二道河子银铅锌矿床地质特征及找矿方向研究

二道河子矿床是得尔布干深断裂带北东侧发现的一个银铅锌矿床,具有大型矿床的成矿潜力。区域地层在NW-SE向水平挤压力作用下,沿莫尔道嘎—上护林一带经多次形变后产生弯曲、倒转,发育中生界中侏罗统塔木兰沟组及上侏罗统满克头鄂博组,岩性主要由火山岩—碎屑岩组成,二者呈不整合接触。主矿体呈脉状赋存于中侏罗统塔木兰沟组断裂破碎带中,受NW和NNW向张性断裂控制;主要金属矿物有方铅矿、闪锌矿及黄铁矿等。成矿过程如下:火山活动晚期,酸性熔浆携带着Pb、Zn、Ac等有用元素变为中低温热液,沿早期形成的NNE、NW、NWW向张性断裂破碎带上侵,在NW向构造及派生次一级构造的有利部位富集成矿。通过对该矿区地质特征进行较为详细的研究,认为该矿床是以火山岩为容矿岩石的构造—热液改造型中低温热液型银铅锌矿床,并提出了主要找矿方向。

Research on Geological Characteristics and Prospecting Direction of Erdaohezi Ag-Pb-Zn Deposit in Inner Mongolia

Erdaohezi deposit is found in NW side of deerbugan deep fault zone Ag-Pb-Zn deposit,with large deposits metallogenic potential.Regional stratigraphy in NW-SE under the action of horizontal pressure along the Moerdaoga and the Shanghulin by many after deformation,bent,turned,development of Jurassic in the Middle the tamulangou formation and the upper Jurassic manketouebo formation,rock composed primarily of volcanic-clastic rocks,they are unconformable contact.Main orebodies are veins hosted in Jurassic Middle tamulangou formation in the fracture zone,NW,NNW to extensional tectonic control;the main metallic minerals,such as galena,sphalerite and pyrite. Ore-forming processes can be considered: volcanic activity later, acidic lava carrying lead,zinc,silver and other useful elements to hydrothermal along the early formation of NNE,NW,NWW on tensile fracture zone of the invasion,in NW derived structure and secondary structure favorable for enrichment.Through the study of the geologic al characteristics in detail,we think that the deposit is the structure of the volcanic rocks of ore rock-hydrothermal reformation type liquid medium to low temperature type Ag-Pb-Zn deposit,and the main prospecting directions.