A lithospheric-scale seismogenic thrust in central Italy

摘要: In this paper, the relatively deep (up to 90 km) seismicity of central Italy is considered in comparison with upper crust at outer front Apennine fold-and-thrust belt system and major crust-scale tectonic discontinuities outlined by seismic reflection refraction profiles. particular, attention given presence a Plio-Quaternary SW-dipping thrust zone cutting entire Adriatic emerging system, along Po Plain-Adriatic belt. This discontinuity, detectable from CROP 03 near-vertical profile, but only partially highlighted previous studies, here named Thrust (AT). The geometry AT compared distribution kinematics Coastal-Adriatic seismicity, Marche Foothill lower (base mantle). A good spatial correspondence between down-dip fault observed. rheological stratification lithosphere controls location activity different depth intervals plane (0–10, 15–25, 35–45 km). reconstructed conditions do not allow justify terms brittle behavior deepest earthquakes, located depths 55 70 km within possible intra-mantle prosecution AT. These events might represent either co-seismic plastic instabilities due high strain concentrations shear or failure continental strong increase pore fluid pressure (infiltration asthenosphere hydroxil-CO2 rich volatiles). proposed interpretation as lithosphere-scale seismogenic zone, has several implications: (1) still active; (2) associated subduction plane; (3) deformation association lithospheric possible.