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LA GEOLOGIA MARINA IN ITALIA- Secondo convegno dei geologi marini italiani, 23 - 24 febbraio 2017



            Crustal deformation and active tectonics in the NW Sicily Channel
            based on multi-scale analysis of seismic reflection profiles

            M. MECCARIELLO (*), L. FERRANTI (*) & F. PEPE (**)

            (*) DIPARTIMENTO DI SCIENZE DELLA TERRA, DELL’AMBIENTE E DELLE RISORSE (DISTAR), UNIVERSITÀ DI NAPOLI “FEDERICO II”, LARGO S.
            MARCELLINO 10, 80138 NAPOLI, ITALY.
            (**) DIPARTIMENTO DI SCIENZE DELLA TERRA E DEL MARE, UNIVERSITÀ DI PALERMO, VIA ARCHIRAFI 22, 90133 PALERMO, ITALY.

            Keywords: Active tectonics, Compression, Sicily Channel.

            The NW Sicily Channel is an important area of deformation within the Mediterranean Sea. Through the last
            50’ years, seismic images calibrated with well-log data have allowed to visualize and study the submerged
            areas (Argnani et al., 1986; 1990; Catalano, 1986; 1996; Antonelli et al., 1988; Roure et al., 2012; Civile et al.,
            2014). The geodynamic setting of this sector is controlled by Africa-Europe convergence. The associated
            compression is responsible of the formation of the Sicilian-Maghrebian chain that links northern Africa with
            Sicily.
            The proposed deformational history of the NW Sicily Channel is based on the analysis of seismic reflection
            profiles  from  the  VIDEPI  database,  industry  and  newly  acquired  high-resolution  sparker  profiles.  As
            documented by previous studies, the front chain migrated from NW towards the SE (Catalano, 1986; 1996;
            Antonelli et al., 1988; Roure et al., 2012; Civile et al., 2014). We refine this view and, through a multi-scale
            analysis, 1) propose a thick-skinned deformation style; and 2) perform an accurate location the actual front
            of the chain.
            Starting from Miocene, contractional deformation affected the Egadi area with deep-seated thrust-ramp
            (ETF,  Egadi  Thrust  Front).  This  activity  ended  ~8  My  ago,  as  evidenced  by  the  high-amplitude  reflector
            associated to the sandy member of Terravecchia formation that sealed the deformation. During the Late
            Miocene, a new thrust front acted along the eastern side of the Adventure Bank also reactivating an inherited
            Mesozoic crustal boundary which separated the proximal shelf facies (Trapanese domain) from the distal
            ramp facies (Saccense domain) in the Miocene Terravecchia foredeep.
            The study shows the actual front of the chain is located offshore Capo Granitola. Onshore, its continuation is
            expressed by a gentle fold affecting Quaternary deposits in the area of Castelvetrano-Campobello di Mazara.
            During  the  Plio-Pleistocene,  the  offshore  area  between  Capo  Granitola  and  Sciacca  experienced  a
            transcurrent deformation with either normal or reverse component of motion. Contemporarily, in the Egadi
            area we assist to a transtensional re-activation of normal faults related to the Early Pliocene rift system and
            a new generation of distributed back-thrust reverse faults.

            Bibliografia:
                  Antonelli M. et alii, 1988. Paleogeographic evolution and structural setting of the northern side of
                    the Sicily Channel. In: Mem. Soc. Geol. It., 41, 141-157.
                  Argnani A. et alii, 1986. Neogene-Quaternary foredeep system in the Strait of Sicily. In: Mem. Soc.
                    Geol. It., 36, 123-130.
                  Argnani A. (1990). The Strait of Sicily rift zone: foreland deformation related to the evolution of a
                    back-arc basin. In: J. of Geodynamics, 12, 311-331.
                  Catalano  R., 1986.  Northeastern  Sicily  Straits  stratigraphy  and  structures  from  seismic  reflection
                    profiles. In: Rend. Soc. Geol. It., 9, 103-112.
                  Catalano R. et alii, 1996. Paleogeography and structure of the central Mediterranean: Sicily and its
                    offshore area. In: Tectonophysics, 260, 291-323.
                  Civile D. et alii, 2014. Seismic stratigraphy and structural setting of the Adventure Plateau (Sicily
                    Channel). In: Mar. Geoph. Res., 35, 37-53.
                  Roure F. et alii, 2012. Alpine inversion of the North African margin and delamination of its
                    continental lithosphere. In: Tectonics, 31(3).

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