The Tyrrhenian margin of central Italy has undergone Plio-Quaternary extension, developing NW-SE normal faults and NE-SW faults. The NE-SW faults decrease in frequency towards NE with the stretching factor , becoming negligible for <1.3. Plio-Quaternary volcanoes, aligned NW-SE, formed at the intersection among NE-SW and NW-SE faults; fissure eruptions are mostly controlled by NE-SW faults. Structural field data show normal motions for 76% of NW-SE Quaternary faults and transtensive for 73% of NE-SW Quaternary faults. Analogue experiments simulating the NE-SW Tyrrhenian extension show that transverse transtensive faults form with differential extension >0.21. These data suggest that the NE-SW transtensive structures are transfer faults of the NW-SE normal faults, due to relevant differential extension (>0.21) within a stretched crust (>1.3). The minor dip-slip and strike-slip components of the NE-SW and NW-SE faults respectively, possibly result from the NW-SE extension due to the SE-ward slab retreat beneath the Calabrian arc. The NE-SW and NW-SE extensions in the central-southern Tyrrhenian Sea account for the composite kinematics of the NE-SW structures, which, in turn, exert a two-fold role in controlling volcanism. Where their dip-slip component forms basins, the associated decompression induces magma accumulation (developing central volcanoes) at the intersection among NW-SE and NE-SW systems. Where transfer faults are mainly strike-slip, their inferred subvertical attitude enhances their permeability to magma, accounting for the observed NE-SW fissure eruptions. Regional extension, forming NW-SE faults, enhances the overall generation and rise of magma along the margin, but NE-SW structures focus magma rise and emplacement at shallower levels.

Acocella, V., Funiciello, R. (2006). Transverse systems along the extensional Tyrrhenian margin of central Italy and their influence on volcanism. TECTONICS, 25 [10.1029/2005TC001845].

Transverse systems along the extensional Tyrrhenian margin of central Italy and their influence on volcanism

ACOCELLA, Valerio;
2006-01-01

Abstract

The Tyrrhenian margin of central Italy has undergone Plio-Quaternary extension, developing NW-SE normal faults and NE-SW faults. The NE-SW faults decrease in frequency towards NE with the stretching factor , becoming negligible for <1.3. Plio-Quaternary volcanoes, aligned NW-SE, formed at the intersection among NE-SW and NW-SE faults; fissure eruptions are mostly controlled by NE-SW faults. Structural field data show normal motions for 76% of NW-SE Quaternary faults and transtensive for 73% of NE-SW Quaternary faults. Analogue experiments simulating the NE-SW Tyrrhenian extension show that transverse transtensive faults form with differential extension >0.21. These data suggest that the NE-SW transtensive structures are transfer faults of the NW-SE normal faults, due to relevant differential extension (>0.21) within a stretched crust (>1.3). The minor dip-slip and strike-slip components of the NE-SW and NW-SE faults respectively, possibly result from the NW-SE extension due to the SE-ward slab retreat beneath the Calabrian arc. The NE-SW and NW-SE extensions in the central-southern Tyrrhenian Sea account for the composite kinematics of the NE-SW structures, which, in turn, exert a two-fold role in controlling volcanism. Where their dip-slip component forms basins, the associated decompression induces magma accumulation (developing central volcanoes) at the intersection among NW-SE and NE-SW systems. Where transfer faults are mainly strike-slip, their inferred subvertical attitude enhances their permeability to magma, accounting for the observed NE-SW fissure eruptions. Regional extension, forming NW-SE faults, enhances the overall generation and rise of magma along the margin, but NE-SW structures focus magma rise and emplacement at shallower levels.
2006
Acocella, V., Funiciello, R. (2006). Transverse systems along the extensional Tyrrhenian margin of central Italy and their influence on volcanism. TECTONICS, 25 [10.1029/2005TC001845].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11590/138836
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