物探方法在复兴屯银铅锌多金属矿区构造与成矿机理研究中的应用

复兴屯银铅锌多金属矿是近两年在大兴安岭成矿带中生代陆相火山盆地里首次发现的特大型银铅锌多金属矿床。在矿床普查与勘查期间开展了地面高精度磁测、时间域激发极化法面积性测量、AMT电磁测深等物探方法,发挥了重要指导作用。①通过地面磁异常数据RGIS软件处理解释判定了普查区构造构局;②综合利用地磁异常和视电阻率异常特征,结合地表出露岩性判定了破火山口断陷盆地位置;③利用激电测深判定了断陷盆地形成过程与构造特征及断裂构造的多期次与硫化物沉淀的多期次性;④依据视极化率异常特征,结合地质构造环境判定了场源性质和成矿物质来源;⑤利用AMT电磁测深资料圈定了筒状次火山岩侵入体。本文在上述研究结果和钻探基础上,还研究了该矿床形成机理,给出了一套寻找该类矿床的物探方法应用思路。

Application of geophysical methods in the exploration of Fuxingtun silver-lead-zinc polymetallic deposit and its metallogenic mechanism

The Fuxingtun silver-lead-zinc polymetallic deposit is the first large-scale silver-lead-zinc polymetallic deposit discovered in the Mesozoic continental volcanic basin in the Daxinganling metallogenic belt in the past two years.During the census of the deposit,geophysical methods such as high-precision magnetic survey on the ground,time-domain induced polarization method,and AMT sounding method were conducted.Geophysical methods played an important guiding role in the exploration of Fuxingtun silver-lead-zinc polymetallic deposit.①Through the processing and interpretation of ground magnetic anomaly data(using RGIS software),the structure of the census area were determined;②Using the characteristics of geomagnetic anomaly and apparent resistivity anomaly,combined with the exposed lithology on the surface,the caldera rifted basin was determined;③Using the electrical sounding data,the formation process and structural characteristics of the faulted basin was determined,as well as the multi-stage of fault structure and the multi-stage of sulfide precipitation;④Based on the abnormal characteristics of apparent polarizability and the geological structure environment,the nature of the field source and the source of mineralization materials were determined;⑤The intrusive body of cylindrical subvolcanic rock was delineated by AMT sounding data.Based on the above research results and drilling data,this paper studies the formation mechanism of the deposit and summarizes a set of application ideas for geophysical methods to find such deposits.