@article{93e37521b4214aebb350449923e46278,
title = "Dehydration of δ-AIOOH in earth{\textquoteright}s deep lower mantle",
abstract = "δ-AlOOH has been shown to be stable at the pressure–temperature conditions of the lower mantle. However, its stability remains uncertain at the conditions expected for the lowermost mantle where temperature is expected to rise quickly with increasing depth. Our laser-heated diamonδ-anvil cell experiments show that δ-AlOOH undergoes dehydration at ~2000 K above 90 GPa. This dehydration temperature is lower than geotherm temperatures expected at the bottom ~700 km of the mantle and suggests that δ-AlOOH in warm slabs would dehydrate in this region. Our experiments also show that the released H2O from dehydration of δ-AlOOH can react with metallic iron, forming iron oxide, iron hydroxide, and possibly iron hydride. Our observations suggest that H2O from the dehydration of subducting slabs, if it occurs, could alter the chemical composition of the surrounding mantle and core regions.",
keywords = "Dehydration, Hydrogen cycle, Hydrous minerals, Lowermost mantle, δ-AlOOH",
author = "H{\'e}l{\`e}ne Piet and Leinenweber, {Kurt D.} and Jacqueline Tappan and Eran Greenberg and Prakapenka, {Vitali B.} and Buseck, {Peter R.} and Shim Sang-Heon",
note = "Funding Information: Funding: This work has been supported by the research grant “Water from the Heavens: The Origins of Earth{\textquoteright}s Hydrogen” sponsored by the W. M. Keck Foundation (P.I. Peter Buseck). S.-H.S. and H.P. were also supported by NASA (80NSSC18K0353). S.-H.S. was supported by NSF (EAR1338810). Portions of this work were performed at GSECARS (University of Chicago, Sector 13). GSECARS is supported by the NSF (EAR-1634415) and DOE (DE-FG02-94ER14466). APS is the U.S. DOE Office of Science User Facilities operated for the DOE Office of Science by ANL (DE-AC02-06CH11357). All the data are either presented in the main text or in the supporting information. Funding Information: This work has been supported by the research grant “Water from the Heavens: The Origins of Earth{\textquoteright}s Hydrogen” sponsored by the W. M. Keck Foundation (P.I. Peter Buseck). S.-H.S. and H.P. were also supported by NASA (80NSSC18K0353). S.-H.S. was supported by NSF (EAR1338810). Portions of this work were performed at GSECARS (University of Chicago, Sector 13). GSECARS is supported by the NSF (EAR-1634415) and DOE (DE-FG02-94ER14466). APS is the U.S. DOE Office of Science User Facilities operated for the DOE Office of Science by ANL (DE-AC02-06CH11357). All the data are either presented in the main text or in the supporting information. Publisher Copyright: {\textcopyright} 2020 by the authors. Licensee MDPI, Basel, Switzerland.",
year = "2020",
month = apr,
doi = "10.3390/min10040384",
language = "English (US)",
volume = "10",
journal = "Minerals",
issn = "2075-163X",
publisher = "Multidisciplinary Digital Publishing Institute (MDPI)",
number = "4",
}