Experimental Investigations of the Partitioning of Oxygen Isotopes Between Vapor and Silicate Glasses and Melts at High Temperatures

该研究项目的主要目的是通过实验确定在广泛的温度和硅酸盐组成范围内的低压下，18-O和16-O在含氧蒸汽和硅酸盐玻璃、熔体和晶体之间的平衡分配。特别令人感兴趣的是在2000巴压力下硅酸盐和二氧化碳气体之间的平衡分馏系数，二氧化碳气体与长英质玻璃和熔体之间交换的平衡分馏系数和表观自扩散系数，以及二氧化碳气体与矿物之间的分馏系数。研究结果将有助于从成岩作用的角度解释共生火成岩的氧同位素组成，并对影响氧同位素在地质物质中分配的成分和结构因素有更全面的认识。

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.