气候变化领域集成服务门户(CCPortal): Lunar compositional asymmetry explained by mantle overturn following the South Pole

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DOI	10.1038/s41561-021-00872-4
	Lunar compositional asymmetry explained by mantle overturn following the South Pole–Aitken impact
	Zhang N.; Ding M.; Zhu M.-H.; Li H.; Li H.; Yue Z.
发表日期	2022
ISSN	1752-0894
卷号	15 期号:1
英文摘要	The spatial distribution of mare basalts, titanium and KREEP (potassium, rare earth elements and phosphorus) on the Moon is asymmetrical between the nearside and farside. These asymmetries cannot be readily explained by solidification of a global magma ocean and subsequent mantle overturn, which should result in a layered and spherically symmetric lunar interior. Alternative scenarios have been proposed to explain the observed compositional asymmetry, but its origin remains enigmatic. Here, we present hydro- and mantle convection numerical simulations of the giant impact event that formed the South Pole–Aitken basin—the largest impact basin on the Moon—and the subsequent impact-induced convection with the assistance of gravitational instability. We find that the impact induces thermochemical instabilities that drive the dense KREEP-rich ilmenite-bearing cumulate to migrate towards the nearside following lunar magma ocean solidification. This results in the formation of a chemical reservoir under the nearside crust that could explain the observed geochemical asymmetries. We suggest that enrichments of ilmenite and KREEP in the nearside hemisphere following the South Pole–Aitken impact event provide a viable explanation for the wide composition range of mare basalts observed on the lunar surface. © 2022, The Author(s), under exclusive licence to Springer Nature Limited.
语种	英语
scopus关键词	asymmetry; cumulate; magma; mantle; mantle convection; Moon; overturn; solidification; spatial distribution; titanium; Antarctica; East Antarctica; South Pole
来源期刊	Nature Geoscience
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/250807
作者单位	Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing, China; Earth Dynamics Group, School of Earth and Planetary Sciences, Curtin University, Perth, WA, Australia; State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau; CNSA Macau Center for Space Exploration and Science, Macau; State Key Laboratory of Remote Sensing Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, China
推荐引用方式 GB/T 7714	Zhang N.,Ding M.,Zhu M.-H.,等. Lunar compositional asymmetry explained by mantle overturn following the South Pole–Aitken impact[J],2022,15(1).
APA	Zhang N.,Ding M.,Zhu M.-H.,Li H.,Li H.,&Yue Z..(2022).Lunar compositional asymmetry explained by mantle overturn following the South Pole–Aitken impact.Nature Geoscience,15(1).
MLA	Zhang N.,et al."Lunar compositional asymmetry explained by mantle overturn following the South Pole–Aitken impact".Nature Geoscience 15.1(2022).