^1,2Guozhu Chen,^1,2Zhipeng Xia,^1,2Bingkui Miao,^3,4Zilong Wang,³Wei Tian,^1,2Yikai Zhang,^1,2Hao Liu,^1,2Chuangtong Zhang,^1,2Lanfang Xie,^1,2Yanhua Peng,^1,2Hongyi Chen,^1,2Xi Wang
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14058]
¹Institution of Meteorites and Planetary Materials Research, Key Laboratory of Planetary Geological Evolution, Education Department of Guangxi Zhuang Autonomous Region, Guilin University of Technology, Guilin, China
²Guangxi Key Laboratory of Hidden Metallic Ore Deposits Exploration, Guilin University of Technology, Guilin, China
³Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Ministry of Education, Peking University, Beijing, China
⁴Key Laboratory of Paleomagnetism and Tectonic Reconstruction of MNR, Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing, China
Published by arrangement with John Wiley & Sons

The study of lunar magma evolution holds significant importance within the scientific community due to its relevance in understanding the Moon’s thermal and geological history. However, the intricate task of unraveling the history of early volcanic activity on the Moon is hindered by the high flux of impactors, which have substantially changed the morphology of pristine volcanic constructs. In this study, we focus on a unique volcanic glass found in the lunar meteorite Northwest Africa 11801. This kind of volcanic glass is bead-like in shape and compositionally similar to the Apollo-14 and Apollo-17 very low-Ti glass. Our research approach involves conducting a comprehensive analysis of the petrology and mineralogy of the volcanic glass, coupled with multiple thermodynamic modeling techniques. Through the investigation, we aim to shed light on the petrological characteristics and evolutionary history of the glass. The results indicate that the primitive magma of the glass was created at 1398–1436°C and 8.3–11.9 kbar (166–238 km) from an olivine+orthopyroxene mantle source region. Then, the magma ascended toward the surface along a non-adiabatic path with an ascent rate of ~40 m s−1 or 0.2 MPa s−1. During the magma ascent, only olivine crystallized and the onset of magma eruption occurred at ~1320–1343°C. Finally, the glass cooled rapidly on the lunar surface with a cooling rate ranging between 20 and 200 K min−1. Considerable evidence from petrology, mineralogy, cooling rate, and the eruption rate of the glass beads strongly supports the occurrence of ancient explosive volcanism on the Moon.

¹I-Huan Chiu,²Kentaro Terada,³Takahito Osawa,⁴Changkun Park,⁵Soshi Takeshita,⁵Yasuhiro Miyake,¹Kazuhiko Ninomiya
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14059]
¹Institute Radiation Sciences, Osaka University, Osaka, Japan
²Graduate School of Science, Osaka University, Osaka, Japan
³Nuclear Science Research Institute, Japan Atomic Energy Agency, Ibaraki, Japan
⁴Korea Polar Research Institute, Incheon, Republic of Korea
⁵High Energy Accelerator Research Organization (KEK), Ibaraki, Japan
Published by arrangement with John Wiley & Sons

We report the result of a non-destructive elemental analysis of lunar meteorites using a negative muon beam at J-PARC. An experimental system of six Ge semiconductor detectors and a newly designed He analysis chamber (to enable quantitative analysis of Al) was used to provide a high signal-to-noise ratio for the detection of major elements from lunar rocks (Mg, Si, Fe, O, Ca, and Al). We performed a Monte Carlo simulation to determine the chemical compositions at two sides and the center of a sample (at depths of 0.33 and 0.96 mm below the sample surface, respectively) of the lunar meteorite DEW 12007. These results indicate that the three interior regions of DEW 12007 are likely to be 55.8:44.2, 51.4:48.6, and 54.4:45.6 wt% mixtures of anorthositic and basaltic clasts, respectively. This study is the first quantitative analysis of a heterogeneous meteorite interior using a negative muon beam. As elemental analysis using a muon beam is non-destructive and highly sensitive to light elements, including C, N, and O, the protocols established in this study are applicable to initial characterization of returned samples from the South Pole of the Moon.