甘肃贾公台金矿床地质特征与流体包裹体研究  

Study on Geological Characteristics and Fluid Inclusion of Jiagongtai Gold Deposit in Gansu

作　　者：汪禄波[1,2] 戴霜[1,2] 张莉莉[1,2] 张翔[1,2,3] 李荣西[4] 张瑞[1,2] 张明震[1,2] 

机构地区：[1]兰州大学西部环境与气候变化研究院,甘肃兰州730000 [2]兰州大学西部环境教育部重点实验室,甘肃兰州730000 [3]甘肃省地质调查院,甘肃兰州730000 [4]长安大学地球科学与资源学院,陕西西安710054

出　　处：《地球科学与环境学报》2014年第1期111-119,共9页Journal of Earth Sciences and Environment

基　　金：甘肃省科技重大专项项目(1203FKDA038);国家自然科学基金项目(41272127)

摘　　要：贾公台金矿床是秦祁昆造山系南祁连党河南山地区最具代表性的金矿床之一。为了查明其矿床成因类型，对贾公台金矿床进行矿床地质特征的系统性研究和成矿主阶段流体包裹体的测温及激光拉曼测试分析。结果表明：矿床位于 NW 向与 NE向构造的交汇部位，矿化产于下奥陶统上岩组浅变质海相碎屑岩和花岗岩中，严格受NW向断裂控制；矿体主要呈脉状、透镜状，Au品位较高（1.98×10^-6），有害组分少，且伴生Ag；成矿主阶段流体包裹体类型为气液两相包裹体及少量气体包裹体；成矿流体为低盐度、低CO2含量的NaCl-H2O体系，成矿温度为236℃～245℃（中温），成矿压力为48.7～51.4 MPa，对应深度为5.56～5.72 km；经与浅成热液型金矿、造山型金矿主要特征进行对比，初步厘定贾公台金矿床为浅成热液型金矿床。Jiagongtai gold deposit is one of the most representative gold deposits in the south of Danghenanshan Mountain,Qinling-Qilian-Kunlun orogenic system.In order to find out the genetic type of Jiagongtai gold deposit,the geological characteristics were studied,and microthermometry and Laser Raman analysis of fluid inclusions in quartz of metallogenic stages were explained.The results show that the gold deposit locates at the intersection of NW-structure and NE-structure, mineralization occurs in the granite and epimetamorphic marine clastic rocks of Lower Ordovician upper group and is strictly controlled by the NW-structure;most of the ore bodies are vein or lens-like with high grade of Au （1.98×10^-6 ）,accompanying Ag and a small amount of harmful components;fluid inclusions in quartz of metallogenic stage have mainly two types,including gas-liquid two-phase and a little of gas-rich phase;the ore-forming fluid is NaCl-H 2 O system with low salinity and low CO2 ,the metallogenic temperatures （236 ℃-245 ℃） are middle,metallogenic pressures are 48.7-51.4 MPa,and the corresponding depths for gold mineralization are 5.56-5.72 km;compared with the key features of epizonogenic hydrothermal-and orogenic-types gold deposits,it is preliminarily confirmed that Jiagongtai gold deposit is an epizonogenic hydrothermal deposit.

关 键 词：金矿床 流体包裹体 地质特征 浅成热液型矿床 花岗岩 下奥陶统 甘肃 

分 类 号：P618.51[天文地球—矿床学]