黑龙江二十一站—宝兴沟(铜)金矿床特征及其热液成矿系统

Characteristics of the 21 site—Baoxinggou(Cu)——Au deposit and its hydrothermal ore-forming system of Heilongjiang

二十一站—宝兴沟(铜)金矿床(点)位于上黑龙江断陷盆地的东南部。区域地质背景及典型矿床研究表明,矿床不仅受NE向断裂构造控制,还受其同期的岩浆岩控制。对宝兴沟金矿床的流体包裹体测试结果、矿床围岩蚀变和与火山穹窿构造间的关系等研究,表明宝兴沟金矿可能是中硫型浅成低温热液型矿床,二十一站和十五里桥(铜)金矿床可能是高硫型浅成低温热液型矿床(点)。区域地质特征、遥感解译、航磁异常及Au、Ag、Cu化探异常分布特征显示了本区可能存在两种环境的斑岩型--浅成低温热液型成矿热液系统。在此基础上,结合铜元素化探异常和火山穹窿等特征,提出了在十五桥金矿床、二十一站铜金矿一带寻找斑岩型铜钼矿化类型,在NW、NNE向构造带内找寻与浅成低温热液系统有关的矿床。

The 21 site—Baoxinggou（Cu）——Au deposit is located at the southeast margin of Heilongjiang subsidence basin.The regional geology and typical deposit study suggested that this（Cu）——Au deposit were controlled not only by the NE-trending faults,but also by contemporaneous magmatic activity.The study of fluid inclusion,wall-rock alternation and the relationship among volcanic domes showed that Baoxinggou gold deposit might be a medium sulfidation epithermal deposit,and Shiwuliqiao and the 21 site（Cu）——Au gold deposits were likely high sulfidation epithermal deposits.The characteristics of regional geology,remote senseing interpretation,aeromagnetic anormaly and geochemical anormaly indicated that there were 2 types of porphyry hydrothermal ore-forming systerms in this area.Combining with Au anormaly and volcanic dome characteristics,the authors proposed that porphyry Cu——Mu deposits could be found nearby Shiwuliqiao and the 21 site（Cu）——Au gold deposits,and epithermal deposit could be found in NW or NNE-trending faults.