气候变化领域集成服务门户(CCPortal): Petrogenesis of Middle-Late Triassic volcanic rocks from the Gangdese belt, southern Lhasa terrane: Implications for early subduction of Neo-Tethyan oceanic lithosphere

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DOI	10.1016/j.lithos.2016.07.021
	Petrogenesis of Middle-Late Triassic volcanic rocks from the Gangdese belt, southern Lhasa terrane: Implications for early subduction of Neo-Tethyan oceanic lithosphere
	Wang, Chao; Ding, Lin; Zhang, Li-Yun; Kapp, Paul; Pullen, Alex; Yue, Ya-Hui
通讯作者	Wang, C (通讯作者)
发表日期	2016
ISSN	0024-4937
EISSN	1872-6143
起始页码	320
结束页码	333
卷号	262
英文摘要	The Gangdese belt is dominantly composed of igneous rocks that formed during the northward subduction of Neo-Tethyan oceanic lithosphere beneath the Lhasa terrane and has played a crucial role in understanding the pre-collisional evolution of southern Tibet. This paper presents new geochronological and geochemical (whole-rock major and trace element and Sr-Nd and zircon Hf isotope) data for recently identified volcanic rocks exposed in Changguo area, southernmost part of the Lhasa terrane. Zircon U-Pb dating from six samples yields consistent ages of 237.1 +/- 1.1 Ma to 211.7 +/- 1.5 Ma for magma emplacement through volcanic eruption, showing the Middle-Late Triassic magmatic activity in the southernmost Gangdese Belt. The Changguo volcanic rocks are mainly composed of basaltic and andesitic rocks and exhibit LILE enrichment and HFSE depletion. They also exhibit relatively uniform Nd-Hf isotopic compositions (epsilon(Nd)(t) = +5.20 to +7.74 and epsilon(Hf)(t)(zircon) = +10.2 to + 15.9). The basaltic magmas were likely sourced from partial melting of sub-arc mantle wedge that was metasomatized by not only the aqueous fluid derived from subducting altered oceanic crust but also hydrous melt derived from subducting seafloor sediments, and subsequently experienced fractional crystallization and juvenile crustal contamination during ascent. The andesitic magmas were generated by partial melting of maficultramafic metasomes through melt/fluid-peridotite reaction at slab-mantle interface. Taking into account the temporal and spatial distribution of the Early Mesozoic magmatic rocks and regional detrital zircon data, we further propose that the northward subduction of Neo-Tethyan oceanic lithosphere beneath the Lhasa terrane commenced by Middle Triassic. (C) 2016 Elsevier B.V. All rights reserved.
关键词	ZIRCON U-PB TRACE-ELEMENT HF ISOTOPE TECTONIC EVOLUTION NEO-TETHYS LU-HF MAGMATIC EVOLUTION CRETACEOUS STRATA THERMAL STRUCTURE CENOZOIC BASALTS
英文关键词	Middle-Late Triassic magmatic activity; Subduction of Neo-Tethyan oceanic lithosphere; Gangdese; Lhasa terrane; Tibet
语种	英语
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
WOS类目	Geochemistry & Geophysics ; Mineralogy
WOS记录号	WOS:000384783500020
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/258734
推荐引用方式 GB/T 7714	Wang, Chao,Ding, Lin,Zhang, Li-Yun,et al. Petrogenesis of Middle-Late Triassic volcanic rocks from the Gangdese belt, southern Lhasa terrane: Implications for early subduction of Neo-Tethyan oceanic lithosphere[J]. 中国科学院青藏高原研究所,2016,262.
APA	Wang, Chao,Ding, Lin,Zhang, Li-Yun,Kapp, Paul,Pullen, Alex,&Yue, Ya-Hui.(2016).Petrogenesis of Middle-Late Triassic volcanic rocks from the Gangdese belt, southern Lhasa terrane: Implications for early subduction of Neo-Tethyan oceanic lithosphere.LITHOS,262.
MLA	Wang, Chao,et al."Petrogenesis of Middle-Late Triassic volcanic rocks from the Gangdese belt, southern Lhasa terrane: Implications for early subduction of Neo-Tethyan oceanic lithosphere".LITHOS 262(2016).