THE DISTRIBUTION OF NICKEL AND IRON BETWEEN OLIVINE AND MAGMATIC SULFIDES IN SOME NATURAL ASSEMBLAGES

The distribution of nickel and iron between olivine and bulk sulfide has been determined in four nickel-copper-PGE (platinum-group-element) sulfide deposits. The mean distribution-coetticient 1f$iff{$!il is 5.0 + 1.7 in the Katahdin deposit (Maine), 8.3 + 3.1 in the Moxie pluton (Maine), 10.8 I 2.3 in the Dumont deposit (Quebec), and 1 1.4 t 4.8 in the Platinum Reef of the Stillwater complex (Montana). The weight of the evidence from this and previous studies of natural assemblages, as well as various dfuect and indirect experimental determinations, indicates that the distribution coefficient to be expected from the equilibration of olivine and molten sulfide under normal magmatic conditions will be in the range of 5 to 20, and most likely in the low part of the range