Titre :

Stress Balance in Synthetic Serpentinized Peridotites Deformed at Subduction Zone Pressures

Auteur(s) :

Hilairet, Nadege [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207
Guignard, J. [Auteur]
European Synchrotron Radiation Facility [ESRF]
Ferrand, T. P. [Auteur]
Merkel, Sébastien [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207
Raterron, Paul [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207
Ildefonse, B. [Auteur]
Géosciences Montpellier
Fadel, Alexandre [Auteur]
Institut Michel Eugène Chevreul - FR 2638 [IMEC]
Crichton, W. [Auteur]
European Synchrotron Radiation Facility [ESRF]

Titre de la revue :

Journal of Geophysical Research: Solid Earth

Nom court de la revue :

JGR Solid Earth

Numéro :

129

Pagination :

e2023JB028073

Éditeur :

American Geophysical Union (AGU)

Date de publication :

2024-03

ISSN :

2169-9313

Discipline(s) HAL :

Physique [physics]/Matière Condensée [cond-mat]/Science des matériaux [cond-mat.mtrl-sci]
Physique [physics]/Matière Condensée [cond-mat]/Matière Molle [cond-mat.soft]
Physique [physics]/Matière Condensée [cond-mat]/Systèmes désordonnés et réseaux de neurones [cond-mat.dis-nn]

Résumé en anglais : [en]

AbstractWeak serpentine minerals affect the mechanical behavior of serpentinized peridotites at depth, and may play a significant role in deformation localization within subduction zones, at local or regional scale. Mixtures ...
Lire la suite >AbstractWeak serpentine minerals affect the mechanical behavior of serpentinized peridotites at depth, and may play a significant role in deformation localization within subduction zones, at local or regional scale. Mixtures of olivine with 5, 10, 20 and 50 vol. % fraction of antigorite, proxies for serpentinized peridotites, were deformed in axial shortening geometry under high pressures (ca. 2–5 GPa) and moderate temperatures (ca. 350°C), with in situ stress and strain measurements using synchrotron X‐rays. We evaluate the average partitioning of stresses at the grains scale within each phase (mineral) of the aggregate and compare with pure olivine aggregates in the same conditions. The in situ stress balance is different between low antigorite contents up to 10 vol. %, and higher contents above 20 vol. %. Microstructure and stress levels suggest the deformation mechanisms under these experimental conditions are akin to (semi)brittle and frictional processes. Unlike when close to dehydration temperatures, hardening of the aggregate is observed at low serpentine fractions, due to an increase in local stress concentrations. Below and above the 10–20 vol. % threshold, the stress state in the aggregate corresponds to friction laws already measured for pure olivine aggregates and pure antigorite aggregates respectively. As expected, the behavior of the two‐phase aggregate does not evolve as calculated from simple iso‐stress or iso‐strain bounds, and calls for more advanced physical models of two‐phase mixtures.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Internationale

Vulgarisation :

Non

Projet ANR :

Deformation des roches multiphasées des zones de subduction
Séismes Profonds : du Laboratoire au Terrain

Autre(s) projet(s) ou source(s) de financement :

CPER ARCHI-CM
INSU-PNP

Établissement(s) :

Université de Lille
CNRS
INRAE
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Équipe(s) de recherche :

Matériaux Terrestres et Planétaires

Date de dépôt :

2024-03-21T12:52:36Z
2024-03-22T09:01:10Z