論文

査読有り
2014年

Stability of hydrous silicate at high pressures and water transport to the deep lower mantle

Nature Geoscience
  • M. Nishi
  • ,
  • T. Irifune
  • ,
  • J. Tsuchiya
  • ,
  • Y. Tange, Y
  • ,
  • Nishihara
  • ,
  • K. Fujino
  • ,
  • Y. Higo

7
3
開始ページ
224
終了ページ
227
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1038/ngeo2074

The presence of water strongly influences the structure, composition and dynamics of the Earth's deep mantle. Hydrous magnesium-rich silicates play an important role in transporting water into the deep mantle when oceanic plates subduct as slabs. The highest-pressure form of such hydrous silicates, phase D, was reported to dissociate into an assemblage of nominally anhydrous phases plus water at pressures of about 44 GPa, equivalent to 1,250 km depth. In this way, free water would be released in the middle region of the lower mantle, which suggests that no water can reach the deeper regions of the lower mantle. Here we use in situ X-ray measurements in conjunction with a multi-anvil apparatus using sintered diamond anvils to show that hydrous phases are stable under lower mantle conditions up to 50 GPa. We found that phase D transforms to an assemblage with another hydrous silicate (MgSiH 2 O 4), named phase H, at pressures above about 48 GPa. Our results suggest that phase H is the dominant hydrous silicate in descending slabs, and may be found at depths far deeper than 1,250 km. We conclude that a significant amount of water is retained in the descending slabs and may be delivered to the deepest part of the lower mantle. © 2014 Macmillan Publishers Limited.

リンク情報
DOI
https://doi.org/10.1038/ngeo2074
Scopus Url
http://www.scopus.com/inward/record.url?eid=2-s2.0-84895467742&partnerID=MN8TOARS
URL
http://www.scopus.com/inward/record.url?partnerID=HzOxMe3b&scp=84895467742&origin=inward
ID情報
  • DOI : 10.1038/ngeo2074
  • ISSN : 1752-0894
  • ORCIDのPut Code : 49519630
  • SCOPUS ID : 84895467742

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