综合物探方法在云南澜沧老厂多金属矿区深部找矿中的应用  

Application of integrated geophysical methods in deep ore prospecting of Laochang polymetallic mining area in Lancang,Yunnan

作　　者：游越新 邓居智[1,2] 陈辉 余辉[1,2] 高科宁 YOU Yue-Xin;DENG Ju-Zhi;CHEN Hui;YU Hui;GAO Ke-Ning(State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang 330013,China;School of Geophysics and Measurement-control Technology,East China University of Technology,Nanchang 330013,China)

机构地区：[1]东华理工大学核资源与环境国家重点实验室,江西南昌330013 [2]东华理工大学地球物理与测控技术学院,江西南昌330013

出　　处：《物探与化探》2023年第3期638-647,共10页Geophysical and Geochemical Exploration

基　　金：国家自然科学基金项目(42130811、41864004);江西省主要学科学术带头人培养计划项目(20204BCJL23058);核资源与环境国家重点实验室开放基金(2022NRE18、2020NRE26);自然资源部深地科学与探测技术实验室开放课题(Sinoprobe Lab 202214)。

摘　　要：云南澜沧老厂是三江特提斯成矿带南段最重要的多金属矿区之一,经多年开采后浅部资源已近枯竭。近年来矿区深部新发现了花岗斑岩和斑岩型多金属矿化,凸显深部多金属的找矿潜力。为查明研究区深部控矿地层和构造的赋存情况,助力深部找矿突破,本文采用大功率激电法和音频大地电磁法对矿区深部结构进行探测。对采集的激电和电磁数据进行处理和反演后,获得了研究区的激电异常分布和深部电性结构特征,结合区域地质资料,得出以下主要结论:测区西北部的低阻、高极化异常为地表铁锰矿、银锰矿和深部多金属矿化的共同反映,测区中东部的高阻高极化异常与深部多金属矿化有关。中上石炭统灰岩及白云岩地层西厚东薄,其中西侧地层向SW方向倾伏,东侧地层上覆于下石炭统依柳组;隐伏花岗斑岩向NE方向倾伏,其深部2300~2800 m水平范围段与深断裂的耦合部位为深部多金属矿化有利区。将大功率激电法和音频大地电磁法相结合可提升深部多金属矿探测的可靠性,指导后续钻孔布设。Laochang,Lancang,Yunnan is one of the most important polymetallic mining areas in the southern part of Sanjiang Tethys metallogenic belt.After years of mining,the shallow resources are nearly exhausted.In recent years,granite porphyry and porphyry polymetallic mineralization have been newly discovered in the deep part of the mining area,highlighting the prospecting potential of deep polymetallic deposits.In order to trace the occurrence of deep ore-controlling strata and structures in the study area and help to make a breakthrough in deep ore prospecting,high-power induced polarization method and audio magnetotelluric method were implemented to image the deep structure situated.Results obtained from the inversion of the measured induced polarization and electromagnetic data recuperated the distribution of induced polarization anomalies and the characteristics of deep electrical structure within the study area.Combined with the available regional geological settings,the main conclusions are as follows:The low resistance and high polarization anomalies in the northwest of the survey area are deeply related to the surface ferromanganese,silver manganese,and deep polymetallic mineralization,and the high resistance and high polarization anomalies in the middle and east of the survey area are in good agreement with the deep polymetallic mineralization.The upper Carboniferous limestone and dolomite strata are thick in the west and thin in the east,with the west strata dipping to SW and the east strata overlying the Yiliu Formation of the lower Carboniferous.The concealed granite porphyry dips in NE direction,and the coupling part between its deep 2300~2800 m horizontal section and deep fault is a favorable area for deep polymetallic mineralization.Notably,joint interpretation yielded from the high-power induced polarization method and the audio magnetotelluric method applied improved the reliability of deep polymetallic ore detection and provided more information of positioning the subsequent drilling layout.

关 键 词：老厂多金属矿区 大功率激电 音频大地电磁 综合物探 深部找矿 

分 类 号：P631[天文地球—地质矿产勘探]