准噶尔盆地南缘硫磺沟地区头屯河组沉积特征及其铀成矿远景分析  

Sedimentary characteristics and uranium mineralization prospect analysis of the Toutunhe Formation in the Liuhuanggou Area of the southern margin of the Junggar Basin

作　　者：李琪 吴柏林[1] 周玉 杨佐怀 王苗 张效瑞 林周洋 LI Qi;WU Bailin;ZHOU Yu;YANG Zuohuai;WANG Miao;ZHANG Xiaorui;LIN Zhouyang(State Key Laboratory of Continental Dynamics,Northwest University,Xi’an 710069,China;Urumqi Natural Resources Comprehensive Survey Center,China Geological Survey,Urumqi 830057,China)

机构地区：[1]西北大学大陆动力学国家重点实验室,陕西西安710069 [2]中国地质调查局乌鲁木齐自然资源综合调查中心,新疆乌鲁木齐830057

出　　处：《西北大学学报（自然科学版）》2023年第4期635-654,共20页Journal of Northwest University（Natural Science Edition）

基　　金：陕西省自然科学基础研究计划(重点)项目(2022JZ-18);中国地质调查局项目(DD20211550);辽河油田公司科技项目(2021DJ5301)。

摘　　要：为了准确客观评价准噶尔盆地南缘砂岩型铀矿的成矿潜力和成矿远景,以层序地层学、沉积学和水成铀矿理论为指导,通过野外调研,钻井和测井等资料分析,对盆地南缘各地层进行分析,探究准南砂岩型铀矿的沉积与分布规律,重点对硫磺沟地区中侏罗统头屯河组(J_(2)t)进行研究,建立等时地层桥架,分析头屯河组沉积期的物源方向、砂体厚度、沉积环境及沉积体系,明确头屯河组的空间展布及主砂体发育特征。根据研究结果,结合已知的准南铀矿化分布和头屯河组岩相岩性地球化学性质综合分析,认为:硫磺沟地区头屯河组可细分为下段下亚段(J_(2)t^(1-1))、下段上亚段(J_(2)t^(1-2))、上段下亚段(J_(2)t^(2-1))和上段上亚段(J_(2)t 2-2),自下而上为辫状河—曲流河沉积体系,其中下段下亚段的大型辫状河道砂体是最有利的成矿层位,其次上段下亚段(J_(2)t^(2-1))也是潜在的找矿层位;砂体沿NWW向展布,往NE向逐渐变薄,与主体矿化趋势方向一致,目的层物源主要来自于该区的西南方向;矿化受盆地后期改造及油气保护作用明显,剥蚀程度中等;铀矿化受新构造运动的断褶带的背斜构造核部两翼地层控制。因此,准南硫磺沟地区头屯河组具备有利的砂岩铀矿的成矿和找矿条件与潜力。A number of small uranium deposits,occurrences and anomalies have been discovered in the exploration of the Junggar Basin,two-thirds of which are located in the southern edge of the basin.But no uranium deposits of medium size or above have been found,and no fundamental breakthrough in mineral search has been achieved.In order to understand the deposition and distribution pattern of sandstone type uranium ore in the southern margin of Junggar Basin,objectively evaluate the mineralization potential and uranium metallogenic prospect,guided by stratigraphic stratigraphy,sedimentology and hydrogenic uranium ore theory,after analyzing the data from field research drilling and logging,and analyzing various strata in the southern margin of the basin,we focused on the Middle Jurassic Toutunhe Formation(J_(2)t)in the Liuhuanggou area,and established the isochronous stratigraphic bridge of the Toutunhe Formation in this area.Then,we analyzed the material source direction,sand body thickness,sedimentary environment and depositional system of the Toutunhe Formation during the depositional period.Finally,the spatial spreading and the development characteristics of the main sand body of the Tutunhe Formation have been clarified.Combined with the distribution of known uranium mineralization and the geochemical properties of the petrographic phases of the Tourtunhe Formation,it is concluded that the Tourtunhe Formation can be subdivided into the lower sub-section(J_(2)t^(1-1)),the upper sub-section(J_(2)t^(1-2))of the lower section,the lower sub-section(J_(2)t^(2-1))and the upper sub-section(J_(2)t 2-2)of the upper section in the Liuhuanggou area,which is a braided river-quadrangular river sedimentary system from the bottom up.The large braided river sand body in J_(2)t^(1-1)is the most favorable mineralization formation.And J_(2)t^(2-1)is also a potential prospective formation.Secondly,the sand body spreads along the NWW direction and gradually thins toward NE,which is consistent with the trend of the main mineralization,and th

关 键 词：砂岩型铀矿 准噶尔盆地南缘 头屯河组 成矿远景 沉积 硫磺沟地区 

分 类 号：P612[天文地球—矿床学]