Mineralogy and provenance of the Chang'e-6 shoveled lunar samples

Abstract

<p>Lunar regolith develops through continuous gardening resulting from various space weathering processes. The Chang'e-6 (CE-6) mission landed on the lunar farside within the geologically complex South Pole-Aitken basin that was modified by impact events. Soil collected from this site preserves a detailed record of lunar geological evolution. The fine-grained regoliths reflect extensive mechanical fragmentation and mixing, and they closely match the landing area's average mineralogy. This study provides a statistical evaluation of the mineralogy, bulk geochemistry, and provenance of the CE-6 fine-grained soils (70,437 particles) using automated quantitative mineralogy and mineral chemistry analysis. The examined particles, mostly ≤30 μm in size, comprise approximately 93.5 vol% of mare basalts (plagioclase: 27.5 %; glass: 32.3 %; pyroxene: 28.2 %; olivine: 0.7 %; ilmenite: 1.9 %; Si-rich phase: 1.2 %) and approximately 6.5 vol% of exotic non-mare components. Exotic components consist mainly of anorthite (An ≥ 95) and pyroxene (En < 50) from ferroan anorthosite (FAN) (0.9 %; 0.3 %), low-Ca pyroxene (Wo ≤ 5, 1.2 %, norite), Mg-rich pyroxene (En ≥ 50, 1.3 %), equivalent plagioclase from Mg-suite clast (∼2.5 %) and magnesian olivine from the troctolite and mantle materials (Fa ≤ 20, 0.3 %). Compared to Chang'e-5 basalts, the CE-6 samples show higher glass abundance and elevated Al2O3, CaO, and Mg^#, but lower FeO levels. These differences suggest a longer history of impact gardening with more exotic non-mare components at the CE-6 sampling site. This study provides the first direct and statistically robust mineralogical evidence constraining the provenance of CE-6 soils, supporting and refining previous interpretations of lunar regolith evolution.</p>