FullText URL natute_539_7627_81.pdf natute_539_7627_81_methods.pdf natute_539_7627_81_fig.pdf
Author Tsujino, Noriyoshi| Nishihara, Yu| Yamazaki, Daisuke| Seto, Yusuke| Higo, Yuji| Takahashi, Eiichi|
Abstract  Seismic shear wave anisotropy is observed in Earth's uppermost lower mantle around several subducted slabs. The anisotropy caused by the deformation-induced crystallographic preferred orientation (CPO) of bridgmanite (perovskite-structured (Mg,Fe)SiO3) is the most plausible explanation for these seismic observations. However, the rheological properties of bridgmanite are largely unknown. Uniaxial deformation experiments have been carried out to determine the deformation texture of bridgmanite, but the dominant slip system (the slip direction and plane) has not been determined. Here we report the CPO pattern and dominant slip system of bridgmanite under conditions that correspond to the uppermost lower mantle (25 gigapascals and 1,873 kelvin) obtained through simple shear deformation experiments using the Kawai-type deformation-DIA apparatus. The fabrics obtained are characterized by [100] perpendicular to the shear plane and [001] parallel to the shear direction, implying that the dominant slip system of bridgmanite is [001](100). The observed seismic shear- wave anisotropies near several subducted slabs (Tonga-Kermadec, Kurile, Peru and Java) can be explained in terms of the CPO of bridgmanite as induced by mantle flow parallel to the direction of subduction.
Keywords Geophysics Geodynamics Mineralogy
Published Date 2016-11
Publication Title Nature
Volume volume539
Issue issue7627
Publisher Nature Publishing Group
Start Page 81
End Page 84
ISSN 0028-0836
NCID AA00752384
Content Type Journal Article
language 英語
OAI-PMH Set 岡山大学
Copyright Holders https://creativecommons.org/licenses/by-nc-nd/4.0/deed.ja
File Version author
PubMed ID 27750277
DOI 10.1038/nature19777
Web of Sience KeyUT 000386670100033
Related Url https://doi.org/10.1038/nature19777