松辽盆地钱家店地区姚家组铀储层岩石学特征及成岩作用  

Petrology and diagenesis of the uranium reservoir in the Yaojia formation of Songliao Basin,Qianjiadian area

作　　者：朱强[1] 焦养泉[2] 吴立群[2] 荣辉[2] 谢惠丽 马小东 

机构地区：[1]天津地质矿产研究所,天津300170 [2]中国地质大学资源学院,武汉430074 [3]东北煤田地质局勘察设计研究总院,沈阳110013

出　　处：《中国科技论文》2015年第15期1802-1808,共7页China Sciencepaper

基　　金：国家重点基础研究发展计划(973计划)资助项目(2015CB453000);华北地区铀矿地质调查与选区项目(1212011220494)

摘　　要：通过岩心观察、薄片鉴定、扫描电镜分析等手段,将松辽盆地钱家店地区姚家组铀储层划分为姜黄色-紫红色氧化砂岩、含矿灰色砂岩、原生灰色砂岩3种类型,并讨论了含矿岩系主要的成岩作用类型,划分了成岩演化序列。研究表明:该区砂岩的成分成熟度和结构成熟度都较低,轻矿物的成熟度指数(Q/(F+R))平均值仅为0.56,SiO2/Al2O3为6.69;含矿岩系成岩作用较强,主要类型有压实作用、胶结作用、交代作用、溶蚀作用及黏土矿物的转化等;通过对矿物之间穿插关系的分析,确立了成岩演化序列为苺球状、细粒状黄铁矿—早期方解石胶结(泥晶方解石)—石英次生加大—碎屑颗粒溶解次生矿物形成(黏土矿物交代碎屑颗粒)—孔隙充填方解石(亮晶方解石、含铁白云石形成)—方解石交代碎屑颗粒—黑云母水解、自形、他形黄铁矿。本研究探讨了砂岩赋铀性与岩石结构组分的关系,为揭示成岩作用对铀运移沉淀富集的影响提供参考。Based on drill core observation,thin section identification,scanning electron microscopy （SEM）analysis,quantitative statistics and other techniques,the uranium reservoir of the Yaojia formation in the Songliao Basin Qianjiadian area is divided into three types,i.e.ginger-purple oxide sandstone,ore gray sandstone and primary grey sandstone.Additionally,characteristics of ore-containing sandstones and diagenesis process are discussed.Results show that both compositional and structural maturity of the sandstone are low,the average light mineral compositional maturity index only 0.56,SiO2/Al2 O3 is 6.69.The diagenesis in-tensity of uranium bearing rock series is strong,which include compaction,cementation,metasomatism,dissolution and clay mineral transformation.By analyzing intervening relationships of diagenetic minerals,the following diagenetic evolutionary se-quence is determined：framboidal and fine grained pyrite,early calcite cementation （micrite calcite）,the secondary overgrowth of quartz,dissolution of clastic particles,secondary mineral formation（clay mineral replacing clastic particles）,pore filling calcite （sparry calcite and iron dolomite formation）,calcite replacement of clastic particles,biotite hydrolysis,euhedral and anhedral py-rite.This research provides an important discussion on relationships between sandstone uraniferous characteristics and rock com-ponents,and reveal the influence of diagenesis on uranium’s migration and precipitation.

关 键 词：岩石学特征 成岩作用类型 成岩演化序列 铀储层 钱家店地区 松辽盆地 

分 类 号：P618.13[天文地球—矿床学]