Chemical equilibrium between ferropericlase and molten iron to 134 GPa and implications for iron content at the bottom of the mantle

Haruka Ozawa, Kei Hirose, Masanori Mitome, Yoshio Bando, Nagayoshi Sata, Yasuo Ohishi

Research output: Contribution to journalArticle

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Abstract

We have examined the solubility of oxygen in molten iron coexisting with ferropericlase up to 134 GPa and 3200 K by using laser-heated diamond-anvil cell (LHDAC) and analytical transmission electron microscope (TEM). The results demonstrate that the oxygen solubility in liquid iron decreases with pressure to 38 GPa, whereas the pressure effect is small at higher pressures. If the molten outer core is in chemical equilibrium with the bottom thin layer of the mantle, ferropericlase could be significantly depleted in FeO at the core-mantle boundary (CMB). The liquid core containing 8 wt% oxygen, which is high enough to account for the core density deficit, coexists with ferropericlase with Mg#96 when the temperature is 4000 K. The very bottom of the mantle becomes depleted in iron by the consequences of chemical reaction with the core.

Original languageEnglish
Article numberL05308
JournalGeophysical Research Letters
Volume35
Issue number5
DOIs
Publication statusPublished - Mar 16 2008
Externally publishedYes

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chemical equilibrium
Earth mantle
mantle
iron
oxygen
solubility
diamond anvil cell
outer core
pressure effect
liquid
core-mantle boundary
chemical reaction
pressure effects
liquids
anvils
laser
electron
chemical reactions
electron microscopes
diamonds

ASJC Scopus subject areas

  • Earth and Planetary Sciences (miscellaneous)

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Chemical equilibrium between ferropericlase and molten iron to 134 GPa and implications for iron content at the bottom of the mantle. / Ozawa, Haruka; Hirose, Kei; Mitome, Masanori; Bando, Yoshio; Sata, Nagayoshi; Ohishi, Yasuo.

In: Geophysical Research Letters, Vol. 35, No. 5, L05308, 16.03.2008.

Research output: Contribution to journalArticle

Ozawa, Haruka ; Hirose, Kei ; Mitome, Masanori ; Bando, Yoshio ; Sata, Nagayoshi ; Ohishi, Yasuo. / Chemical equilibrium between ferropericlase and molten iron to 134 GPa and implications for iron content at the bottom of the mantle. In: Geophysical Research Letters. 2008 ; Vol. 35, No. 5.
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AU - Sata, Nagayoshi

AU - Ohishi, Yasuo

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