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324 A. Sulli / Tectonophysics 324 (2000) 321–336
merges southwards with the shallow-water
Adventure Bank. This sector is separated from the
Tunisian platform by narrow deep-water areas
(Sicily Straits), joined to the southernmost
Pantelleria and Malta basins. Towards the north,
the Egadi valley divides the Egadi shelf from the
Skerki Bank, a morphological high stretching from
the Tunisian platform towards the NE.
In the central part the Scuso Bank, a N–S-
trending morphological high, separates the
Trapani basin in the west from the Erice basin to
the east. Westwards, a widespread morphological
flat, between −300 and −600 m deep, occurs,
interrupted by the Elimi chain and by small basins
and isolated morphological highs.
Northward the SW–NE-trending Elimi chain is
a widespread submarine (volcanic, carbonatic,
metamorphic) belt that reaches tops between −600
and −100 m, and crops out to the east, in the
Ustica Island. The Elimi chain bounds to the south
the Cornaglia terrace, a flat area occurring between
−1000 and −2000 m, passing northwards to the
>2500 m deep Cornaglia basin.
3. Data set
The data set used here is a dense grid of
multichannel seismic profiles (Fig. 4), integrated
by a crustal line, at places calibrated by strati-
graphic and geophysical data (seismic refraction,
heat flow, gravimetry, magnetic anomalies). These
data have provided the basis for a reinterpretation
of the seismic facies and geometries of the struc-
tural edifice.
There is little borehole controlled, stratigraphic 7. Facies G shows very continuous reflectors, with
and chronological data in the investigated area.
The analysis of seismic attributes and the reflector
pattern, compared with well-calibrated seismic
data (Catalano et al., 1996; Sulli, 1996), made it
possible to distinguish several seismic facies that
were able to estimate the lithology and geometry
of the reflecting body (Fig. 5). The main facies are
reported here for the sake of information:
1. Facies A is characterized by high-amplitude,
low-frequency reflectors; it is found at great
depth, with poor lateral continuity. As a result
of comparison with refraction seismic data
(Rehault et al., 1987), such reflectors may be
considered as associated with the crust–mantle
discontinuity (Moho).
2. Facies B is characterized by a transparent layer
limited upwards by a group of high-amplitude,
high-frequency reflectors with good lateral con-
tinuity. The seismic fabric of this portion is
typical of the lower crust (Ponziani et al., 1995;
Barchi et al., 1998).
3. Facies C is characterized by high to medium
amplitude, variable frequency and very high
velocity, topped by a strong reflector. The
seismic signal is discontinuous and often cov-
ered by diffraction effects. We associate this
facies with crystalline basement rocks or, gen-
erally, with the upper crust.
4. Facies D is topped by a reflector with high
amplitude and velocity, while the internal
reflectors have low frequency and variable lat-
eral continuity. Internal geometries are regular
over wide areas. The signal refers to thick-
bedded carbonate platform rocks, in agreement
with Anselmetti and Eberli (1993), and is con-
firmed by well calibrations.
5. Facies E shows reflectors with intermediate
amplitudes and velocities, and high frequency.
This signal, which is homogeneous but not
continuous, was correlated to thin-bedded
pelagic carbonates and marl successions.
Similar seismic facies has been found in the
adjacent western Sicily (Catalano et al., 1998a),
where it is calibrated by well data.
6. Facies F is characterized by discontinuous and
non-homogeneous horizons, with alternation of
high and low amplitude, high frequency and
lower velocity. This facies corresponds to
coarser clastic and argillaceous successions.
high amplitudes and velocities; it is known to
be representative of evaporitic horizons (hori-
zon M in the Messinian evaporites).
8. Facies H is represented by low-amplitude and
high-frequency reflectors, with very low velocity
and good lateral continuity, generated by Plio-
Pleistocene sandy and marly successions.
Sequence stratigraphy methods have been used
for the analysis of these deposits, taking into