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the onshore Sicilian thrust belt continuing to the Apennine mountain chain (Figure 1). Only one well, Ermione-1 (Agip/Deutche Shell, 1989, P&A,
dry), has been drilled in the offshore thrust belt, while the foredeep and foreland have been explored in the 1970’-80’s with one significant
developed discovery, the Nilde oil field (Figure 2).

A geochemical fieldtrip was undertaken in Sicily, sampling the thrust belt with the aim of determining the hydrocarbon potential of all possible
source rocks and trying to tie source rocks to oil & bitumen seeps. In order to determine the hydrocarbon potential of the offshore Sicilian thrust
belt, the results of geochemical analyses (pyrolysis, GC and total extract data, biomarkers, isotopes, etc.) have been correlated with existing
geochemical data from northern Tunisia and offshore Sicily. Geochemical data have been integrated with a regional geological model which also
included an inferred stratigraphy and tectonic evolution for the offshore Sicilian thrust belt.

Paleotectonic Setting of Sicily and its Relation to the Hydrocarbon System

The Sicilian fold and thrust belt is characterized by the convergence and thrusting of different paleogeographical domains, most of which have clear
affinities with African geology with the exception of the northeastern corner of Sicily (Peloritani Mt.), which includes European derived Hercynian
basement and a related sedimentary cover (Figure 4 and Figure 5). Different tectonic processes from the Late Triassic to the Early Tertiary allowed
the formation of a complex pattern of pelagic basins adjacent to shallow water carbonate platforms, separated by geometrically articulated margins.
The main basinal units (Late Triassic-Early Tertiary) are represented by the Sicanian succession in central Sicily, the Imerese unit in the Termini
Imerese and Palermo Mountains areas, and the Prepanormide unit in westernmost Sicily and in the Marettimo Island (G.Granath et al., 2004,
R.Catalano et al., 2002). All these basinal units have formed allochthnous nappes which have been tectonically emplaced with a general southward
vergence on thick carbonate units: the Panormide and Trapanese sequences. Source rocks of significant petroleum potential are not present in the
basinal units. The importance of the latter units for the petroleum system is linked to the possible seal effectiveness of the pelagic lithofacies and the
presence of intercalations of resedimented carbonates in the Early Lias and Late Cretaceous (i.e. Imerese units, L. Basilone, 2009) which could
provide multiple reservoir intervals.

The Panormide and Trapanese units are marked by shallow water carbonate sedimentation in the Late Triassic to Lias. From the Middle-Late
Jurassic to the Early Tertiary the Trapanese unit shows a tectono-stratigraphic evolution typical of a drowned platform, whereas shallow water
carbonate sedimentation continued in the Panormide domain throughout the Cretaceous, representing an anomaly in the Tethyan realm (G.Zarcone
et al., 2008). Equivalent Cretaceous shallow water carbonates are present in Tunisia (Zeggab Formation), however the Late Cretaceous interval
(Campanian-Maastrichtian) is characterised by deep water pelagic deposits of the Abiod Formation.

Associated with the Panormide and Imerese units, there are nappes of Numidian Flysch (Oligocene, Early Miocene) formed in distal portions of the
African margin and subsequently caught up in the accretionary prism in the early phases of deformation in Sicily (G. Granath et al., 2004).