滇东北地区MVT型隐伏铅锌矿床的勘查模式研究:以茂租铅锌矿床为例  

Study on the prospecting model of concealed MVT lead-zinc deposits in northeastern Yunnan Province:A case study of Maozu lead-zinc deposit

作　　者：张伟 廖国忠[1] 廖震文 杨剑 王桥 李华 张陈 蒋诗鹏 ZHANG Wei;LIAO Guozhong;LIAO Zhenwen;YANG Jian;WANG Qiao;LI Hua;ZHANG Chen;JIANG Shipeng(Chengdu Center,China Geological Survey(Geosciences Innovation Center of Southwest China),Chengdu 610218,China;Civil-military Integration Center of Geological Survey,China Geological Survey,Chengdu 610036,China;Qiaojia Maozu Lead and Zinc Company Limited,Zhaotong 654604,China;School of Geophysics,Chengdu University Of Technology,Chengdu 610059,China)

机构地区：[1]中国地质调查局成都地质调查中心(西南地质科技创新中心),四川成都610218 [2]中国地质调查局军民融合地质调查中心,四川成都610036 [3]巧家县茂租铅锌有限公司,云南昭通654604 [4]成都理工大学地球物理学院,四川成都610059

出　　处：《沉积与特提斯地质》2023年第4期779-796,共18页Sedimentary Geology and Tethyan Geology

基　　金：国家自然科学基金项目(42230311,41804144);中国地质调查局“四川会理-盐源地区地球物理调查”(DD20190033);“川滇黔地区隐伏铅锌矿综合勘查技术方法试验研究”(12120113050700)。

摘　　要：滇东北地区是我国MVT型铅锌矿床的重要集中产出地之一,区内浅表资源经长时间开采而逐渐枯竭,亟需在已知矿床的外围及深部寻找到新的接替资源。本文以区内典型的巧家县茂租铅锌矿床为例,通过在矿区已知矿床点开展综合找矿方法试验,并结合前人对本区地质背景、成矿模式、矿床特征、找矿标志等的认识,对本区MVT型铅锌矿床深部找矿的勘查模式进行了研究。研究表明,岩石地球化学测量中沿断层破碎带浓集的Pb-Zn-Ag元素高值异常指示了其深部具备成矿热液活动“痕迹”,音频大地电磁法能够查明地下深部有利赋矿层位(震旦系灯影组和寒武系筇竹寺组)的顶底界面埋深和导(控)矿断层的倾向、规模等地质成矿“格架”背景,面积性激电中梯测量能够在“横向平面尺度”圈定出有利的找矿靶区(高极化异常区),大比例尺激电测深剖面能够在“纵向空间尺度”定位矿(床)体位置(低电阻率、高极化异常体),通过深浅结合的组合勘查技术方法(浅表化探组合元素异常+电阻率剖面深部地质结构+平、剖面激电异常体),可以从多学科交叉的角度为深部找矿靶区优选提供证据支撑。据此,本文提出了“构造地球化学+多维度电法勘探”的勘查模式,此模式有望推广到滇东北铅锌成矿带内的其他铅锌矿区进行找矿示范应用。Northeast Yunnan Province is one of the most important production areas of MVT lead-zinc deposits in China.In recent years,with the gradual depletion of resources in shallow mining areas,it is urgent to find new replacement resources in the peripheral and deep parts of mining areas.Taking the typical MVT Maozu lead-zinc deposit in Qiaojia county as an example,this paper puts forward a prospecting model suitable for deep exploration of MVT lead-zinc deposits in this area.This prospecting model is based on comprehensive exploration methods tests of known deposits around the mining area and detailed study of the geological background,metallogenic model,deposit characteristics,and prospecting indicators of MVT deposits in this area.The experimental data show that the high-value Pb-Zn-Ag anomalies concentrated along the fault fracture zone in the geochemical survey indicate that there are signatures of ore-forming hydrothermal activity in the deep parts of the faults.The audio frequency magnetotelluric method can be used to identify the burial depth of concealed orebodies,the fluctuations in favorable ore-forming interfaces between the Ediacaran Dengying Formation and the Cambrian Qiongzhusi Formation in the deep underground,and the tendency and scale of the ore-forming faults.The intermediate gradient IP(Induced Polarization Method)measurement of an area can delineate the favorable prospecting area(high polarization anomaly area)on the“horizontal plane scale”,and large-scale IP sounding profiles can further delineate the favorable ore body target areas that are of low resistivity and high polarization anomaly on the“vertical space scale”.The research results show that the combined use of the shallow and deep exploration technologies described in this paper,including the combined element anomalies of shallow geochemical exploration,the deep geological structure of the resistivity profile,and the IP anomaly bodies of the plane and profile,can provide interdisciplinary evidence support for optimizing the deep pr

关 键 词：滇东北 MVT型 铅锌矿 茂租矿区 深部综合找矿方法 找矿靶区 

分 类 号：P611.1[天文地球—矿床学] P622.6[天文地球—地质学]