Page 2 - Gueguen_alii_2002

78 E. GUEGUEN ET ALII

10° 12° 14° 16° 18°
42° 42°

A
IT
CAM
D
C L P R
A
I
N AL
A
I
T
A Y IC

Baronie S
L U C
APULIA
Mts. A N E
I A
A
40° 40°
Vavilov 3000 m 2000 m 1000 m
A
I
TYRHENIAN
Marsili Paola R
SARDINIA
SEA Basin
B
U E L U E L A
2000 m T F Ustica Eolie A L
1000 m M F S V F P F E F C 1000 m
Egadi
38° 38°
*
oceanic K A L 2000 m
crust SICIL
3000 m
Y A
Apennine transform E
front faults S
N
S F M E I O N I A
main extensional
volcanoes faults
36° 36°
10° 12° 14° 16° 18°
Fig. 1 - Tectonic map of the Southen Tyrrhenian Sea. The asterisk marks the location of the Madonie Mountains, and of the Gratteri-Mt. Mufara
Line (see text). CL) Circeo Line; UEL) Ustica-Eolie Line; KAL) Kumeta-Alcantara Line; MF) Marettimo Fault; SVF) San Vito Fault; PF) Palermo
Fault; EF) Etna Fault, SF) Scicli Fault, ME) Malta Escarpment. Dotted lines indicate bathymetry (modified after RENDA et alii, 2000).
– Schema tettonico del bacino Tirrenico meridionale. L’asterisco mostra la posizione dei Monti delle Madonie, e della Linea Gratteri-Mt Muffa-
ra (c.f. testo). CL) Linea Circeo; UEL) Linea Ustica-Eolie; KAL) Linea Kumeta-Alcantara; MF) Faglia di Marettimo; SVF) Faglia di San Vito; PF)
Faglia di Palermo; EF) Faglia dell’Etna, SF) Faglia di Scicli, ME) Scarpata di Malta. Le linee trattegiate indicano la batimetria (da RENDA et
alii, 2000, modificato).

tent with a deformation model, based on geological evi- the Apennines-Maghrebides fold-and-thrust system (CATA-
dence from exposed faults onshore northern Sicily and LANO & D’ARGENIO, 1982; CATALANO et alii, 1984). The
the Egadi Islands, where the southern Tyrrhenian Sea thrust surfaces have been offset by recent structures rela-
margin is interpreted as a major dextral strike-slip defor- ted to the opening of the Tyrrhenian Sea during Neogene-
mation zone, namely a strike-slip duplex (RENDA et alii, Quaternary time (SELLI, 1974; MALINVERNO & RYAN,
2000). 1986). The opening involved significant anticlockwise
rotations (REHAULT et alii, 1987; DEWEY et alii, 1989;
GUEGUEN et alii, 1997, 1998), and was controlled by faults
of different orientations (fig. 1; BOCCALETTI et alii, 1982,
GEODYNAMIC SETTING OF THE SOUTHERN
TYRRHENIAN SEA MARGIN 1984, 1990a, b; WEZEL, 1985). The most important recog-
nised fault trends are: N-S, E-W and NW-SE (BOCCALETTI
The tectonic setting of Sicily is characterised by the et alii, 1982). NE-SW trending faults, although present
superposition of different tectonic units that were origi- and locally important in the central Mediterranean
nated at expense of distinct paleogeographic domains of region, are poorly developed along the southern Tyrrhen-
the african mesozoic continental margin (OGNIBEN, ian Sea margin (e.g. see NIGRO et alii, 2000).
1960). The main recognised units in central-northern Sic- N-S trending faults display a marked extensional
ily are the basin-derived Sicilide and Imerese Units, and character. Slip along these faults led to attenuation of the
the platform-derived Panormide Unit. From Oligocene previously thickened continental lithosphere, and to crea-
time onwards, these units were piled along shallow thru- tion of new oceanic floor (KASTENS et alii, 1987). The
sts and translated southwards during the construction of main recognised structures extend for over 300 km and