Sulfur in lunar mare basalts as a function of bulk composition

Sulfur abundances and metallic iron abundances in 18 Apollo 12 mare basalts were determined. No correlation between sulfur abundance and metallic iron content was detected; metallic iron abundances are not primarily caused by S loss. Sulfur abundances, directly related to the bulk composition of the rocks and especially to the TiO2 content, increase with increasing degrees of fractionation and appear to result from S concentration in the melts during fractionation. Unlike the Apollo 17 melts, the Apollo 12 melts were unsaturated with respect to sulfide. Composition appears to control S content for Apollo 17 basalts, and cumulus processes may cause Fe-FeS enrichment.