^1,2,3Denton S. Ebel,^1,4Marina E. Gemma,^1,3,5Michael K. Weisberg,^1,6Jon M. Friedrich
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14328]
¹Department of Earth and Planetary Sciences, American Museum of Natural History, New York, New York, USA
²Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York, USA
³Department of Earth and Environmental Sciences, Graduate Center of the City University of New York, New York, New York, USA
⁴Department of Geosciences, Stony Brook University, Stony Brook, New York, US
⁵Department of Physical Sciences, Kingsborough College, City University of New York, Brooklyn, New York, USA
⁶Department of Chemistry, Fordham University, Bronx, New York, USA
Published by arrangement with John Wiley & Sons

Compared to the carbonaceous chondrites (CCs), ordinary chondrites (OCs) are depleted in Mg and refractory lithophile elements. The OCs are classified by a trend from high metal (H) to low total iron (L) to low total iron and low metal (LL) compositions with increasing heavy O isotopes and refractory siderophile enrichment. We surveyed many CC for primitive materials that might be analogs of components that formed in, and then escaped, originally solar composition reservoirs from which OCs formed. Amoeboid olivine aggregates (AOA) are nodular accretions with discrete refractory Ca-, Al-, Ti-rich mineral assemblages and often with separate Fe-metal alloy nodules, all surrounded by 16O-rich, near-pure olivine Mg2SiO4 rinds. Most AOAs contain the daughter products of extinct 26Al revealing their very early ages. We find relatively large metal grains with olivine rims forming isolated or clumped nodules or “metal–olivine inclusions” in AOAs in many carbonaceous chondrites, particularly the highly primitive CO-like chondrite Acfer 094 (C2 ungr). Similar nodules have been reported in samples returned from the highly altered, CI-like asteroid Bennu by the OSIRIS-REx mission. In discrete regions and times in the protoplanetary disk, differing drift velocities of these 10s of micron scale components could have caused the correlated loss of both refractory siderophiles (in metal), refractory lithophiles, and Mg and 16O (in olivine). Varying degrees of loss of nodules similar to these “MOI,” from the chondrule-forming reservoirs from which H, L, and LL chondrites accreted could, simultaneously, explain the multiple aspects of their chemical compositions.

^1,2Wenqing Chang, ^1,2Zhiguo Meng, ²Yi Xu, ²Xiaoping Zhang, ²Roberto Bugiolacchi, ^2,3Long Xiao, ^4,5Jinsong Ping, ⁴Hongbo Zhang, ^4,5Yuanzhi Zhang
Earth and Planetary Science Letters 658, 119326 Link to Article [https://doi.org/10.1016/j.epsl.2025.119326]

¹College of Geoexploration Science and Technology, Jilin University, No.6 Ximinzhu Street, Changchun 130026, China
²State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau 999078, China
³Planetary Science Institute, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China
⁴Key Laboratory of Lunar and Deep Space Exploration, National Astronomical Observatories, CAS, Beijing 100101, China
⁵School of Astronomy and Space Science, University of Chinese Academy of Sciences, Beijing 100049, China
Copyright Elsevier

The Apollo basin, situated on the northeastern edge of the South Pole-Aitken (SPA) basin, is the sampling area for the Chang’e -6 (CE-6) mission. In this study, we investigated the microwave thermophysical properties of surface deposits in the region by comparing brightness temperature (TB) and TB difference (dTB) maps derived from CE-2 Microwave Radiometer data combined with topography, chemical elements, and Moon Mineralogy Mapper products. The main results are as follows. (1) High dTB anomaly: A significant high dTB anomaly is identified near the CE-6 landing region, characterized by the highest FeO and TiO2 contents estimated from the small-fresh craters; (2) Basaltic Volcanism: High dTB anomaly is proposed as a new basaltic unit in late stage of mare infill, and, by combining derived ages and geomorphology, we provide a new perspective on the basaltic volcanism with four episodes of magma infill in the CE-6 landing region; (3) Thermophysical Parameters: The high dTB anomaly indicates the potential importance of analyzing the returned CE-6 samples to enhance our understanding of the Moon’s surface deposits using the passive microwave remote sensing data.