The Hanshan gold deposit in the Caledonian North Qilian orogenic belt, NW China
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- 作者：Mao Jingwen ; Zhang Zuoheng ; Yang Jianmin and Zhang Zhaochong
- 刊名：Mineralium Deposita
- 出版年：2000
- 出版时间：January 2000
- 年：2000
- 卷：35
- 期：1
- 页码：63-71
- 全文大小：393 KB
- 刊物类别：Earth and Environmental Science
- 刊物主题：Earth sciences
Geology
Mineral Resources
Mineralogy - 出版者：Springer Berlin / Heidelberg
- ISSN：1432-1866
文摘
The recently discovered Hanshan gold deposit in northern Gansu Province, northwestern China, is hosted by a WNW-striking shear zone in Ordovician andesite and basalt. Mineralization consists of surface to near-surface oxidized ore (the yellow sandy gossan type) and three types of primary ore, i.e. early-stage quartz-sericite-pyrite ores in stockworks, early-stage disseminated ore, and the most important late-stage quartz?±?calcite-sulfide veins. The ore system is characterized by variable degrees of potassic and silicic alteration. Late-stage gold-related fluid inclusions have homogenization temperatures between 170 to 310?°C, with a peak around 260?°C and low salinities. The ore fluids had high contents of CO2, CH4, and N2. Sulfur isotope measurements of ?1.9 to +1.7?per mil for hydrothermal pyrites could be consistent with a hydrothermal fluid source from the mantle, but the oxygen and carbon isotope data from calcite and quartz suggest mixing between mantle and crustal fluid sources. K-Ar ages for hydrothermal sericite from ore zones are 213.9?±?3.1 and 224.4?±?3.2?Ma. Due to the arid Cenozoic climate, a yellow gold-bearing gossan developed, which consists of jarosite, gypsum, and relict quartz. It could be a widespread and useful prospecting guide for gold in northwestern China.