内蒙古二道河子铅锌矿床构造控矿作用及找矿方向  

Tectonic Ore-controlling and Prospecting Direction of Erdaohezi Pb-Zn Deposit in Inner Mongolia

作　　者：李兴[1] 刘云华[1] 关强兵 刘方杰 李欢[1] 尚志辉 

机构地区：[1]长安大学地球科学与资源学院,陕西西安710054 [2]陕西有色金属控股集团有限责任公司,陕西西安710075 [3]西南能矿集团股份有限公司,贵州贵阳550004

出　　处：《地球科学与环境学报》2016年第6期791-802,共12页Journal of Earth Sciences and Environment

基　　金：陕西有色金属控股集团有限责任公司科研项目(20140201);中央高校基本科研业务费专项资金项目(310827153407)

摘　　要：内蒙古二道河子铅锌矿床位于大兴安岭得尔布干多金属成矿带。通过详细的野外地质调查,矿区发育有NE、NW、近SN向等3组断裂构造。矿体主要呈脉状—网脉状产出于NW向断裂构造带中,断层面平直,延伸稳定。矿体与围岩界线明显,矿石结构完整。矿化围岩主要为流纹质岩屑晶屑凝灰岩;NE向次级断层内充填梳状石英脉,矿化较弱,截断NW向矿体但位移距离不大;SN向断层挫距较大,对矿床起一定的破坏作用。矿区发育的NE、NW向构造为成矿期前或成矿期得尔布干断裂的次级断裂构造,NW向构造早期具有压剪性构造特征,成矿期为张性环境,成矿期后封闭;NE向断裂在成矿期为挤压环境,成矿期后有继承性活动;SN向断裂为成矿期后构造。围岩岩性对成矿具有重要的控制作用。结合物探与化探异常特征,矿区西北部偏酸性岩石分布范围内的NW、NE向构造交汇部位是寻找厚大富集型矿体的最有利靶区,深部岩性不整合面及火山穹窿可能是寻找似层状矿体的有利位置。Located in the northwest of Derbugan fault,the Erdaohezi Pb-Zn deposit belongs to Derbugan metallogenic belt in Great Xing＇an Range.Through the detailed field geological survey,NE-,NW-,nearly SN-trending fault systems develop in Erdaohezi mining area.The orebodies are controlled by NW-trending faults,which have flat fault plane and stable extension,with mainly vein-stockwork type.The lines between orebodies and wall-rocks are obvious,and the ore textures are integrated.The ore-hosting rocks are mainly rhyolitic lithic crystal tuff.NE-trending secondary faults are filled with a lot of comb-type quartz,and the mineralization is weak;they crosscut the NW-trending orebodies with little displacement;SN-trending faults break the deposits because of the bigger displacement.NE-and NW-trending structures are the secondaryfaults of Derbugan fault before and during the metallogenic period;NW-trending structures are pressure shear in the early period,and tensional environment during the metallogenic period,and closed after the metallogenic period;NE-trending faults are compressional environment during the metallogenic period,and have successive activity after the metallogenic period;SN-trending faults form after the metallogenic period.The lithology of host-rock is an important control factor for metallogenesis.Combined with the characteristics of geophysical and geochemical anomalies,the overprinting zones of NE-and NW-trending structures with intermediate-felsic volcanic rocks in the northwest of Erdaohezi mining area are the most favorable targets for prospecting large industrial orebodies,and some heterolithic unconformity interfaces and volcanic domes are the vantage points for finding stratiform-like orebodies.

关 键 词：铅锌矿床 控矿构造 找矿方向 岩浆热液 岩屑晶屑凝灰岩 得尔布干断裂 内蒙古 

分 类 号：P613[天文地球—矿床学] P618.4[天文地球—地质学]