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DOI	10.1016/j.lithos.2014.03.025
	Geochronology, geochemistry, and zircon Hf isotopic compositions of Mesozoic intermediate-felsic intrusions in central Tibet: Petrogenetic and tectonic implications
	Li, Jin-Xiang; Qin, Ke-Zhang; Li, Guang-Ming; Richards, Jeremy P.; Zhao, Jun-Xing; Cao, Ming-Jian
通讯作者	Li, JX (通讯作者)
发表日期	2014
ISSN	0024-4937
EISSN	1872-6143
起始页码	77
结束页码	91
卷号	198
英文摘要	Mesozoic intermediate-felsic intrusions are widely distributed in the southern Qiangtang terrane, central Tibet. Zircon U-Pb dating shows that these intrusions formed in two periods in the Jurassic (169-150 Ma) and Cretaceous (127-113 Ma). They mostly belong to the high-K calc-alkaline series, and show strong enrichments in large ion lithophile elements (e.g., Cs, Rb, and K), depletions in Nb,Ta, and Ti, and negative Ba anomalies on primitive mantle-normalized diagrams. P2O5 contents decrease with increasing SiO2 content, and Th contents increase with increasing Rb content, consistent with the evolution trend of l-type magmas. These intrusions show a wide range of zircon epsilon Hf(t) values from -19.4 to 11.2, including in rocks with similar SiO2 contents, suggesting variable contributions from mantle and Qiangtang crustal sources. Fine-grained mafic to intermediate igneous enclaves in Jurassic intrusions have similar zircon U-Pb ages and similar or slightly higher zircon sHf(t) values to the host rocks, suggesting that the enclave magmas were derived from mixed magmas at depth and injected into more evolved magmas in upper crustal magma chambers. Magma mixing is also supported by the wide range of zircon Hf isotopic compositions (epsilon Hf(t) = -19.4 to 2.5) from within individual Jurassic and Cretaceous intrusions, and Jurassic enclaves. The Jurassic-Cretaceous magmas likely formed in a continental arc setting during subduction of the Bangong-Nujiang ocean between 170 and 110 Ma, and evolved in the upper plate crust by MASH processes. (C) 2014 Elsevier B.V. All rights reserved.
关键词	U-PB GEOCHRONOLOGY BANGONG-NUJIANG SUTURE EAST-WEST EXTENSION CU-AU DEPOSIT SOUTHERN TIBET TRACE-ELEMENT LU-HF VOLCANIC-ROCKS BASEMENT ROCKS CRUSTAL GROWTH
英文关键词	Geochronology; Zircon Hf isotopes; Jurassic-Cretaceous; Granitoids; Petrogenesis; Tibet
语种	英语
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
WOS类目	Geochemistry & Geophysics ; Mineralogy
WOS记录号	WOS:000337851100006
来源期刊	LITHOS
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/258293
推荐引用方式 GB/T 7714	Li, Jin-Xiang,Qin, Ke-Zhang,Li, Guang-Ming,et al. Geochronology, geochemistry, and zircon Hf isotopic compositions of Mesozoic intermediate-felsic intrusions in central Tibet: Petrogenetic and tectonic implications[J]. 中国科学院青藏高原研究所,2014,198.
APA	Li, Jin-Xiang,Qin, Ke-Zhang,Li, Guang-Ming,Richards, Jeremy P.,Zhao, Jun-Xing,&Cao, Ming-Jian.(2014).Geochronology, geochemistry, and zircon Hf isotopic compositions of Mesozoic intermediate-felsic intrusions in central Tibet: Petrogenetic and tectonic implications.LITHOS,198.
MLA	Li, Jin-Xiang,et al."Geochronology, geochemistry, and zircon Hf isotopic compositions of Mesozoic intermediate-felsic intrusions in central Tibet: Petrogenetic and tectonic implications".LITHOS 198(2014).