^1,2Ronghua Pang et al. (>10)
Earth and Planetary Science Letters 669, 119572 Link to Article [https://doi.org/10.1016/j.epsl.2025.119572]
¹Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, 550081 Guiyang, China
²University of Chinese Academy of Sciences, 100049 Beijing, China
Copyright Elsevier

The redox processes and the formation of magnetic anomalies on the lunar surface are hot topics in lunar science research. Magnetite is the only confirmed ferromagnetic and high-valence iron oxide mineral in lunar soil samples, making it a key target for studying these processes. A recent study of Chang’e-5 (CE5) lunar samples found that magnetite was widespread in the high-Ti lunar basalt regolith and was formed by impacts on the lunar surface. It remains to be confirmed whether this type of magnetite is broadly distributed, and its magnetic characteristics require further analysis. We conducted a micro-analysis of impact-sputtered troilite in the CE5 and Chang’e-6 (CE6) lunar samples. Submicron magnetite and associated α-Fe were widespread in the impact-sputtered troilite. The oxygen-bearing volatiles generated or released by the impact may be critical in the formation of magnetite. Further analysis of ferromagnetic materials indicates this magnetite type exhibits magnetic vortices that are weaker than those of α-Fe. Impact-derived magnetite and α-Fe may be potential magnetic minerals responsible for the magnetic anomalies on the lunar surface. Our research confirms that impact-induced redox reactions and their products, such as magnetite, are widely distributed in the lunar basalt regolith, which may be one reason for magnetic anomalies on the lunar surface.