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SEISMOSTRATIGRAPHIC ANALYSIS OFTHE NEOGENE BASINS SUPERPOSED ON
               THE MAGHREBIAN OROGEN WEST OF THE EGADI ISLANDS:

                                           PRELIMINARY RESULTS

Fabiano Gamberi· & Andrea Argnanj••

• Istituto per la Geologia Marina- CNR                  ..

•• Università degli Studi di Bologna & Istituto per la Geologia Manna- CNR, ltaly

                        Introduction                   The internai thrust sheets consist of late

The presence of a submerged Fore1and Thrust         Triassic-ear1y Tertiary carbonates and shale
Belt (FfB) in the northwestern part of the          that were deposited in four different
                                                    paleogeographic domains equivalent to those
Sicily channe1 has been recognized only             of Sicily (Panorn1ide, Imerese, Trapanese,
recently (Argnani et aL 1986; Catalano & D'         Sicano). In contrast, the externa1 thrust sheets
Argenio 1986; Sestini & Flores 1986).               consist of Oligocene-Early Miocene
Offshore the Egadi islands, where a good            quartzarenitic Numidian flysch (Antonelli et
seismic grid is available, the FTB is affected      al., 1988).
by extensional faulting that has led to the
fonnation of severa! basins connected by the
Egadi Valley to the trough system of the
Sicily channe1 (Fig. 1). Preliminary results of
a seismostratigraphic analysis of some of
these basins 1ocated west of the Egadi islands
is presented here.

                                                    372:!00l=========== ================:.J

                                                    Figurt.: 2. Scismic grid . Bold lincs are profiles in
                                                    Figs. 3 aJ1CI 5-10.

Figure l. Sketcll of mai n physiographic and           Thc timc of the compression that
structural clemcnts of thc western Sicily channel.  originated this FTB is not well established.
Bl: Basinl; 82: Basin 2.; El : Egadi lsland: EV:
Egadi Vallcy: MTF: Maghrebian thrust front: P:      According to the Neotectonic map of Italy
Pantelleria trough .                                (C.N.R.. 1987) structures were active till the
                                                    Pliocenc. Argnani et al. (1987), however,
                  Geologie Setting                  relate the defonnative event to Midd le- Upper
   The Egadi FfB links the African and the
Sicilian Maghrebides and is composed of a           Miocene .
pile of thrust shcets detachcd from their               In the area lO thc southeast of Favignana
substrata and overthrust toward SE. They
fom1 an imbricate fan with ramp and flat            Island. near the Sicilian coast, structure.s
geometry and have a main NE-SW strike               begins to rotate from their NW-SE main
(Argnani et al., 1987).                             orientation to E-W, which is the orientation of
                                                    the equivalant FfB in Sicily (Argnani et al.,
                                                    1987). The southemmost part of this FfB has

                                                    not yet been investigated and its features in
                                                    the area of the Talbot Bank and the Egadi

                                                    Valley are not known.
                                                       Severa! basins are developed in the Egadi

                                                    FfB; they are connected by the Egadi valley

                                                    to the Pantelleria trough. the westemmost of a

                                                    system of fault bounded deep basins present
                                                    in the centre of the Sicily channel.

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