The principal goals of this research are to investigate Re- Os systematics in the upper mantle and the nature of processes that produce Os isotopic variations in the mantle. To achieve these goals, the P.I.s will implement a two-phase research program. First, they will expand the characterization of Os isotope ratios in OIBs by analyzing selected basalts from Iceland, Hawaii, St. Helena and the Canary Islands. Second, they will investigate the extent to which assimilation of altered crust may be important in determining the Os isotopic composition of OIBs by comparing Re-Os systematics in differentiated and undifferentiated basalts, and by direct characterization of altered submarine basalt sections.
