DOI: 10.1038/ngeo2074
论文题名: Stability of hydrous silicate at high pressures and water transport to the deep lower mantle
作者: Nishi M. ; Irifune T. ; Tsuchiya J. ; Tange Y. ; Nishihara Y. ; Fujino K. ; Higo Y.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2014
卷: 7, 期: 3 起始页码: 224
结束页码: 227
语种: 英语
Scopus关键词: groundwater flow
; high pressure
; mantle
; plate boundary
; retention
; silica
; subduction
; transport process
; water depth
; water resource
英文摘要: 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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106502
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: Geodynamics Research Center, Ehime University, Ehime 790-8577, Japan; Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo 152-8550, Japan; Japan Synchrotron Radiation Research Institute, Hyogo 679-5198, Japan
Recommended Citation:
Nishi M.,Irifune T.,Tsuchiya J.,et al. Stability of hydrous silicate at high pressures and water transport to the deep lower mantle[J]. Nature Geoscience,2014-01-01,7(3)