Abstract
A novel geological framework is presented to address the origin of Orthopyroxene, Olivine, Mg-spinel (OOS) lithologies on the Moon, an emerging component of the lunar crust. The new framework can explain multiple remote sensing observations including the rare occurrence of OOS lithologies in close proximity, lack of mafic mineral association with Mg-spinel lithology and the contrasting observation of mafic mineral association with Mg-spinel in returned lunar samples. We further report new OOS exposures at Thomson crater and present the first remote-sensing-based evidence of mafic mixing among various OOS components. Collectively, the new framework and observations provide a testable set of geological scenarios to understand the origin and diversity of the OOS lithologies and their role in lunar crustal diversity. Future missions would directly benefit from this knowledge towards collecting the best OOS lithology samples, currently absent from the returned lunar sample collection.