This grant provides three years of partial salary support for technical assistance in the Radiogenic Isotope Laboratory in the Department of Geological Sciences at the Ohio State University. The Radiogenic Isotope Laboratory is a modern facility with new, first-class physical facilities that house a clean room and both thermal-ionization and noble-gas mass spectrometers, plus a full array of ancillary equipment, to support the research measurements. The laboratory conducts isotope geochemical and geochronologic research on diverse and wide-ranging issues. The principal isotopic systems of current investigation are Rb-Sr, Sm-Nd, U-Pb, K-Ca and also K-Ar especially with the 40Ar/39Ar technique. Studies include both isotope tracer research, using the radiogenic isotopes (e.g., Sr, Nd, and Pb), and geochronologic determinations (e.g., 40Ar/39Ar and Rb-Sr). Overall, the research objectives range from the fundamental and methodological to the applied and topical. In addition to the PI and intramural colleagues and students, the laboratory is utilized by a large number of extramural professionals and students, either as guest workers or by sending specimens for analysis. Research activities of the PI and Ohio State University colleagues as well as a number of external scientists with on-going collaborative and cooperative projects are quite varied. The topics range from geological and geochemical earth science to environmental and biomedical. ***
