气候变化领域集成服务门户(CCPortal): Stability and Solubility of the FeAlO3 Component in Bridgmanite at Uppermost Lower Mantle Conditions

CCPortal

DOI	10.1029/2019JB018447
	Stability and Solubility of the FeAlO3 Component in Bridgmanite at Uppermost Lower Mantle Conditions
	Liu Z.; McCammon C.; Wang B.; Dubrovinsky L.; Ishii T.; Bondar D.; Nakajima A.; Tange Y.; Higo Y.; Cui T.; Liu B.; Katsura T.
发表日期	2020
ISSN	21699313
卷号	125 期号:2
英文摘要	We report the stability and solubility of the FeAlO3 component in bridgmanite based on phase relations in the system MgSiO3-FeAlO3 at 27 GPa and 2000 K using a multi-anvil apparatus combined with in situ synchrotron X-ray diffraction measurements. The results demonstrate that the FeAlO3 component dominates Fe3+ and Al3+ substitution in bridgmanite, although trace amounts of oxygen- and Mg-site vacancy components are also present. Bridgmanite with more than 40 mol% FeAlO3 transforms into the LiNbO3-type phase upon decompression. The FeAlO3 end-member decomposes into corundum and hematite and does not form single-phase bridgmanite. We determined the maximum solubility of the FeAlO3 component in bridgmanite at 27 GPa and 2000 K to be 67 mol%, which is significantly higher than previously reported values (25–36 mol%). We determined the partial molar volume (27.9 mol/cm3) and bulk modulus (197 GPa) of hypothetical FeAlO3 bridgmanite, which are significantly higher and lower than those of AlAlO3 and FeSiO3 bridgmanite, respectively. The non-ideality of MgSiO3-FeAlO3 solid solution (W = 13 kJ/mol, where W is the interaction parameter) is significantly larger than that for MgSiO3-AlAlO3 (5 kJ/mol) and MgSiO3-FeSiO3 (3 kJ/mol) solid solutions. The rapid decrease in abundance of the MgAlO2.5 component in bridgmanite with increasing pressure is enhanced by the presence of the FeAlO3 component. The FeAlO3 content in pyrolite and mid-ocean ridge basalt is far below its solubility limit in bridgmanite and provides new insight into the mineralogy of the lower mantle. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	bridgmanite; FeAlO3 solubility; non-ideality; the LiNbO3-type phase; the lower mantle
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187974
作者单位	Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, Germany; State Key Laboratory of Superhard Materials, Jilin University, Changchun, China; Department of Earth Sciences, Graduate School of Science, Tohoku University, Sendai, Japan; SPring-8, Japan Synchrotron Radiation Institute, Hyogo, Japan; Center for High Pressure Science and Technology Advanced Research, Beijing, China
推荐引用方式 GB/T 7714	Liu Z.,McCammon C.,Wang B.,et al. Stability and Solubility of the FeAlO3 Component in Bridgmanite at Uppermost Lower Mantle Conditions[J],2020,125(2).
APA	Liu Z..,McCammon C..,Wang B..,Dubrovinsky L..,Ishii T..,...&Katsura T..(2020).Stability and Solubility of the FeAlO3 Component in Bridgmanite at Uppermost Lower Mantle Conditions.Journal of Geophysical Research: Solid Earth,125(2).
MLA	Liu Z.,et al."Stability and Solubility of the FeAlO3 Component in Bridgmanite at Uppermost Lower Mantle Conditions".Journal of Geophysical Research: Solid Earth 125.2(2020).