Zircon U-Pb age and Hf isotopic compositions of Mesozoic granitoids in southern Qiangtang, Tibet: Implications for the subduction of the Bangong-Nujiang Tethyan Ocean

doi:10.1016/j.gr.2015.04.007

	Zircon U-Pb age and Hf isotopic compositions of Mesozoic granitoids in southern Qiangtang, Tibet: Implications for the subduction of the Bangong-Nujiang Tethyan Ocean
	Liu, DL (Liu, Deliang)1,2; Shi, RD (Shi, Rendeng)1,2; Ding, L (Ding, Lin)1,2; Huang, QS (Huang, Qishuai)1,2; Zhang, XR (Zhang, Xiaoran)3; Yue, YH (Yue, Yahui)1,2; Zhang, LY (Zhang, Liyun)1,2; Liu, DL
刊名	GONDWANA RESEARCH
	2017
卷号	41 期号:0 页码:157-172
关键词	EARLY CONTINENTAL-CRUST TECTONIC EVOLUTION LAKE OPHIOLITE NORTHERN TIBET WESTERN TIBET SUTURE ZONE GEOCHEMICAL CHARACTERISTICS AR-40/AR-39 GEOCHRONOLOGY NORTHWESTERN TIBET GANGDESE BATHOLITH
DOI	10.1016/j.gr.2015.04.007
文献子类	Article
英文摘要	The southern Qiangtang magmatic belt was formed by the north-dipping subduction of the Bangong-Nujiang Tethyan Ocean during Mesozoic. To better understand the petrogenesis, time-space distribution along the length of this belt, 21 samples of several granitoid bodies, from west to east, in the Bangong Co, Gaize, Dongqiao and Amdo areas were selected for in-situ zircon U-Pb dating, Hf isotopic and whole-rock chemical analyses. The results suggest a prolonged period of magmatic activity (185-84 Ma) with two major stages during the Jurassic (185-150 Ma) and the Early Cretaceous (126-100 Ma). Both the Jurassic and Cretaceous granitoids are high-K calc-alkaline I-type rocks, except the Cretaceous two-mica granite from Amdo in the east, which belongs to S-type. The granitoids are generated from different source materials as indicated by zircon Hf isotopic compositions. The Bangong Co and Dongqiao granitoids show high zircon epsilon(Hf)(t) values of -1.3-13.6 with younger T-DM(C) ages of 293-1263 Ma, suggesting a relatively juvenile source; whereas the Gaize and Amdo granitoids have low epsilon(Hf)(t) values of -16.1-2.9 with older T-DM(C) ages of 999-2024 Ma, indicating an old crustal contribution. These source rocks melt at different P-T conditions as suggested by Sr/Y ratio and T-Zr. The Sr/Y ratio of both stage granitoids increases with decreasing age. However, the T-Zr of the Jurassic granitoids decreases, whereas the T-Zr of the Cretaceous granitoids increases with decreasing age. The contrasting geochemical signatures of these granitoids may be controlled by the varying contribution of slab-derived fluids involved in the generation of the Jurassic and Cretaceous granitic magmas; i.e. increasing amount of fluids in the Jurassic, whereas decreasing amount of fluids in the Cretaceous. Therefore, it is proposed that the Jurassic and Cretaceous magmatism may be related to subduction and closure of the Bangong-Nujiang Tethyan Ocean, respectively. The age pattern of the Jurassic and Cretaceous granitoids suggests an oblique subduction of the Bangong-Nujiang Tethyan Ocean and a diachronous collision between the Lhasa and Qiangtang blocks. (C) 2015 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.
学科主题	地质学
WOS研究方向	Geology
语种	英语
WOS记录号	WOS:000397873300011
内容类型	期刊论文
源URL	[http://ir.itpcas.ac.cn/handle/131C11/8386]
专题	青藏高原研究所_图书馆
通讯作者	Liu, DL
作者单位	1.Chinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Continental Collis & Plateau Uplift, Beijing 100101, Peoples R China. 2.Chinese Acad Sci, Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China. 3.Univ Hong Kong, Dept Earth Sci, Pokfulam Rd,James Lee Sci Bldg, Hong Kong, Hong Kong, Peoples R China.
推荐引用方式 GB/T 7714	Liu, DL ,Shi, RD ,Ding, L ,et al. Zircon U-Pb age and Hf isotopic compositions of Mesozoic granitoids in southern Qiangtang, Tibet: Implications for the subduction of the Bangong-Nujiang Tethyan Ocean[J]. GONDWANA RESEARCH,2017,41(0):157-172.
APA	Liu, DL .,Shi, RD .,Ding, L .,Huang, QS .,Zhang, XR .,...&Liu, DL.(2017).Zircon U-Pb age and Hf isotopic compositions of Mesozoic granitoids in southern Qiangtang, Tibet: Implications for the subduction of the Bangong-Nujiang Tethyan Ocean.GONDWANA RESEARCH,41(0),157-172.
MLA	Liu, DL ,et al."Zircon U-Pb age and Hf isotopic compositions of Mesozoic granitoids in southern Qiangtang, Tibet: Implications for the subduction of the Bangong-Nujiang Tethyan Ocean".GONDWANA RESEARCH 41.0(2017):157-172.