盆山耦合机制下库车坳陷砂岩型铀成矿的构造约束作用  

Structural Constraints of Sandstone-type Uranium Mineralization in Kuqa Depression Under Basin-mountain Coupling Mechanism

作　　者：王国荣[1] 焦养泉[2] 陈正乐[3] 王强强[1] 阿种明[1] 鲁克改[1] 王元元[1] 孙潇[1] 杨军锋[1] WANG Guorong;JIAO Yangquan;CHEN Zhengle;WANG Qiangqiang;AZhongming;LU Kegai;WANG Yuanyuan;SUN Xiao;YANG Junfeng(Geologic Party No.216,CNNC,Urumqi,Xinjiang 830011,China;School of Earth Resources,China University of Geosciences,Wuhan,Hubei 430074,China;Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China)

机构地区：[1]核工业二一六大队,新疆乌鲁木齐830011 [2]中国地质大学资源学院,湖北武汉430074 [3]中国地质科学院地质力学研究所,北京100081

出　　处：《铀矿地质》2023年第4期581-594,共14页Uranium Geology

基　　金：中国核工业地质局全国铀矿资源调查评价计划项目“新疆塔里木盆地乌恰-轮台地区铀矿资源调查评价与勘查”(编号:201907);中国核工业地质局全国铀矿资源调查评价计划项目“新疆塔里木盆地乌恰-尉犁地区铀矿资源调查评价与勘查”(编号:202207);中国核工业地质局生产中科研项目“塔里木盆地库车坳陷中新生代构造沉积特征与铀成矿远景区优选”(编号:201907-4)联合资助。

摘　　要：库车坳陷处于的塔里木盆地北部,其局部地区已有新的找矿发现,但整体而言仍未获得实质性找矿突破。文章依据区域地质和勘查钻孔资料,结合野外地质调查和样品采集测试,通过综合分析,探讨了库车坳陷在构造-地形地貌的盆山耦合过程中,上新统库车组区域成矿流场的迁移、汇聚过程,区域氧化带及砂岩型铀矿的构造改造特点和分类,并分析了不同构造改造型氧化带的铀成矿潜力。主要认识有:库车坳陷新生代以来的盆山耦合体制有利于“盆地”尺度初始氧化带及铀成矿流场的发育,上新统库车组中的含氧含铀成矿流体总体具自北向南渗流趋势。在库车坳陷内,东西向构造带限定了库车组成矿流场和大规模氧化带的发育空间和南部边界。随着同生长性质的秋里塔格构造带的逐步褶皱抬升,在拜城凹陷南部形成大型“拦水坝”(构造阻水带)和区域性排泄区,库车组区域成矿流场和氧化带被“阻拦”在秋里塔格构造带北翼,“新”“老”两套铀成矿系统在此处叠加,从而形成库车组最具规模的工业铀成矿带。库车组的构造改造型氧化带可划分为3类:早期铀成矿系统被后续氧化成矿流体进一步叠加改造型,铀成矿规模最大并最具找矿潜力,代表区段为日达里克—赛里木一带;早期铀成矿系统后期被构造阻断型,具备一定的成矿潜力,代表区段为温宿、东阿瓦特及却勒一带;早期铀成矿系统被后期氧化再迁移型,成矿潜力有限,代表区段为吐孜塔格及克拉苏构造带。Kuqa depression is located in the northern Tarim Basin and there are new prospecting discoveries in some areas.However,no substantive prospecting breakthrough was achieved on the whole depression.Based on regional geological and borehole data,this paper discussed the migration and convergence process of oreforming flow field,the structural transformation characteristics and classification of regional oxidation zone and sandstone-type uranium deposits in Kuqa depression during the basin-mountain coupling process of structuretopography and geomorphology,analyzed the uranium metallogenic potential of different structural transformation oxidation zones combined with field geological survey and samples assay.The main conclusions are as follows.The basin-mountain coupling system in Kuqa depression since Cenozoic is beneficial to the development of the initial oxidation zone and uranium ore-forming flow field at the"basin"scale,and the uranous-oxygenous ore-forming fluids in the Upper Cretaceous Kuqa Formation generally have a seepage trend from north to south.The east-west structural belt constrained southern boundary of Kuqa ore-forming flow field and the development space of large-scale oxidation zone.With the gradual folding and uplifting of Qiulitage structural belt in the same growth nature,a large-scale"dam"(water blocking structural belt)and regional drainage area were formed in the south of Baicheng Sag,and the regional metallogenic flow field and oxidation zone of Kuqa Formation were"blocked"in the north wing of Qiulitage structural belt,where the two sets of uranium metallogenic systems,"new"and"old",were superimposed.As a result,it formed the largest industrial uranium metallogenic belt in Kuqa Formation.The structural reformed oxidation zone of Kuqa Formation can be divided into three categories:The early uranium metallogenic system was further superimposed and reformed by subsequent oxidation ore-forming fluids,and form the largest uranium metallogenic area with greatest prospecting potential,the represent

关 键 词：盆山耦合 构造变形 库车组 成矿流场 铀矿化 

分 类 号：P619.14[天文地球—矿床学]