The Solubility of Water in Alkali-Alumino-Silicate Melts to 8 Kbars

Abstract

To investigate some aspects of the mechanisms of solubility of water in silicate melts we have determined the maximum amount of water which can dissolve in a number of alkali-alumino-silicate melts as a function of temperature and pressure. The melt compositions used are shown in Table I and are plotted in Fig. 1. They may be conveniently considered to be modifications of the feldspar albite (Ab), Na₂OAl₂O₃6SiO₂; e.g., the composition marked AbQ is albite plus 4SiO₂ and the one marked 2:1:12 is 2 albite minus 1Al₂O₃. For future comparison with published data, the molecular weights used in calculating the mole percent solubilities from the weight percent values are one-half of the above compositions, i.e., Ab is NaAlSi₃O₈ with a molecular weight of 262.