Titre :

Elasto-Visco Plastic Modeling of CaGeO3 (pv) + MgO Deformation : Applicability for Understanding the Multiphase Rheology of the Lower Mantle

Auteur(s) :

Hilairet, Nadege [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Gasc, Julien [Auteur]
Tomé, Carlos [Auteur]
Wang, Huamiao [Auteur]
Shi, Feng [Auteur]
Wang, Yanbin [Auteur]
Merkel, Sébastien [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]

Titre de la manifestation scientifique :

AGU Fall Meeting 2019

Organisateur(s) de la manifestation scientifique :

American Geophysical Union

Ville :

San Francisco, CA

Pays :

France

Date de début de la manifestation scientifique :

2019-12

Discipline(s) HAL :

Chimie/Matériaux
Physique [physics]/Matière Condensée [cond-mat]/Science des matériaux [cond-mat.mtrl-sci]
Physique [physics]/Physique [physics]/Géophysique [physics.geo-ph]
Physique [physics]/Astrophysique [astro-ph]
Planète et Univers [physics]/Astrophysique [astro-ph]
Planète et Univers [physics]/Sciences de la Terre

Résumé en anglais : [en]

As the largest rocky layer in the Earth, the lower mantle plays a critical role in controlling convective patterns in our planet. Current mineralogical models suggest that the lower mantle is dominated by (Mg,Fe)SiO3 ...
Lire la suite >As the largest rocky layer in the Earth, the lower mantle plays a critical role in controlling convective patterns in our planet. Current mineralogical models suggest that the lower mantle is dominated by (Mg,Fe)SiO3 perovskite (SiPv; about 70 – 90% in volume fraction) and (Mg,Fe)O ferropericlase (Fp). Knowledge of rheological properties and textures of the major constituent minerals is critical in understanding dynamic processes of the deep Earth, and relating seismic observations to mineralogy. While individual properties of these phases have been studied, fewer informations on polyphase aggregates are available. Fundamental understanding about the stress-strain interactions among the phases and their effect on the bulk rheology still remains to be properly addressed. Here we examine stress/strain partitioning and rheological properties of two-phases polycrystals of CaGeO3 perovskite (GePv) and MgO, using Elasto-Visco Plastic Self-Consistent modeling (EVPSC). The models are based on deformation experiments at high pressures and temperatures, with in-situ measurements using synchrotron X-ray diffraction. We explore the applicability of these models for understanding yielding, rheological and textures properties of these polycrystals. We also discuss stress distributions between the two phases, relationships with active slip systems, and finally the implications for rheological and seismic properties of the lower mantle.Lire moins >

Langue :

Anglais

Comité de lecture :

Non

Audience :

Internationale

Projet ANR :

Deformation des roches multiphasées des zones de subduction

Établissement(s) :

Université de Lille
CNRS
INRA
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Équipe(s) de recherche :

Matériaux Terrestres et Planétaires

Date de dépôt :

2020-10-13T13:09:22Z
2020-10-15T08:28:48Z