The Himalayan Yulong porphyry copper belt: Product of large-scale;strike-slip faulting in eastern Tibet

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	The Himalayan Yulong porphyry copper belt: Product of large-scale;strike-slip faulting in eastern Tibet
	Hou, ZQ 7; Ma, HW ; Zaw, K ; Zhang, YQ ; Wang, MJ ; Wang, Z ; Pan, GT ; Tang, RL
刊名	ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS
	2003
卷号	98 期号:1 页码:125-145
ISSN号	0361-0128
英文摘要	The Yulong porphyry copper belt is the most significant porphyry copper belt in Tibet and is located in the Qiangtang terrane of the Hinialayan-Tibetan orogen. The terrane is a collage of continental blocks joined by ophiolitic sutures and volcano-plutonic arc complexes. The Yulong belt is approximately 300 kin long and 15 to 30 kin wide, contains one giant, two large, and two medium-to small-sized porphyry copper deposits, and more than 20 mineralized porphyry bodies. The Yulong belt is located in the Changdu continental block that comprises Proterozoic to early Paleozoic crystalline folded basement and middle to late Paleozoic platform facies carbonate and elastic sedimentary rocks similar to the Yangtze continent. The porphyry belt is closely associated with Tertiary potassic volcanic rocks and alkali-rich intrusions in the area and controlled by north-south-north-northwest, large-scale, strike-slip faults, which are perpendicular to the collision zone between the Indian and Asian continents. Isotopic age determinations of the ore-bearing porphyries indicate that the magmatism occurred over at least three stages, peaking around 52, 41, and 33 Ma, respectively. The timing of middle and late shallow-level emplacement of these magmas is consistent with the ages of associated potassic volcanism and alkali-rich magmatism in the area. Although the porphyry deposits in the Yulong belt were developed in the intracontinental convergent environment, their mineralization styles and features are comparable to porphyry copper deposits in arc environments.;Compared to ore-bearing cale-alkaline porphyries in island arcs or continental margin arcs, the porphyritic intrusions in the Yulong belt are characterized by high K2O contents and enrichment in Rb and Ba, suggesting a shoshonitic magmatic affinity. Strong negative anomalies for Nb, Ta, P, and Ti and positive anomalies for Rb, Ba, Th, and LREE, normalized by chondrite, are characteristic of arc magmas. These intrusions yield a narrow Nd-143/Nd-144 range varying from (.51243 to 0.51253 and Sr-87/Sr-86 values from 0.7065 to 0.7077, which are transitional between type II enriched mantle and mid-ocean ridge basalt (MORB) values and closer to the former in terms of epsilon(Nd)-epsilon(Sr) This suggests that the porphyritic magmas were derived either from a hydrous-enriched mantle metasomatized by components such as H2O, K, Rb, Ba, Th, and LRee or by melt derived from the subducted oceanic slab of the Paleozoi Jinshajiang oceanic plate. The hypothesis is supported by Pb isotype supported by Pb isotope data for the intrusions.;Large-scale strike-slip faults in eastern Tibet, which accommodated the compressive strains produced by the Asian-Indian continent collision, also localized the porphyry Cu mineralization. North to north-northeast-directed convergence and collision produced a dextral strike-slip fault system around 60 to 70 Ma. Northeast-directed wedging of the Indian continent and subsequent collision with tire Yangtze continent during the Paleocene-Eocene produced conjugate strike-slip fault zones. The transition from a dextral strike-slip fault system to conjugate strike-slip, zones resulted in stress relaxation and formation of strike-slip pull-apart basins. Crustal-scale strike-slip faulting may have caused upwelling and partial melting of the hydrous-enriched mantle by decompression and facilitated the rise of a large volume of volatile-enriched porphyry magma that had ponded near the base of the lithosphere during this period.
学科主题	矿床地质
WOS关键词	FLU##ID#INCLUSION ; LATERAL SHEAR ; DEPOSITS ; EVOLUTION ; CHINA ; MANTLE ; ORIGIN ; MINERALIZATION ; GEOCHEMISTRY ; TECTONICS
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	ECONOMIC GEOLOGY PUBL CO
WOS记录号	WOS:000181610500007
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/37566]
专题	中国地质调查局沈阳地质调查中心
作者单位	1.Chinese Acad Geol Sci, Inst Mineral Resources, Beijing 100037, Peoples R China. 2.China Univ Geosci, Beijing 100082, Peoples R China. 3.Univ Tasmania, Ctr Ore Deposit Res, Hobart, Tas 7001, Australia. 4.Chinese Acad Sci, Guangzhou Inst Geochem, Guangzhou 510640, Peoples R China. 5.Chengdu Inst Geol & Mineral Resources, Chengdu, Peoples R China. 6.Xizang Bur Geol & Mineral Resources, Lahsa, Peoples R China. 7.中国地质科学院矿产资源研究所
推荐引用方式 GB/T 7714	Hou, ZQ,Ma, HW,Zaw, K,et al. The Himalayan Yulong porphyry copper belt: Product of large-scale;strike-slip faulting in eastern Tibet[J]. ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS,2003,98(1):125-145.
APA	Hou, ZQ.,Ma, HW.,Zaw, K.,Zhang, YQ.,Wang, MJ.,...&Tang, RL.(2003).The Himalayan Yulong porphyry copper belt: Product of large-scale;strike-slip faulting in eastern Tibet.ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS,98(1),125-145.
MLA	Hou, ZQ,et al."The Himalayan Yulong porphyry copper belt: Product of large-scale;strike-slip faulting in eastern Tibet".ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS 98.1(2003):125-145.