气候变化领域集成服务门户(CCPortal): The Nadun Cu-Au mineralization, central Tibet: Root of a high sulfidation epithermal deposit

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DOI	10.1016/j.oregeorev.2016.04.019
	The Nadun Cu-Au mineralization, central Tibet: Root of a high sulfidation epithermal deposit
	Li, Jin-Xiang; Qin, Ke-Zhang; Li, Guang-Ming; Evans, Noreen J.; Zhao, Jun-Xing; Cao, Ming-Jian; Huang, Fang
通讯作者	Li, JX (通讯作者)
发表日期	2016
ISSN	0169-1368
EISSN	1872-7360
起始页码	371
结束页码	387
卷号	78
英文摘要	A new high sulfidation epithermal Cu-Au occurrence (Nadun) has been discovered adjacent to the Cretaceous Duolong porphyry Cu-Au deposit within the Bangong-Nujiang metallogenic belt, central Tibet. The Nadun Cu-Au mineralization is hosted in a tectonic-hydrothermal breccia with advanced argillic alteration, which occurs above sandstone, associated with quartz-pyrite veins. The granodiorite porphyry with strong argillic alteration yields a zircon U-Pb age of 119.1 +/- 1.3 Ma, whereas the weakly argillic granodiorite porphyry intruded into the breccia has a younger age of 116.1 +/- 1.3 Ma. This indicates that Cu-Au epithermal mineralization likely occurred between similar to 116 Ma and similar to 119 Ma, consistent with the duration of magmatic-hydrothermal activity at Duolong (similar to 115-118 Ma), and providing evidence that Nadun and Duolong were formed during the same event. Moreover, the Nadun and Duolong porphyries have similar Hf isotopic compositions (epsilon Hf(t) values ranging from -8.8 to 8.1; mean = 5.0 +/- 1.1, n=32), likely indicating that the deposits are comagmatic. In addition, boiling assemblages in vapor-rich inclusions coexisting with brines occur in early stage quartz-pyrite veins, and likely record phase separation at a temperature of > 550-300 degrees C and pressure of 700-110 bars. Most liquid-rich fluid inclusions formed at the breccia stage show similar salinity (1.7-19.3 wt.% NaCl equiv) to vapor-rich inclusions from the underlying quartz-pyrite veins, likely indicating vapor contraction during cooling at elevated presssure. This suggests that quartz-pyrite veins may act as conduits for ore-forming fluid traveling from the porphyry to the epithermal hydrothermal system. O and H isotopic compositions (delta O-18(fluid) = 0.42-9.71 parts per thousand and delta D = -102 to -66 parts per thousand) suggest that ore-forming fluids are dominantly from a magmatic source with a minor addition of meteoric water at a later stage. The S and Fe isotope compositions of sulfides (delta S-34 = -5.9 to 0.5 parts per thousand and delta Fe-57 = -2.15 to 0.17 parts per thousand) decrease from the quartz-pyrite vein to breccia ore, indicating that ore-forming fluids gradually become SO42-enriched and relatively oxidized. This body of evidence suggests that the Nadun Cu-Au mineralization may represent the root of a high sulfidation epithermal deposit. (C) 2016 Elsevier B.V. All rights reserved.
关键词	U-PB GEOCHRONOLOGY ZIRCON REFERENCE MATERIAL HF ISOTOPIC COMPOSITIONS PORPHYRY COPPER-DEPOSIT STABLE-ISOTOPE MAGMATIC FLUIDS LU-HF HYDROTHERMAL ALTERATION QIANGTANG TERRANE HIGH-TEMPERATURE
英文关键词	Zircon U-Pb ages; Fluid inclusions; H-O-Fe-S isotopes; Epithermal mineralization; Tibet
语种	英语
WOS研究方向	Geology ; Mineralogy ; Mining & Mineral Processing
WOS类目	Geology ; Mineralogy ; Mining & Mineral Processing
WOS记录号	WOS:000378450300024
来源期刊	ORE GEOLOGY REVIEWS
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/258785
推荐引用方式 GB/T 7714	Li, Jin-Xiang,Qin, Ke-Zhang,Li, Guang-Ming,et al. The Nadun Cu-Au mineralization, central Tibet: Root of a high sulfidation epithermal deposit[J]. 中国科学院青藏高原研究所,2016,78.
APA	Li, Jin-Xiang.,Qin, Ke-Zhang.,Li, Guang-Ming.,Evans, Noreen J..,Zhao, Jun-Xing.,...&Huang, Fang.(2016).The Nadun Cu-Au mineralization, central Tibet: Root of a high sulfidation epithermal deposit.ORE GEOLOGY REVIEWS,78.
MLA	Li, Jin-Xiang,et al."The Nadun Cu-Au mineralization, central Tibet: Root of a high sulfidation epithermal deposit".ORE GEOLOGY REVIEWS 78(2016).