松辽盆地北部三肇凹陷四方台组含铀砂岩岩石学、矿物学特征及其地质意义  

Petrology and mineralogy characteristics of the Uranium-bearing Sandstone from Sifantai Formation in Sanzhao Depression of Northern Songliao Basin and their geological implications

作　　者：陈路路 李名[5] 汤超 贺静 陈印[1] 赵华雷 唐力 CHEN Lu-lu;LI Ming;TANG Chao;HE Jing;CHEN Yin;ZHAO Hua-lei;TANG Li(Tianjin Center,China Geology Survey,Tianjin 300170,China;State Key Laboratory of Nuclear Resources and Environment(East China University of Technology),Nanchang,330013,China;Key Laboratory of Uranium Geology,China Geological Survey,Tianjin 300170,China;North China Center of Geoscience Innovation,Tianjin 300170,China;PetroChina Huabei Oilfield Company,Renqiu 062552,China;Research Institute of Exploration and Development of Changqing Oilfield Company,PetroChina,Xi’an 710018,China;Key Laboratory of Tectonics and Petroleum Resources(China University of Geosciences),Ministry of Education,Wuhan 430074,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]东华理工大学核资源与环境国家重点实验室,南昌330013 [3]中国地质调查局铀矿地质重点实验室,天津300170 [4]华北地质科技创新中心,天津300170 [5]中国石油华北油田公司,河北任丘062552 [6]长庆油田分公司勘探开发研究院,西安710018 [7]中国地质大学构造与油气资源教育部重点实验室,武汉430074

出　　处：《华北地质》2022年第4期10-20,共11页North China Geology

基　　金：国家自然科学基金项目(92162212);构造与油气资源教育部重点实验室开放基金(TPR-2022-22);东华理工大学核资源与环境国家重点实验室开放基金项目(2020NRE10);国家重点研发计划(2018YFC0604200);中国地质调查局项目(DD20190119、DD20221678);中国石油华北油田科技项目(HBYT-L-2022-JS-180);国际地球科学计划(IGCP-675)。

摘　　要：研究区位于松辽盆地北部三肇凹陷西南缘,含矿层位为上白垩统四方台组下段。通过铸体薄片岩矿鉴定、电子探针、X衍射及扫描电镜等综合测试与分析,进一步细化了含矿目的层的岩石矿物学特征,并探讨了研究区物源及铀赋存形式。结果表明研究区含铀砂岩类型主要为长石岩屑砂岩,岩屑主要为以喷发岩、隐晶岩为主的火成岩屑和以石英岩、板岩、高变岩为主变质岩屑,另有少量沉积岩屑以及凝灰岩岩屑。碎屑组分表明物源主要来自张广才岭及盆地东南部一带的太古-元古宙变质岩系、中生代火山岩及花岗岩。电子探针及背散射图像表明该区铀矿物以铀石为主,少量沥青铀矿。研究区除铀矿化外,矿物蚀变包括黄铁矿化、碳酸盐化、钛铁矿蚀变、黑云母蚀变以及黏土化等,其中早期黄铁矿与铀共生关系较密切。矿物蚀变序列大致反映了含矿层经历了氧化到还原、弱酸到偏碱性的环境演化,而该区砂岩型铀矿是早期沉积预富集基础上叠加改造的结果。The study area is located in the southwest of Sanzhao Depression in northern Songliao Basin. The sandbody from the lower member of Sifantai Formation in Late Cretaceous is the metallogenic host rock. By means of the rock-mineral determination of the casting thin sections, the analysis of electron probe, X-diffraction,and scanning electron microscope, the paper has further refined and detailed studied the characteristics of petrology and mineralogy. And it has made some discussion about the provenance of source region and occurrence form of uranium. The results show that the type of uraniferous sandstone is mainly feldspathic litharenite. The debris is mainly igneous debris mainly composed of eruptive rocks and cryptocrystalline rocks,metamorphic debris mainly composed of quartzite, slate and hypermetamorphic rocks, and a small amount of sedimentary debris and tuff debris. Clastic component displays that the provenance of study area is likely to come from the Zhangguangcai mountains and the southwest of Songliao basin, where develop the ArchaeanProterozoic metamorphic series and Mesozoic volcanic rocks and granites. Electron probe analysis and backscatter images show that uranium minerals are mainly coffinite and a small amount of pitchblende. In addition to uranium mineralization, the alteration of minerals mainly includes pyritization, carbonation, ilmenite alteration, biotite alteration and clay alteration in the study area. The main mineral closely associated with uranium is early pyrite. The mineral alteration sequence roughly reflects an oxidized to reductive, acidic to alkaline environment during the sedimentary and diagenetic stages. The sandstone-type uranium deposit in this area is the result of superposition and reformation on the basis of pre-enrichment of early sedimentation.

关 键 词：松辽盆地 三肇凹陷 四方台组 岩石矿物学 砂岩型铀矿 

分 类 号：P619.14[天文地球—矿床学]