河北丰宁大西沟金矿流体地球化学研究  

Fluid geochemistry of the Daxigou gold deposit in Fengning,Hebei Province

作　　者：邓磊[1] 王建国[2] 王圣文[2] 曹烨[2] 熬翀[2] 

机构地区：[1]长江大学工程技术学院,湖北荆州434000 [2]中国地质大学地质过程与矿产资源国家重点实验室,北京100083

出　　处：《中国地质》2009年第1期184-193,共10页Geology in China

基　　金：高等学校创新引智计划项目(B07011)资助。

摘　　要：笔者利用显微测温、成分及氢氧同位素测试对大西沟金矿流体包裹体参数以及成矿流体性质进行了较为深入的探讨,结果显示,大西沟金矿与矿化关系密切的石英中,包裹体可以分为气体包裹体、气液包裹体、液体包裹体3种类型,其中气液包裹体、液体包裹体最为常见。包裹体均一温度主要集中在175℃～275℃,盐度为2%～7%,流体密度为0.804～0.959g/cm^3,成矿深度为1.01～2.24 km。流体包裹体气相成分主要为H_2O和CO_2;包裹体液相成分中阳离子以Na^+为主,Ca^(2+)、K^+次之,阴离子以SO_4^(2-)、Cl^-为主,仅含微量的F^-。石英中δ^(18)O水值是2.1‰～5.8‰,δD值为-87‰～-103.67‰,反映成矿流体来源于岩浆水与大气降水。通过气体逸度的计算,大西沟金矿成矿流体中金主要以[Au (HS)_2]^-络合物的形式迁移,混合作用和热液蚀变作用是导致金沉淀与富集的主要因素。The experimental results of fluid inclusion microthermometry, material constituents, H-O isotopes and ore-forming fluids in the Daxigou gold deposit suggest that there exist three types of fluid inclusions in the ore deposit, namely gas inclusions （V type）, gas-liquid inclusions （V-L type） and liquid inclusions （L type）. Fluid inclusions occur in vein quartz, with their homogenization temperature, salinity, fluid density and ore-forming depth being 175-275℃, 2%-7%, 0.804-0.959g/cm^3 and 1.01-2.24 km respectively. The gases in fluid inclusions are chiefly composed of H2O and CO2. As for liquid composition, the cations are mainly Na^＋ and subordinately Ca^2＋ and K^＋, and the anions are mainly comprised of SO4^2- and Cl^- with minor amounts of F^-. The δ^18O H2O values of quartz from the ore-forming fluids range from 2.1‰ to 5.8‰, and δ D values from -87‰- 103.67‰, indicating a mixed source of magmatic water and atmospheric precipitation. The gas fugacity determinations show that Au was transported in the form of complex compound [Au（HS）2]- in the ore-forming fluids. In addition, the mixing process and the hydrothermal alteration contributed to gold deposition and concentration.

关 键 词：流体包裹体 成矿流体 地球化学 大西沟金矿 河北 

分 类 号：P618.51[天文地球—矿床学]