Activity coefficients for FeS and NiS in monosulfide liquid and NiSi sub 1/2 O sub 2 in olivine from sulfide-silicate equilibria

Journal Article · Sat Apr 01 04:00:00 EST 1989 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(89)90025-2· OSTI ID:5022863

Fleet, M E ^[1]

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1. Univ. of Western Ontario, London (Canada)

Data for the partition of FeO and NiO between (Mg, Fe, Ni)-olivine and oxide-bearing (Fe, Ni)-monosulfide liquid at 1,300 to 1,395{degree}C and low pressure have been analyzed to derive activity coefficients for FeS, NiS and NiSi{sub {1/2}}O{sub 2} relative to literature values for {gamma}{sub FeSi{sub {1/2}}}{sub O{sub 2}}. FeS and NiS exhibit positive deviations from ideal solution in the monosulfide-oxide liquid, which vary from small for f{sub O{sub 2}} values 1 log unit above the iron-wustite (IW) buffer to moderate for f{sub O{sub 2}} values 0.5 log units below the fayalite-magnetite-quartz (FMQ) buffer and appear to be largely related to oxygen content. The mixing of FeS and NiS is only approximately consistent with a regular solution model. The activity coefficient of NiSi{sub {1/2}}O{sub 2} in (Mg, Fe, Ni)-olivine is consistent with small to moderate positive deviations from ideal solution in the (Mg, Fe, Ni)-composition field of natural olivine, increasing with an increase in fayalite content and a decrease in NiSi{sub {1/2}}O{sub 2} content. For natural olivine at 1,300 to 1,395{degree}C, {gamma}{sub NiSi{sub {1/2}}}{sub O{sub 2}} is 1.1 at Fo96 and about 1.8 at Fo80.

• OSTI ID: 5022863
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Journal Name: Geochimica et Cosmochimica Acta; (USA) Vol. 53:4; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ALKALINE EARTH METAL COMPOUNDS
CHALCOGENIDES
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
CHEMISTRY
GEOCHEMISTRY
IRON COMPOUNDS
IRON SILICATES
IRON SULFIDES
KINETICS
MAGNESIUM COMPOUNDS
MAGNESIUM SILICATES
MINERALS
NICKEL COMPOUNDS
NICKEL SILICATES
NICKEL SULFIDES
OLIVINE
OXYGEN COMPOUNDS
REACTION KINETICS
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
SULFIDES
SULFUR COMPOUNDS
THERMODYNAMIC ACTIVITY
TRANSITION ELEMENT COMPOUNDS