青海省柴北缘独树沟金矿床成矿流体特征及矿床成因  

Ore-forming fluid characteristics and genesis of the Dushugou Gold Deposit in the northern margin of Qaidam Basin,Qinghai Province

作　　者：邓元良 杨佰慧 赵呈祥 李鹏 Deng Yuanliang;Yang Baihui;Zhao Chengxiang;Li Peng(The First Exploration Institute of Geology and Mineral Resources in Qinghai Province;College of Earth Science,Jilin University)

机构地区：[1]青海省第一地质矿产勘查院 [2]吉林大学地球科学学院

出　　处：《黄金》2018年第11期7-13,共7页Gold

基　　金：中国地质调查局整装勘查项目(121201004000150017)

摘　　要：独树沟金矿床成矿过程由早至晚主要分为3个阶段:黄铁矿-石英阶段(Ⅰ)、石英-黄铁矿-多金属硫化物阶段(Ⅱ)和含黄铁矿-石英-碳酸盐阶段(Ⅲ)。其中,成矿Ⅱ阶段为主成矿阶段。成矿流体主要有富液相、富气相和含CO_2三相包裹体。成矿流体均一温度为134. 8℃～310. 2℃,盐度为1. 39%～12. 31%NaCleqv,密度为0. 77～0. 99 g/cm^3,显示为中低温、低盐度、低密度的特点,成矿流体属于含CO_2的中温、低盐度的NaCl-H_2O热液体系。综合矿床地质特征和成矿流体特征,确定矿床成因类型为中温热液脉型金矿床,估算矿床成矿深度为1. 5～2. 3 km,成矿与海西期中酸性侵入岩有关。The ore-forming process of Dushugou Gold Deposit is mainly divided into thine mineralization stages： pyrite - quartz stage （Ⅰ）, quartz - pyrite - polymetallic sulphide stage （Ⅱ） and pyrite - quartz - carbonate containing stage （Ⅲ） , of which stage Ⅱ is the main metallogenic stage. The ore-forming fluids are mainly composed of liquid-rich phase,gas-rich phase, CO2-containing thine-phase inclusions. The homogeneous temperature of the ore-forming fluids ranges 134.8℃ - 310.2℃ ,the salinity of the fluids ranges 1.39% - 12.31% and the density ranges 0.77 -0.99 g/cm^3 mainly indicative of the characteristics of medium temperature, low salinity and low density. The ore-forming fluids belong to a medium-temperature low-salinity CO2-containing NaCl-H2O hydrothermal system. Based on comprehensive analysis of the characteristics of deposit geology and ore-forming fluids, it is determined that the genetic type of the deposit is mesothermal vein-type gold deposit with the estimated mineralization depth 1.5 - 2.3 km and the mineralization should be related to the intermediate-acid intrusions of the Hercynian period.

关 键 词：矿床地质特征 矿床成因 成矿流体 成矿阶段 流体包裹体 独树沟金矿床 柴北缘 

分 类 号：TD11[矿业工程—矿山地质测量] P618.51[天文地球—矿床学]