MnO/FeO ratios in pyroxene, texture (abundant brown, swirly glass, in general typical of lunar regolith breccias), and overall composition (~75% plagioclase) all indicate that Allan Hills A81005 is of lunar origin. It is presumably from a heretofore unsampled region of the Moon. It differs in detail from other regolith samples, e.g., it has exceptionally low contents of Na and KREEP. A pristine clast contains exceptionally coarse augite, compared to similar Apollo samples. ALHA81005 is not preceptibly more shocked than typical Apollo regolith breccias. Therefore, its discovery on Earth lends further credence to suggestions that SNC achondrites were derived by impact ejection from Mars. |