The Nadun Cu-Au mineralization, central Tibet: Root of a high sulfidation epithermal deposit | |
Li, JX (Li, Jin-Xiang)1,2; Qin, KZ (Qin, Ke-Zhang)2,3; Li, GM (Li, Guang-Ming)2,3; Evans, NJ (Evans, Noreen J.)4; Zhao, JX (Zhao, Jun-Xing)3; Cao, MJ (Cao, Ming-Jian)3; Huang, F (Huang, Fang)5; Li, JX | |
Source Publication | ORE GEOLOGY REVIEWS |
2016 | |
Volume | 78Issue:0Pages:371-387 |
DOI | 10.1016/j.oregeorev.2016.04.019 |
Abstract | 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. |
Subject Area | 地质学 |
WOS ID | WOS:000378450300024 |
Language | 英语 |
Indexed By | SCI |
Keyword | U-pb Geochronology o Isotope Characteristics Zircon Reference Material Porphyry Copper-deposit Stable-isotope Fluid Inclusions Magmatic Fluids Lu-hf Hydrothermal Alteration Northwestern Tibet |
Cooperation Status | 国际 |
Department | 碰撞与隆升 |
Subtype | Article |
Citation statistics | |
Document Type | 期刊论文 |
Identifier | http://ir.itpcas.ac.cn/handle/131C11/7601 |
Collection | 图书馆 |
Corresponding Author | Li, JX |
Affiliation | 1.Chinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Continental Collis & Plateau Uplift, Beijing 100101, Peoples R China 2.CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China 3.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Mineral Resources, Beijing 100029, Peoples R China 4.Curtin Univ, Appl Geol, TIGeR, John de Laeter Ctr, Perth, WA 6945, Australia 5.Univ Sci & Technol China, Sch Earth & Space Sci, CAS Key Lab Crust Mantle Mat & Environm, Hefei 230026, Peoples R China |
Recommended Citation GB/T 7714 | Li, JX ,Qin, KZ ,Li, GM ,et al. The Nadun Cu-Au mineralization, central Tibet: Root of a high sulfidation epithermal deposit[J]. ORE GEOLOGY REVIEWS,2016,78(0):371-387. |
APA | Li, JX .,Qin, KZ .,Li, GM .,Evans, NJ .,Zhao, JX .,...&Li, JX.(2016).The Nadun Cu-Au mineralization, central Tibet: Root of a high sulfidation epithermal deposit.ORE GEOLOGY REVIEWS,78(0),371-387. |
MLA | Li, JX ,et al."The Nadun Cu-Au mineralization, central Tibet: Root of a high sulfidation epithermal deposit".ORE GEOLOGY REVIEWS 78.0(2016):371-387. |
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