Ultra‐thick Triassic dolomites control the rupture behavior of the central Apennine seismicity: Evidence from magnetic modeling of the L'Aquila fault zone

摘要: High-resolution tomography from the 2009 L'Aquila extensional seismic sequence has shown that Mw 6.1 main shock and most of aftershocks occurred within a high velocity body (6.6 ≤ Vp ≤ 6.8 km/s), located between depths 3 12 km. The nature high-Vp remained speculative, although exhumed mafic deep crustal upper mantle rocks (serpentinites) have been favored. We used 3D magnetic anomaly modeling to investigate plausibility these favored sources for L'Aquila body. does not support presence high-velocity serpentinites with 30–50% serpentinization degree gabbros. Accordingly, we conclude may represent non-magnetic Triassic possibly lower Liassic dolomites drilled in neighboring wells 2–4 km. This conclusion is also consistent lack coherent gravity speculate ultra-thick reaching thickness 8 km deposited syntectonic wedges formed at northern margin Ionian Sea, where oceanic spreading mid-late times.