The 187Os/188Os of abyssal peridotites show a wide range from values near those expected for primitive depleted mantle, to higher and lower values. The higher values may be explained by interaction of abyssal peridotites with sea water. This proposal is for a 1-yr pilot study to explore the possibility that chromite grains in the AP may be used to extract real values of 187Os/188Os unaffected by seawater. Preliminary data are presented. In stage 2, the PIs will analyze chromites from suites of normal and plume-affected abyssal peridotites.
