Igneous thermometers and barometers based on plagioclase + liquid equilibria: Tests of some existing models and new calibrations
2005; Mineralogical Society of America; Volume: 90; Issue: 2-3 Linguagem: Inglês
10.2138/am.2005.1449
ISSN1945-3027
Autores Tópico(s)High-pressure geophysics and materials
ResumoAlthough many formulations of plagioclase + liquid equilibria have been calibrated in the last decade, few models specifically address the issue of temperature (T) prediction. Moreover, for those that do, T error is not addressed, greatly limiting their use as geothermometers. Several recent models of plagioclase-liquid equilibria are thus tested for their ability to recover T from their calibration data, and predict T from experiments not used for calibration. The models of Sugawara (2001) and Ghiorso et al. (1995, 2002) outperform earlier calibrations. These models perform reasonably well at T > 1100 °C, though recovery and prediction of T is less precise for hydrous compositions. In addition, these models cannot be integrated with geo-hygrometers, or other mineral-melt thermometers and barometers; the following expression predicts T with up to 40% greater precision:
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