Influence of the Thickness of the Overriding Plate on Convergence Zone Dynamics
Abstract The important role played by the upper plate in convergence zones dynamics has long been underestimated but is now more and more emphasized. However, the influence of its thickness and/or strength on orogenic systems evolution remains largely unknown. Here we present results from 3D thermo‐...
Main Authors: | , , , , , |
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Format: | Article |
Language: | English |
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Wiley
2020-02-01
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Series: | Geochemistry, Geophysics, Geosystems |
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Online Access: | https://doi.org/10.1029/2019GC008678 |
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author | Solenn Hertgen Philippe Yamato Benjamin Guillaume Valentina Magni Nicholas Schliffke Jeroen vanHunen |
author_facet | Solenn Hertgen Philippe Yamato Benjamin Guillaume Valentina Magni Nicholas Schliffke Jeroen vanHunen |
author_sort | Solenn Hertgen |
collection | DOAJ |
description | Abstract The important role played by the upper plate in convergence zones dynamics has long been underestimated but is now more and more emphasized. However, the influence of its thickness and/or strength on orogenic systems evolution remains largely unknown. Here we present results from 3D thermo‐mechanical numerical simulations of convergence zones (including oceanic subduction followed by continental subduction/collision), in which we vary the rheological profile of the overriding plate (OP). For this, we systematically modify the crustal thickness of the overriding lithosphere and the temperature at the Moho to obtain a thermal thickness of the overriding lithosphere ranging from 80 to 180 km. While all models share a common global evolution (i.e., slab sinking, interaction between slab and the 660 km discontinuity, continental subduction/collision, and slab breakoff), they also highlight first‐order differences arising from the variations in the OP strength (thermal thickness). With a thin/weak OP, slab rollback is favored, the slab dip is low, the mantle flow above the slab is vigorous, and the trench migrates at a high rate compared to a thick/strong OP. In addition, slab breakoff and back‐arc basin formation events occur significantly earlier than in models involving a thick OP. Our models therefore highlight the major role played by the thickness/strength of the OP on convergence zone dynamics and illustrate its influence in a quantitative way. |
first_indexed | 2024-03-11T12:58:52Z |
format | Article |
id | doaj.art-c6689bbb499e45d3a836c3c003ee0226 |
institution | Directory Open Access Journal |
issn | 1525-2027 |
language | English |
last_indexed | 2024-03-11T12:58:52Z |
publishDate | 2020-02-01 |
publisher | Wiley |
record_format | Article |
series | Geochemistry, Geophysics, Geosystems |
spelling | doaj.art-c6689bbb499e45d3a836c3c003ee02262023-11-03T16:55:47ZengWileyGeochemistry, Geophysics, Geosystems1525-20272020-02-01212n/an/a10.1029/2019GC008678Influence of the Thickness of the Overriding Plate on Convergence Zone DynamicsSolenn Hertgen0Philippe Yamato1Benjamin Guillaume2Valentina Magni3Nicholas Schliffke4Jeroen vanHunen5Univ Rennes, CNRS, Géosciences Rennes ‐ UMR 6118 Rennes FranceUniv Rennes, CNRS, Géosciences Rennes ‐ UMR 6118 Rennes FranceUniv Rennes, CNRS, Géosciences Rennes ‐ UMR 6118 Rennes FranceThe Centre for Earth Evolution and Dynamics, Department of Geosciences University of Oslo Oslo NorwayEarth Sciences Durham University Durham UKEarth Sciences Durham University Durham UKAbstract The important role played by the upper plate in convergence zones dynamics has long been underestimated but is now more and more emphasized. However, the influence of its thickness and/or strength on orogenic systems evolution remains largely unknown. Here we present results from 3D thermo‐mechanical numerical simulations of convergence zones (including oceanic subduction followed by continental subduction/collision), in which we vary the rheological profile of the overriding plate (OP). For this, we systematically modify the crustal thickness of the overriding lithosphere and the temperature at the Moho to obtain a thermal thickness of the overriding lithosphere ranging from 80 to 180 km. While all models share a common global evolution (i.e., slab sinking, interaction between slab and the 660 km discontinuity, continental subduction/collision, and slab breakoff), they also highlight first‐order differences arising from the variations in the OP strength (thermal thickness). With a thin/weak OP, slab rollback is favored, the slab dip is low, the mantle flow above the slab is vigorous, and the trench migrates at a high rate compared to a thick/strong OP. In addition, slab breakoff and back‐arc basin formation events occur significantly earlier than in models involving a thick OP. Our models therefore highlight the major role played by the thickness/strength of the OP on convergence zone dynamics and illustrate its influence in a quantitative way.https://doi.org/10.1029/2019GC008678convergence zone dynamicsoverriding platerheology of the lithospheresubduction/collision processesmantle dynamics3D numerical modeling |
spellingShingle | Solenn Hertgen Philippe Yamato Benjamin Guillaume Valentina Magni Nicholas Schliffke Jeroen vanHunen Influence of the Thickness of the Overriding Plate on Convergence Zone Dynamics Geochemistry, Geophysics, Geosystems convergence zone dynamics overriding plate rheology of the lithosphere subduction/collision processes mantle dynamics 3D numerical modeling |
title | Influence of the Thickness of the Overriding Plate on Convergence Zone Dynamics |
title_full | Influence of the Thickness of the Overriding Plate on Convergence Zone Dynamics |
title_fullStr | Influence of the Thickness of the Overriding Plate on Convergence Zone Dynamics |
title_full_unstemmed | Influence of the Thickness of the Overriding Plate on Convergence Zone Dynamics |
title_short | Influence of the Thickness of the Overriding Plate on Convergence Zone Dynamics |
title_sort | influence of the thickness of the overriding plate on convergence zone dynamics |
topic | convergence zone dynamics overriding plate rheology of the lithosphere subduction/collision processes mantle dynamics 3D numerical modeling |
url | https://doi.org/10.1029/2019GC008678 |
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