鄂尔多斯盆地店头地区直罗组流体包裹体特征及油气与铀成矿关系  

Characteristics of Fluid Inclusion and Relationship between Oil-gas Charging and Uranium Metallogenesis in the Zhiluo Formation in Diantou,Ordos Basin

作　　者：张字龙[1] 贺锋[1] 邱林飞[1] 范洪海 蔡煜琦[1] 衣龙升[1] 刘红旭[1] 贾翠[1] ZHANG Zi-long;HE Feng;QIU Lin-fei;FAN Hong-hai;CAI Yu-qi;YI Long-sheng;LIU Hong-xu;JIA Cui(Key Laboratory of Uranium Resources Exploration and Evaluation Technology(CNNC),Beijing Research Institute of Uranium Geology,Beijing 100029,China)

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

出　　处：《东华理工大学学报（自然科学版）》2020年第4期313-322,共10页Journal of East China University of Technology(Natural Science)

基　　金：核工业地质局生产中科研项目(201902-7);中核集团集中研发项目(LTD1601-3)。

摘　　要：以店头地区直罗组赋铀砂岩为研究对象,通过偏光显微镜观察了赋铀砂岩的岩石矿物学和包裹体特征,运用扫描电镜分析了铀矿化特征,并利用电子探针分析了与铀成矿相关包裹体的盐度、温度、成分及其分布情况,结合成岩和成矿作用、铀成矿时代、烃源岩生烃和排烃期,研究了油气充注与成岩作用先后关系,油气充注与铀成矿的关系。综合分析认为,直罗组赋铀砂体至少存在2次较强的成岩作用,导致砂体渗透率低;充注于直罗组赋铀砂体的油气作用至少有2期,成分以富含沥青的液态烃和气液烃为主;第2期油气充注作用晚于第2次强成岩作用,油气流体充注作用同时伴有热液作用,进一步促进了铀成矿作用。The uranium-hosting sand body of the Zhiluo Formation in Diantou area was studied.First,the micro characteristics of rocks,minerals and fluid inclusions were analyzed through thin section identification.Then,the features of uranium mineralization and the distribution of the fluid inclusions associated with the uranium mineralization were identified using EPMA and SEM methods.Subsequently,the salinity,temperature and composition of fluid inclusions were studied.At last,the subsequences of oil-gas charging and diagenesis and the relationship between oil-gas charging activities and uranium mineralization are discussed based on the diagenesis of uranium-hosting sand bodies,uranium mineralization ages,and the periods of hydrocarbon generation and discharging from the source rocks.The comprehensive analysis suggests that there were at least two periods of intensive diagenesis in the uranium-hosting sand bodies of the Zhiluo Formation,which resulted in a low permeability of the sand bodies.There were at least two periods of oil-gas charging in the uranium-hosting sand bodies of the Zhiluo Formation,which were dominated with pitch-rich liquidous and gaseous hydrocarbon.The second period of oil-gas charging was later than the second period of intensive diagenesis,and the process of this oil-gas charging was accompanied with hydrothermal activities,which led to the uranium mineralization.

关 键 词：砂岩型铀矿 流体包裹体 成矿作用 直罗组 店头地区 

分 类 号：P619.14[天文地球—矿床学]