Whole-rock Nd-Hf isotopic study of I-type and peraluminous granitic rocks from the Chinese Altai: Constraints on the nature of the lower crust and tectonic setting

doi:10.1016/j.gr.2016.07.003

CORC > 地质与地球物理研究所 > 中国科学院地质与地球物理研究所 > 岩石圈演化国家重点实验室

	Whole-rock Nd-Hf isotopic study of I-type and peraluminous granitic rocks from the Chinese Altai: Constraints on the nature of the lower crust and tectonic setting
	Yu, Yang 1; Sun, Min 1; Long, Xiaoping 2; Li, Pengfei 1; Zhao, Guochun 1; Kroener, Alfred 3; Broussolle, Arnaud 1; Yang, Jinhui 4
刊名	GONDWANA RESEARCH
	2017-07-01
卷号	47 页码:131-141
关键词	Nd-Hf decoupling Chinese Altai Central Asian Orogenic Belt Continental growth Accretionary orogeny
ISSN号	1342-937X
DOI	10.1016/j.gr.2016.07.003
文献子类	Article
英文摘要	The nature of the lower crust and tectonic setting of the Chinese Altai in the early to middle Paleozoic are still hotly debated. Decoupling between zircon Hf and whole-rock Nd isotopic systems for granites results in different interpretations for the above issues. In order to solve the problem, whole-rock Nd-Hf isotopic analyses were conducted on representative early to middle Paleozoic I-type granite and strongly peraluminous granites and rhyolites from the Chinese Altai. The I-type granites show metaluminous to weakly peraluminous feature and have epsilon(Nd)(t) values ranging from-2.2 to+ 0.8 and epsilon(Hf)(t) from+ 3.9 to+12.9,respectively. The strongly peraluminous granites and rhyolites have similar epsilon(Nd)(t) and epsilon(Hf)(t) values ranging from -3.0 to +1.7 and from +2.1 to +10.4, respectively. All samples plot above the Terrestrial Array on Nd-Hf isotopic diagram, indicating significant Nd-Hf isotopic decoupling in the magma sources. These samples show flatten HREE pattern and have Lu/Hf ratios similar to the average crust, suggesting that Nd-Hf isotopic decoupling was not originated from an ancient basement with elevated Lu/Hf ratios. The observed isotopic decoupling is similar to those modern island arcs, such as the Lesser Antilles and Sunda, where Nd selectively enriched over Hf due to metasomatism in the mantle wedge and consequently resulted in decoupling between the Sm-Nd and Lu-Hf isotopic systems. Our results, combined with the available data, showthat prolonged subduction and crust-mantle interaction caused the Nd-Hf isotopic decoupling in the lithosphericmantle beneath the Chinese Altai. The crust of the Chinese Altai was extracted from the lithospheric mantle and inherited the Nd-Hf isotopic decoupling feature. Therefore, the Hf, rather than Nd, isotopic data more faithfully reflect the nature of the lower crust that was quite juvenile in the Paleozoic, and the Chinese Altai represents an early Paleozoic magmatic arc possibly built near western Mongolia. (C) 2016 Published by Elsevier B.V. on behalf of International Association for Gondwana Research.
WOS关键词	ASIAN OROGENIC BELT ; A-TYPE GRANITES ; ZIRCON U-PB ; NW CHINA ; LU-HF ; CONTINENTAL-CRUST ; NORTHWEST CHINA ; ICP-MS ; ACCRETIONARY OROGENESIS ; PARTITION-COEFFICIENTS
WOS研究方向	Geology
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000400971500007
资助机构	Hong Kong RGC grants(HKU704013P) ; National Science Foundation of China(41273048) ; Ministry of Science and Technology of China(2014CB440801) ; Hong Kong Germany Joint Research Scheme(G-HKU706115) ; HKU CRCG(201209176180) ; Hong Kong RGC grants(HKU704013P) ; National Science Foundation of China(41273048) ; Ministry of Science and Technology of China(2014CB440801) ; Hong Kong Germany Joint Research Scheme(G-HKU706115) ; HKU CRCG(201209176180) ; Hong Kong RGC grants(HKU704013P) ; National Science Foundation of China(41273048) ; Ministry of Science and Technology of China(2014CB440801) ; Hong Kong Germany Joint Research Scheme(G-HKU706115) ; HKU CRCG(201209176180) ; Hong Kong RGC grants(HKU704013P) ; National Science Foundation of China(41273048) ; Ministry of Science and Technology of China(2014CB440801) ; Hong Kong Germany Joint Research Scheme(G-HKU706115) ; HKU CRCG(201209176180)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/42516]
专题	地质与地球物理研究所_岩石圈演化国家重点实验室
通讯作者	Sun, Min
作者单位	1.Univ Hong Kong, Dept Earth Sci, Pokfulam Rd, Hong Kong, Hong Kong, Peoples R China 2.Northwest Univ, Dept Geol, State Key Lab Continental Dynam, Northern Taibai St 229, Xian 710069, Peoples R China 3.Johannes Gutenberg Univ Mainz, Dept Geosci, Mainz, Germany 4.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, POB 9825, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Yu, Yang,Sun, Min,Long, Xiaoping,et al. Whole-rock Nd-Hf isotopic study of I-type and peraluminous granitic rocks from the Chinese Altai: Constraints on the nature of the lower crust and tectonic setting[J]. GONDWANA RESEARCH,2017,47:131-141.
APA	Yu, Yang.,Sun, Min.,Long, Xiaoping.,Li, Pengfei.,Zhao, Guochun.,...&Yang, Jinhui.(2017).Whole-rock Nd-Hf isotopic study of I-type and peraluminous granitic rocks from the Chinese Altai: Constraints on the nature of the lower crust and tectonic setting.GONDWANA RESEARCH,47,131-141.
MLA	Yu, Yang,et al."Whole-rock Nd-Hf isotopic study of I-type and peraluminous granitic rocks from the Chinese Altai: Constraints on the nature of the lower crust and tectonic setting".GONDWANA RESEARCH 47(2017):131-141.