Discovery of the REE minerals in the Wulong-Nanchuan bauxite deposits,;Chongqing, China: Insights on conditions of formation and processes

doi:10.1016/j.gexplo.2013.06.016

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	Discovery of the REE minerals in the Wulong-Nanchuan bauxite deposits,;Chongqing, China: Insights on conditions of formation and processes
	Li, Zaihui 2; Din, Jun ; Xu, Jinsha ; Liao, Chaogui ; Yin, Fuguang ; Lu, Tao ; Cheng, Li ; Li, Junmin
刊名	JOURNAL OF GEOCHEMICAL EXPLORATION
	2013
卷号	133 页码:88-102
关键词	Bauxite REE minerals Synchysite Cerianite Churchite Chongqing
ISSN号	0375-6742;EI 1879-1689
DOI	10.1016/j.gexplo.2013.06.016
英文摘要	The karstic bauxite deposits in the south Chongqing-north Guizhou Province bauxite belt are enriched in rare earth elements (REEs). REEs in this belt have been considered to be adsorbed on the surface of clay or diaspore minerals in the ion state. However, extracting tests have demonstrated that the amount of REE adsorption in bauxite ore is very low. In order to comprehensively understand the occurrence of REE in bauxite ores, the chemical and mineralogical compositions of Wulong-Nanchuan karst bauxites and their textural components have been studied. The bulk samples are composed of diaspore, boehmite, kaolinite, illite, hematite, anatase, and pyrite. The Sigma REE concentrations vary widely, from 17 to 3610 ppm REE, in the bauxite ores and most of the ores show an obvious positive Ce anomaly.;Many kinds of REE minerals were identified in these bauxite ores including synchysite, bastnaesite, cerianite, and churchite. These minerals seldom occur in the same sample (with the exception of synchysite and bastnaesite). Synchysite occurs rarely as homogeneously single crystals, but typically contains a microfine phase of bastnaesite. Cerianite occurs mainly as framboidal clusters among chamosite or as fracture or micro-crack fillings. The existence of REE mineral phases is responsible for the high REE content and positive Ce anomaly in the ores. The compositions of the REE minerals show that the Eu anomaly can change subtly during the weathering. The REE compositions of the bauxite ores suggest that the REE mainly derives from the weathered remnants of the underlying Hanjiadian Formation shales and probably, a minor fraction derives from the Huanglong carbonates.;The formation processes of these REE minerals can be explained assuming: (1) Ce oxidation and cerianite precipitation in the uppermost part of the deposits; (2) the mobile phosphates combined with the Y-enriched sediments and the HREE-enriched solutions under an acidic environment allow the precipitation of churchite-(Y); and (3) remobilization of cerium as fluoride complex, as a consequence of more acidic conditions in the uppermost part of the deposit, and precipitation of Ce3+ as fluorocarbonate mineral toward the carbonate bedrock barrier, at alkaline pH. (C) 2013 Elsevier B.V. All rights reserved.
学科主题	矿床地质
WOS关键词	RARE-EARTH-ELEMENTS ; NORTHERN GUIZHOU PROVINCE ; PB ZIRCON GEOCHRONOLOGY ; GA CONTINENTAL-CRUST ; ZHENGAN-DAOZHEN AREA ; LA-ICP-MS ; SOUTH CHINA ; GEOCHEMICAL EVOLUTION ; YANGTZE CRATON ; VOLCANIC-ROCKS
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000326206000008
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/39988]
专题	中国地质调查局成都地质调查中心
作者单位	1.Chengdu Inst Geol & Mineral Resources, Chengdu 610081, Peoples R China. 2.中国地质调查局成都地质调查中心
推荐引用方式 GB/T 7714	Li, Zaihui,Din, Jun,Xu, Jinsha,et al. Discovery of the REE minerals in the Wulong-Nanchuan bauxite deposits,;Chongqing, China: Insights on conditions of formation and processes[J]. JOURNAL OF GEOCHEMICAL EXPLORATION,2013,133:88-102.
APA	Li, Zaihui.,Din, Jun.,Xu, Jinsha.,Liao, Chaogui.,Yin, Fuguang.,...&Li, Junmin.(2013).Discovery of the REE minerals in the Wulong-Nanchuan bauxite deposits,;Chongqing, China: Insights on conditions of formation and processes.JOURNAL OF GEOCHEMICAL EXPLORATION,133,88-102.
MLA	Li, Zaihui,et al."Discovery of the REE minerals in the Wulong-Nanchuan bauxite deposits,;Chongqing, China: Insights on conditions of formation and processes".JOURNAL OF GEOCHEMICAL EXPLORATION 133(2013):88-102.