Hydrothermal alteration of allanite promotes the generation of ion-adsorption LREE deposits in South China

doi:10.1016/j.oregeorev.2023.105377

	Zhao, Xu 1,2; Li, Ning-Bo 1,2; Niu, He-Cai 1,2; Jiang, Yu-hang 1,2; Yan, Shuang 1,2; Yang, Yu-Yuan 1,2; Fu, Rui-Xin 1,2,3
	Hydrothermal alteration of allanite promotes the generation of ion-adsorption LREE deposits in South China
刊名	ORE GEOLOGY REVIEWS
ISSN号	0169-1368
	2023
卷号	155 页码:105377
DOI	10.1016/j.oregeorev.2023.105377
语种	英语
WOS研究方向	Geology ; Mineralogy ; Mining & Mineral Processing
摘要	Most ion adsorption rare earth element (REE) deposits (>85%) are light REE (LREE) enriched, but it is unclear whether the magmatic and hydrothermal activity have a control to the LREE mineralization, and why only some granitoids generate ion adsorption LREE deposits despite similar weathering conditions and REE contents. In this study, we investigated the main LREE-bearing mineral (i.e., allanite) in the bedrocks of the large Bachi ion adsorption LREE deposit (REE oxide reserves of 42,589 t) in South China. The allanite hosts at least 80% of the LREE in the bedrocks of the Bachi deposit. The allanite comprises primary (Aln-1) and altered (Aln-2) allanite. Aln-2 shows larger lattice parameters, smaller diagnostic Raman spectroscopy peaks, with extensive micro-pores and -fractures infilled by synchysite-(Ce), indicating a lower crystallinity and less stable mineral structure. In addition, Aln-2 has lower LREE contents, higher Sr, Ba, and Th contents, more negative Eu anomalies, and less positive Ce anomalies than Aln-1, but both types of allanite have similar Nd isotopic compositions with those of the whole-rock samples. These morphological and geochemical features suggest that F?, CO2, and Th4+-rich, REE-undersaturated, medium–low-temperature, and oxidizing fluids interacted with the allanite, leached LREE from the allanite, and then formed synchysite-(Ce). The LREE leached from the allanite and precipitated as synchysite-(Ce) on a micron scale, and external materials carried in the fluid did not make a significant contribution to the REE budget and Sm–Nd isotopic compositions of the allanite. The structural and geochemical changes from Aln-1 to Aln-2 made it easier for the allanite to be weathered, and synchysite-(Ce) was also easily weathered, which released LREE3+ ions and generated the ion adsorption LREE deposits. This study highlights that the LREE could be migrated from allanite to synchysite-(Ce) during hydrothermal alteration, which contributed to the generation of ion adsorption REE deposits. The LREE mobilization during hydrothermal alteration may explain why only some granitoids generated ion adsorption LREE mineralization in South China. ? 2023
关键词	RARE-EARTH-ELEMENTS U-PB REE MINERALIZATION AQUEOUS-SOLUTIONS JIANGXI PROVINCE GEOCHEMISTRY GRANITES GENESIS ROCKS SR
WOS记录号	WOS:000951685000001
收录类别	SCI
引用统计	被引频次：5[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.gig.ac.cn/handle/344008/80197
专题	中国科学院矿物学与成矿学重点实验室
作者单位	1.CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou; 510640, China 2.CAS Center for Excellence in Deep Earth Science, Guangzhou; 510640, China 3.University of Chinese Academy of Sciences, Beijing; 100049, China
推荐引用方式 GB/T 7714	Zhao, Xu,Li, Ning-Bo,Niu, He-Cai,et al. Hydrothermal alteration of allanite promotes the generation of ion-adsorption LREE deposits in South China[J]. ORE GEOLOGY REVIEWS,2023,155:105377.
APA	Zhao, Xu.,Li, Ning-Bo.,Niu, He-Cai.,Jiang, Yu-hang.,Yan, Shuang.,...&Fu, Rui-Xin.(2023).Hydrothermal alteration of allanite promotes the generation of ion-adsorption LREE deposits in South China.ORE GEOLOGY REVIEWS,155,105377.
MLA	Zhao, Xu,et al."Hydrothermal alteration of allanite promotes the generation of ion-adsorption LREE deposits in South China".ORE GEOLOGY REVIEWS 155(2023):105377.