The principal goal of this research project is to determine by experiment the equilibrium partitioning of 18-O and 16-O between oxygen-bearing vapor and silicate glasses, melts, and crystals at low pressures over a wide range of temperature and silicate composition. Of particular interest are the equilibrium fractionation factors between silicates and CO2 gas at pressures to 2000 bars, the equilibrium fractionation factors and apparent self diffusion coefficients for exchange between CO2 gas and felsic glasses and melts, and the fractionation factors between CO2 gas and minerals. The results of the research will be applicable to interpreting the oxygen isotopic compositions of cogenetic igneous rocks in terms of petrogenetic processes and to developing a more complete understanding of the compositional and structural factors influencing the partitioning of oxygen isotopes in geological materials.
