松辽盆地中央坳陷区长岭地区上白垩统姚家组砂岩型铀矿成矿条件分析  

Discussion on Metallogenic Conditions of Sandstone-type Uranium Deposits in Upper Cretaceous Yaojia Formation in Changling Area,Central Depression,Songliao Basin

作　　者：张红静 于浩依 张玲玲 王俊[1,4] 李可睿 ZHANG Hongjing;YU Haoyi;ZHANG Lingling;WANG Jun;LI Kerui(State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang,Jiangxi 330013,China;School of Geophysics and Measurement-Control Technology,East China University of Technology,Nanchang,Jiangxi 330013,China;PEGETE Group Inc.,Beijing 100102,China;School of Earth Sciences,East China University of Technology,Nanchang,Jiangxi 330013,China)

机构地区：[1]东华理工大学核资源与环境国家重点实验室,江西南昌330013 [2]东华理工大学地球物理与测控技术学院,江西南昌330013 [3]北京中恒利华石油技术研究所,北京100102 [4]东华理工大学地球科学学院,江西南昌330013

出　　处：《铀矿地质》2024年第5期850-863,共14页Uranium Geology

基　　金：核资源与环境国家重点实验室开放基金项目(编号:2022NRE16);江西省教育厅科学技术研究项目(编号:GJJ2200706);东华理工大学博士科研启动基金项目(编号:DHBK2019083)联合资助。

摘　　要：近年来,在松辽盆地南部的开鲁坳陷和西南隆起带中相继发现大型砂岩型铀矿,如何在含矿层地质条件相似的中央凹陷区姚家组中取得找矿突破,对其砂岩型铀矿成矿条件展开研究是亟待解决的问题。文章通过对油气勘探开发资料的二次利用,基于沉积学和铀成矿理论的指导,对松辽盆地南部中央坳陷区长岭地区砂岩型铀矿的成矿条件进行综合分析,认为:长岭地区位于背斜构造之上,其中南北向为缓坡,东西向为陡坡,靠近西北部陡坡一带发育一系列沿北北西向展布的断层,可能连通构造天窗,使含铀含氧水更易深入;研究区内主要铀源体为西部蚀源区的黑云母花岗岩和白岗质花岗岩,U含量最高可达9.1×10^(-6),浸出率可达37.5%,说明铀成矿过程中可能有大量来自外部的铀资源供给;姚一段主要发育浅水三角洲前缘亚相水下分支河道微相,河道砂体连通性较好、延伸距离远;与地沥青相伴生的黄铁矿、渗透性砂岩段的油气后期还原褪色蚀变以及砂岩中的褐铁矿化、赤铁矿化作用,说明姚家组一段具有较好的氧化还原条件。综合分析认为长岭地区乾深2井一带为Ⅰ类砂岩型铀矿远景区,乾深4井一带为Ⅱ类砂岩型铀矿远景区。In recent years,large-scale sandstone-type uranium deposits have been discovered in Kailu Depression and the southwest uplift belt of Songliao Basin.Searching correspondent deposit in same target horizons with similar metallogenic condition the central depression become an urgent and important question problem.With the guidance of sedimentology and uranium mineralization theory and the secondary utilization of oilfield data,this paper comprehensively analyzed the metallogenic conditions of sandstone type uranium deposit in Changling area,southern Songliao Basin.Changling area is stetted on an anticlinal structure,which is gentle in the SN extending slope,and steep in the EW extending slope.Near the northwestern steep slope,a series of faults developed along the NW direction,which may connect the structural skylight and make the uranium-containing oxygen water easily circling deep.The main uranium source body in the study area is granite in the western erosion source area,with high U content and high leaching rate,which provided abundant external uranium source for uranium mineralization.The subaqueous distributary channel microfacies of shallow-water delta front subfacies were mainly developed in the first member of Yaojia Formation,and the channel sand body has good connectivity and long extension distance.Pyrite with asphalt,color fading of the permeable sandstone by hydrocarbon fluid and limoization,hematitization in sandstone,indicate that the K_(2)y^(1)developed a good redox condition.The comprehensive analysis shows that area near well Qs2 in Changling area is prospective to formⅠ-type sandstone type uranium deposit,and area near well Qs4 is prospective for theⅡ-type sandstone type uranium deposit.

关 键 词：成矿条件 砂岩型铀矿 姚家组 长岭地区 

分 类 号：P619.14[天文地球—矿床学]