論文

2013年3月

Seismic anisotropy in the mantle transition zone induced by shear deformation of wadsleyite

Physics of the Earth and Planetary Interiors
  • Takaaki Kawazoe
  • ,
  • Tomohiro Ohuchi
  • ,
  • Yu Nishihara
  • ,
  • Yu Nishihara
  • ,
  • Norimasa Nishiyama
  • ,
  • Norimasa Nishiyama
  • ,
  • Kiyoshi Fujino
  • ,
  • Tetsuo Irifune

216
開始ページ
91
終了ページ
98
DOI
10.1016/j.pepi.2012.12.005

Mantle flow in the Earth's mantle transition zone (between 410 and 660km depth) plays a key role to understand the nature of mantle convection, which can be mapped by observed seismic anisotropy combined with crystallographic preferred orientations of mantle minerals. Although wadsleyite is the most important mineral to cause seismic anisotropy observed in the mantle transition zone, there have been limited experimental data on its crystallographic preferred orientation because of experimental limitations. We experimentally evaluated the preferred orientation of wadsleyite developed by shear deformation at pressure-temperature conditions of the mantle transition zone (17.6GPa and 1800-1900K) using a deformation-DIA apparatus. The deformation experiments reveal that the [001] axis and the (010) plane of wadsleyite tend to be subparallel to the shear direction and the shear plane during deformation, respectively. These results demonstrate that polarization seismic anisotropy (velocity contrast between horizontally-polarized and vertically-polarized S-waves, VSH/VSV) observed in the mantle transition zone might be attributed to the preferred orientation of wadsleyite caused by horizontal mantle flow. © 2013 Elsevier B.V.

リンク情報
DOI
https://doi.org/10.1016/j.pepi.2012.12.005
Scopus
https://www.scopus.com/record/display.uri?eid=2-s2.0-84874300243&origin=inward
URL
https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84874300243&origin=inward