气候变化领域集成服务门户(CCPortal): Early Jurassic highly fractioned rhyolites and associated sedimentary rocks in southern Tibet: constraints on the early evolution of the Neo-Tethyan Ocean

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DOI	10.1007/s00531-018-1646-2
	Early Jurassic highly fractioned rhyolites and associated sedimentary rocks in southern Tibet: constraints on the early evolution of the Neo-Tethyan Ocean
	Wang, Chao; Ding, Lin; Zhang, Li-Yun; Ding, Xiang-Li; Yue, Ya-Hui
通讯作者	Wang, C (通讯作者)
发表日期	2019
ISSN	1437-3254
EISSN	1437-3262
起始页码	137
结束页码	154
卷号	108 期号:1
英文摘要	An integrated investigation of Lower Jurassic Jialapu Formation (including U-Pb dating of igneous and detrital zircons, geochemical analysis of igneous rocks, and analysis of detrital modes of sandstone interbeds) in the southern margin of the Lhasa terrane, Tibet, provides new constraints on the early evolution of the Neo-Tethyan Ocean. Our new data reveal a stage of silicic magmatism, with an arc affinity along the southernmost Eurasian margin at 193-190 Ma, which is characterized by high SiO2 (76.5-80.0 wt%), Na2O (5.30-7.22 wt%) and low K2O (0.07-0.55 wt%), MgO (0.16-0.54 wt%), Cr (1.44-4.37 ppm), and Ni (0.67-1.62 ppm) contents with low epsilon(Nd)(t) values of +1.21 to +2.33. These silicic volcanic rocks are enriched in large ion lithophile elements (LILEs) and light rare earth elements (LREEs) and can be classified as highly fractionated I-type rhyolites. They show a wide range of zircon epsilon(Hf)(t) values from -11.7 to +9.4, suggesting variable contributions from both juvenile and ancient crustal sources. It is concluded that the Jialapu Na-rich rhyolites were derived by the partial melting of a highly differentiated residual melt separated from the K-rich magma, triggered by upwelling asthenospheric mantle. Detrital zircons in the sandstones from the Lower Jurassic Jialapu Formation are dominantly the Mesozoic ones, which are likely derived from Lhasa terrane sources. Considering the associated sedimentary records as well as literature data, it is suggested that an Early Jurassic back-arc basin developed along the southern Lhasa terrane in response to the northward subduction of the Neo-Tethyan Ocean.
关键词	LHASA TERRANE IMPLICATIONS INDIA-ASIA COLLISION ZIRCON U-PB VOLCANIC-ROCKS GANGDESE BATHOLITH ISOTOPIC CONSTRAINTS TECTONIC EVOLUTION CONTINENTAL-CRUST EARLY SUBDUCTION GRANITIC-ROCKS
英文关键词	Na-rich rhyolites; Early Jurassic; Arc-back-arc basin; Lhasa terrane; Neo-Tethyan Ocean
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:000458652200007
来源期刊	INTERNATIONAL JOURNAL OF EARTH SCIENCES
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/259398
推荐引用方式 GB/T 7714	Wang, Chao,Ding, Lin,Zhang, Li-Yun,et al. Early Jurassic highly fractioned rhyolites and associated sedimentary rocks in southern Tibet: constraints on the early evolution of the Neo-Tethyan Ocean[J]. 中国科学院青藏高原研究所,2019,108(1).
APA	Wang, Chao,Ding, Lin,Zhang, Li-Yun,Ding, Xiang-Li,&Yue, Ya-Hui.(2019).Early Jurassic highly fractioned rhyolites and associated sedimentary rocks in southern Tibet: constraints on the early evolution of the Neo-Tethyan Ocean.INTERNATIONAL JOURNAL OF EARTH SCIENCES,108(1).
MLA	Wang, Chao,et al."Early Jurassic highly fractioned rhyolites and associated sedimentary rocks in southern Tibet: constraints on the early evolution of the Neo-Tethyan Ocean".INTERNATIONAL JOURNAL OF EARTH SCIENCES 108.1(2019).