Solution properties of almandine-pyrope garnet as determined by phase equilibrium experiments
- Geologial Survey, Menlo Park, CA (United States)
Garnet is the essential constituent in many metamorphic reactions that have been calibrated as thermobarometers. The thermodynamic mixing properties of almandine-pyrope garnet were derived from phase equilibrium experiments at temperatures of 900 and 1,000 C and pressures from 8 to 14 kbar for the assemblage garnet + rutile + sillimanite + ilmenite + quartz (GRAIL). Almandine (Alm) has essentially ideal behavior in almandine-pyrope garnet over the composition range Alm[sub 89]-Alm[sub 61] at the above experimental conditions. In all experimental products a systematic partitioning of Fe and Mg between garnet and ilmenite was seen with ln K[sub d] [approx] 1.59. This partitioning does not appear to be temperature sensitive. The results of this study support the use of garnet mixing models that incorporate ideal or nearly ideal Fe-Mg parameters.
- OSTI ID:
- 6937682
- Journal Information:
- American Mineralogist; (United States), Journal Name: American Mineralogist; (United States) Vol. 77:7-8; ISSN AMMIAY; ISSN 0003-004X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
580000* -- Geosciences
DISPERSIONS
DISSOLUTION
EQUILIBRIUM
GARNETS
GEOBAROMETRY
GEOLOGIC MODELS
MATHEMATICAL MODELS
METAMORPHIC ROCKS
METAMORPHISM
MINERALS
MIXTURES
OXYGEN COMPOUNDS
PARAGENESIS
PARTICLE MODELS
PHASE STUDIES
PHYSICAL PROPERTIES
ROCKS
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
SOLID SOLUTIONS
SOLUTIONS
STATISTICAL MODELS
THERMODYNAMIC MODEL
THERMODYNAMIC PROPERTIES