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Geoscience ›› 2019, Vol. 33 ›› Issue (05): 1036-1045.DOI: 10.19657/j.geoscience.1000-8527.2019.05.10

• Geochemistry • Previous Articles     Next Articles

The Alteration Characteristics and Element Migration Law of the Jinchiling Gold Deposit, Shandong Province

GAO Jianwei1(), TENG Chao1, ZHAO Guochun2(), LIU Wenqing1, ZHOU Yi1   

  1. 1. Cores and Samples Center of Natural Resources, CGS, Yanjiao, Hebei 065201,China
    2. School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083,China
  • Received:2019-02-24 Revised:2019-06-11 Online:2019-10-26 Published:2019-10-28
  • Contact: ZHAO Guochun

Abstract:

Jiaodong area,the most important gold province in China,is an area with concentration occurrence of large and super large gold deposits,the proved reserves in Jiaodong Peninsula account for nearly 1/3 of the country. Among them, the quartz vein type gold deposit is an important type of deposits in the area, and the Jinchiling gold deposit in Shandong is the representative of this type. Based on the detailed geologic observations in the field and indoor research, this paper found out the alteration type and mineral combination characteristics of the gold deposit, collected rock samples of different alteration types, conducted geochemical analysis of rock elements, and summarized the migration law of elements during hydrothermal alteration by using mass balance method. The surrounding rock of the deposit is granite, and the ore-bearing hydrothermal fluid surges along the fault, which has a strong alteration effect on the surrounding rock. This paper argues that the alteration types are mainly potash-alteration, silicification-sericitization and pyritization silicification-sericitization. The material exchange in the alteration process changes the composition of the fluid and so on. The fluid provides a large amount of SiO2 to the altered rock. At the same time, the surrounding rock of the alteration process provides a large amount of K and Na to the fluid, which promotes the activation of Au in the fluid, causing the stability of AuH3SiO4 in the hydrothermal fluid to decrease, and causing the decomposition of AuH3SiO4, and then the Fe2+ and Fe3+ are consumed to form pyrite, resulting in gold mineralization.

Key words: hydrothermal alteration, mass balance, Jinchiling gold deposit, Jiaodong

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