9506631 Candela The P.I.s will obtain experimental data and construct models that bear on problems of geothermal energy systems, volcanic hazards, volcanic inputs to the atmosphere, and exploration for mineral deposits. In the first, and most extensive part of this research endeavor, experiments will be performed on the partitioning of many elements, between melt, brine, vapor, and crystals, covering a range of melt compositions, temperatures, oxygen fugacities and pressures at and below 1 kilobar. In the second part, the P.I.s will completely redo their magmatic devolatilization model to account for the effects of a percolation model on the chemistry of devolatilized vapor+brine, and account for the new equilibria that have been collected by our lab and by other workers. The third part of the proposed research will study the observable effects of volatile exsolution on hydrous minerals, and on textures of the associated granitic rocks. Detailed mineralogy, geochemistry and petrography (micro- and marcroscopic) will be conbined with, and interpreted in light of , the results of modeling and experimental efforts outlined above.
