Recognition of early Carboniferous alkaline granite in the southern Altai orogen post-orogenic processes constrained by U-Pb zircon ages, Nd isotopes, and geochemical data

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	Recognition of early Carboniferous alkaline granite in the southern Altai orogen post-orogenic processes constrained by U-Pb zircon ages, Nd isotopes, and geochemical data
	Tong, Y (Tong, Ying); Wang, T (Wang, Tao); Siebel, W (Siebel, Wolfgang); Hong, DW (Hong, Da-Wei); Sun, M (Sun, Min)
刊名	INTERNATIONAL JOURNAL OF EARTH SCIENCES
	2012
卷号	101 期号:4 页码:937-950
关键词	Zircon U-Pb Chinese Altai Alkaline granite Post-orogenic Central Asian Orogenic Belt
ISSN号	1437-3254
英文摘要	The Altai orogen forms the southern part of the Central Asian Orogenic Belt (CAOB), the world's largest accretionary orogen. However, its tectonic evolution, particularly during the late Paleozoic, is still not well understood. U-Pb zircon analyses for the Bulgen alkaline granite yield crystallization ages of 358 +/- A 4 Ma (SHRIMP) and 354 +/- A 4 Ma (LA-ICP-MS). These ages are significantly younger than published emplacement ages for subduction/collision-related syn-orogenic granitoids (460-375 Ma) in this region. The Bulgen granite has high SiO2, total alkalis, rare earth elements, HFSE (Th, Zr, Hf, Nb, and Ce), and low Ba, Sr with pronounced negative anomalies in Eu, Ba, Sr, P, and Ti, showing a clear A-type geochemical signature. The granite records high epsilon Nd() values of +6.3 to +6.4 and young model ages ( (DM)) of ca. 600 Ma. The Bulgen alkaline granite is largely undeformed as opposed to the early-middle Paleozoic counterparts, which form elongated deformed bodies parallel to the prevailing tectonic fabric (NW direction). Available data suggest that magmatism in the southern Altai region evolved from early-middle Paleozoic I-type tholeiitic and calc-alkaline granitoids to late Paleozoic A-type alkaline granitoids. The high epsilon Nd() values of the Bulgen alkaline granite indicate a homogeneous juvenile mantle source, whereas the early-middle Paleozoic granitoids are characterized by lower and more variable epsilon Nd() values (-2.6 to +4.2). These differences provide an important insight into the late Paleozoic orogenic processes of the Chinese Altai and indicate a significant change of the tectonic regime from a syn-orogenic regional compression setting to a post-orogenic extensional one. Major tectonic movements in this region ceased after the early Carboniferous.
学科主题	地层学与地史学
WOS关键词	A-TYPE GRANITES ; PHANEROZOIC CRUSTAL GROWTH ; CHINESE ALTAI ; TECTONIC EVOLUTION ; CONTINENTAL GROWTH ; NORTH XINJIANG ; CENTRAL-ASIA ; NW CHINA ; ACCRETIONARY OROGENESIS ; EASTERN JUNGGAR
WOS研究方向	Geology
语种	英语
出版者	SPRINGER
WOS记录号	WOS:000304175900003
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/39675]
专题	中国地质调查局
作者单位	Univ Hong Kong, Dept Earth Sci, Hong Kong, Hong Kong, Peoples R China
推荐引用方式 GB/T 7714	Tong, Y ,Wang, T ,Siebel, W ,et al. Recognition of early Carboniferous alkaline granite in the southern Altai orogen post-orogenic processes constrained by U-Pb zircon ages, Nd isotopes, and geochemical data[J]. INTERNATIONAL JOURNAL OF EARTH SCIENCES,2012,101(4):937-950.
APA	Tong, Y ,Wang, T ,Siebel, W ,Hong, DW ,&Sun, M .(2012).Recognition of early Carboniferous alkaline granite in the southern Altai orogen post-orogenic processes constrained by U-Pb zircon ages, Nd isotopes, and geochemical data.INTERNATIONAL JOURNAL OF EARTH SCIENCES,101(4),937-950.
MLA	Tong, Y ,et al."Recognition of early Carboniferous alkaline granite in the southern Altai orogen post-orogenic processes constrained by U-Pb zircon ages, Nd isotopes, and geochemical data".INTERNATIONAL JOURNAL OF EARTH SCIENCES 101.4(2012):937-950.