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Plagioclase-alkali-feldspar geothermometry revisited

Published online by Cambridge University Press:  05 July 2018

Marjorie Powell
Affiliation:
Department of Earth Sciences, University of Leeds, Leeds LS2 9JT
Roger Powell
Affiliation:
Department of Earth Sciences, University of Leeds, Leeds LS2 9JT

Summary

The plagioclase-alkali-feldspar geothermometer formulated by Stormer (1975) does not take into account the effect of small amounts of calcium in the alkali feldspar. This geothermometer has been reformulated using ternary regular solution model equations, and it is shown that as the Ca content of the alkali feldspar increases the temperature calculated using the Stormer geothermometer will be increasingly too high.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1977

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References

Barth, (T. F. W.), 1951. The feldspar geological thermometers. Neues Jb. Mineral. Abh. 82, 143–54.Google Scholar
Carmichael, (I. S. E.), 1965. Trachytes and their feldspar phenocrysts. Mineral. Mag. 34, 107–25.Google Scholar
Emeleus, (C. H.) and Harry, (W. T.), 1970. The Igaliko complex. General Description. Meddr. Gren. 186, nr. 3.Google Scholar
Kerrick, (D. M.) and Darken, (L. S.), 1975. Statistical thermodynamic models for ideal oxide and silicate solid solutions, with application to plagioclase. Geochim. Cosmochim. Ada, 39, 1431-42.CrossRefGoogle Scholar
Orville, (P. N.), 1972. Plagioclase cation exchange equilibria with aqueous chloride solutions: results at 700 °C and 2000 bars in the presence of quartz. Am. J. Sci. 272, 234.72.CrossRefGoogle Scholar
Powell, (M.) and Powell, (R.). A nepheline-alkali feldspar geothermometer. In press. Contrib. Mineral. Petrol. Google Scholar
Powell, (R.), 1974. A comparison of some mixing models for crystalline silicate solid solutions. Contrib. Mineral. Petrol. 46, 265–74.CrossRefGoogle Scholar
Stormer, (J. C, Jr.), 1975. A practical two feldspar geothermometer. Am. Mineral. 60, 667–74.Google Scholar
Thompson, (J. B.) and Waldbaum, (D. R.), 1969. Mixing properties of sanidine crystalline solutions. III. Calculations based on two-phase data. Am. Mineral. 54, 811–38.Google Scholar
Whitney, (J. A.) and Stormer, (J. C), 1976. Geothermometry and geobarometry in epizonal granitic intrusions: a comparison of iron-titanium oxides and coexisting feldspars. Am. Mineral. 61, 751–61.Google Scholar
Wohl, (K.), 1946. Thermodynamic evaluation of binary and ternary liquid systems. Trans. Am. Inst. Chem. Engnrs. 42, 215–49.Google Scholar