Continental subduction of Adria in the Apennines and relation with seismicity and hazard

The subduction of continental lithosphere is a complex process because the buoyancy of the crust is higher than the oceanic and should resist sinking into the mantle. Anyway, studies on the Alpine-Himalayan collision system indicate that a large portion of the continental crust is subducted, while s...

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Main Authors: C. Chiarabba, I. Menichelli, I. Bianchi, G. Giacomuzzi, P. De Gori
Format: Article
Language:English
Published: Frontiers Media S.A. 2023-10-01
Series:Frontiers in Earth Science
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/feart.2023.1253443/full
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author C. Chiarabba
I. Menichelli
I. Bianchi
G. Giacomuzzi
P. De Gori
author_facet C. Chiarabba
I. Menichelli
I. Bianchi
G. Giacomuzzi
P. De Gori
author_sort C. Chiarabba
collection DOAJ
description The subduction of continental lithosphere is a complex process because the buoyancy of the crust is higher than the oceanic and should resist sinking into the mantle. Anyway, studies on the Alpine-Himalayan collision system indicate that a large portion of the continental crust is subducted, while some material is accreted in the orogens. The Apennine is a perfect case for studying how such processes evolve, thanks to high quality seismic images that illuminate a critical depth range not commonly resolved in many collisional settings. In this paper, we show the structure of the Apennines orogen, as jointly revealed by seismicity and deep structure from regional and teleseismic tomography and receiver function profiles. The westward subducting Adria lithosphere is well defined along the orogen showing a mid-crustal delamination. Seismicity within the underthrusting lower crust and velocity anomalies in the mantle wedge highlight how the subduction evolution is entangled with the liberation of fluids. The eclogitization of subducted material enhances the fluid release into the wedge, the delamination and retreat of the Adria plate. This delamination/subduction generates a coupled compression and extension system that migrates eastward following the retreat of the lithosphere, with broad sets of normal faults that invert or interfere with pre-existing compressional structures all over the roof plate. The sparseness and non-ubiquity of intermediate depth earthquakes along the subduction panel suggest that the brittle response of the subducting crust is governed by its different composition and fluid content. Therefore, the lower crust composition appears essential in conditioning the evolution of continental subduction.
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spelling doaj.art-c23c80882e094df2ac795d58d67a47882023-10-17T15:48:58ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632023-10-011110.3389/feart.2023.12534431253443Continental subduction of Adria in the Apennines and relation with seismicity and hazardC. Chiarabba0I. Menichelli1I. Bianchi2G. Giacomuzzi3P. De Gori4Istituto Nazionale di Geofisica and Vulcanologia, Rome, ItalyDipartimento di Scienze, Sezione di Scienze Geologiche, Università Roma TRE, Rome, ItalyIstituto Nazionale di Geofisica and Vulcanologia, Rome, ItalyIstituto Nazionale di Geofisica and Vulcanologia, Rome, ItalyIstituto Nazionale di Geofisica and Vulcanologia, Rome, ItalyThe subduction of continental lithosphere is a complex process because the buoyancy of the crust is higher than the oceanic and should resist sinking into the mantle. Anyway, studies on the Alpine-Himalayan collision system indicate that a large portion of the continental crust is subducted, while some material is accreted in the orogens. The Apennine is a perfect case for studying how such processes evolve, thanks to high quality seismic images that illuminate a critical depth range not commonly resolved in many collisional settings. In this paper, we show the structure of the Apennines orogen, as jointly revealed by seismicity and deep structure from regional and teleseismic tomography and receiver function profiles. The westward subducting Adria lithosphere is well defined along the orogen showing a mid-crustal delamination. Seismicity within the underthrusting lower crust and velocity anomalies in the mantle wedge highlight how the subduction evolution is entangled with the liberation of fluids. The eclogitization of subducted material enhances the fluid release into the wedge, the delamination and retreat of the Adria plate. This delamination/subduction generates a coupled compression and extension system that migrates eastward following the retreat of the lithosphere, with broad sets of normal faults that invert or interfere with pre-existing compressional structures all over the roof plate. The sparseness and non-ubiquity of intermediate depth earthquakes along the subduction panel suggest that the brittle response of the subducting crust is governed by its different composition and fluid content. Therefore, the lower crust composition appears essential in conditioning the evolution of continental subduction.https://www.frontiersin.org/articles/10.3389/feart.2023.1253443/fullcontinental subduction and collision beltlithosphere delaminationtomographic modelsseismicity and crustal structureseismicity and deformation
spellingShingle C. Chiarabba
I. Menichelli
I. Bianchi
G. Giacomuzzi
P. De Gori
Continental subduction of Adria in the Apennines and relation with seismicity and hazard
Frontiers in Earth Science
continental subduction and collision belt
lithosphere delamination
tomographic models
seismicity and crustal structure
seismicity and deformation
title Continental subduction of Adria in the Apennines and relation with seismicity and hazard
title_full Continental subduction of Adria in the Apennines and relation with seismicity and hazard
title_fullStr Continental subduction of Adria in the Apennines and relation with seismicity and hazard
title_full_unstemmed Continental subduction of Adria in the Apennines and relation with seismicity and hazard
title_short Continental subduction of Adria in the Apennines and relation with seismicity and hazard
title_sort continental subduction of adria in the apennines and relation with seismicity and hazard
topic continental subduction and collision belt
lithosphere delamination
tomographic models
seismicity and crustal structure
seismicity and deformation
url https://www.frontiersin.org/articles/10.3389/feart.2023.1253443/full
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