Deformation across the mantle transition ...
Document type :
Article dans une revue scientifique: Article original
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Title :
Deformation across the mantle transition zone: A theoretical mineral physics view
Author(s) :
Ritterbex, Sebastian [Auteur]
Carrez, Philippe [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Cordier, Patrick [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Carrez, Philippe [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Cordier, Patrick [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Journal title :
Earth and Planetary Science Letters
Abbreviated title :
Earth Planet. Sci. Lett.
Volume number :
547
Pages :
116438
Publisher :
Elsevier BV
Publication date :
2020-10-01
Article status :
Publié
ISSN :
0012-821X
English keyword(s) :
deformation
modeling
transition zone
pure climb creep
wadsleyite
ringwoodite
majorite
modeling
transition zone
pure climb creep
wadsleyite
ringwoodite
majorite
English abstract : [en]
The dynamics of the Earth’s mantle is still poorly constrained due to the lack of understanding the transfer of matter between the upper and the lower mantle and their convective vigor. The transition zone (TZ) might play ...
Show more >The dynamics of the Earth’s mantle is still poorly constrained due to the lack of understanding the transfer of matter between the upper and the lower mantle and their convective vigor. The transition zone (TZ) might play a crucial role as the interface connecting the upper to the lower mantle. Here, we examine the rheology of the main TZ minerals, wadsleyite, ringwoodite and majorite garnet based on a mineral physics approach. Using the results of lattice friction modeling and dislocation glide mobilities together with the available data on self-diffusion in the TZ minerals, we quantify their plastic deformation by diffusion and dislocation creep from theoretical plasticity models. We show that pure climb creep is expected to contribute to the plasticity of the TZ without the need of significant diffusion-related hydrolytic weakening, matching well the geophysical observations. Our model results predict that crystallographic preferred orientations (CPO) might only develop along with stress concentrations as present around cold subducting slabs which can be locally weaker than the surrounding TZ despite their lower temperatures.Show less >
Show more >The dynamics of the Earth’s mantle is still poorly constrained due to the lack of understanding the transfer of matter between the upper and the lower mantle and their convective vigor. The transition zone (TZ) might play a crucial role as the interface connecting the upper to the lower mantle. Here, we examine the rheology of the main TZ minerals, wadsleyite, ringwoodite and majorite garnet based on a mineral physics approach. Using the results of lattice friction modeling and dislocation glide mobilities together with the available data on self-diffusion in the TZ minerals, we quantify their plastic deformation by diffusion and dislocation creep from theoretical plasticity models. We show that pure climb creep is expected to contribute to the plasticity of the TZ without the need of significant diffusion-related hydrolytic weakening, matching well the geophysical observations. Our model results predict that crystallographic preferred orientations (CPO) might only develop along with stress concentrations as present around cold subducting slabs which can be locally weaker than the surrounding TZ despite their lower temperatures.Show less >
Language :
Anglais
Peer reviewed article :
Oui
Audience :
Non spécifiée
European Project :
Administrative institution(s) :
Université de Lille
CNRS
INRA
ENSCL
CNRS
INRA
ENSCL
Collections :
Research team(s) :
Plasticité
Submission date :
2020-07-13T11:36:51Z
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