This research will focus on the effect of mixed volatiles (H2O and CO2) on the evolution of primitive arc-related magmas. As recent evidence has shown the presence of significant amounts of CO2 in arc magmas, and that the thermodynamic behavior of these components appears to be non-Henrian, high pressure and temperature experiments will be conducted on two different (but related) melt compositions in order to 1) determine the solubility relations of mixed H2O-CO2 fluids in the melt phase, and 2) determine the effect of mixed fluid composition on the sub-liquidus phase equilibria. Once determined, these parameters will place the direct measurements of volatile and major-element concentrations in trapped melt inclusions from arc volcanics in a context of melt generation, migration, and segregation in the mantle wedge, greatly increasing our ability to unravel petrogenetic processes giving rise to subduction-related volcanism. This project will be laboratory intensive, engaging undergraduate students in the use of high pressure/temperature experimental apparatus and the subsequent analysis of experimental run products.
