Petrogenesis and geochronology of the ore-bearing porphyritic rocks in Tangbula porphyry molybdenum-copper deposit in the eastern segment of the Gangdese metallogenic belt.

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	Petrogenesis and geochronology of the ore-bearing porphyritic rocks in Tangbula porphyry molybdenum-copper deposit in the eastern segment of the Gangdese metallogenic belt.
	Wang, BD (Wang BaoDi); Xu, JF (Xu JiFeng); Chen, JL (Chen JianLin); Zhang, XG (Zhang XingGuo); Wang, LQ (Wang LiQuan); Xia, BB (Xia BaoBen)
刊名	ACTA PETROLOGICA SINICA
	2010
卷号	26 期号:6 页码:1820-1832
关键词	Adakitic rocks Porphyry molybdenum-copper deposit Post-collisional extension Tangbula Gangdese metallogenic belt
ISSN号	1000-0569
英文摘要	Tangbula porphyry molybdenum-copper deposit recently discovered in Tibet is located in the most eastern segment of the Gangdese metallogenic belt. However, the forming time of the both porphyritic intrusion and deposit are lack of chronological constraints. This paper attempts to systematically study geochemical characteristics of Tangbula porphyritic rocks and Mo-Cu deposit, and determine the both ages by LA-ICPMS zircon U-Pb and molybdenites Re-Os isotopic dating. The results show that granitic porphyritic rocks and molybdenites were formed at 19.72 +/- 0.20Ma, and 20.9 +/- 1.3Ma, respectively. Within the error range, the both age are consistent with each other, indicating that the formation of porphyritic body and mineralization are at a same time. Geochemically, porphyritic rocks in Tangbula porphyry Mo-Cu deposit are similar to an adakitic rock, e.g., high Sr, Sr/Y and (La/Yb)(N), low Y and Yb contents, and enriched in LILE (Rb, Ba and Th) and depleted in HFSE (Nb, Ta and Ti), specially, they have relatively low initial (87)Sr/(86)Sr (0.70598 similar to 0.70676) and epsilon(Nd)t (-1.75 similar to -3.27), which are similar to those of volcanic rocks of Linzizong Group. We suggest that ore-bearing porphyritic adakitic magmas were possibly produced by partial melting of the thickened mafic lower crust beneath the Gangdese block, which were heated by asthenosphere upwelling related to slab break-off in Miocene. In addition, the age range of the Gangdese metallogenic belt in post-collisional extension setting is from 21 to 12Ma, mainly focusing on 17 similar to 13Ma. Therefore, the main porphyritic mineralization probably lasted for about 4Ma. Tangbula porphyry Mo-Cu deposit was one of the earliest porphyry deposits formed during post-collision stage in the Gangdese metallogenic belt.
学科主题	矿床地质
WOS关键词	CONTINENTAL COLLISION ZONES ; CALC-ALKALINE MAGMATISM ; SOUTHERN TIBET ; TRACE-ELEMENTS ; NORTHERN CHILE ; CENOZOIC AGE ; ADAKITE ; CHINA ; CRUST ; GENESIS
WOS研究方向	Geology
语种	中文
出版者	SCIENCE CHINA PRESS
WOS记录号	WOS:000279740400016
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/39113]
专题	中国地质调查局
作者单位	Reg Geol Surveying Party Tibet Bur Geol & Explora, Lhasa 851400, Peoples R China
推荐引用方式 GB/T 7714	Wang, BD ,Xu, JF ,Chen, JL ,et al. Petrogenesis and geochronology of the ore-bearing porphyritic rocks in Tangbula porphyry molybdenum-copper deposit in the eastern segment of the Gangdese metallogenic belt.[J]. ACTA PETROLOGICA SINICA,2010,26(6):1820-1832.
APA	Wang, BD ,Xu, JF ,Chen, JL ,Zhang, XG ,Wang, LQ ,&Xia, BB .(2010).Petrogenesis and geochronology of the ore-bearing porphyritic rocks in Tangbula porphyry molybdenum-copper deposit in the eastern segment of the Gangdese metallogenic belt..ACTA PETROLOGICA SINICA,26(6),1820-1832.
MLA	Wang, BD ,et al."Petrogenesis and geochronology of the ore-bearing porphyritic rocks in Tangbula porphyry molybdenum-copper deposit in the eastern segment of the Gangdese metallogenic belt.".ACTA PETROLOGICA SINICA 26.6(2010):1820-1832.