Publication Date:
2013-09-24
Description:
[1] In this study we present new high-resolution, regional-scale, Vp and Vp/Vs models of the northern-central Apennines along with accurate 3D locations of a large set of local earthquakes. The main velocity anomalies are consistent with the surface geology in the shallow layers and present evidence for fluids stored within the basement at greater depths beneath the extensional belt. The Adria and Tyrrhenian mantle are defined by positive velocity anomalies below 30 km depth, while a low Vp, high Vp/Vs region in between indicates the existence of an hydrated wedge. The results yield new constraints on active processes in the Apennines and more generally envisage the evolution of a post-collisional belt. Velocity anomalies and earthquakes are consistent with a complex system of delamination and sinking of the Adria continental lithosphere, with the peeling of the crust identified by intermediate-depth seismicity. Change of seismicity and structural patterns along the belt indicates that this tectonic process is diachronous and that fluids, released by sunken lithosphere, are stored within the crust conditioning the occurrence of seismicity and the onset of extension.
Print ISSN:
0148-0227
Topics:
Geosciences
,
Physics
