Sicily’s Foreland Fold/Thrust Belt and Slab Roll-back: the SI.RI.PRO. Seismic Crustal Transect
Raimondo Catalano, Vera Valenti, Cinzia Albanese, Attilio Sulli, Maurizio Gasparo Morticelli, Giuseppe Avellone, and Luca Basilone
Sicily is a thick orogenic wedge formed by a) the foreland (African) and its Sicilian orogen and b) the thick-skinned Calabrian-Peloritani wedge. The crust under central Sicily, from Tyrrhenian margin to the Sicily Channel coastline, has been investigated by the multidisciplinary research (SI.RI.PRO.) Project.
The project dealt with the nature and thickness of crust and depth and geometry of Moho, essential in formulating subduction models and improving knowledge of African and Tyrrhenian/European lithospheres. Results resolve features such as: (a) the main orogenic wedge, (b) the very steep NW trending regional monocline suggesting inflection of the foreland crust, (c) the deep Caltanissetta synform imaged, for the first time, to about 25 km and (d) the top of the crystalline basement and the inferred crust/mantle boundary.
Gravity studies support the geological interpretation, accounting for i) a negative Bouguer anomaly in the Caltanissetta synform ii) a positive gravity anomaly in the northern Sicily, produced by higher density rocks within the crust. Two different interpretations of the observed crustal thickening suggest either the occurrence of a thin mantle edge wedge or a continental basement repetition by basement-involved fault. Both alternatives support the idea of a subducting continental lithosphere in recent times.
AAPG Search and Discovery Article #90161©2013 AAPG European Regional Conference, Barcelona, Spain, 8-10 April 2013