Titre :

Olivine intergranular plasticity at mantle pressures and temperatures

Auteur(s) :

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

Titre de la revue :

Comptes Rendus Geoscience

Nom court de la revue :

Comptes Rendus Geoscience

Numéro :

351

Pagination :

80-85

Éditeur :

Elsevier BV

Date de publication :

2019-02

ISSN :

1631-0713

Discipline(s) HAL :

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

Résumé en anglais : [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 ...
Lire la suite >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.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Internationale

Projet ANR :

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

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Équipe(s) de recherche :

Matériaux Terrestres et Planétaires

Date de dépôt :

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