摘要
石湖地区金、银多金属矿床位于太行山中北段,产出于太古界阜平群变质岩系,燕山期麻棚岩体的周边。本文以石湖地区代表性矿床为例,根据多金属矿床黄铁矿流体包裹体中He、Ar同位素及与黄铁矿共生的石英流体包裹体中C、H、O同位素组成,探讨了石湖地区金、银多金属矿床成矿流体来源。分析结果表明石湖地区金、银多金属矿床黄铁矿流体包裹体中3He/4He介于0.43~2.40 Ra,40Ar/36Ar介于477~879,显示出本区金、银多金属矿床的成矿流体为地幔流体与地壳流体混合的产物。石英包裹体中δDV-SMOW介于-62‰^-105‰,δ18OV-SMOW介于9.6‰~13.8‰,表明成矿流体为岩浆水与大气降水的混合;δ13CPDB介于-3.5‰^-5.0‰,表明矿区成矿热液来自地幔。氢、氧、碳同位素体系与氦、氩同位素体系的示踪具有一致性,均显示出石湖地区金、银多金属矿床成矿流体为地幔流体与地壳流体混合的产物。
The gold,silver and polymetallic deposits in Shihu area are located in the mid-northern Taihang Mountains and occur in Archean Fuping Group metamorphic rock series around Yanshanian Mapeng granitic intrusion.The gold,silver and polymetallic deposits in Shihu area have attracted the attention of many geologists,and their metallogenesis has long been in dispute.The authors chose pyrite and quartz samples from these deposits in Shihu area to analyze their helium,argon,carbon,hydrogen and oxygen isotopic composition of fluid inclusions and the hydrogen,oxygen and carbon isotopic composition of the quartz in the same ore sample.The analytical results show that 3He/4He ratios in pyrite range from 0.43 to 2.40 Ra,and 40Ar/36Ar ratios range from 477 to 879.The composition of helium and argon isotopic system suggests that the source of ore-forming hydrothermal fluids was the mixture of mantle-derived fluids and crust-derived fluids.It is estimated that the δDV-SMOW values of the ore-forming fluid responsible for the formation of the quartz are-62％‰～-105‰,and the δ18OV-sMoW values of the fluid inclusions of the quartz are 9.6‰ ～13.8‰,showing that the ore-forming hydrothermal fluids were formed by the mixture of magmatic water and meteoric water.The δ13CPDB values of quartz vary in a relative narrow range of-3.5‰～-5.0‰,showing that the ore-forming hydrothermal fluids were derived from the mantle.The relationship between hydrogen,oxygen,carbon and helium and the argon isotopic systems of oreforming hydrothermal fluids show tracing consistency in gold,silver and polymetallic deposits of Shihu area.All the noble gas isotopic data,combined with stable isotopic data from five deposits,demonstrate that the ore-forming fluids were a mixture between mantle-derived fluids and crustal-derived fluids.
出处
《中国地质》
CAS
CSCD
北大核心
2014年第2期577-588,共12页
Geology in China
基金
公益性行业科研专项经费项目(200911007)
国家自然科学基金(40872137)联合资助
