Title :

Olivine intergranular plasticity at mantle pressures and temperatures

Author(s) :

Raterron, Paul [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Bollinger, Caroline [Auteur]
Merkel, Sébastien [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]

Journal title :

Comptes Rendus Geoscience

Abbreviated title :

Comptes Rendus Geoscience

Volume number :

351

Pages :

80-85

Publisher :

Elsevier BV

Publication date :

2019-02

ISSN :

1631-0713

HAL domain(s) :

Physique [physics]/Physique [physics]/Géophysique [physics.geo-ph]
Planète et Univers [physics]/Sciences de la Terre

English abstract : [en]

The ductile behavior of olivine-rich rocks is critical to constrain thermal convection in the Earth's upper mantle. Classical olivine flow laws for dislocation or diffusion creep fail to explain the fast post-seismic surface ...
Show more >The ductile behavior of olivine-rich rocks is critical to constrain thermal convection in the Earth's upper mantle. Classical olivine flow laws for dislocation or diffusion creep fail to explain the fast post-seismic surface displacements observed by GPS, which requires a much weaker lithosphere than predicted by classical laws. Here we compare the plasticity of olivine aggregates deformed experimentally at mantle pressures and temperatures to that of single crystals and demonstrate that, depending on conditions of stress and temperature, strain accommodated through grain-to-grain interactions – here called intergranular strain – can be orders of magnitude larger than intracrystalline strain, which significantly weakens olivine strength. This result, extrapolated along mantle geotherms, suggests that intergranular plasticity could be dominant in most of the upper mantle. Consequently, the strength of olivine-rich aggregates in the upper mantle may be significantly lower than predicted by flow laws based on intracrystalline plasticity models.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

ANR Project :

Multi-scale Investigation of Upper-Mantle Rheology: From High-P Experiments to Micromechanical Modeling

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Research team(s) :

Matériaux Terrestres et Planétaires

Submission date :

2019-05-20T09:19:56Z
2019-06-28T12:55:27Z