东胜铀矿田的铀石研究  

Research on Coffinite in Dongsheng Uranium Field

作　　者：方锡珩[1] 李子颖[1] FANG Xiheng LI Ziying(Beijing Research Institute of Uranium Geology, Beijing 100029, China)

机构地区：[1]核工业北京地质研究院,北京100029

出　　处：《铀矿地质》2017年第5期257-265,共9页Uranium Geology

摘　　要：东胜铀矿田位于鄂尔多斯盆地东北部,铀矿床均产于侏罗系中统直罗组下段下亚段的砂岩中,为砂岩型铀矿床。矿床中铀矿物颗粒非常细小(多为0.n^nμm),通过电子探针对矿石的详细研究,发现铀矿物以铀石为主,铀石主要产于砂岩的杂基中,多围绕细粒黄铁矿(或白铁矿)产出,并部分交代黄铁矿。部分铀石围绕氧化的钛铁矿或砂岩的碎屑颗粒边缘产出。经扫描电镜研究发现,铀石为颗粒极为细小的四方柱状与锥面的聚形晶体,呈浸染状或聚集成放射状的球粒分布。同时通过重矿物分离出的铀矿物,经X-射线衍射分析,确认为铀石无疑。Dongsheng uranium field is located in the northeast part of Erdose basin. Uranium deposits oc- curred in the sandstone of lower part of the lower member of Middle Jurassic Zhiluo formation. Uranium minerals are very small in size. The main uranium mineral is found to be coffinite by the electron-micro- probe analysis. Coffinite occuerrs in the matrix of sandstone, often distributed around the rims of frag- ments, pyrite or marcasite, oxidizing illmenite in the sandstone. The crystal form of coffinite is the combination of tetragonal columnar prism and pyramidal face by SEM and often form spherulites of crys- talline aggregate. The separated uranium minerals from the ore are confirmed to be coffinite by the X-ray diffraction analysis.

关 键 词：鄂尔多斯盆地东北部 直罗组下段下亚段 砂岩型铀矿床 铀石 

分 类 号：P571[天文地球—矿物学]