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unconformably overlain by Early Miocene shallow the Trapanese and Saccense paleogeographic
clastics and open shelf ca:bonates (Fig. 4, 7, 8). These domains.
deposits appear to pass westwards, where they are
recognized as Panormide and Pre·Panormide domains Stratigraphy and facies domains
(Catalano. 1987; Catalano et al., 1987, 1989). These Stratigraphic and palinspastic restorations of the
units are unconformably overlain by late Tortonian Sicilian-Maghrebian chain reveal two main depositional
terrigenous and clastic cartonatic overstep sequences, areas: a northem internai basin and a southem extemal
Messinian evapornes, pelagic marly limestones and carbonate and evaporìtic platform. These were founded
Plio-Pieistocene clastics. on a common Permian substrate (Catalano et al.,
1991 }. Tbey belong to paleogeographic domains that
b. The outer sector. A reflecting body on formed the Sicilian continental margin, prior to collision
Adventure Plateau includes: a) a topmost thick (almost wlth European Sardinia. Some can be correlated with
3000m), deformed thin-layered wedge bounded on the onshore domains (e .g. Imerese, Pre-Panormide,
NW by the Egadi Tbrust Front and to SE by the Panormide, Saccense. Trapanese and Hyblean;
Adven ture Thrust Front (Fig. 4). and b) a lower Catalano et al.,1987). Basinal sequences forming the
deformed carbonate substrate. This deformed, thin- geometrically bigher carbonate thrust sheets (Fig. 4) are
layered terrigenous and clastic carbonatic wedge here informally assigned to the "Marettimo basin"
includes uppermost folded and fau~ed late Tortonian to (Catalano et al., this vol.}.
early Messinian deposits equivalen! to the T€rravecchia Widespread Triassic-Liassic carbonate and
Fm. on land (Catalano, 1987; Catalano et al, 1987, evaporitic platform rocks and their s!ope to basìn
1989; Antonelli et al, 1983: Argnani et al, 1989). These Ju rassic-Paleogene cover, bave been assigned
deposits unconformabl; o·;erlie early Miocene to early respeclively to the Pre·Panormide (and its lateral
Tortonian ctastic thrust slices abo·1e the carbonatic continuation, Panormide), Trapanese and Saccense
substrate (Fig. 9). These r-.rusts ha·:e a common basai paleogeographic domains (Catalano 1987; Catalano et
detachme nt pian e (F i ;~. 4). Th: n skinned thrust al., 1987. 1989).
packages of basinal La:~ r'1esozo:.:;-Tertiary rocks are
tectonically sandvviched ~2ì·Neen the lower and upper Tectonic histOiy
Miocene rocks (Fig. ~ . 9). Carb.:Jnate substrate is Tectonic analysis of the Sicilian-Maghrebian
stacked in large ramp ar.-:J nat thrus:s. displaying intemal sector indicates that deformation began after Langhian
for the more internai and geometrically higher tectonic
duplex geometry (Fig 4; ,t,!l untts •::ere tbrust towards units (Catalano et al, 1987,1989). Ouring the Langhian-
ear1y Tortonian inteNal the Paleogene-lower Miocene
southeast o•1er even th~ most recent foredeei) basin cover of the internai basin as well as carbonate p/atform
(Gela basin}. A post e2·;..• L~essini.::~ erosicr:al surface domains was detached and then thru st over more
lorrns the top of the enl:re sediment2.ry bod;. progressively externa l domains (Pre -Panormide,
Trapanese and Saccense}. Numidian Flysch type and
Ttìe structural un ~ beneath consists of Triassic- chrono stra tigraphically equivalent deposits were
Li t~ssic carbonate pla: ':.rm sed'-nents o•:e:lain by stacked to form the highest thrust sheets. Cretaceous-
s~amou n t type dapos ~ s :,c..rnmor.::·:::o Ross');. pe iagi~ lo·ner Miocene bas inal packages are thrust over
marly cartx:>nates (Sca;i?. type) a~d open s:-~~~ clastic external ca1bonates (Fig. 2,4). Synchroneously, or just
carbonates of earliesl r.~ Jcene <:Je (Ca1a'ano et al. afterward basin and platform carbonates of the
1987. 1989). These beds 2~~ knm·:n in western Sk:ily as substrate were detached and accreted as ramp and flat
thrusts. Duplex developmant appears to be the normal
Figure B. NW-SE trendi:lg seismic profila showing. thrust expression. Some of the ramp blocks lack their
between 6 an d 8 sec t. w.t.. som e strong reflectors Paleogene-lower Miocene cover.
interpreted as carbonate t ~p s of dee;:>er thrus!. This thrust sheet pile reaches ns main elevation
along the Egadi Thrust Front that trends NNE-SSW
along a belt of almost 60 km (Fig. 2,4). The Egadi Front
cou ld be also the result ot post late Miocene '1hrust
envelopment". Southwards, a new foredeep developed
on the Pre-Panormide, Trapanese and Saccense units,
composed of undeformed carbonatics. during the lower
Miocene-lower Tortonian. Already detached clastic
cover rocks were complexly accreted southeastward
almost contemporaneously with their carbonatic
substrate. The present day structural depression, on the
Adventure Plateau, is not an originai Late Miocene
foredeep as previously believed (Catalano et al, 1988;
Argnani et al , 1989}. lt is the result of a severe
47
