Title :

Stress Balance in Synthetic Serpentinized Peridotites Deformed at Subduction Zone Pressures

Author(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]

Journal title :

Journal of Geophysical Research: Solid Earth

Abbreviated title :

JGR Solid Earth

Volume number :

129

Pages :

e2023JB028073

Publisher :

American Geophysical Union (AGU)

Publication date :

2024-03

ISSN :

2169-9313

HAL domain(s) :

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]

English abstract : [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 ...
Show more >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.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

Popular science :

Non

ANR Project :

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

Other project(s) or funding source(s) :

CPER ARCHI-CM
INSU-PNP

Administrative institution(s) :

Université de Lille
CNRS
INRAE
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Research team(s) :

Matériaux Terrestres et Planétaires

Submission date :

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