DOI: 10.1016/j.epsl.2020.116551
论文题名: A new hydrous iron oxide phase stable at mid-mantle pressures
作者: Chen H. ; Xie S.-Y. ; Ko B. ; Kim T. ; Nisr C. ; Prakapenka V. ; Greenberg E. ; Zhang D. ; Bi W. ; Ercan A.E. ; Lee Y. ; Shim S.-H.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 550 语种: 英语
中文关键词: crystal structure
; hydrogen
; hydrous iron oxide
; lower mantle
英文关键词: Crystal structure
; Earth atmosphere
; Iron oxides
; Magnesia
; Oxide minerals
; Phosphorus compounds
; Pyrites
; Earth's interior
; Epsilon phase
; Hydrous iron oxides
; Mantle transition zone
; Potential storage sites
; Storage capacity
; Volatile elements
; Water transport
; Hydrogen storage
; crystal structure
; experimental study
; iron oxide
; lower mantle
; mantle source
; periclase
; pressure gradient
; pyrite
英文摘要: The amount of hydrogen stored in the Earth's interior is important for a range of issues, including the volatile incorporation during the Earth formation and the co-evolution of the atmosphere, the hydrosphere, and the interior. Recent experiments found titanium bearing ε-FeOOH in a hydrous basaltic system at 12–19 GPa and 1300 K. Pyrite-type FeOOH was found to be stable at pressures higher than 80 GPa. These discoveries suggest possible hydrogen storage in the mantle transition zone and in the mantle below 1800 km depths, respectively. However, it remains uncertain how the potential deep hydrogen storage can be connected to the shallower storage. Here, we report a new hydrous iron oxide (η-Fe12O18+x/2Hx, x≈2) stable at pressures between the stability fields of the ε- and the pyrite-type FeOOH. Our experiment also shows that the new η phase can exist together with the major lower mantle minerals including bridgmanite and periclase, making it an important hydrogen-bearing phase in the Earth's deep interior. Because of its limited H2O storage capacity, which is less than 1/6 of the storage capacity of the pyrite-type phase and the ε phase, the stability of the η phase would result in H2O loss during water transport in the mid mantle and therefore limit the amount of H2O potentially stored in the Fe–O–H system of the lower mantle. The large channel in the crystal structure of the η phase could provide potential storage sites for other volatile elements in the deep mantle. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164913
Appears in Collections: 气候变化与战略
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作者单位: School of Earth Sciences, China University of Geosciences, Wuhan, Hubei, China; School of Earth and Space Exploration, Arizona State University, Tempe, AZ, United States; School of Physics and Electronics, Hunan University, Changsha, Hunan, China; Department of Earth System Sciences, Yonsei University, Seoul, South Korea; GeoSoilEnviroCars, University of Chicago, Chicago, IL, United States; Advanced Photon Source, Argonne National Laboratory, Argonne, IL, United States
Recommended Citation:
Chen H.,Xie S.-Y.,Ko B.,et al. A new hydrous iron oxide phase stable at mid-mantle pressures[J]. Earth and Planetary Science Letters,2020-01-01,550