Constraints on mantle circulation around the deforming Calabrian slab

Abstract

Combining tectonics, with seismological and geochemical data, we reconstruct the deformation history of the presently narrow Calabrian slab and the path of mantle circulation during the last 10 Ma. We show that during the slab deformation the mantle laterally flowed inside the back arc region permitting its retrograde motion and giving a seismological and volcanological record after 1–2 myr

Evolution of the southern Tyrrhenian slab tear and active tectonics along the western edge of the Tyrrhenian subducted slab

“…Moreover, GPS data indicate that the convergence between Nubia and Eurasia is absorbed completely, or by a large extent (2.1 mm/a), in the seismic belt located in the southern Tyrrhenian Sea (Hollenstein et al 2003;D'Agostino & Selvaggi 2004;Serpelloni et al 2007), whereas there is no active shortening between the Hyblean plateau and the Aeolian Islands. These pieces of evidence have led to infer the onset of a new tectonic regime, with the young Tyrrhenian lithosphere that has possibly started being subducted to the south, underneath Sicily (Goes et al 2004;D'Agostino & Selvaggi 2004;Faccenna et al 2005).…”

“…Wortel & Spakman 2000), and S-wave propagation from intermediate to deep earthquakes located within the Tyrrhenian slab indicates that S-waves could not efficiently reach many stations located in the Southern Apennines and western Sicily, on either side of the slab, because they were attenuated when travelling through the asthenosphere (Mele 1998). Theoretical work and laboratory models strongly suggest that tears within the subducted lithosphere play a major role in the dynamic behaviour of subducted slab, particularly in controlling the extent and velocity of trench retreat, together with slab width (Dvorkin et al 1993;Kincaid & Griffiths 2003;Funiciello et al 2006;Schellart et al 2007). The conceptual implications of slab tears have been widely applied to the tectonic evolution of the Mediterranean, with the slab window imaged by tomography in the southern Tyrrhenian as a chief example (Carminati et al 1998;Wortel & Spakman 2000;Argnani 2000;Faccenna et al 2004;Goes et al 2004;Rosenbaum & Lister 2004).…”

“…Theoretical work and laboratory models strongly suggest that tears within the subducted lithosphere play a major role in the dynamic behaviour of subducted slab, particularly in controlling the extent and velocity of trench retreat, together with slab width (Dvorkin et al 1993;Kincaid & Griffiths 2003;Funiciello et al 2006;Schellart et al 2007). The conceptual implications of slab tears have been widely applied to the tectonic evolution of the Mediterranean, with the slab window imaged by tomography in the southern Tyrrhenian as a chief example (Carminati et al 1998;Wortel & Spakman 2000;Argnani 2000;Faccenna et al 2004;Goes et al 2004;Rosenbaum & Lister 2004). Moreover, recent studies on SKS splitting in the central Mediterranean show some indication of the toroidal flow that is expected on the western side of the Tyrrhenian slab to compensate for its rollback (Civello & Margheriti 2004;Faccenna et al 2005: Baccheschi et al 2007.…”

“…The conceptual implications of slab tears have been widely applied to the tectonic evolution of the Mediterranean, with the slab window imaged by tomography in the southern Tyrrhenian as a chief example (Carminati et al 1998;Wortel & Spakman 2000;Argnani 2000;Faccenna et al 2004;Goes et al 2004;Rosenbaum & Lister 2004). Moreover, recent studies on SKS splitting in the central Mediterranean show some indication of the toroidal flow that is expected on the western side of the Tyrrhenian slab to compensate for its rollback (Civello & Margheriti 2004;Faccenna et al 2005: Baccheschi et al 2007.…”

Tectonic evolution of the Sicilian Thrust System (central Mediterranean)

“…were de formed from the Oligocene to the Late Miocene; an extensional set ting de vel oped dur ing the Late Mio cene-Early Plio cene, al low ing the de po si tion of evaporites and deep-wa ter marls (Trubi Fm. ); these con di tions al lowed re newed de for ma tion of the Imerese-Sicanian and pre vi ous foredeep de pos its ("Gela Nappe em place ment; mod i fied af ter Nigro and Renda, 2000); Ge -"Gela Nappe", Ib -Hyblean-Pelagian, Is -Imerese-Sicanian, Pa -Panormide, Pl -Peloritani, Si -Sicilide Liguro-Provençal oce anic spread ing phase (Faccenna et al, , 2005Cifelli et al, 2007;Mattei et al, 2007;Chiarabba et al, 2008) and the Late Mio cene and the Pleis to cene, dur ing the open ing of the Tyrrhenian Sea. Be tween 15 and 10 Ma, the re treat dras ti cally de cel er ated .…”