Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/3876
AuthorsChiarabba, C.* 
De Gori, P.* 
Speranza, F.* 
TitleThe southern Tyrrhenian subduction zone: Deep geometry, magmatism and Plio-Pleistocene evolution
Issue Date2008
Series/Report no./ 268 (2008)
DOI10.1016/j.epsl.2008.01.036
URIhttp://hdl.handle.net/2122/3876
Keywordsseismic tomography
recent evolution of the Ionian slab
deep earthquakes slab dehydration and magmatism
Subject Classification04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics 
04. Solid Earth::04.07. Tectonophysics::04.07.06. Subduction related processes 
04. Solid Earth::04.07. Tectonophysics::04.07.08. Volcanic arcs 
AbstractWe report on a high-resolution Vp, Vp/Vs and Qp model of the southern Tyrrhenian subduction zone, obtained by the inversion of P- and S wave arrival times and t* values from intraslab seismicity. The arcuate shape of the southern Apennines–Calabrian arc-Sicilian Maghrebides is perfectly mirrored by two rather continuous low and high Vp bands lying beneath the belt system at ca. 25 and 100 km, respectively. Between 100 and 300 km, two independent high Vp slabs lie beneath the Neapolitan region and the southern Tyrrhenian Sea, separated by unperturbed mantle. We suggest that the ca. 150 km-wide slab window beneath the southern Apennines opened after a tear occurring within a composite subduction system, formed by the Apulian continental lithosphere and the Ionian oceanic slab. The abrupt slab rupture induced ultrafast southeastward retreat of the Ionian slab, and the 19 cm/yr spreading of the back-arc oceanic Marsili basin between ca. 2.1 and 1.6 Ma ago. The 25 km low Vp zone beneath the arc denotes continental upper crustal rocks below the chain. Its striking continuity requires a unique orogenic wedge at 25 km depth below the southern Apennines, the Calabrian arc, and the Sicilian Maghrebides. The alternative explanation would imply the ubiquitous occurrence of autochthonous lower plate rocks at 25 km depth, i.e. a puzzling autochthonous continental Calabria. The Ionian slab beneath Calabria shows high Vp, high Qp and low Vp/Vs anomalies, typical of old oceanic lithosphere. Intermediate depth seismicity is concentrated within its thin oceanic crust, suggesting the occurrence of vigorous metamorphism. The slab dehydration promotes the melting of the overlying mantle, as testified by high Vp/Vs and low Qp anomalies between the slab and the Aeolian magmatic arc.
Appears in Collections:Papers Published / Papers in press

Files in This Item:
File Description SizeFormat 
2008-Tomografia-Tirreno.pdf1.74 MBAdobe PDFView/Open
Show full item record

Page view(s)

77
Last Week
0
Last month
checked on Jun 23, 2017

Download(s)

28
checked on Jun 23, 2017

Google ScholarTM

Check

Altmetric