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A. Sulli / Tectonophysics 324 (2000) 321–336 331

5.2. From the Elimi chain to the western Sicily mentary bodies. The carbonate platform ramps
offshore are separated by variably thick clastic deposits,
probably Tertiary in age. Shape, geometry and
The Apenninic–Maghrebian chain (Fig. 3) seismic characteristics well differentiate these struc-
develops southeastwards from the Drepano thrust tures from the overlying stacked duplexes of thinly
front toward the western Sicily offshore. It appears layered bodies with acoustic characteristics of
as a strongly deformed sedimentary thrust stack, Mesozoic pelagic carbonates (Catalano et al., 1996;
which is clearly detached from the crystalline base- Sulli, 1996).
ment (Fig. 9). The underlying crust, apparently
not deformed, is bounded by a fairly deep Moho The highest deformed units in the reflecting
that dips to the north (Fig. 9). The basement lies body consist of clastics, recognized as Numidian
at about 15 km, while the thickness of the whole or equivalent syntectonic terrigenuous deposits
crust reaches about 25 km. ( Fig. 12), originally filling the foredeep of the
Kabilian–Calabrian chain. Similar rocks occur
From NW to SE the chain shows four main westward also in the La Galite Archipelago and
embricate fans bounded by the Inner Maghrebian, on Skerki Bank ( Fig. 2), where Numidian nappes
Egadi, Belice and Sciacca thrust fronts (respec- overlie Mesozoic–Eocene deep-water marly car-
tively a, b, c, d in Fig. 3). These thrust fronts face bonates which, in turn, overthrust Triassic evapo-
sedimentary basins filled by progressively more rites and shallow-water carbonates ( Tricart et al.,
recent foredeep deposits. 1993 ).

Internal geometries of the inner sector of this In the study area the stack of basinal carbonates
chain are well represented in Figs. 12 and 13 where and Numidian units override carbonate platform
the structural edifice shows from the bottom: (a) rock units (Fig. 12) through the Inner Maghrebian
fairly inclined carbonate platform thrust sheets; thrust front (a in Fig. 3).
(b) thinner pelagic carbonate nappes; and (c) a
stack of folded and thrust thick terrigenous sedi- In the above-mentioned inner sector the reflect-
ing body points out that the basement has a depth

Fig. 12. The seismic section shows from the top: roof complex of Numidian Flysch terrigenous successions, overlying a duplex wedge
of interpreted basin-type carbonates, in turn overthrust on carbonate platform units. Key: M, Messinian horizon; FN, Numidian
Flysch; Tb, top of basinal successions; Tp, top of platform carbonates.