¹Yong Wu et al. (>10)
Icarus (in Press) Link to Artile [https://doi.org/10.1016/j.icarus.2025.116459]
¹National Key Laboratory of Uranium Resources Exploration-Mining and Nuclear Remote Sensing, 100029 Beijing, China
Copyright ELsevier

Chang’E-5 samples provide unique insights into the composition of the lunar interior ~2 billion years ago, but geochemical models of their formation show a significant degree of discrepancy. Trace element abundance measurements in olivine grains in Chang’E-5 sub-sample CE5C0600YJFM002GP provide additional constraints on the basalt source. Geochemical modeling indicates that low-degree (4 %) batch melting of an olivine-pyroxenite lunar magma ocean cumulate, incorporating high levels of trapped lunar magma ocean liquid and plagioclase, can reproduce the rare earth element, Sr, Rb, Sc, Co and Ni abundances in our and previously reported Chang’E-5 samples, as well as observed Rb-Sr and Sm-Nd isotope systematics. Overall, these results strengthen the direct geochemical links between lunar magma ocean evolution and basaltic volcanism occurring ~2.5 billion years later. Additionally, Chang’E-5 high-Fo olivine is enriched in the volatile element Ge (1.38–3.94 μg/g) by ~2 orders of magnitude compared to model results (< 0.02 μg/g). As Ge is a mildly compatible element with bulk Ge partition coefficients close to 1, a Ge-depleted initial LMO proposed by previous research cannot yield a high-Ge mantle source for Chang’E-5 basalt, even when invoking assimilation of high-Ge LMO cumulates. The overabundance of Ge requires either a high-Ge, volatile rich initial bulk Moon with chondritic composition or a late Ge chloride vapor-phase metasomatism.

¹Christian Potiszil, ¹Tsutomu Ota, ¹Masahiro Yamanaka, ¹Katsura Kobayashi, ¹Tanaka, ¹Nakamura
Earth and Planetary Science Letters 653, 119205 Open Access Link to Article [https://doi.org/10.1016/j.epsl.2025.119205]
¹Pheasant Memorial Laboratory, Institute for Planetary Materials, Okayama University, Yamada 827, Misasa, Tottori 682-0193, Japan
Copyright Elsevier

Carbonaceous chondrites (CC) and asteroid return samples contain amino acids (AA), which are essential for an origin of life on the early Earth and can provide important information concerning planetesimal alteration processes. While many studies have investigated AA from CC, separate studies have often found differing abundances for the same meteorite. Accordingly, analytical bias, differing terrestrial contamination levels and intrinsic sample heterogeneity have been proposed as potential reasons. However, current analytical techniques allow for the analysis of several mg-sized samples and can thus enable an investigation of AA heterogeneity within single meteorite specimens. Here, such an analytical technique is applied to characterise the AA in triplicate aliquots of three CCs. The results indicate that CCs are heterogenous in terms of their AA at the mm-scale. Furthermore, the results help to further constrain the effects of planetesimal alteration on organic matter and the requirements of future sample return missions that aim to obtain organic-bearing extraterrestrial materials.