FIG. 9. S/Se ratios of the samples studied (laurite and Cu-Ni-Fe sulphides) compared to the values for the primitive mantle, sulphides from sub-arc mantle, mid-oceanic ridge basalts, and sedimentary rocks. Data sources: primitive mantle (McDonough and Sun, 1995), sulphides from sub-arc mantle (Hattori et al., 2002), mid-oceanic ridge basalts (Hamlyn and Keays, 1986; Peach et al., 1990), sedimentary rocks (Stanton, 1972; Leutwein, 1978) and seawater (Measures and Burton, 1980).