摘要
鄂尔多斯盆地南部彬州地区作为近年来中侏罗统直罗组砂岩型铀矿勘查的重点区域,对其铀储层粒度特征与古水动力意义的研究可为该地区铀成矿沉积条件、成矿机理分析提供重要依据。文章以覆盖全区的310个钻孔为基础,通过统计学原理,对中侏罗统直罗组下段铀储层砂体厚度进行统计并绘图,通过采集铀储层粒度样品33件,研究其相应的C-M图、累积概率曲线图、频率直方图、粒度参数散点图,结合该区中侏罗统直罗组下段沉积相特征,明确研究区铀储层的空间分布特征,分析铀储层沉积环境和古水动力条件。结果表明:研究区存在水口-胡家河近南北向铀储层砂体和景家河东西向铀储层砂体,其中水口-胡家河铀储层砂体可细分为水口-鸭河湾、朱家山-鸭河湾两部分,皆从南东向北西方向延伸。从样品分析得出直罗组下段铀储层具有较典型的辫状河沉积体系特征,且水口-胡家河铀储层砂体具有靠近物源、水流能量较高的特点,铀储层砂体沉积期水口-胡家河水动力自南向北逐渐有减弱趋势,景家河地段水动力自西向东逐渐有减弱趋势,水口-胡家河水动力条件整体较景家河偏低,证明水口-胡家河地区辫状河自南向北汇入景家河地区主河道。
Binzhou area in the southern part of Ordos Basin has become a key sector of sandstone-type uranium exploration in the Upper Jurassic Zhiluo Formation.The Understanding of grain size characteristics and paleo-hydrodynamic condition of the uranium host layer will provide a vital insights into the depositional conditions and mineralization mechanisms of uranium deposits.Based on 310 drillholes data covering the entire region,this study statistically analyzed and mapped the thickness of the sandbodies in the lower member of the Upper Jurassic Zhiluo Formation.A total of 33 the grain size samples of the uranium host layer were collected for detailed analysis.Various analytical methods,including C-M diagrams,cumulative probability curve graphs,frequency histograms,and grain size parameter scatter plots were employed for the statistic study.The findings were then combined with the sedimentary facies characteristics of the lower member of the Upper Jurassic Zhiluo Formation to determine the spatial distribution characteristics of the uranium reservoirs and analyze the depositional environment and paleo-hydrodynamic conditions.The results suggested that there are north-south-oriented uranium-bearing sandbodies in huikou-Hujiahe region and east-west-oriented uranium-bearing sandbodies in the Jingjiahe region.Specifically,the Shuikou-Hujiahe region exhibits two subdivisions,namely Shuikou-Yahewan and Zhujiashan-Yahewan,which both extend from the southeast to the northwest.Based on the sample analysis,it was observed that the lower member of the Upper Jurassic Zhiluo Formation is with the typical characteristics of a braided river depositional system.Furthermore,the uranium-bearing sandbodies in the Shuikou-Hujiahe region were found to be located close to the sediment source and characterized by relatively high water flow energy.The paleo-hydrodynamic power of the uranium-bearing sandbodies in Shuikou-Hujiahe region gradually weaken in the northward direction,while those in Jingjiahe region weaken in the eastward direction.O
作者
王奇辉
周伟
武正乾
冯博
赵友东
王晓鹏
WANG Qihui;ZHOU Wei;WU Zhengqian;FENG Bo;ZHAO Youdong;WANG Xiaopeng(Research Institute No.203,CNNC,Xian,Shaanxi 710000,China)
出处
《铀矿地质》
CAS
CSCD
2023年第6期979-986,共8页
Uranium Geology
基金
中国核工业地勘基金项目“鄂尔多斯盆地南部旬邑-盐池地区铀矿资源评价与勘查”(编号:2022-17)
中核集团集中研发项目“砂岩型铀矿多重耦合地质成矿作用与时空定位(编号:中核科发2021-143号)”联合资助。
关键词
铀储层
粒度分析
古水动力学
彬州
uranium host layer
granular analysis
paleo-hydrodynamics
Binzhou
