摘要
水井金矿床赋存于哀牢山造山带红河断裂东缘韧-脆性剪切构造破碎带中,容矿岩石为砂-泥岩、灰岩之角砾岩、碎裂岩。硫、碳同位素研究表明,流体中碳、硫来自深部或地幔;氢氧同位素的组成特征则表明成矿热液主要为天水下渗及地下水循环从构造活动及岩体获得热源而形成的混合热液流体。矿物包裹体类型以液相为主,少量气相出现。矿石中的石英包裹体液相成分阳离子以Na＋、K＋为主,阴离子以Cl-、SO42-为主,气相成分以H2O、CO2为主,间有CH4、CO出现,属H2O—CO2—NaCl体系。主要成矿阶段包裹体均一温度为180℃~260℃之间,成矿深度约为1.0km,流体密度0.65~0.9g/？3,流体盐度w（NaCleq）4.97%~7.76%。小水井金矿床属于浅成条件下,由中低温、低盐度、低密度的混合热液流体在韧-脆性剪切构造带中形成的金矿床,成因类型应归属于浅成造山型金矿床,应用类型为构造蚀变岩型金矿。
Xiaoshuijing gold deposit occurs in tough-brittle shear fracturing structure zone on the eastern margin of Honghe fracture of Ailaoshan orogenic belt with host rock being sandstone-mudstone,limestone breccias and fracturing rocks.Study on sulfur and carbon shows that carbon and sulfur in fluid originated in depth or mantle while the characteristics of hydrogen and oxygen Composition shows that ore-forming hot water was mainly mixed hydrothermal fluid formed by meteoric water penetration and underground water circulation and heat source obtained from magmatic rock.The type of mineral inclusion is mostly gaseous to liquid phase with less gaseous phase.The cations in liquid inclusion of quartz in ore is mainly Na＋、K＋,and the ratio of Na＋/K＋varies from3.056 to 4.940;anions are mainly Cl-、SO42-and characterized by Cl-SO42-F-HCO3-while gaseous compositions are mainly H2O、CO2Belonging to H2O—CO2—NaCl system.Homogeneous temperature of inclusion during major mineralization stage accumulated between 180℃～260℃,metalogenic depth is approximately 1.0Km,with fluid density 0.65～0.9g/㎝3 fluid salinity ω（NaCleq）4.97%～7.76%.Xiaoshuijing gold deposit belongs to the gold deposit formed by middle to low temperature,low salinity and low density mixed hydrothermal fluid in tough-brittle shear zone under epizonal condition,with the characteristics of geology and geochemistry similar with that of orogenic type gold deposit.The genetic type of the ore is attributed to epizonal orogenic type gold deposit while its applied type is structure-altered rock type gold deposit.
出处
《矿产与地质》
2010年第5期445-453,共9页
Mineral Resources and Geology
基金
云南黄金矿业集团股份有限公司科研项目"云南省楚雄市龙岗金矿带成矿规律及成矿预测"的资助
关键词
金矿床
成矿流体
地球化学特征
矿床类型
滇中小水井
geology
ore-forming fluid
geochemical characteristics
deposit type
Xiaoshuijing gold deposit in center Yunnnan
