广西贵港砷矿沟银铅锌矿床控矿因素分析及成矿预测  

Ore-controlling Factors and Metallogenic Prediction of the Shenkuanggou Ag-Pb-Zn Deposit in Guigang,Guangxi

作　　者：陈港 陈懋弘[1] 葛锐 郭申祥 吴启强[4] CHEN Gang;CHEN Maohong;GE Rui;GUO Shenxiang;WU Qiqiang(MNR Key Laboratory of Metallogeny and Mineral Assessment,Institute of Mineral Resources,CAGS,Beijing 100037,China;Wanbao Mining Ltd.,Beijing 100053,China;Hubei Branch of China National Geological Exploration Center of Building Materials Industry,Wuhan 430000,Hubei,China;No.6 Geological Team of Guangxi,Guigang 537100,Guangxi,China)

机构地区：[1]中国地质科学院矿产资源研究所,自然资源部成矿作用与评价重点实验室,北京100037 [2]万宝矿产有限公司,北京100053 [3]中国建筑材料工业地质勘查中心湖北总队,湖北武汉430000 [4]广西壮族自治区第六地质队,广西贵港537100

出　　处：《大地构造与成矿学》2022年第4期662-676,共15页Geotectonica et Metallogenia

基　　金：国家重点基础研究发展计划项目(973计划)(2012CB416704);中国地质调查局地质调查二级项目(DD20201173);广西壮族自治区部门前期地质勘查项目(桂地矿地[2014]17号)联合资助。

摘　　要：一般而言,岩浆热液矿床除与侵入岩体有关外,与地层和构造关系也比较密切,控矿因素往往比较复杂,确定其中最主要的控矿因素往往是成矿预测成败的关键。广西贵港砷矿沟银铅锌矿床位于大瑶山隆起西南部龙山鼻状构造的最西南段,是大平天山岩浆热液成矿系统的一部分。矿床以顺层产出的矽卡岩型矿体为主,切层的脉状矿体为辅。系统的野外测量和研究表明,脉状矿体形态简单,主要受控于近直立的NNW向断层;层状矽卡岩型矿体形态十分复杂,除受控于大平天山和龙头山岩体外,还受寒武系黄洞口组灰岩夹层、加里东期复杂褶皱形态以及NNW向断层的联合控制。其中大平天山和龙头山岩体为矿床的形成提供了成矿物质、成矿流体和热源,并控制了成矿元素的空间分带;寒武系黄洞口组灰岩夹层是形成矽卡岩型矿体的岩性条件,控制了矿层的数量和厚度;近EW走向的复式褶皱控制了矿体的具体形态和产状;NNW向断层控制了矿段的平面空间位置。本文在正确理解上述岩浆-地层岩性-褶皱-断层等控矿因素的基础上,确定NNW向断层为主要的流体通道,其东西两侧20~70m的范围内寒武系黄洞口组灰岩夹层可以形成层状矽卡岩型矿体,据此由东往西划分了3个矿段,经钻探验证成功在矿区西部发现了新的矿段。本次成矿预测改变了前人以近EW走向灰岩追索找矿的思路,转为沿NNW走向断层(节理)追索层状矿体,把一个被前人否定评价的矿床给予了肯定评价并获得成功。这一认识和经验对复杂褶皱地区,受多要素控制的岩浆热液矿床的成矿预测具有一定的借鉴意义。Generally speaking,magmatic-hydrothermal deposits are not only related to intrusions but also closely related to strata and structures.The ore-controlling factors are often complex,and recognition of the most important factor is often critical for a successful metallogenic prediction.Being part of the Dapingtianshan magmatic-hydrothermal metallogenic system,the Shenkuanggou Ag-Pb-Zn deposit in Guangxi is located in the southwestern part of the Longshan nose-like structure in the Southwest of the Dayaoshan uplift.The ores of the deposit are mainly strata-like skarn-type and minor vein-type.Systematic field surveys and research show that the vein-type ores are simple in shape and mainly controlled by the nearly vertical NNW-trending fault.The layered skarn-type ores are very complex in shape,controlled by the Dapingtianshan and Longtoushan plutons and the limestone intercalation in the Cambrian Huangdongkou Formation,the Caledonian complex folding,and the NNW-trending faults as well.The Dapingtianshan and Longtoushan plutons provided ore-forming materials,ore-forming fluids,and heat sources for the formation of the deposit,and controlled the spatial zoning of the ore-forming elements.Limestone intercalation in the Cambrian Huangdongkou Formation is an indispensable material condition for the formation of the skarn-type orebodies,which controls the number and thickness of the ore beds.The EW-trending and NNW-trending composite folds control the specific shape and occurrence of the ore bodies.Faults control the plane space position of the ore block.Based on the understanding of the above ore controlling factors,such as intrusion,stratigraphic lithology,fold,and fault,this paper determines that the NNW-trending fault is the main fluid channel.The Cambrian Huangdongkou Formation limestone interlayer can form a layered skarn-type ore body.Based on this,three ore sections are divided from East to West.A new section was successfully discovered in the West of the mine.This metallogenic prediction has changed the previous f

关 键 词：岩浆热液成矿系统 控矿因素 成矿预测 砷矿沟银铅锌矿床 广西贵港 

分 类 号：P612[天文地球—矿床学]