Interaction between iron and post-perovskite at core-mantle boundary and core signature in plume source region

Takeshi Sakai, Tadashi Kondo, Eiji Ohtani, Hidenori Terasaki, Noriaki Endo, Toshiko Kuba, Toshiaki Suzuki, Takumi Kikegawa

Research output: Contribution to journalArticlepeer-review

62 Citations (Scopus)

Abstract

Interaction between the lower mantle and core is essential for understanding the nature of D″ layer at the core-mantle boundary (CMB). Here, we report the reaction between post-perovskite (PPv) and metallic iron under the condition of the CMB, for example, 139 GPa and 3000 Kelvin. Analytical transmission electron microscope (ATEM) analysis revealed that significant amount of oxygen up to 6.3 weight percent (wt.%) and silicon up to 4.0 wt.% can be dissolved into molten iron. The dihedral angle between PPv and molten iron is 67 degrees. Thus, a small amount of core metal of about 2 volume percent (vol.%) can be trapped without separation in the PPv region at the CMB. The amount of core metal trapped by this mechanism can produce the isotopic signature of the outer core in the plume source at the base of the lower mantle.

Original languageEnglish
Article numberL15317
JournalGeophysical Research Letters
Volume33
Issue number15
DOIs
Publication statusPublished - Aug 2006

ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)

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