The interactions between water and silicate melt are a fundamental component of the chemical and physical properties of magmatic systems. Whereas the effects of water solution into silicate melts has been studied extensively in experimental systems, the difficulty/impossibility of quenching the silicate component dissolved in water has made this a relatively under-studied region of the experimental literature. In particular, little is know about the degree to which multi-component silicate melts are soluble in high temperature hydrothermal fluids.

Here, we investigate the mutual solubilities of haplogranite silicate melt and water over a range of temperatures and pressures using a Bassett-type hydrothermal diamond anvil cell. Experiments were observed in situ using FTIR and Raman to determine speciation and and concentrations of said species dissolved in this two phase (water + silicate) system. Measured water solubilities in silicate conform with previous experimental observations. Surprisingly, we show that- even at temperatures as low as 450-500 oC- there is a significant component of silicate dissolved in water. This result has broad implications for material transport in water-saturated magmatic systems, the modification of crystal-rich magmatic systems at or below the solidus, and the formation of ore deposits associated with magmatic systems.