Fig. 7: Ni and Cu contents of globular and massive sulphide ores in Noril’sk-Talnakh intrusions.

Data for globular sulphides (in yellow) are recalculated to 100% sulphide and are from ref. ²; the average of 30 analyses is shown. Data for massive sulphides (in blue) are from refs. ^{2, 43}; the average of 64 analyses is shown. The solid and the dotted lines indicate equilibrium contents for variable silicate/sulphide mass ratios, i.e., R (indicated on the lines), calculated following Campbell and Naldrett’s equation⁹ using Dsulf/sil values determined in this study for the most reducing and the most oxidising redox conditions (Table 1), and initial Ni and Cu concentration in the parental magma of 120 ppm and 150 ppm, respectively.