鄂尔多斯盆地西南缘白垩系洛河组砂岩型铀矿床铀赋存特征及铀成矿作用浅析  

Analysis on the uranium metallogenic conditions and uranium occurrence characteristics of the sandstone-hosted uranium deposit in Cretaceous Luohe Formation in the southwestern margin of the Ordos Basin

作　　者：胡永兴[1] 张翔[1] 胡妍 杨涛[1] 欧扬剑 刘子锐[1] HU Yongxing;ZHANG Xiang;HU Yan;YANG Tao;OU Yangjian;LIU Zirui(Geological Survey of Gansu Province, Lanzhou 730030, China)

机构地区：[1]甘肃省地质调查院,兰州730030

出　　处：《地质找矿论丛》2020年第4期380-389,共10页Contributions to Geology and Mineral Resources Research

基　　金：中国地质调查局项目“甘肃省鄂尔多斯盆地南缘泾川一带铀矿地质调查”(编号:DD20160128-06);甘肃省科技重大专项“核铀矿分布规律研究及核储存取样装置研发”(编号:18ZD2GF019);2020年陇原青年创新创业人才项目“陇东地区砂岩型铀矿成矿规律与找矿方向”;2020年甘肃省青年科技人才托举工程项目“陇东地区白垩系砂岩型铀矿成矿规律与战略选取研究”联合资助。

摘　　要：本文在对鄂尔多斯盆地西南缘白垩系洛河组含铀地层构造特征及沉积环境分析基础上,对铀矿床的成矿地质条件和成因进行了初步探讨;并采用电子探针分析方法,对该砂岩型铀矿中铀矿物的赋存状态进行了初步研究。研究结果表明,该区砂岩型铀矿物主要为沥青铀矿,其主要有两种存在形式:1)铀矿物赋存在碎屑颗粒间、胶结物和岩屑颗粒中,呈粒状或团块状,颗粒大小不一,且主要集中在2~15μm之间,局部团块可达20~25μm;2)铀矿物与黄铁矿共生,以粒状、网状和团块状分布在不规则黄铁矿中或包裹在其表面。初步分析认为研究区主要存在两期铀成矿作用。This paper discusses the metallogenic conditions and genesis of the sandstone-hosted uranium deposit based on the analysis of the tectonic characteristics and sedimentary environment of the Cretaceous Luohe Formation in the southwestern margin of the Ordos Basin.The electron probe analysis shows that uranium occurs mainly in pitchblende.There are two type occurrence of the pitchblende:1)it occurs in grain or mass between debris or in cement and debris.Size of the grain and mass are varied,the grain mainly in 2-15μm,and locally the mass 20-25μm;2)it co-exsist with pyrite in grains,net works and masses in irregular pyrites or on their surface.In the study area took place mainly two phases of uranium mineralization.

关 键 词：砂岩型铀矿 成矿条件 铀的赋存状态 洛河组 鄂尔多斯盆地 

分 类 号：P619.14[天文地球—矿床学]