Palladium, platinum, and rhodium contents of rocks near the lower margin of the Stillwater complex, Montana

Economic Geology
By: , and 

Links

Abstract

SPalladium, platinum, and rhodium concentrations are reported for rocks belonging to the Peridotite zone of the Ultramafic series and the Basal series of the late Archcan Stillwater Complex, a suite of Stillwater-associated sills and dikes, and the metamorphic rocks lying within the contact aureole of the complex. Mean values do not exceed 20 ppb for any rock unit and the tenth percentile rarely exceeds 200 ppb. The concentration of Pd is greater than Pt for most rock groups; both of these elements have higher concentrations than Rh.A large part of the variability in the data appears to be related to rock types containing different proportions of sulfide. It is also notable that sulfur does not correlate with the platinum-group element concentrations for many lithologies, and when it does, it commonly is not a useful predictor of platinum-group element content. Further, calculated values of R, the mass ratio of silicate liquid which has equilibrated with sulfide liquid, are low (1 to 320). Analysis of this information suggests that the immiscible sulfide liquids, from which the sulfides formed, did not completely equilibrate with the silicate liquids with respect to their platinum-group element contents and that the silicate liquids were characterized by different concentrations and ratios of platinum-group elements.

Publication type Article
Publication Subtype Journal Article
Title Palladium, platinum, and rhodium contents of rocks near the lower margin of the Stillwater complex, Montana
Series title Economic Geology
DOI 10.2113/gsecongeo.81.5.1169
Volume 81
Issue 5
Year Published 1986
Language English
Publisher Society of Economic Geologists
Description 10 p.
First page 1169
Last page 1178
Google Analytic Metrics Metrics page
Additional publication details