松辽盆地北部三肇凹陷四方台组层序地层及其与砂岩型铀矿化的关系  

Sequence stratigraphy of the Sifangtai Formation and its relationship with uranium mineralization in the Sanzhao depression,northern Songliao basin

作　　者：徐增连 汤超 李建国[1,2] 魏佳林 曾辉[1,2] 肖鹏 刘华健 陈路路 XU Zeng-lian;TANG Chao;LI Jian-guo;WEI Jia-lin;ZENG Hui;XIAO Peng;LIU Hua-jian;CHEN Lu-lu(Tianjin Centre,China Geological Survey,Tianjin 300170,China;Laboratory of Non-Fossil Energy Minerals,Tianjin Center,CGS,Tianjin 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24-32,共9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(2015CB453000)";中国地质调查项目"油田勘查区砂岩型铀矿调查与勘查示范(DD20160128)";国家青年自然科学基金(41502195)

摘　　要：根据岩心、测井、录井及区域地质背景等资料,对三肇凹陷四方台组进行了层序地层学研究,并讨论了其沉积特征和砂体展布规律。四方台组可划分为两个三级层序(SQ1和SQ2),每个层序发育4个完整的体系域:低水位体系域、水进体系域、高水位体系域和水退体系域;共识别出1种曲流河沉积相,河床、堤岸和河漫3种沉积亚相,滞留沉积、边滩、天然堤、决口扇、决口水道、河漫滩、河漫沼泽和河漫湖泊8种沉积微相。根据砂岩型铀矿赋存特征及其在层序地层格架中的位置,指出本区铀矿化主要产于四方台组底部低水位体系域厚大砂体中,并与水进体系域密切相关。通过沉积微相与砂岩型铀矿的成矿关系研究,表明滞留沉积和边滩微相是松辽盆地北部最有利的沉积微相。Based on comprehensive analysis of core observation,well data,and regional geologic background,the sequence stratigraphic division,the sedimentary characteristics and distribution of the sandbodies in the Upper Cretaceous Sifangtai Formation are studied in Sanzhao Depression of northern Songliao basin.Three sequence boundaries were recognized in Sifangtai Formation,which further divided Sifangtai Formation into 2 third-order sequences(SQ1 and SQ2).Each sequence is composed of four system tracts(LST,TST,HST and RST).Moreover,one sedimentary facies(meandering river),three sedimentary subfacies(channel,bank and overbank),and eight sedimentary microfacies(channel floor lag,point bar,natural levee,crevasse splay,crevasse channel,alluvial flat,alluvial lack and bank swamp)were identified in Sifangtai Formation.According to the occurrence feature of sandstone-type uranium deposits and its position in the sequence column,it can be deduced that the uranium mineralization occurs mainly in the thick and large sand bodies of lowstand system tract at the bottom of Sifangtai Formation,and is closely related to the transgressive system tract.In addition,this paper also reveals that the channel floor lag and point bar microfacies are the most favorable position in the northern Songliao basin.

关 键 词：松辽盆地 三肇凹陷 四方台组 层序地层学 砂岩型铀矿 

分 类 号：P512.2[天文地球—地质学]