Zircon U-Pb ages, geochemistry, and Sr-Nd-Pb-Hf isotopes of the Nuri intrusive rocks in the Gangdese area, southern Tibet: Constraints on timing, petrogenesis, and tectonic transformation

doi:10.1016/j.lithos.2014.11.014

	Zircon U-Pb ages, geochemistry, and Sr-Nd-Pb-Hf isotopes of the Nuri intrusive rocks in the Gangdese area, southern Tibet: Constraints on timing, petrogenesis, and tectonic transformation
	Chen, Lei 1,2; Qin, Ke-Zhang 2; Li, Guang-Ming 2; Li, Jin-Xiang 2; Xiao, Bo 2; Zhao, Jun-Xing 2; Fan, Xin 2
刊名	LITHOS
	2015
卷号	212 页码:379-396
关键词	Magmatism Tectonic transformation Cretaceous to Oligocene Gangdese Southern Tibet
ISSN号	0024-4937
DOI	10.1016/j.lithos.2014.11.014
文献子类	Article
英文摘要	Abundant magmatic rocks of various ages are exposed in Gangdese, southern Tibet. These rocks play an important role in understanding the tectonic transformation from the subduction of Neo-Tethyan oceanic crust to the collision of the Indian and Asian continents. Based on zircon U-Pb ages, geochemistry, and Sr-Nd-Pb-Hf isotopic data of the Late Cretaceous to early Oligocene (similar to 96-30 Ma) intrusive rocks in the Nuri Cu-W-Mo deposit we discuss the Late Cretaceous to early Oligocene tectonic transformation of the region and the origin of Oligocene Cu-W-Mo mineralization in southern Gangdese. The Nuri intrusive rocks represent three magmatic episodes: 96-91, 56-52, and 33-30 Ma. The 96-91 and 56-52 Ma rocks have relatively low (Sr-87/Sr-86); (0.7041 to 0.7060), and high epsilon Nd(t) (+3.1 to +3.5) and epsilon Hf(t) values (+3.7 to +15); the 33-30 Ma rocks have relatively high (Sr-87/Sr-86)(1) (0.7061 to 0.7063) and Pb isotopes, and low epsilon Nd(t) (-3.8 to -1.8) and epsilon Hf(t) values (+0.6 to +10.1). The three stages of intrusive rocks have geochemical characteristics that are similar to those of coeval rocks in Gangdese. The 96-91 and 33-30 Ma rocks are adakitic, whereas the 56-52 Ma rocks have characteristics of arc calc-alkaline magmatic rocks. The 96-91 Ma rocks were produced by the partial melting of Neo-Tethyan basaltic oceanic crust and minor sediments, whereas the 56-52 Ma rocks were generated by the partial melting of juvenile crust and the 33-30 Ma rocks were formed by the melting of Indian plate lower crust contaminated with overlying mantle materials. On the basis of the regional tectonic and magmatic characteristics, we suggest that Neo-Tethyan oceanic slab subduction and slab roll-back occurred from similar to 100 to 65 Ma, collision between the Indian and Asian continents occurred at 65 to 40 Ma, Neo-Tethyan oceanic slab break-off took place at similar to 50 Ma, and the Indian continent subducted northwards beneath the Asian continent at similar to 30 Ma. From the Late Cretaceous (96-91 Ma) to Oligocene (similar to 30 Ma), the geodynamic setting of Gangdese was changed from Neo-Tethyan oceanic subduction to Indian continental subduction. In contrast to the Miocene metallogenic rocks, the magmatic source of Oligocene metallogenic rocks contains old Indian continental crust materials, which result in the formation of intense, unique Cu-W-Mo mineralization, especially W mineralization, in the southern Gangdese. (C) 2014 Elsevier B.V. All rights reserved.
WOS关键词	CONTINENTAL COLLISION ZONES ; THICKENED LOWER CRUST ; CU-AU MINERALIZATION ; YARDOI GNEISS DOME ; SLAB-DERIVED MELTS ; VOLCANIC-ROCKS ; MANTLE WEDGE ; MO DEPOSIT ; LU-HF ; SUBDUCTED LITHOSPHERE
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000348879200026
资助机构	NSFC(40772066 ; NSFC(40772066 ; China Metallurgical Geology Bureau ; China Metallurgical Geology Bureau ; 41072059 ; 41072059 ; 41202056) ; 41202056) ; NSFC(40772066 ; NSFC(40772066 ; China Metallurgical Geology Bureau ; China Metallurgical Geology Bureau ; 41072059 ; 41072059 ; 41202056) ; 41202056) ; NSFC(40772066 ; NSFC(40772066 ; China Metallurgical Geology Bureau ; China Metallurgical Geology Bureau ; 41072059 ; 41072059 ; 41202056) ; 41202056) ; NSFC(40772066 ; NSFC(40772066 ; China Metallurgical Geology Bureau ; China Metallurgical Geology Bureau ; 41072059 ; 41072059 ; 41202056) ; 41202056)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/86832]
专题	中国科学院地质与地球物理研究所
通讯作者	Chen, Lei
作者单位	1.Chinese Acad Geol Sci, MLR Key Lab Metallogeny & Mineral Assessment, Inst Mineral Resources, Beijing 100037, Peoples R China 2.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Mineral Resources, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Chen, Lei,Qin, Ke-Zhang,Li, Guang-Ming,et al. Zircon U-Pb ages, geochemistry, and Sr-Nd-Pb-Hf isotopes of the Nuri intrusive rocks in the Gangdese area, southern Tibet: Constraints on timing, petrogenesis, and tectonic transformation[J]. LITHOS,2015,212:379-396.
APA	Chen, Lei.,Qin, Ke-Zhang.,Li, Guang-Ming.,Li, Jin-Xiang.,Xiao, Bo.,...&Fan, Xin.(2015).Zircon U-Pb ages, geochemistry, and Sr-Nd-Pb-Hf isotopes of the Nuri intrusive rocks in the Gangdese area, southern Tibet: Constraints on timing, petrogenesis, and tectonic transformation.LITHOS,212,379-396.
MLA	Chen, Lei,et al."Zircon U-Pb ages, geochemistry, and Sr-Nd-Pb-Hf isotopes of the Nuri intrusive rocks in the Gangdese area, southern Tibet: Constraints on timing, petrogenesis, and tectonic transformation".LITHOS 212(2015):379-396.