气候变化领域集成服务门户(CCPortal): Late Triassic island-arc-back-arc basin development along the Bangong-Nujiang suture zone (central Tibet): Geological, geochemical and chronological evidence from volcanic rocks

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DOI	10.1016/j.lithos.2015.05.009
	Late Triassic island-arc-back-arc basin development along the Bangong-Nujiang suture zone (central Tibet): Geological, geochemical and chronological evidence from volcanic rocks
	Chen, Sheng-Sheng; Shi, Ren-Deng; Zou, Hai-Bo; Huang, Qi-Shuai; Liu, De-Liang; Gong, Xiao-Han; Yi, Guo-Ding; Wu, Kang
通讯作者	Chen, SS (通讯作者)
发表日期	2015
ISSN	0024-4937
EISSN	1872-6143
起始页码	30
结束页码	45
卷号	230
英文摘要	A major debate related to the evolution of the Tibetan Plateau is centered on whether or not an island arc-back-arc basin system occurred along the Bangong-Nujiang suture zone, central Tibet. Here we present new zircon U-Pb geochronology, rare earth elements (REEs) and bulk-rock geochemistry of these magmatic rocks in the Amdo area, the middle Bangong-Nujiang suture zone, central Tibet, to identify significant and new records of Mesozoic tectonomagmatic processes. Zircon U-Pb dating using LA-ICP-MS techniques yields a concordant age with a weighted mean Pb-206/U-238 age of 228.6 +/- 1.6 Ma (n = 7, MSWD = 1.19) for the Quehala basalts, and a mean age of 220.0 +/- 2.1 (n = 8, MSWD = 1.5) for the Amdo pillow lavas. On the normalized REE patterns of zircon, significant Ce enrichment indicates that the magma sources of these magmatic rocks have been subjected to modification of slab-derived fluid. Geochemical features suggest that the Quehala basalts (ca. 228 Ma), displaying an island arc tholeiites (IATs) affinity, resulted from partial melting of an relatively enriched mantle wedge in the subduction zone, whereas the Amdo pillow lavas (ca. 220 Ma) characterized by both arc-like and N-MORB-like geochemical characteristics occurred as associated back-arc basin basalts (BABBs) at the spreading center of back-arc basin after the formation of island arc tholeiites. In conclusion, the volcanic rocks in the Amdo area have documented the magmatic processes from early-stage subduction to development of associated back-arc basin, confirming the occurrence of intra-oceanic subduction within the Bangong-Nujiang Tethys during the late Triassic. Furthermore, the spatial relationships among the Quehala formation, Tumengela formation and Amdo pillow lavas indicate likely northward subduction of the Bangong-Nujiang Tethyan Ocean during the Late Triassic to middle Jurassic. (C) 2015 Elsevier B.V. All rights reserved.
关键词	U-PB GEOCHRONOLOGY TECTONIC EVOLUTION SUBDUCTION COMPONENTS PODIFORM CHROMITITES MESOZOIC TECTONISM ISOTOPIC EVIDENCE DEPLETED MANTLE BASEMENT ROCKS MARIANA TROUGH WESTERN TIBET
英文关键词	Island arc tholeiite; Late Triassic; Intra-oceanic subduction; The Bangong-Nujiang Tethys; Tibet
语种	英语
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
WOS类目	Geochemistry & Geophysics ; Mineralogy
WOS记录号	WOS:000357839000003
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/258534
推荐引用方式 GB/T 7714	Chen, Sheng-Sheng,Shi, Ren-Deng,Zou, Hai-Bo,et al. Late Triassic island-arc-back-arc basin development along the Bangong-Nujiang suture zone (central Tibet): Geological, geochemical and chronological evidence from volcanic rocks[J]. 中国科学院青藏高原研究所,2015,230.
APA	Chen, Sheng-Sheng.,Shi, Ren-Deng.,Zou, Hai-Bo.,Huang, Qi-Shuai.,Liu, De-Liang.,...&Wu, Kang.(2015).Late Triassic island-arc-back-arc basin development along the Bangong-Nujiang suture zone (central Tibet): Geological, geochemical and chronological evidence from volcanic rocks.LITHOS,230.
MLA	Chen, Sheng-Sheng,et al."Late Triassic island-arc-back-arc basin development along the Bangong-Nujiang suture zone (central Tibet): Geological, geochemical and chronological evidence from volcanic rocks".LITHOS 230(2015).