^1,2Le Zhang; Ya-Nan Yang,^1,2Jintuan Wang,^1,2Ze-Xian Cui,^1,2Cheng-Yuan Wang,^1,2Peng-Li He,^1,2Yan-Qiang Zhang,^1,2Mang Lin,^1,2Yi-Gang Xu
American Mineralogist 110, 1462-1471 Link to Article [https://doi.org/10.2138/am-2024-9577]
¹State Key Laboratory of Deep Earth Processes and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
²CAS Center for Excellence in Deep Earth Science, Guangzhou 510640, China
Copyright: The Mineralogical Society of America

Silicate liquid immiscibility was a common mechanism during the late-stage evolution of lunar basaltic magmas, which produced coexisting and immiscible Si- and Fe-rich melts. However, the relationship between silicate liquid immiscibility and lunar granitic rocks is debated. In this study, we investigated Si-rich melt inclusions hosted in fayalite fragments from lunar soil returned by the Chang’e 5 mission. These melt inclusions have high SiO2 (76.4 wt%), Al2O3 (11.1 wt%), and K2O (5.8 wt%), and low FeO (2.8 wt%), TiO2 (0.42 wt%), and MgO (0.02 wt%) contents. The texture and chemical composition indicate that these Si-rich melt inclusions formed through late-stage silicate liquid immiscibility of the Chang’e 5 mare basaltic magma. Mass balance considerations show that the unfractionated rare earth element patterns and Eu anomalies of these melt inclusions are similar to those of lunar granitic rocks. Dynamic calculations indicate that the accumulation of Si-rich melt was hindered by the high cooling rate of the Chang’e 5 basaltic magma after eruption. However, in deep-crustal magma chambers, basaltic magma would have cooled slowly, and the Si-rich melt generated by late-stage silicate liquid immiscibility would possibly have had enough time to migrate upward and accumulate to form a granitic melt body of significant size. The results of this study support the possibility that lunar granitic rocks are products of silicate liquid immiscibility.

^1,2Guangliang Zhang et al. (>10)
Earth and Planetary Science Letters 670, 119613 Link to Article [https://doi.org/10.1016/j.epsl.2025.119613]
¹Key Laboratory of Lunar and Deep Space Exploration, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100101, China
²University of Chinese Academy of Sciences, Beijing 100049, China
Copyright Elsevier

The Chang’e-4 mission lander and the rover landed in the Von Karman impact crater in the South Pole Aitken (SPA) basin on the far side of the moon. Using the optical images and spectral data obtained from 57 exploration points during the 60 lunar months by the Chang’e-4 rover, we have acquired information on the shallow structure of the lunar soil and the composition of the lunar surface materials. The results show that the main demonstration types in the landing area are basalt, weathered deposits, and highland rocks. The lunar soil layer in the landing area can be divided into two categories in terms of surface morphology and deep thickness, namely, thin layer lunar soil with light gray, less gravel, and less alteration, and thick layer lunar soil with dark color, more gravel, and more alteration. It was found that they alternate and appear as strip like structures, extending in a northeast southwest direction. At the same time, research on spectral composition data shows that its composition is uniform, and the composition of the landing zone is consistent with that of the Finsen impact crater, but it contains more olivine and glass components. The shallow radar research results show that the deep part of the landing area is divided into four layers: weathered accumulation layer, gravel layer, coarse gravel layer, basalt basement layer, and bedrock layer. Based on the above results, we found that the landing zone can be divided into the following stages after the formation of the Von Kármán impact crater: the Imbrian basalt filling period, during which the basalt bedrock at the bottom of the Von Kármán impact crater was formed; Next is the Eratosthenian impact modification period, during which large impact craters were formed around it, and the Von Kármán impact crater was modified. The ejecta from nearby impact craters contributed to the accumulation and weathering products of the landmass to a certain extent.