Zircon U-Pb Chronology and Geochemistry of the Rhyolite Porphyry in the Nagengkangqieer Silver Polymetallic Deposit, East Kunlun and Their Geological Significance

被引：5
作者：
Guo X. [1 ,2 ]
Xie W. [3 ]
Zhou H. [3 ]
Tian C. [4 ]
Li J. [2 ]
Kong H. [2 ]
Yang T. [2 ]
Yao X. [1 ]
Jia Q. [2 ]
机构：
[1] Geological Survey of China University of Geosciences, Wuhan
[2] Xi'an Center, China Geological Survey, Key Laboratory for the Study of Focused Magmatism and Giant Ore Deposit, Xi'an
[3] Metallurgical Geological Prospecting Bureau of Sichuan Province, Chengdu
[4] Geological Survey Bureau of Qinghai Province, Xining
来源：
Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences | 2019年 / 44卷 / 07期
关键词：
East Kunlun; Geochemistry; Nagengkangqieer silver polymetallic deposit; Rhyolite porphyry; Zircon U-Pb dating;
D O I：
10.3799/dqkx.2018.101
中图分类号：
学科分类号：
摘要：
The Nagengkangqieer silver polymetallic deposit located in the East Kunlun orogenic belt is a newly discovered large-scale silver deposit in Qinghai Province. Orebodies of the deposit are mainly hosted in rhyolite porphyry. This paper presents zircon U-Pb dating and Lu-Hf isotopes, whole-rock major and trace elements for rhyolite porphyry in the Nagengkangqieer deposit. The LA-ICP-MS zircon U-Pb analyses for rhyolite porphyry show that rocks formed during the Late Triassic with ages of 217.4±3.1 Ma. The rhyolite porphyry has high contents of SiO2 (73.08%-75.78%), Al2O3 (14.05%-16.04%), with K2O+Na2O ranging from 4.31% to 4.77%, and K2O=4.20%-4.61%, belonging to the high-potassium calc-alkaline strong peralkaline volcanic rocks. These rocks are characterized by high silicon, aluminum and high-potassium, the Mg# values range from 45 to 54; and rhyolite porphyry is depleted in high field strength elements (HFSEs; e.g., Nb, Ta, P, and Ti), and enriched in large-ion lithophile elements (LILEs; e.g., Rb, Th and K); εHf(t) values vary from -4.4 to -9.7, and the two-stage model age of TDM2 ranges from 1 533 Ma to 1 864 Ma. According to the petrology, geochemistry and regional tectonic background, we conclude that the rhyolite porphyry was predominantly derived from partial melting of the Paleoproterozoic-Mesoproterozoic continental crust and some mantle derived material, it formed in extension tectonic settings. The Nagengkangqieer silver polymetallic deposit reflects the Late Triassic mineralization, which is essential for future exploration of polymetallic deposit in the area where intrusive rocks or volcanic rocks in East Kunlun orogenic belt would be very obvious. © 2019, Editorial Department of Earth Science. All right reserved.
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页码：2505 / 2518
页数：13
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