Mesozoic granitic magmatism in extensional tectonics near the Mongolian;border in China and its implications for crustal growth

doi:10.1016/S1367-9120(03)00133-0

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	Mesozoic granitic magmatism in extensional tectonics near the Mongolian;border in China and its implications for crustal growth
	Wang, T 4; Zheng, YD ; Li, TB ; Gao, YJ
刊名	JOURNAL OF ASIAN EARTH SCIENCES
	2004
卷号	23 期号:5 页码:715-729
关键词	metamorphic core complex granitoids high potassic U-Pd dating Central Asian orogenic belt
ISSN号	1367-9120
DOI	10.1016/S1367-9120(03)00133-0
英文摘要	The Yagan area of the southernmost Sino-Mongolian border is characterized by an extensional structure where a large metamorphic core complex (Yagan-Onch Hayrhan) and voluminous granitoids are exposed. New isotopic age data indicate that the granitoids, which were previously regarded as Paleozoic in age, were emplaced in early and late Mesozoic times. The early Mesozoic granitoids have 228 +/- 7 Ma U-Pb zircon age, and consist of linear mylonitic quartz monzonites and biotite monzogranites. Their chemical compositions are similar to those of potassic granites and shoshonitic series, and show an intraplate and post-collisional environment in tectonic discrimination diagrams. Their fabrics reveal that they experienced syn-emplacement extensional deformation. All these characteristics suggest that the adjustment, thinning and extensional deformation at middle to lower crustal levels might have occurred in the early Mesozoic. The late Mesozoic granitoids have a U-Pb zircon age of 135 +/- 2 Ma, and are made up of large elliptical granitic plutons. They are high-K calc-alkaline, and were forcefully emplaced in the dome extensional setting. Both the early and late Mesozoic granitoids have epsilonNd (t) values of -2.3 to +5, in strong contrast with the negative epsilonNd (t) values (-11) of the Precambrian host rocks. This suggests that juvenile mantle-derived components were involved in the formation of the granitoids. The similar situation is omnipresent in Central Asia. This study demonstrates that tectonic extension, magmatism and crustal growth are closely related, and that post-collisional and intraplate magmatism was probably a significant process for continental growth in the Phanerozoic. (C) 2003 Elsevier Ltd. All rights reserved.
学科主题	构造地质学
WOS关键词	METAMORPHIC CORE COMPLEX ; ND ISOTOPIC EVIDENCE ; EAST-CENTRAL-ASIA ; A-TYPE GRANITES ; INNER-MONGOLIA ; U-PB ; GEOCHRONOLOGICAL EVIDENCE ; CONTINENTAL GROWTH ; SOUTHERN MONGOLIA ; OROGENIC BELT
WOS研究方向	Geology
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000223837700008
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/37777]
专题	中国地质调查局成都地质调查中心
作者单位	1.Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China. 2.Peking Univ, Dept Geol, Beijing 100871, Peoples R China. 3.Reg Survey Inst, Ningxian 750021, Yinchuan, Peoples R China. 4.中国地质科学院地质研究所
推荐引用方式 GB/T 7714	Wang, T,Zheng, YD,Li, TB,et al. Mesozoic granitic magmatism in extensional tectonics near the Mongolian;border in China and its implications for crustal growth[J]. JOURNAL OF ASIAN EARTH SCIENCES,2004,23(5):715-729.
APA	Wang, T,Zheng, YD,Li, TB,&Gao, YJ.(2004).Mesozoic granitic magmatism in extensional tectonics near the Mongolian;border in China and its implications for crustal growth.JOURNAL OF ASIAN EARTH SCIENCES,23(5),715-729.
MLA	Wang, T,et al."Mesozoic granitic magmatism in extensional tectonics near the Mongolian;border in China and its implications for crustal growth".JOURNAL OF ASIAN EARTH SCIENCES 23.5(2004):715-729.