广域电磁法在滇西北斑岩铜矿中的应用研究

The application of wide field electromagnetic method in the porphyry copper deposit in northwestern Yunnan

普朗超大斑岩型铜多金属矿床产于石英闪长玢岩-石英二长斑岩-花岗闪长斑岩复式侵入体内,其成矿作用跟岩体密切相关,为了探测矿区深部隐伏岩体的形态及规模,拓展深部找矿空间,运用广域电磁法在矿区进行测深勘探。对采集数据进行了精细处理和综合地质解译分析,成果显示广域电磁法能有效地识别深部隐伏岩体和大型构造,通过与施工钻孔揭露的地质信息对比,较完整且规模较大的花岗岩体电阻率更稳定,本方法对岩性分界线响应的准确度也更高。探测结果表明矿区东侧和南部的深部还存在大范围复式岩体,在岩体内构造裂隙发育地段具有较大找矿潜力,可为后期优选深部找矿靶区提供地球物理参数。

The Pulang super-large porphyry copper-polymetallic deposit is hosted within a composite intrusive complex consisting of quartz diorite porphyry,quartz monzonite porphyry,and granodiorite porphyry,with mineralization closely linked to the intrusive bodies.To investigate the morphology and extent of concealed deepseated intrusions and enhance deep exploration potential,wide field electromagnetic method surveys were conducted in the study area.Comprehensive data processing and geological interpretation revealed that the method effectively identifies deep-seated intrusive bodies and major structures.When compared to borehole geological data,the resistivity of large,intact granite bodies was found to be more stable,and the method demonstrated higher accuracy in delineating lithological boundaries.The results indicate that extensive composite intrusions exist in the deep eastern and southern parts of the mining area,with structurally fractured zones within these intru⁃sions offering significant exploration potential.These findings provide key geophysical parameters for identifying deep exploration targets in future prospecting activities.