鄂尔多斯盆地南缘彬县地区水文地球化学及铀成矿作用特征  

Features of hydrogeochemistry and uranium metallogenesis in Binxian County area on the southern margin of Ordos Basin

作　　者：张字龙[1] 范洪海 贺锋[1] 刘红旭[1] 贾立城[1] 衣龙升[1] 杨梦佳[1] ZHANG Zilong;FAN Honghai;HE Feng;LIU Hongxu;JIA Licheng;YI Longsheng;YANG Mengjia(Key Laboratory of Uranium Exploration and Evaluation Techniques, CNNC, Beijing Research Institute of Uranium Geology,Beijing 100029, China)

机构地区：[1]中核集团铀资源勘查与评价技术重点实验室/核工业北京地质研究院,北京100029

出　　处：《地质通报》2017年第4期503-510,共8页Geological Bulletin of China

基　　金：中国核工业地质局项目<鄂尔多斯盆地南缘铀成矿地质特征与远景评价>(编号:201586);中核集团集中研发项目<鄂尔多斯盆地南部砂岩型铀矿关键因素识别与靶区优选>(编号:地LTD1601-3);国家973项目<北方典型产铀盆地成矿机理与成矿模式>(编号:2015CB453004)

摘　　要：水文地质作用是砂岩型铀矿成矿过程中不可缺少的重要作用之一。通过陕西彬县地区水文地质条件和水文地球化学环境分析,将中新生代地层地下水划分为松散岩类孔隙水、碎屑岩类孔隙裂隙水和碎屑岩类裂隙水3种类型。根据地下水的补给、径流、排泄条件,划分出水交替强烈带、水交替缓慢带和水交替滞缓带3个不同的水动力分带。不同类型地下水的含铀性、不同分带铀的运移和富集特征,以及酸、碱性地下水对围岩蚀变与铀成矿的作用表明,中侏罗统直罗组砂岩含矿含水层中铀成矿主要经历了沉积成岩时期铀的预富集作用、古地下水的后生改造叠加成矿作用和深部油田水的还原成矿作用,铀成矿作用为复合成因类型。Hydrogeological action is regarded as one of the important actions in the formation of sandstone type uranium deposits.According to analyzing the hydrogeological conditions and hydrogeochemical environments,the authors classified groundwater in Mesozoic-Cenozoic strata into porous water in loose rocks,porous-fissures water in cataclastic rocks and fissures water in cataclastic rocks.On such a basis,the water zones were divided into strongly,smoothly and steadily alternate aqueous zones based on charging,flowing and discharging conditions of groundwater.The uranium concentration of different groundwater types,the migrating and enriching characteristics of uranium in different zones and the roles played by acidic/alkali groundwater in wall rock alteration and uranium metallogenesis indicate that uranium metallogenesis in U-bearing aqueous sandstone strata of Middle Jurassic Zhiluo Formationmainly experienced sedimentary diagenetic pre-enrichment,paleo-groundwater’s epigenic superimposition,and the reducing deposition of uranium in groundwater from deep oilfield,being a compound genetic type.

关 键 词：水文地质 砂岩型铀矿 地球化学 铀成矿作用 

分 类 号：P641[天文地球—地质矿产勘探] P619.14[天文地球—地质学]