贵州白马洞铀矿构造应力场演化与铀成矿  

Evolution of Tectonic Stress Field and Uranium Mineralization in the Baimadong Uranium Deposit,Guizhou Province

作　　者：田超 金旭 杨正坤 郑明泓 杜蔺 TIAN Chao;JIN Xu;YANG Zhengkun;ZHENG Minghong;DU Lin(No.7 Geological Party,Non-Ferrous Metals and Nuclear Industry Geological Exploration Bureau of Guizhou,Guiyang Guizhou 550005,China;Institute of Geology and Mineral Resources Exploration,Non-Ferrous Metals and Nuclear Industry Geological Exploration Bureau of Guizhou,Guiyang Guizhou 550005,China;Non-ferrous Metals and Nuclear Industry Geological Exploration Bureau of Guizhou,Guiyang Guizhou 550005,China)

机构地区：[1]贵州省有色金属和核工业地质勘查局七总队,贵州贵阳550005 [2]贵州省有色金属和核工业地质勘查局地质矿产勘查院,贵州贵阳550005 [3]贵州省有色金属和核工业地质勘查局,贵州贵阳550005

出　　处：《矿物学报》2024年第3期445-455,共11页Acta Mineralogica Sinica

基　　金：中国核工业地质局铀矿地质调查项目(编号:201922-3)。

摘　　要：白马洞铀矿床是贵州境内发现的唯一具有工业价值并系统开采过的铀矿床,曾为我国核工业事业的发展做出过重要贡献。自上世纪80年代闭坑以来,为扩大铀矿资源量,对其深部和边部开展过多次勘查及研究工作,但找矿效果并不理想。根据已有研究,矿区和矿床构造对白马洞的铀成矿具有重要的控制作用,本次研究以白马洞矿床为研究对象,通过节理裂隙统计测量工作,重建和恢复矿区成矿构造应力场,分析构造演化与铀成矿关系,探讨铀矿化在构造应力作用下的迁移、聚散特征。研究结果表明,与铀成矿控矿有关的区域性构造应力场可分为3期,第Ⅰ期构造应力场产生于加里东期都匀运动南北水平向挤压作用,形成近东西向及北东东向构造形迹,控制区内铀异常矿化分布;第Ⅱ期构造应力场为区内最强烈的构造应力场,形成洋水背斜的主压面及犀牛洞断裂,特别是其力偶作用下派生的2期局部低级序构造应力场,使北西向褶皱和北东向褶皱横跨复合,构成良好的储矿空间;第Ⅲ期构造应力场使研究区产生EW向右旋挤压,对先期构造有一定程度的改造和加强。此外,喜马拉雅运动在继承第Ⅲ期构造格局的基础上,促使黔中东西向构造带再次活动,深部含矿流体沿白马洞断裂破碎带上升,在有利的物理化学条件下形成现今似层状、透镜状铀矿体。白马洞铀矿是多期次构造活动的产物,今后在黔中地区开展铀矿找矿工作,需要重点寻找北东向断裂与近东西区域性大断裂反接复合部位,特别注意在各期次构造应力场作用下形成的隐伏北东向褶皱与北西向褶皱叠加复合部位,复合部位的剥离构造和层间挤压破碎带是有利的铀矿找矿地段。The Baimadong uranium deposit is the unique uranium deposit with industrial value and systematically exploited in Guizhou,which has made important contribution to the development of nuclear industry in China.Since 1980s,many exploration and research works have been carried out in the depth and edge of the pit to enlarge the uranium resources,but the prospecting effect is not ideal.According to the existing research,the ore area and the ore deposit structure have the important control function to the Baimadong uranium mineralization,this research takes the Baimadong deposit as the research object,through the joint fissures statistical survey work,to reconstruct and restore the tectonic stress field,analyze the relationship between tectonic evolution and uranium mineralization,and discuss the characteristics of migration,accumulation and diffusion of uranium mineralization under tectonic stress.The results of the study show that,the regional tectonic stress field related to uranium mineralization and ore-controlling can be divided into three stages.The first stage of tectonic stress field was formed under the north-south horizontal compression during the Caledonian Duyun Movement,which formed the NE and NEE-trend structure and controlled the distribution of uranium mineralization.The second stage,the strongest one in regional,formed the Xiniudong fault and the main compressional surface of the Yangshui anticline;during this stage,two sub-stages of local low-order tectonic stress field combine the NW-trending and the NW-trending folds to form ideal ore-host space.The third stage tectonic stress field dextrally compressed the study area with EW trend,which remade and strengthened the previous tectonic framework.In addition,the Himalayan movement inherited the structural pattern of the third stage and reactivated the W-E trend tectonic belt in the central Guizhou;the deep ore-forming fluids flowed along the Baimadong fault,and the layered and lenticular uranium ore bodies were formed under favorable physical chemistry

关 键 词：白马洞铀矿床 共轭节理 构造演化 构造应力场 

分 类 号：P548[天文地球—构造地质学] P612[天文地球—地质学] P613