大庆长垣南端四方台组沉积相特征及其与铀富集的关系  

Sedimentary facies of the Sifangtai Formation in the southern Daqing placanticline and its controls to uranium mineralization

作　　者：肖鹏 汤超 魏佳林[1,2] 徐增连 曾辉 刘华健 XIAO Peng;TANG Chao;WEI Jia-lin;XU Zeng-lian;ZENG Hui;LIU Hua-jian(Tianjin Center,CGS,Tianjin 300170,China;Laboratory of Non-fossil Energy Minerals,Tianjin Center,CGS,Tianjing 300170,China;Sinosteel Tianjin Geological Academy,Tianjin 300181,China)

机构地区：[1]中国地质调查局天津地质调查中心,天津300170 [2]中国地质调查局天津地质调查中心非化石能源矿产实验室,天津300170 [3]中钢集团天津地质研究院,天津300181

出　　处：《地质调查与研究》2018年第1期18-23,共6页Geological Survey and Research

基　　金：国家重点基础发展计划(973计划)"中国北方巨型砂岩型铀矿陆相沉积环境与大规模铀成矿作用(2015CB45300)";中国地质调查局项目"油气田勘查区砂岩型铀矿调查与勘查示范(DD20160128)"

摘　　要：大庆长垣南端四方台组是松辽盆地新发现的含铀层位。沉积体系控制着砂体的展布与连通性,而砂体特征又是决定铀矿体规模与空间分布的重要因素。本文依托大量全井段岩心、测井资料,开展大庆长垣南端四方台组沉积特征研究,并结合找矿实际效果,探讨了沉积相特征与铀富集的关系,结果表明:四方台组以曲流河相沉积为主;四方台组一段在曲流河沉积环境下形成厚度大、连通性好的砂体为大庆长垣南端最有利的含矿层位;成矿砂体微观特征表明垂向上存在多期河道叠置;微相上河床滞留、边滩、天然堤组合出现处铀富集程度更高。上述认识可为研究松辽盆地晚白垩世沉积环境变化、曲流河相砂岩型铀矿勘探提供地质依据。The Sifangtai Formation from the southern of Daqing placanticline in the Songliao basin is a newly discovered uranium-bearing horizon.Sedimentary system controls the distribution and connectivity of sand bodies,and the characteristics of the sand bodies are also important factors that determine the size and spatial distribution of uranium orebodies.Based on a large number of core and logging data of the whole drilling hole,the sedimentary characteristics of Sifangtai Formation at the southern tip of Daqing placanticline are studied.Combined with the actual effect of prospecting,the relationship between sedimentary facies characteristics and uranium enrichment is discussed.The results show that the Sifangtai Formation is dominated by the sedimentary facies of the meandering river facies.The sand bodies with large thickness and good connectivity which formed in the meandering stream deposit environment of a section of the Sifangtai Formation are the most favorable ore bearing beds in the southern end of Daqing placanticline.The microscopic characteristics of the ore-bearing sand bodies show that there are many river channels superimposed in the vertical direction,and in microfacies the enrichment of uranium is higher in the places combination of river bed retention,marginal bank and natural levees.The above understanding provides a geological basis for the study of Late Cretaceous sedimentary environment changes in Songliao basin and exploration of meandering fluvial sandstone-type uranium deposits.

关 键 词：沉积相 砂岩型铀矿 四方台组 大庆长垣南端 

分 类 号：P512.2[天文地球—地质学]