We obtained a high-resolution seismic tomography of the Ionian lithosphere subduction using a new approach based on: (a) the Double-Difference technique for inversions and (b) the statistical post-processing of a great number of preliminary models (Weighted Average Model, WAM method); the latter was used to increase reliability and resolution. In the tomographic model, the high-velocity portion of the steeply dipping Ionian slab is well imaged, as is an underlying low-Vp (≈7.0 km/s) aseismic region. We propose that the low-velocity region can be assigned to a partially hydrated (serpentinized) mantle of the subducting Ionian slab, which progressively dehydrates with depth in dense high-pressure phases. In the mantle wedge overlying the slab, large areas, characterized by low-Vp (≤7.0 km/s) and high Vp/Vs (≥1.85), have been imaged beneath the Stromboli and Marsili volcanoes down to a maximum depth of 180 km. We have interpreted these areas as being regions where mantle partial melts form and accumulate and which then feed the present-day Aeolian Archipelago magmatism
CALO’, M., DORBATH, C., LUZIO, D., ROTOLO, S.G., D’ ANNA, G. (2009). Local earthquake tomography in the Southern Tyrrhenian region of Italy: Geophysical and petrological inferences on subducting litosphere. In S. Lallemand, F. Funiciello (a cura di), Frontiers in Earth Sciences: Subduction Zone Dynamics (pp. 85-99). SPRINGER [10.1007/978-3-540-87974-9].
Local earthquake tomography in the Southern Tyrrhenian region of Italy: Geophysical and petrological inferences on subducting litosphere
LUZIO, Dario;ROTOLO, Silvio Giuseppe;
2009-01-01
Abstract
We obtained a high-resolution seismic tomography of the Ionian lithosphere subduction using a new approach based on: (a) the Double-Difference technique for inversions and (b) the statistical post-processing of a great number of preliminary models (Weighted Average Model, WAM method); the latter was used to increase reliability and resolution. In the tomographic model, the high-velocity portion of the steeply dipping Ionian slab is well imaged, as is an underlying low-Vp (≈7.0 km/s) aseismic region. We propose that the low-velocity region can be assigned to a partially hydrated (serpentinized) mantle of the subducting Ionian slab, which progressively dehydrates with depth in dense high-pressure phases. In the mantle wedge overlying the slab, large areas, characterized by low-Vp (≤7.0 km/s) and high Vp/Vs (≥1.85), have been imaged beneath the Stromboli and Marsili volcanoes down to a maximum depth of 180 km. We have interpreted these areas as being regions where mantle partial melts form and accumulate and which then feed the present-day Aeolian Archipelago magmatism
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