¹Jingyou Chen, ²Shaolin Li, ³Shiyong Liao, ⁴Jian Chen, ⁵Alexander Nemchin, ⁶Katherine H. Joy, ⁷Xiaochao Che, ³Weibiao Hsu, ⁸Menghua Zhu
Geochimica et Cosmochimica Acta (in Press) Link to Article [https://doi.org/10.1016/j.gca.2026.01.007]
¹State Key Laboratory of Deep Earth Processes and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
²Astronomical Research Center, Shanghai Science and Technology Museum, Shanghai, China
³CAS Center for Excellence in Comparative Planetology, Purple Mountain Observatory, Nanjing 210034, China
⁴Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai 264209, China
⁵School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
⁶Department of Earth and Environmental Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK
⁷The Beijing SHRIMP Center, Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China
⁸State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau
Copyright Elsevier

The increasing identification of magnesian anorthosites (MAN) in lunar meteorites, along with inferences from remote sensing techniques, has intensified research interest in understanding their role in lunar crust formation. However, the lack of robust geochronological constraints for MAN impeded our comprehension of the timeline of crustal evolution. The lunar feldspathic breccia meteorite, Northwest Africa (NWA) 11479, is composed primarily of Mg-rich, KREEP-poor (K, rare earth elements, and P) highland lithic fragments, predominantly consisting of magnesian anorthositic lithologies (including anorthosite noritic/troctolitic anorthosites, and the associated magnesian granulites). The close chemical match between the bulk rock and lunar remote sensing data supports a farside origin, providing evidence for the presence of MAN in the Feldspathic Highlands Terrane (FHT).
Zircon and apatite grains have been discovered within the small Mg-rich anorthositic clasts in NWA 11479. Notably, the occurrence of these highly evolved accessory minerals contrasts with the depletion of incompatible trace elements in the coexisting silicates, suggesting their formation via interactions between the anorthositic crust and a later-stage KREEPy metasomatic melt. In-situ U-Pb isotopic analysis of the zircon and apatite yields a well-defined discordia line, with an upper intercept date of 4328 ± 9 Ma (2σ), and a lower intercept date of 140 ± 64 Ma (2σ). The younger age likely reflects a more recent impact event, whereas the upper intercept is consistent with both the concordant U-Pb zircon date (4327 ± 12 Ma, 2σ) and the weighted average 207Pb/206Pb date of the zircon and apatite (4326 ± 8 Ma, 2σ). This ∼ 4.33 Ga age is interpreted as the timing of metasomatism responsible for the formation of the zircon and apatite, or an impact event. Importantly, this age obtained from the putative-origin meteorite coincides with the period (4.3–4.35 Ga) of the active secondary magmatism recorded in nearside-collected Apollo samples, the proposed formation age of the giant South Pole–Aitken (SPA) basin. These temporal correlations suggest that this epoch represents a major phase of global reworking of the primordial lunar crust, likely driven by the overturn of mantle cumulates and further intensified by basin‑scale impact events, or both.