacca fault systems offshore southwestern Sicily. These two fault arrays are
part of a regional system of transcurrent faults that dissect the foreland block in front of the Neogene Sicilian fold
and thrust belt. The Capo Granitola and Sciacca faults are thought to reactivate inherited Mesozoic to Miocene
normal faults developed on the northern continental margin of Africa. During Latest Miocene-Pliocene, the two
~NNE-SSW striking faults were active in left transpression, which inverted Late Miocene extensional half-grabens
and created push-up ridges along both systems. Tectonic activity decreased during the Pleistocene, but
transpressional folds deform Middle-Late Pleistocene sediments as well, suggesting that the two fault systems are
active. The ~40 km long longitudinal amplitude profile of 1st order folds (Capo Granitola and Sciacca anticlines)
shows ~15–20 km bell-shaped undulations that represents 2nd order folds. The length of these undulations
together with the map pattern of faults allowed to divide the CGFS and SFS into two segments, northern and
southern, respectively. Total uplift of the Sciacca Anticline is twice than the uplift of the Capo Granitola
Anticline. Incremental fold growth rates decreased during time from 0.22 mm/yr (Capo Granitola Anticline) and
0.44 mm/yr (Sciacca Anticline) in the Pliocene, to 0.07 and 0.22 mm/yr, respectively, during the last ~1.8 Ma.