Page 3 - Corti_2006

Coexisting geodynamic processes in the Sicily Channel 85

10˚ 11˚ 12˚ 13˚ 14˚ 15˚
39˚ 39˚
Tyrrhenian Sea 0
315 45
270 90
135
225
180

38˚ 38˚

Sicily

37˚ 37˚

Pantelleria I. Sicily Channel
Tunisia PG

36˚ MG Malta I. 36˚

Linosa I. LG

-4000 -3000 -2000 -1000 0 1000 2000 3000 4000
35˚ 35˚
10˚ 11˚ 12˚ 13˚ 14˚ 15˚

Figure 2. Bathymetry of the Sicily Channel and surrounding areas. PG—Pantelleria graben; LG—Linosa graben; MG—
Malta graben. Data from the GEBCO (General Bathymetric Chart of the Oceans) Digital Atlas (IOC, IHO, and BODC,
2003).

rifting is affecting the Pelagian shelf and Tunisia on-shore and namely the Pantelleria, Malta, and Linosa grabens. Major
continues to the southeast into the Sirte basin (Bosworth, 1994; boundary faults and associated minor normal faults that control
Skuce, 1994; Ahlbrandt, 2001) (Fig. 1). Northwest-trending the deep depressions are clearly observable in seismic lines (see,
normal faults and ENE-trending transfer zones continue on- for instance, the seismic profile in Figure 5 showing the exten-
shore in Libya and Egypt, suggesting a link of the Sicily Chan- sional structures bordering the Pantelleria graben). These faults
nel with the Red Sea and the East African rift in general (Fig. 1). are northwest-southeast-directed; deviations from this principal
Therefore, the rifting in the Sicily Channel seems to be unrelated trend may be accommodated by the presence of transfer zones,
to the subduction process occurring beneath the Apennines- most probably controlled by east-west or north-south transver-
Maghrebides accretionary prism. Stratigraphic columns of the sal structures. Boundary faults of the grabens display variable
study area are reported in Figure 4. throws, which generally increase toward the southeast; esti-
Extension in the area gives rise to the presence of major mated displacements range, indeed, from the ~500 m displace-
morphological structures defining deep tectonic depressions, ment of the Pantelleria graben to the ~1000 m displacement in