Middle Triassic arc magmatism along the northeastern margin of the Tibet U-Pb and Lu-Hf zircon characterization of the Gangcha complex in the West Qinling terrane, central China

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	Middle Triassic arc magmatism along the northeastern margin of the Tibet U-Pb and Lu-Hf zircon characterization of the Gangcha complex in the West Qinling terrane, central China
	Guo, XQ (Guo, Xianqing); Yan, Z (Yan, Zhen); Wang, ZQ (Wang, Zongqi); Wang, T (Wang, Tao); Hou, KJ (Hou, Kejun); Fu, CL (Fu, Changlei); Li, JL (Li, Jiliang)
刊名	JOURNAL OF THE GEOLOGICAL SOCIETY
	2012
卷号	169 期号:3 页码:327-336
ISSN号	0016-7649
英文摘要	The tectonic setting of Mesozoic magmatic complexes in the northeastern margin of the Tibet plateau is disputed, and hence gives rise to uncertainty concerning the tectonic evolution of the northeastern Tibet Plateau and the timing of the closure of the Palaeo-Tethys ocean. The Gangcha complex is typical of these complexes, consisting of andesite, dacite, gabbro, gabbroic diorite, granodiorite, quartz diorite, and diorite with typical chemical traits of continental margin arc rocks. Andesite, gabbroic diorite, and mineralization-associated potassic-altered diorite yield weighted mean Pb-206/U-238 ages of 242.1 perpendicular to 1.2 Ma, 243.8 perpendicular to 1.0 Ma and 234.0 perpendicular to 0.6 Ma respectively. Zircon epsilon(Hf)(t) for magmatic grains ranges from -3.5 to + 5.7, interpreted to demonstrate that the Gangcha complex contains crustally contaminated mantle magmas. Inherited zircons in the complex yield similar U-Pb ages (777-310 Ma) to the A'nyemaqen composite ophiolite assemblage with epsilon(Hf)(t) of -17.4 to + 11.6. This suggests that components of this older ophiolite melted and contributed to the Gangcha complex magmas. Hence the Gangcha complex is considered to have formed as a continental margin arc in northeastern Tibet by northward subduction during consumption of the Palaeo-Tethys ocean. Regionally, it corresponds to the arc magmatism along the eastern and western Kunlun sutures to the west and the Mianlue suture to the east.
学科主题	地质年代学
WOS关键词	NATURAL REFERENCE MATERIAL ; ACCRETIONARY TECTONICS ; CONTINENTAL-CRUST ; OROGENIC BELT ; ISOTOPIC COMPOSITIONS ; TRACE-ELEMENTS ; ROCKS ; GEOCHEMISTRY ; CONSTRAINTS ; SUBDUCTION
WOS研究方向	Geology
语种	英语
出版者	GEOLOGICAL SOC PUBL HOUSE
WOS记录号	WOS:000308669800007
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/39709]
专题	中国地质调查局
作者单位	Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Guo, XQ ,Yan, Z ,Wang, ZQ ,et al. Middle Triassic arc magmatism along the northeastern margin of the Tibet U-Pb and Lu-Hf zircon characterization of the Gangcha complex in the West Qinling terrane, central China[J]. JOURNAL OF THE GEOLOGICAL SOCIETY,2012,169(3):327-336.
APA	Guo, XQ .,Yan, Z .,Wang, ZQ .,Wang, T .,Hou, KJ .,...&Li, JL .(2012).Middle Triassic arc magmatism along the northeastern margin of the Tibet U-Pb and Lu-Hf zircon characterization of the Gangcha complex in the West Qinling terrane, central China.JOURNAL OF THE GEOLOGICAL SOCIETY,169(3),327-336.
MLA	Guo, XQ ,et al."Middle Triassic arc magmatism along the northeastern margin of the Tibet U-Pb and Lu-Hf zircon characterization of the Gangcha complex in the West Qinling terrane, central China".JOURNAL OF THE GEOLOGICAL SOCIETY 169.3(2012):327-336.