1. Lunar Evolution in Light of the Chang'e-5 Returned Samples.
- Author
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Wu, Fu-Yuan, Li, Qiu-Li, Chen, Yi, Hu, Sen, Yue, Zong-Yu, Zhou, Qin, Wang, Hao, Yang, Wei, Tian, Heng-Ci, Zhang, Chi, Li, Jin-Hua, Li, Lin-Xi, Hui, He-Jiu, Li, Chun-Lai, Lin, Yang-Ting, Li, Xian-Hua, and Delano, John W.
- Subjects
RARE earth metals ,CHLORINE ,LUNAR soil ,SIDEROPHILE elements ,REGOLITH ,VOLCANISM ,BASALT ,ANORTHOSITE - Abstract
The Chinese spacecraft Chang'e-5 (CE-5) landed on the northern Ocean Procellarum and returned 1,731 grams of regolith. The CE-5 regolith is composed mostly of fragments of basalt, impact glass, agglutinates, and mineral fragments. The basalts could be classified as of a low-Ti and highly fractionated type based on their TiO
2 content of ∼5.3 wt% and Mg# of ∼28. Independent of petrographic texture, the CE-5 basalts have a uniform eruption age of 2,030 ± 4 Ma, demonstrating that the Moon remained volcanically active until at least ∼2.0 Ga. Although the CE-5 landing site lies within the so-called Procellarum KREEP [potassium (K), rare earth elements (REE), and phosphorus (P)] Terrane, neither the CE-5 basalts nor the mantle source regions of those basalts were enriched in KREEP components, such as incompatible elements, water, sulfur, or chlorine. Therefore, it would be a new and stimulating task in the future to look for the triggering mechanism of the young volcanism on the Moon. The CE-5 spacecraft returned 1,731 grams of lunar regolith in December 2020. It was the first new lunar sample since the last collection in August 1976. CE-5 regolith is basaltic in chemical composition, with only ∼1% highland materials of anorthosite, Mg suite, alkali suite, and KREEP. The CE-5 basalt is low Ti and highly differentiated. It was extruded at ∼2.0 Ga, being the youngest lunar basalt identified so far from the Moon. The triggering mechanism of the ∼2.0 Ga lunar volcanism is not clearly understood because its mantle source was dry and contained low abundances of KREEP elements. [ABSTRACT FROM AUTHOR]- Published
- 2024
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