^1,2Zhiming Chen et al. (>10)
Journal of Geophysical Research (Planets)(in Press) Link to Article [https://doi.org/10.1029/2025JE008976]
¹State Key Laboratory of Deep Earth Processes and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China
²College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
Published by arrangement with John Wiley & Sons

Lunar regolith contains not only materials derived from the local rock unit, but also materials transferred from remote craters, which are crucial for investigating the lithological diversity of the lunar surface. In this study, we conducted detailed petrography and geochemical analyses and measured the cross-sectional area of plagioclase fragments and impact glass particles selected from the Chang’e 6 (CE-6) regolith, the first lunar far-side returned sample. Statistics of plagioclase fragments and impact glass are used to estimate the proportion of the diverse components in the CE-6 regolith. The results reveal 35.7 vol% and 28.2 vol% exotic components in CE-6 plagioclase and impact glass fractions, respectively. As plagioclase, pyroxene and glass particles are the three dominant phases (>95 vol%) in the CE-6 regolith, together with previously reported pyroxene compositions, we estimate that the abundance of the exotic materials is 23.5–33.5 vol%. These exogeneous components include very-low-Ti (VLT) basalt (2%–3%), ferroan anorthosite (5%–9%), Mg-suite (15%–20%), KREEP-related (∼0.1%), and highlands-mare-mixed materials (∼1%). The VLT-basalt component is most likely from the mare basalt unit to the east of the landing site or beneath the local mare layer. Based on the ejecta orientations and model age of impact craters, ferroan anorthite, Mg-suite and KREEP-related materials are likely transferred from Vavilov/Pythagoras (highland anorthosite), Chaffee S/White’ (rich in mafic minerals), and Birkeland (high Th contents) craters, respectively. The abundant non-mare components in the CE-6 regolith contrast to the very scarce exotic materials in the CE-5 lunar regolith, potentially providing valuable insights into the composition of the lunar far-side.

¹Garima Sodha,¹Deepak Dhingra
Journal of Geophysical Research (Planets)(in Press) Link to Article [https://doi.org/10.1029/2024JE008809]
¹Department of Earth Sciences, Indian Institute of Technology Kanpur (IITK), Kanpur, Uttar Pradesh, India
Published by arrangement with John Wiley & Sons

The spatial distribution of Mg-spinel lithology at South Pole-Aitken (SPA) basin is revealed by systematic mineralogical survey along the basin rings. We report Ingenii-Thomson region as a Mg-spinel anomaly, having the largest number of exposures based on newly identified and previously reported occurrences on the Moon. The timing of Mg-spinel formation is constrained by using SPA impact as a key geological time marker. Post-SPA origin of this lithology is favored in this region due to the general lack of pervasive Mg-spinel occurrences along basin rings, being the deepest exposures of the pre-SPA crust. Our detailed mineralogical analyses also highlight several detections of Mg-spinel lithology exhibiting weak 1,000 nm absorption band, emphasizing the need for a detailed analysis of such locations. Collectively, these salient findings have important implications for understanding the compositional diversity of Mg-spinel lithology, refinement of the formation models and determining the role of Mg-spinel lithology in the lunar crustal evolution.