Additional complexity in the lunar crust: Petrology of sodic anorthosites and sulfur‐rich, ferroan noritic anorthosites

Abstract

Lunar breccia 67016 contains two suites of unusual highlands rocks: sulfur‐rich, noritic anorthosites, and sodic anorthosites. Mineral compositions of the sulfur‐rich noritic anorthosites closely match those of ferroan anorthosites. Unusually large amounts of sulfides, and sulfidation reactions involving olivine in these clasts probably reflect endogenous volatile transfer. The sodic anorthosites are mafic‐poor, with mineral compositions intermediate between those of pristine ferroan and alkali anorthosites. Rare examples of pristine rocks with similar mineral compositions are known, and may represent a distinct class of lunar crustal rocks. Show more