FIG. 14. Primitive mantle-normalized plot for Ni, Cu, and PGE of the southern Roby, Twilight, and High-Grade zones. The data have been recalculated to 100 percent sulfide following Naldrett (1981). Note similar patterns for all rocks with low concentrations of Ni, Ir, Os, and Ru and high concentrations of Cu, Rh, Pt, and Pd. Primitive mantle values for Ni and Cu are from McDonough and Sun (1995) and PGE values from Guillot et al. (2000).