气候变化领域集成服务门户(CCPortal): A new hydrous iron oxide phase stable at mid-mantle pressures

CCPortal

DOI	10.1016/j.epsl.2020.116551
	A new hydrous iron oxide phase stable at mid-mantle pressures
	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.
发表日期	2020
ISSN	0012821X
卷号	550
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.
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
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202535
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
推荐引用方式 GB/T 7714	Chen H.,Xie S.-Y.,Ko B.,et al. A new hydrous iron oxide phase stable at mid-mantle pressures[J],2020,550.
APA	Chen H..,Xie S.-Y..,Ko B..,Kim T..,Nisr C..,...&Shim S.-H..(2020).A new hydrous iron oxide phase stable at mid-mantle pressures.Earth and Planetary Science Letters,550.
MLA	Chen H.,et al."A new hydrous iron oxide phase stable at mid-mantle pressures".Earth and Planetary Science Letters 550(2020).