Fig. 1.

D_N^{metal-silicate} as a function of fO_2. Large symbols represent D_N^{metal-silicate} values from this study, and small symbols are results from several previous studies: diamonds and red x’s (17), blue x’s (16), black x’s (21), gray circles (20), empty circles (22), triangles (18, 37, 50, 51), and blue crosses (15). All fO₂ values were recalculated following the procedure described in the text. Following this calculation, only 2 of the 4 samples from Li et al. (16) have log fO₂ < ΔIW. Error bars represent 2σ SDs. P–T conditions have only a small effect on D_N^{metal-silicate} and explain the scatter among the overall decreasing trend with decreasing fO₂. Our data measured using SIMS (Fe-rich basalt and andesite) are in agreement with previously published D_N^{metal-silicate} values measured by EPMA.