New precise timing constraint for the Keketuohai No. 3 pegmatite in Xinjiang, China, and identification of its parental pluton

doi:10.1016/j.oregeorev.2013.08.020

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	New precise timing constraint for the Keketuohai No. 3 pegmatite in Xinjiang, China, and identification of its parental pluton
	Liu, Feng 5; Zhang, Zhi-Xin ; Li, Qi ; Zhang, Chao 2; Li, Chao 3
刊名	ORE GEOLOGY REVIEWS
	2014
卷号	56 页码:209-219
关键词	Altay Keketuohai The aral granite No. 3 pegmatite Geochronology
ISSN号	0169-1368
DOI	10.1016/j.oregeorev.2013.08.020
英文摘要	The Keketuohai pegmatite field is one of the pegmatite-rich regions in the Altay Orogen, with abundant pegmatites and voluminous granite magmatism. The Keketuohai No. 3 pegmatite is renowned for its deposits of rare metals, but despite a lot of in-depth research, the geochronology of the pegmatite remains the subject of dispute, and there is a lack of precise geochronological evidence to support the view that the Aral granite represents the parental magma of the pegmatite. To further our understanding of this pegmatite field, one sample was collected from the Aral granite in the northern part of the ore district, and six molybdenite samples were taken from the marginal zone of the Keketuohai No. 3 pegmatite. The geological context of the molybdenite samples indicates an origin by hydrothermal metasomatism in the zone between the margin of the pegmatite and the wall rock, and the time of its formation should coincide with or immediately follow the formation of the pegmatite margin. This allows the lower time limit of the pegmatite-formation to be set. LA-MC-ICP-MS dating of zircons from the Aral granite gives Pb-206/U-238 ages that range from 209.0 to 215.6 Ma (from 16 spot analyses), and the plotted data are mainly distributed on or around the concordant line. The weighted mean age is 211.4 +/- 0.8 Ma (MSWD = 1.4), which may represent the crystallization age of the granite. The Re-Os isotopic model ages for the six molybdenite samples range from 207.8 to 2122 Ma. The weighted mean age of 209.9 +/- 1.3 Ma (MSWD = 0.69) and the Re-Os isochron age of 208.8 +/- 2.4 Ma (MSWD = 0.89) are consistent within error. If decoupling of the Re-Os isotope system in molybdenite is neglected, this consistency in the age data may indicate the time at which molybdenite was deposited from fluids. After researching in detail the previously published chronological data, we propose that earlier views on the ages of the Keketuohai No. 3 pegmatite and the Aral granite may be incorrect, and we now suggest that the pegmatite started to form around 209-210 Ma, in the Late Triassic. The agreement between the newly determined U-Pb ages for the Aral granite and the Re-Os ages of the molybdenite in the pegmatite strongly indicates a close relationship between the crystallization of the Aral granite and the formation of the pegmatite and its rare-metals deposits. It also points to the Aral granite being the parent of the No. 3 pegmatite. (C) 2013 Elsevier B.V. All rights reserved.
学科主题	火成岩岩石学
WOS关键词	ZIRCON U-PBSHRIMP ; NORTHWEST CHINA ; CONTINENTAL GROWTH ; TECTONIC EVOLUTION ; ALTAY MOUNTAINS ; OROGENIC BELT ; CENTRAL-ASIA ; NW CHINA ; ORIGIN ; ACCRETIONARY
WOS研究方向	Geology ; Mineralogy ; Mining & Mineral Processing
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000329530700013
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/40402]
专题	中国地质调查局发展研究中心
作者单位	1.Chinese Acad Geol Sci, Inst Mineral Resources, MRL Key Lab Metallogeny & Mineral Assessment, Beijing 10037, Peoples R China 2.Chinese Acad Sci, Xinjiang Inst Ecol & Geog, Xinjiang Res Ctr Mineral Resources, Urumqi 830011, Xinjiang, Peoples R China 3.719 Geol Party Bur Geol Explorat Guangdong Prov, Zhaoqing 526020, Guangdong, Peoples R China 4.Natl Res Ctr Geoanal, Beijing 100037, Peoples R China 5.中国地质科学院矿产资源研究所
推荐引用方式 GB/T 7714	Liu, Feng,Zhang, Zhi-Xin,Li, Qi,et al. New precise timing constraint for the Keketuohai No. 3 pegmatite in Xinjiang, China, and identification of its parental pluton[J]. ORE GEOLOGY REVIEWS,2014,56:209-219.
APA	Liu, Feng,Zhang, Zhi-Xin,Li, Qi,Zhang, Chao,&Li, Chao.(2014).New precise timing constraint for the Keketuohai No. 3 pegmatite in Xinjiang, China, and identification of its parental pluton.ORE GEOLOGY REVIEWS,56,209-219.
MLA	Liu, Feng,et al."New precise timing constraint for the Keketuohai No. 3 pegmatite in Xinjiang, China, and identification of its parental pluton".ORE GEOLOGY REVIEWS 56(2014):209-219.