Partitioning of Ni between magnesiowüstite and metal at high pressure: implications for core-mantle equilibrium

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

The partitioning of Ni between metal and magnesiowüstite is experimentally investigated up to 17 GPa. From the thermodynamic analysis of the experimentally determined distribution coefficient, KD( M MW) = ( XNi XFe)metal XNi XFe)oxide, we obtain seven thermodynamic parameters relevant to its dependency on pressure, temperature and chemical composition. KD( M MW) is strongly dependent on pressure, temperature and MgO content in magnesiowüstite. The pressure effect is most effective and KD( M MW) significantly decreases with increasing pressure (i.e., chemical affinity of Ni with magnesiowüstite is enhanced by high pressure). KD between metal and bulk mantle silicates, KD( M BMS), is estimated on the basis of compiled data of KD(M/Silicates) and the extrapolated value of KD( M MW). KD( M BMS) also decreases with pressure. The chemical reaction between sinking Fe alloy and mantle material at high pressure leads that Ni transfer into the mantle material from Fe alloy. From the comparison KD( M BMS) and KD(core/mantle), the present high Ni concentration in the earth's uppermost mantle is well explained by the equilibrium partitioning of Ni during core-mantle separation combined with a subsequent mantle differentiation.

Original languageEnglish
Pages (from-to)293-313
Number of pages21
JournalEarth and Planetary Science Letters
Volume105
Issue number1-3
DOIs
Publication statusPublished - 1991
Externally publishedYes

Fingerprint

Silicates
Earth mantle
partitioning
Metals
mantle
metal
metals
silicates
silicate
Thermodynamics
Pressure effects
thermodynamics
Oxides
Chemical reactions
sinking
pressure effect
Earth (planet)
pressure effects
chemical reaction
Temperature

ASJC Scopus subject areas

  • Earth and Planetary Sciences (miscellaneous)
  • Geochemistry and Petrology
  • Geophysics
  • Earth and Planetary Sciences(all)
  • Environmental Science(all)

Cite this

@article{0f4a3e9d2ec946e19425d80a05df5748,
title = "Partitioning of Ni between magnesiow{\"u}stite and metal at high pressure: implications for core-mantle equilibrium",
abstract = "The partitioning of Ni between metal and magnesiow{\"u}stite is experimentally investigated up to 17 GPa. From the thermodynamic analysis of the experimentally determined distribution coefficient, KD( M MW) = ( XNi XFe)metal XNi XFe)oxide, we obtain seven thermodynamic parameters relevant to its dependency on pressure, temperature and chemical composition. KD( M MW) is strongly dependent on pressure, temperature and MgO content in magnesiow{\"u}stite. The pressure effect is most effective and KD( M MW) significantly decreases with increasing pressure (i.e., chemical affinity of Ni with magnesiow{\"u}stite is enhanced by high pressure). KD between metal and bulk mantle silicates, KD( M BMS), is estimated on the basis of compiled data of KD(M/Silicates) and the extrapolated value of KD( M MW). KD( M BMS) also decreases with pressure. The chemical reaction between sinking Fe alloy and mantle material at high pressure leads that Ni transfer into the mantle material from Fe alloy. From the comparison KD( M BMS) and KD(core/mantle), the present high Ni concentration in the earth's uppermost mantle is well explained by the equilibrium partitioning of Ni during core-mantle separation combined with a subsequent mantle differentiation.",
author = "Satoru Urakawa",
year = "1991",
doi = "10.1016/0012-821X(91)90138-8",
language = "English",
volume = "105",
pages = "293--313",
journal = "Earth and Planetary Sciences Letters",
issn = "0012-821X",
publisher = "Elsevier",
number = "1-3",

}

TY - JOUR

T1 - Partitioning of Ni between magnesiowüstite and metal at high pressure

T2 - implications for core-mantle equilibrium

AU - Urakawa, Satoru

PY - 1991

Y1 - 1991

N2 - The partitioning of Ni between metal and magnesiowüstite is experimentally investigated up to 17 GPa. From the thermodynamic analysis of the experimentally determined distribution coefficient, KD( M MW) = ( XNi XFe)metal XNi XFe)oxide, we obtain seven thermodynamic parameters relevant to its dependency on pressure, temperature and chemical composition. KD( M MW) is strongly dependent on pressure, temperature and MgO content in magnesiowüstite. The pressure effect is most effective and KD( M MW) significantly decreases with increasing pressure (i.e., chemical affinity of Ni with magnesiowüstite is enhanced by high pressure). KD between metal and bulk mantle silicates, KD( M BMS), is estimated on the basis of compiled data of KD(M/Silicates) and the extrapolated value of KD( M MW). KD( M BMS) also decreases with pressure. The chemical reaction between sinking Fe alloy and mantle material at high pressure leads that Ni transfer into the mantle material from Fe alloy. From the comparison KD( M BMS) and KD(core/mantle), the present high Ni concentration in the earth's uppermost mantle is well explained by the equilibrium partitioning of Ni during core-mantle separation combined with a subsequent mantle differentiation.

AB - The partitioning of Ni between metal and magnesiowüstite is experimentally investigated up to 17 GPa. From the thermodynamic analysis of the experimentally determined distribution coefficient, KD( M MW) = ( XNi XFe)metal XNi XFe)oxide, we obtain seven thermodynamic parameters relevant to its dependency on pressure, temperature and chemical composition. KD( M MW) is strongly dependent on pressure, temperature and MgO content in magnesiowüstite. The pressure effect is most effective and KD( M MW) significantly decreases with increasing pressure (i.e., chemical affinity of Ni with magnesiowüstite is enhanced by high pressure). KD between metal and bulk mantle silicates, KD( M BMS), is estimated on the basis of compiled data of KD(M/Silicates) and the extrapolated value of KD( M MW). KD( M BMS) also decreases with pressure. The chemical reaction between sinking Fe alloy and mantle material at high pressure leads that Ni transfer into the mantle material from Fe alloy. From the comparison KD( M BMS) and KD(core/mantle), the present high Ni concentration in the earth's uppermost mantle is well explained by the equilibrium partitioning of Ni during core-mantle separation combined with a subsequent mantle differentiation.

UR - http://www.scopus.com/inward/record.url?scp=0026268772&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0026268772&partnerID=8YFLogxK

U2 - 10.1016/0012-821X(91)90138-8

DO - 10.1016/0012-821X(91)90138-8

M3 - Article

AN - SCOPUS:0026268772

VL - 105

SP - 293

EP - 313

JO - Earth and Planetary Sciences Letters

JF - Earth and Planetary Sciences Letters

SN - 0012-821X

IS - 1-3

ER -