フルテキストURL natute_539_7627_81.pdf natute_539_7627_81_methods.pdf natute_539_7627_81_fig.pdf
著者 Tsujino, Noriyoshi| Nishihara, Yu| Yamazaki, Daisuke| Seto, Yusuke| Higo, Yuji| Takahashi, Eiichi|
抄録  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.
キーワード Geophysics Geodynamics Mineralogy
発行日 2016-11
出版物タイトル Nature
539巻
7627号
出版者 Nature Publishing Group
開始ページ 81
終了ページ 84
ISSN 0028-0836
NCID AA00752384
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
著作権者 https://creativecommons.org/licenses/by-nc-nd/4.0/deed.ja
論文のバージョン author
PubMed ID 27750277
DOI 10.1038/nature19777
Web of Sience KeyUT 000386670100033
関連URL https://doi.org/10.1038/nature19777