High water concentrations (4-6 wt%) are found in the quenched glass
inclusions of phenocrysts of explosive silicic and intermediate
eruptions, Accordingly, we have measured the solubility of water in a
wide range of natural liquids up to 2 kbar. With data from the
literature, we have developed a simple, thermodynamically based
empirical model for the solubility of water as a function of temperature
(700-1200 degrees C), pressure (1-2000 bar), and composition, The model
works well for both pure H2O and mixed fluid compositions, fits the data
to +/-0.5 wt% (2 sigma), and may be used to successfully model the
degassing and eruption behavior in most volcanic systems, as well as the
magmatic exsolution processes that lead to ore deposition, Due to the
nature of the regression, however, it should not be extrapolated to
conditions beyond the range of the data.