北山内蒙新发现的黑山咀金多金属矿区四级构造系统及其控矿规律研究  

Four-level Ore-controlling Structural System in the Newly Discovered Heishanju Gold Polymetallic Orefield,Beishan,Inner Mongolia

作　　者：张善明[1,2] 王根厚 赵士宝[3] 胡二红 陈强 何泽宇 ZHANG Shanming;WANG Genhou;ZHAO Shibao;HU Erhong;CHEN Qiang;HE Zeyu(School of Earth Science and Resources,China University of Geosciences(Beijing),Beijing 100083,China;Inner Mongolia Mining Development Co.,Ltd,Hohhot 010011,Inner Mongolia,China;Inner Mongolia Geology and Mineral Resources(Group)Co.,Ltd.Hohhot 010011,Inner Mongolia,China)

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]内蒙古矿业开发有限责任公司,内蒙古呼和浩特010011 [3]内蒙古地质矿产(集团)有限责任公司,内蒙古呼和浩特010011

出　　处：《大地构造与成矿学》2020年第3期367-384,共18页Geotectonica et Metallogenia

基　　金：内蒙古自治区国土资源厅项目(NMKD2014-10、NMKD2016-06)资助。

摘　　要：2015年,在北山内蒙黑山咀新发现了3条金多金属矿带,找矿潜力巨大。黑山咀矿区构造发育,形成四级构造系统,并表现出多级控矿规律。一级构造——火山盆地:金多金属矿带位于早古生代火山盆地边缘;二级构造——NWW向逆冲断层系:矿带主要分布在NWW向逆冲断层上盘前缘向上盘主体过渡之主体侧内的线理、面理化带内;三级构造——NE向左旋走滑断层:各类容矿空间的形成与NE向左旋走滑断层关系密切;四级构造——各种容矿构造:主要有NWW向线理和板劈理化带、NW(NWW)向节理裂隙、NE(近SN)向节理裂隙、NWW向破碎带四类。通过分析矿区自早古生代以来的构造演化,将本区构造控岩控矿作用划分为四个阶段,第一阶段:中奥陶世,研究区一带发生了广泛的海相火山喷发,金多金属在合适的物理化学空间完成初始预富集;第二阶段:海西晚期,北山内蒙地区进入板块俯冲阶段,导致在区内形成一系列NWW向逆冲断层;第三阶段:闪长岩脉侵位于与NWW向逆冲断层相关的薄弱空间内;第四阶段:印支期‒燕山期,北山内蒙地区发生广泛的NE向左旋走滑,各类容矿空间形成,强烈的成矿作用发生。通过对四级构造系统及其控矿作用的研究,笔者认为:下一步应在全面分析四级构造系统的基础上,开展更精细、更定量、更全面的构造控矿测量及分析,推断深部富厚矿体的位置,同时也应注意矿体遭受的剥蚀及保存情况。应先探测赋矿母岩闪长岩脉的深部特征,再圈定矿化地段。同时可以通过重力测量探测深部是否有上规模块状方铅矿体存在。The Heishanju,located in the westernmost of Inner Mongolia,is a new gold polymetallic orefield with very good prospective discovered in 2015.The well-developed structures in this orefield constitute a typical four-level ore-controlling structural system.The Early Paleozoic volcanic basin is the first-level ore-controlling structure,and gold polymetallic ore belts occur along its margin.The NWW thrust faults are the second-level ore-controlling structures,within which the gold polymetallic ore belts are hosted in the lineation and foliation structures that developed in the transitional zone between the frontal area and the center of the upper wall of these faults.The NE sinistral strike-slip faults are the third-level ore-controlling structures,which provide host spaces for orebodies.Individual orebodies are controlled by the fourth-level ore-controlling structures which include the NWW lineation and plate cleavages,the NW(NWW)joint fissures,the NE(near SN)joint fissures,and the NWW crushed zones.Based on the analysis of the tectonic evolution since the Early Paleozoic Era,the tectonic evolution is divided into four stages.The first stage,the widespread Middle Ordovician marine-facies volcanic rocks enriched Au and other metals.The second stage,the plate subduction since the Late Hercynian resulted in the formation of a series of NWW thrust faults.The third stage,diorite dykes emplaced in the structurally weak spaces related to the NWW thrust faults.The fourth stage,the extensive NE sinistral strike-slipping in the Indosinian-Yanshanian provided host spaces and filled with orebodies during mineralization.Considering the structures and their multi-level ore controlling features of the study area,we suggest that the future work should focus on spatial coupling of the four-level ore-controlling structural system,and more precise,quantitative,and comprehensive evaluation of the structural controls,which combining with investigation of erosion and denudation may enable us to locate the rich and thick ore bodies at dept

关 键 词：控矿构造 多级控矿 构造演化 金多金属矿带 北山内蒙 

分 类 号：P613[天文地球—矿床学]