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Tectonophysics 324 (2000) 321–336

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Structural framework and crustal characteristics of the
Sardinia Channel Alpine transect in the central Mediterranean

Attilio Sulli

Department of Geology and Geodesy, University of Palermo, Via Archiraﬁ 26, 90123 Palermo, Italy
Received 13 January 2000; accepted 28 January 2000

Abstract

The submerged area located between the Sardinia Channel and the western Sicily oﬀshore has been investigated
based on deep crustal and conventional seismic lines with the aim of illustrating the relationships between the crust
and its overlying crystalline and sedimentary thrust wedge. Analyses of seismic attributes and reﬂector pattern,
supported by dredge hauls, also provided data in areas where stratigraphic and lithologic control is absent. Crustal
geometries, tectonic processes and timing of the deformation are discussed here.

North of the Elimi chain (central Sardinia Channel ) the reﬂecting body consists of superposed tectonic wedges of
crystalline rocks and their Meso-Cenozoic carbonatic and terrigenous cover (Sardinian and Kabilian–Calabrian units).
The Kabilian–Calabrian units overthrust the Maghrebian–Apenninic units along the Drepano thrust front (Elimi
chain), which is traceable on-land in eastern Sicily (Nebrodi–Peloritani Mountains). This lineament roots on the
crustal–mantle discontinuity, where the local superposition of two diﬀerent crusts occurs. The thrust front of the
crystalline Kabilian–Calabrian units marks the boundary between thick-skinned and thin-skinned tectonics in the chain.

The Apenninic segment of the chain develops between the Elimi sector and the Sciacca oﬀshore (south-west Sicily).
The crust is not as thick as expected in Alpine chain areas, suggesting pre-orogenic thinning of the African continental
crust. The accretionary wedge is a southeast-vergent embricate fan consisting of four groups of thrust units formed
by carbonate basinal and platform ramps with duplex geometries. The Mesozoic carbonate units are detached from
the crystalline basement not involved in the deformation. The Tertiary terrigenous rocks are their roof thrust. The
Upper Miocene clastic–terrigenous successions, sealing most of the structures, appear, in turn, detached and piled up.
The intramountain Plio-Pleistocene basins display tectonic features that point out the area underwent both extensional
and contractional tectonics. © 2000 Elsevier Science B.V. All rights reserved.

Keywords: Sardinia channel; seismostratigraphy; crustal structures; Apenninic–Maghrebian chain

1. Introduction of a submerged segment of the Alpine collisional
belt. This belt is believed to develop along the
The study region located between Sicily, Africa–Europe plate boundary (Bellon et al., 1977;
Sardinia and Tunisia (Figs. 1 and 2) is a key area Channell et al., 1979; Dercourt et al., 1986) and
to understanding the geological framework of the links the African Maghrebides with Calabria and
central Mediterranean, because of the occurrence the Apennines. In the central Mediterranean three
main tectonic elements mark the submerged
* E-mail address: attsu@unipa.it accretionary wedge (Fig. 3): (a) foreland area,
located in the Sicily Channel; (b) Plio-Pleistocene

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