Title :

Depth Dependent Deformation and Anisotropy of Pyrolite in the Earth's Lower Mantle

Author(s) :

Gay, Jeffrey-Phillip [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207
Ledoux, Estelle [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207
Krug, Matthias [Auteur]
Westfälische Wilhelms-Universität Münster = University of Münster [WWU]
Chantel, Julien [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207
Pakhomova, Anna [Auteur]
Deutsches Elektronen-Synchrotron [Hamburg] [DESY]
Sanchez‐Valle, Carmen [Auteur]
Westfälische Wilhelms-Universität Münster = University of Münster [WWU]
Speziale, Sergio [Auteur]
German Research Centre for Geosciences - Helmholtz-Centre Potsdam [GFZ]
Merkel, Sébastien [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207

Journal title :

Geophysical Research Letters

Abbreviated title :

Geophysical Research Letters

Volume number :

51

Pages :

e2024GL109433

Publisher :

American Geophysical Union (AGU)

Publication date :

2024-06-08

HAL domain(s) :

Physique [physics]/Matière Condensée [cond-mat]/Science des matériaux [cond-mat.mtrl-sci]

English abstract : [en]

AbstractSeismic anisotropy is a powerful tool to map deformation processes in the deep Earth. Below 660 km, however, observations are scarce and conflicting. In addition, the underlying crystal scale mechanisms, leading ...
Show more >AbstractSeismic anisotropy is a powerful tool to map deformation processes in the deep Earth. Below 660 km, however, observations are scarce and conflicting. In addition, the underlying crystal scale mechanisms, leading to microstructures and crystal orientations, remain poorly constrained. Here, we use multigrain X‐ray diffraction in the laser‐heated diamond anvil cell to investigate the orientations of hundreds of grains in pyrolite, a model composition of the Earth's mantle, at in situ pressure and temperature. Bridgmanite in pyrolite exhibits three regimes of microstructures, due to transformation and deformation at low and high pressure. These microstructures result in predictions of 1.5%–2% shear wave splitting between 660 and 2,000 km with reversals in fast S‐wave polarization direction at about 1,300 km depth. Anisotropy can develop in pyrolite at lower mantle conditions, but pressure has a significant impact on the plastic behavior of bridgmanite, and hence seismic observations, which may explain conflicting anisotropy observations.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

Popular science :

Non

ANR Project :

Transformations de phase, microstructures, et leur signatures sismiques dans le manteau terrestre

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 :

2024-06-09T20:47:10Z
2024-06-10T15:57:29Z
2024-06-11T06:46:54Z
2024-06-12T07:35:23Z