Geochronology, petrogenesis and tectonic implications of Triassic granitoids from Beishan, NW China

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	Geochronology, petrogenesis and tectonic implications of Triassic granitoids from Beishan, NW China
	Li, S (Li, Shan); Wang, T (Wang, Tao); Wilde, SA (Wilde, Simon A.); Tong, Y (Tong, Ying); Hong, DW (Hong, Dawei); Guo, QQ (Guo, Qianqian)
刊名	LITHOS
	2012
卷号	134 页 123-145 页码:123-145
关键词	Triassic Granitoids Zircon U-Pb ages Petrogenesis Beishan orogen
ISSN号	0024-4937
英文摘要	Five Triassic granitic plutons have been identified from the Beishan orogen by zircon U-Pb dating that defines two age groups 240-238 Ma and 225-217 Ma. They belong to the high-K calc-alkaline and shoshonitic series and have alkalic and alkali-calcic characteristics, and are weakly peraluminous-metaluminous. These granitolds are mainly highly fractionated I-type granite and A-type granite. They have high l values (0.70490.7096) and negative epsilon(Nd)(t) values of -0.9 to -2.8, with Nd model ages of 0.89-1.13 Ga, suggesting a crustal contribution. They also exhibit relatively high zircon epsilon(Hf)(t) values ( -1.3 to +6.1) and two-stage Hf model ages of 1.34-0.87 Ga, suggesting a mixture of mantle and various amounts of crustal components. The mantle component probably originated from underplated magmas produced by partial melting of lithospheric mantle metasomatized by fluids or melts, possibly derived from pre-existing subducted materials. The mid-Triassic (240-238 Ma) pluton has relatively high Sr/Y (15.9-41.8) ratios and MgO (1.22-3.77%) contents, with negligibly to weakly negative Eu anomalies (delta Eu = 0.57-0.80), indicating adakite-like features. This was likely the result of partial melting of crustal components in response to voluminous underplated mantle-derived magmas, probably linked to lithospheric delamination and asthenospheric upwelling. The Late Triassic (217-225 Ma) granitic plutons show strong negative anomalies of Eu, Ba, Nb, Ta, Sr, P and Ti. These were likely the result of fractional crystallization and crustal contamination for the granitic magma emplaced in a post-orogenic setting. (C) 2011 Elsevier B.V. All rights reserved.
学科主题	火成岩岩石学
WOS关键词	PHANEROZOIC CRUSTAL GROWTH ; ND ISOTOPIC EVIDENCE ; ASIAN OROGENIC BELT ; A-TYPE GRANITES ; MESOZOIC TECTONOMAGMATIC AREA ; TRANSBAIKALIA MAGMATIC REGION ; NORTHERN INNER-MONGOLIA ; LOWER CONTINENTAL-CRUST ; U-PB AGE ; NORTHWEST CHINA
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000301762300008
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/39814]
专题	中国地质调查局
作者单位	Chinese Acad Sci, Grad Univ, Key Lab Computat Geodynam, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Li, S ,Wang, T ,Wilde, SA ,et al. Geochronology, petrogenesis and tectonic implications of Triassic granitoids from Beishan, NW China[J]. LITHOS,2012,134 页 123-145:123-145.
APA	Li, S ,Wang, T ,Wilde, SA ,Tong, Y ,Hong, DW ,&Guo, QQ .(2012).Geochronology, petrogenesis and tectonic implications of Triassic granitoids from Beishan, NW China.LITHOS,134 页 123-145,123-145.
MLA	Li, S ,et al."Geochronology, petrogenesis and tectonic implications of Triassic granitoids from Beishan, NW China".LITHOS 134 页 123-145(2012):123-145.