Experimental Evidence for Partially Dehydrogenated ε-FeOOH
- Center for High Pressure Science and Technology Advanced Research, Beijing (China)
- Univ. of Hawaii at Manoa, Honolulu, HI (United States)
- Carnegie Inst. of Washington, Washington, DC (United States)
Hydrogen in hydrous minerals becomes highly mobile as it approaches the geotherm of the lower mantle. Its diffusion and transportation behaviors under high pressure are important in order to understand the crystallographic properties of hydrous minerals. However, they are difficult to characterize due to the limit of weak X-ray signals from hydrogen. In this study, we measured the volume changes of hydrous ε-FeOOH under quasi-hydrostatic and non-hydrostatic conditions. Its equation of states was set as the cap line to compare with ε-FeOOH reheated and decompression from the higher pressure pyrite-FeO2Hx phase with 0 < x < 1. We found the volumes of those re-crystallized ε-FeOOH were generally 2.2% to 2.7% lower than fully hydrogenated ε-FeOOH. Our observations indicated that ε-FeOOH transformed from pyrite-FeO2Hx may inherit the hydrogen loss that occurred at the pyrite-phase. Hydrous minerals with partial dehydrogenation like ε-FeOOHx may bring it to a shallower depth (e.g., < 1700 km) of the lower mantle.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division; National Science Foundation (NSF); China Postdoctoral Science Foundation
- Grant/Contract Number:
- FG02-94ER14466; EAR-1128799; 18NZ021-0213-216308L; U1530402
- OSTI ID:
- 1544838
- Journal Information:
- Crystals, Vol. 9, Issue 7; ISSN 2073-4352
- Publisher:
- MDPICopyright Statement
- Country of Publication:
- United States
- Language:
- ENGLISH
Web of Science
The dynamics and impact of compositionally originating provinces in a mantle convection model featuring rheologically obtained plates
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journal | December 2019 |
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