- 责任者：Zhu Jiang (Wuhan Center of Geological Survey ; China Geological Survey ; Wuhan 430205 ; China) ; Lü Xinbiao
- 刊名：Geotectonica et Metallogenia
- 出版年：2013
- 卷期：37(4)
- 关键词：金矿 ; gold ores ; 流体包裹体 ; fluid inclusions ; 甘肃 ; Gansu Province
- 页码：p.641-652
- 图表：10 illus., 5 tables, 32 refs.
- 分类号：1001
- issnNo：ISSN1001-1552
- isbnNo：CN44-1595/P
The Huaniushan skarn-type gold deposit is located in the southern Beishan area. The ore bodies occur in the contact zone between the Huaniushan granite and the marble. Re-Os dating of a molybdenite sample yields a model age of 221.0-3.4 Ma, which is consistent with the zircon U-Pb age of the granite （225.6--2.2 Ma） within errors. The gold mineralization is therefore considered to be genetically related to the Huaniushan granite. Four main types of fluid inclusions are recognized： （1） two-phase liquid-rich inclusions, （2） two-phase gas-rich inclusions, （3） three-phase CH4-CO2-H20 inclusions, and （4） monophase vapor inclusions. Fluids associated with Au-bearing quartz veins （the early stage） have medium-high temperatures （285~C to 436~C） and moderate salinities （6.59% to 16.14% NaC1 equivalent）; whereas fluids associated with calcite veins （the late stage） have low temperatures of 121 ~C to 182 ~C and low salinities of about 4.34% to 8.01% NaC1 equivalent. The temperature and salinity of the ore-forming fluids decrease progressively. Fluid boiling happened during the main Au mineralization period at the temperature of about 300℃ to 415℃. Oxygen and hydrogen isotopic compositions of the ore fluids range from -0.01‰ to 0.29‰ and -116‰ to -109‰, respectively, which is compatible with mixing between the magmatic and meteoric components. Measured 348 values for sulfide minerals are 4.21‰-to 6.53‰, indicating a magmatic sulfur origin. Considering the regional geology, we further propose that the Huaniushan skarn-type gold deposit was probably formed in the post-orogenic extensional setting.