Tectonic overpressure in weak crustal-scale shear zones and implications for the exhumation of high-pressure rocks

Details

Serval ID
serval:BIB_D3462E79F20F
Type
Article: article from journal or magazin.
Collection
Publications
Title
Tectonic overpressure in weak crustal-scale shear zones and implications for the exhumation of high-pressure rocks
Journal
Geophysical Research Letters
Author(s)
Schmalholz Stefan M., Podladchikov Yuri Y.
ISSN-L
0094-8276; 1944-8007
Publication state
Published
Issued date
2013
Volume
40
Number
10
Pages
1984-1988
Notes
Times Cited: 3
0
3
Abstract
A two-dimensional numerical simulation of lithospheric shortening shows the formation of a stable crustal-scale shear zone due to viscous heating. The shear zone thickness is controlled by thermomechanical coupling that is resolved numerically inside the shear zone. Away from the shear zone, lithospheric deformation is dominated by pure shear, and tectonic overpressure (i.e., pressure larger than the lithostatic pressure) is proportional to the deviatoric stress. Inside the shear zone, deformation is dominated by simple shear, and the deviatoric stress decreases due to thermal weakening of the viscosity. To maintain a constant horizontal total stress across the weak shear zone (i.e., horizontal force balance), the pressure in the shear zone increases to compensate the decrease of the deviatoric stress. Tectonic overpressure in the weak shear zone can be significantly larger than the deviatoric stress at the same location. Implications for the geodynamic history of tectonic nappes including high-pressure/ultrahigh-pressure rocks are discussed.
Open Access
Yes
Create date
02/10/2015 16:33
Last modification date
20/08/2019 15:53
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