9418157 Rutherford This project continues experimental work directed at understanding conditions and magmatic processes in calc-alkaline magma systems. The overall objective of this research is to better understand the evolution of these magmas, and the controls on their degassing, mixing, emplacement in crustal magam chambers, and eruption. These objectives will be achieved by determining crystal melt equilibria for assembalgges in equilibrium with a C-O-H- (+ S + Cl) fluid of fixed or measureable compositions. Of equal interest are solubility measurements of the various C-O-H-S species in melts, and establishment of equations of state which describe changes in fluid phase fugacities with P, T, and composition.