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Thermal softening induced subduction initiation at a passive margin
Thermal softening induced subduction initiation at a passive margin
- Source :
- Geophysical Journal International, Geophysical Journal International, Oxford University Press (OUP), 2020, 220 (3), pp.2068-2073. ⟨10.1093/gji/ggz572⟩, Geophysical Journal International, 2020, 220 (3), pp.2068-2073. ⟨10.1093/gji/ggz572⟩
- Publication Year :
- 2020
- Publisher :
- HAL CCSD, 2020.
-
Abstract
- SUMMARY We present 2-D numerical simulations of convergence at a hyperextended passive margin with exhumed subcontinental mantle. We consider viscoelasto-plastic deformation, heat transfer and thermomechanical coupling by shear heating and associated thermal softening due to temperature dependent viscosity. The simulations show subduction initiation for convergence velocities of 2 cm yr−1, initial Moho temperatures of 525 °C and maximal deviatoric stresses of ca. 800 MPa, around the Moho, prior to localization. Subduction initiates in the region with thinned continental crust and is controlled by a thermally activated ductile shear zone in the mantle lithosphere. The shear zone temperature can be predicted with a recently published analytical expression. The criterion for subduction initiation is a temperature difference of at least 225 °C between predicted temperature and initial Moho temperature. The modelled forced subduction broadly agrees with geological data and reconstructions of subduction during closure of the Piemont-Liguria basin, caused by convergence of the European and Adriatic plates during the Alpine orogeny.
- Subjects :
- [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics
010504 meteorology & atmospheric sciences
Subduction
Continental crust
thermo-mechanics
shear heating
010502 geochemistry & geophysics
01 natural sciences
numerical mod- 20 elling
Mantle (geology)
Subduction initiation
thermal softening
Geophysics
13. Climate action
Geochemistry and Petrology
Lithosphere
Passive margin
Heat transfer
Alpine orogeny
Shear zone
Petrology
Geology
0105 earth and related environmental sciences
Subjects
Details
- Language :
- English
- ISSN :
- 0956540X and 1365246X
- Database :
- OpenAIRE
- Journal :
- Geophysical Journal International, Geophysical Journal International, Oxford University Press (OUP), 2020, 220 (3), pp.2068-2073. ⟨10.1093/gji/ggz572⟩, Geophysical Journal International, 2020, 220 (3), pp.2068-2073. ⟨10.1093/gji/ggz572⟩
- Accession number :
- edsair.doi.dedup.....b58893eecfef9d2002aa474f4e4da6d8
- Full Text :
- https://doi.org/10.1093/gji/ggz572⟩