The influence of upper-plate advance and erosion on overriding plate deformation in orogen syntaxes

<p>Focused, rapid exhumation of rocks is observed at some orogen syntaxes, but the driving mechanisms remain poorly understood and contested. In this study, we use a fully coupled thermomechanical numerical model to investigate the effect of upper-plate advance and different erosion scenari...

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Main Authors: M. Nettesheim, T. A. Ehlers, D. M. Whipp, A. Koptev
Format: Article
Language:English
Published: Copernicus Publications 2018-11-01
Series:Solid Earth
Online Access:https://www.solid-earth.net/9/1207/2018/se-9-1207-2018.pdf
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author M. Nettesheim
T. A. Ehlers
D. M. Whipp
A. Koptev
author_facet M. Nettesheim
T. A. Ehlers
D. M. Whipp
A. Koptev
author_sort M. Nettesheim
collection DOAJ
description <p>Focused, rapid exhumation of rocks is observed at some orogen syntaxes, but the driving mechanisms remain poorly understood and contested. In this study, we use a fully coupled thermomechanical numerical model to investigate the effect of upper-plate advance and different erosion scenarios on overriding plate deformation. The subducting slab in the model is curved in 3-D, analogous to the indenter geometry observed in seismic studies. We find that the amount of upper-plate advance toward the trench dramatically changes the orientation of major shear zones in the upper plate and the location of rock uplift. Shear along the subduction interface facilitates the formation of a basal detachment situated above the indenter, causing localized rock uplift there. We conclude that the change in orientation and dip angle set by the indenter geometry creates a region of localized uplift as long as subduction of the down-going plate is active. Switching from flat (total) erosion to more realistic fluvial erosion using a landscape evolution model leads to variations in rock uplift at the scale of large catchments. In this case, deepest exhumation again occurs above the indenter apex, but tectonic uplift is modulated on even smaller scales by lithostatic pressure from the overburden of the growing orogen. Highest rock uplift can occur when a strong tectonic uplift field spatially coincides with large erosion potential. This implies that both the geometry of the subducting plate and the geomorphic and climatic conditions are important for the creation of focused, rapid exhumation.</p>
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spelling doaj.art-b6f45e914c0d45d8a88b7adf2101851f2022-12-21T19:00:50ZengCopernicus PublicationsSolid Earth1869-95101869-95292018-11-0191207122410.5194/se-9-1207-2018The influence of upper-plate advance and erosion on overriding plate deformation in orogen syntaxesM. Nettesheim0T. A. Ehlers1D. M. Whipp2A. Koptev3Department of Geology, University of Tübingen, Tübingen, GermanyDepartment of Geology, University of Tübingen, Tübingen, GermanyDepartment of Geosciences and Geography, University of Helsinki, Helsinki, FinlandDepartment of Geology, University of Tübingen, Tübingen, Germany<p>Focused, rapid exhumation of rocks is observed at some orogen syntaxes, but the driving mechanisms remain poorly understood and contested. In this study, we use a fully coupled thermomechanical numerical model to investigate the effect of upper-plate advance and different erosion scenarios on overriding plate deformation. The subducting slab in the model is curved in 3-D, analogous to the indenter geometry observed in seismic studies. We find that the amount of upper-plate advance toward the trench dramatically changes the orientation of major shear zones in the upper plate and the location of rock uplift. Shear along the subduction interface facilitates the formation of a basal detachment situated above the indenter, causing localized rock uplift there. We conclude that the change in orientation and dip angle set by the indenter geometry creates a region of localized uplift as long as subduction of the down-going plate is active. Switching from flat (total) erosion to more realistic fluvial erosion using a landscape evolution model leads to variations in rock uplift at the scale of large catchments. In this case, deepest exhumation again occurs above the indenter apex, but tectonic uplift is modulated on even smaller scales by lithostatic pressure from the overburden of the growing orogen. Highest rock uplift can occur when a strong tectonic uplift field spatially coincides with large erosion potential. This implies that both the geometry of the subducting plate and the geomorphic and climatic conditions are important for the creation of focused, rapid exhumation.</p>https://www.solid-earth.net/9/1207/2018/se-9-1207-2018.pdf
spellingShingle M. Nettesheim
T. A. Ehlers
D. M. Whipp
A. Koptev
The influence of upper-plate advance and erosion on overriding plate deformation in orogen syntaxes
Solid Earth
title The influence of upper-plate advance and erosion on overriding plate deformation in orogen syntaxes
title_full The influence of upper-plate advance and erosion on overriding plate deformation in orogen syntaxes
title_fullStr The influence of upper-plate advance and erosion on overriding plate deformation in orogen syntaxes
title_full_unstemmed The influence of upper-plate advance and erosion on overriding plate deformation in orogen syntaxes
title_short The influence of upper-plate advance and erosion on overriding plate deformation in orogen syntaxes
title_sort influence of upper plate advance and erosion on overriding plate deformation in orogen syntaxes
url https://www.solid-earth.net/9/1207/2018/se-9-1207-2018.pdf
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