铀矿地质2026，Vol.42Issue(1)：31-46,16.DOI:10.3969/j.issn.1000-0658.2025.42.003
鄂尔多斯盆地西南部下白垩统铀成矿关键控矿因素与找矿方向
Key Ore-controlling Factors and Exploration Directions of Uranium Mineralization in Lower Cretaceous of Southwestern Ordos Basin
摘要
Abstract
In recent years,Xinzhuang large-scale sandstone-type uranium deposit has been discovered in southwestern Ordos Basin.The main ore-hosting horizons are Huanhe Formation and Luohe Formation of Lower Cretaceous.Therefore,the clarification of the key ore-controlling factors is of great significance for the next step of expanding prospecting work.This study analyzed key ore-controlling factors by traverse geological surveys,drilling core logging,geochemical testing,electron microscope observation and identification,map compilation,etc..It was found that uranium mineralization is jointly controlled by the paleo-uplift of Lower Cretaceous basement and NE-SW trending faults developed on the uplift zone,sandstone bodies of braided river delta plain,oxidation-reduction alteration zones,and the sequence boundary between Huanhe Formation and Luohe Formation.The paleo-uplift zone of the Lower Cretaceous basement developed on the slope zone of the western limb of Tianhuan syncline controled both the sedimentary system type and sandstone body size of the mineralization horizon and the deep oil and gas expulsion,making it the most critical ore-controlling factor for regional uranium mineralization.NE-SW trending fault structures developed on the uplift zone provided channels for the ascending migration of deep exudative reducing fluids and form necessary reducing barriers during the uranium mineralization process.They were also the discharge areas for infiltrating oxygen-rich uranium-bearing fluids.Uranium mineralization is concentrated in NWW-SEE trending main channel of the braided river delta plain and the phase transition zones on both sides,with the percentage of gray sandstone bodies ranging from 20%to 60%,as well as the sequence boundary between Huanhe Formation and Luohe Formation,indicating significant lithology-lithofacies-redox interface ore control.Based on the analysis and determination of the key ore-controlling factors of uranium mineralization,Zhenyuan(Kaibian-Xinzhuang-Sancha Town)-Huanxian area,Beishikusi area,and Yanchi area were proposed as the key favorable areas for the next step prospecting.关键词
控矿因素/找矿方向/砂岩型铀矿/鄂尔多斯盆地西南部Key words
ore-controlling factors/exploration directions/sandstone-type uranium deposit/southwestern Ordos Basin分类
天文与地球科学引用本文复制引用
武正乾,贺峰,冯博,刘持恒,毛宁..鄂尔多斯盆地西南部下白垩统铀成矿关键控矿因素与找矿方向[J].铀矿地质,2026,42(1):31-46,16.基金项目
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)资助. （编号:2022-17）
