The principal investigator will develop a new stable isotope mass spectrometer capable of measuring oxygen isotope ratios of very small samples. An on-line capability for analyzing tiny silicate and oxide mineral samples, using a new laser fluorination technique, also will be developed. The latter will lead to a study of detailed exchange behavior of aqueous fluids with minerals and volcanic glasses. Additionally, studies will be conducted on isotopic variations in several specific rift-zone environments where enhanced fracture permeability allows deep circulation of surface waters. Investigations also will take place to better understand the isotope geochemistry of the continental crust and upper mantle.
