摘要
松辽盆地西南部钱家店矿田是上白垩统原生红杂色陆源碎屑建造中多重流体耦合叠加作用的产物。根据前人研究成果及最新勘探结果,文章重新系统地总结了该矿田的铀源、构造、沉积建造、水文地质、古气候、后生氧化及深部流体改造等关键铀成矿条件和特征,探讨了板状铀矿体的成因。区内矿床的主要含矿层为半干旱-干旱古气候条件下形成的青山口组和姚家组红杂色建造,内外部的铀源和还原剂均丰富,灰色层控制显著,深部热液和油气流体叠加改造作用明显,地下水具有多向补给,并沿构造剥蚀天窗或断裂统一方向排泄;含矿层中氧化带与矿体总体存在断陷中央“脱节”式和断陷边缘“两红夹一灰”式两种空间展布特征。基于断坳转换型叠合盆地“牛角式”构造-沉积演化特征,初步构建了上白垩统超覆式坳陷层的“基底角度不整合界面、辫状河道灰色砂体、后生氧化带、深部流体及天窗或断裂泄水构造”五位一体的板状铀矿体成矿模式:(1)下白垩统生油含煤断陷沉积建造形成期;(2)泉头期-嫩江期超覆式沉积建造形成和成岩期;(3)嫩江期末-古近纪多重流体耦合叠加层间氧化主成矿期;(4)新近纪表生流体潜水渗入叠加改造期。
Qianjiadian uranium ore field was formed by the coupling superimposed multi fluids within the Upper Cretaceous red-variegated clastic layer from the southwest of the Songliao Basin. On the basis of previous researchments and the latest exploration results, some significant mineralization conditions and characteristics, including uranium source, structure, sedimentary formation, hydrogeology, paleoclimate,epigenetic oxidation and deep fluid transformation, were systematically summarized with the aim to explain the genesis of tabular uranium ore body. The ore bearing beds in the study area are mainly composed of Qingshankou Formation and Yaojia Formation which were developed under the semiarid-arid paleoclimate condition. The deposits evidently controlled by the gray layer within the target formation, were with both characteristic of strong superimposed transformation of deep hydrothermal and hydrocarbon fluids and abundant internal and external uranium sources and reducing agent. Uranium and oxygen bearing groundwater from multi-direction recharged into the layer and discharged along the unified direction of structural denudation or faults. There are two spatial distribution characteristics for the oxidation belt and the gray ore body, i.e. "disconnection" type in the center of fault depression and "one gray within two red belts" type at the edge of fault depression. According to the tectonic and sedimentary evolution from fault depression to depression in the southwest of Songliao Basin, the model of the tabular uranium ore body for the Upper Cretaceous overlying deposition was established. The major controlling factors include the basement angular unconformity interface, braided channel gray sand body, epigenetic oxidation zone, deep fluid and drainage structure of skylight or fault. A four-stage ore-forming process are established as follows, i. e.(1) formation period of Lower Cretaceous oil and coal bearing fault depression;(2) deposition and diagenetic stage of the overlying sedimentary formation from Quantou to Nenjiang period;(3) main ore-forming stage coupling superposed by multi-fluids from Late Nenjiang to Later Paleogene;(4) infiltration and transformation stage by supergene fluid during Neogene.
作者
黄少华
秦明宽
刘章月
刘佳林
郭强
贾立城
江文剑
张亮亮
HUANG Shaohua;QIN Mingkuan;LIU Zhangyue;LIU Jialin;GUO Qiang;JIA Licheng;JIANG Wenjian;ZHANG Liangliang(Beijing Reasearch Institute of Uranium Geology,Beijing 100029,China;Geological Party No.243,CNNC,Chifeng,Inner Mongolia 024000,China)
出处
《铀矿地质》
CAS
CSCD
2022年第3期409-424,共16页
Uranium Geology
基金
松辽盆地核能开发项目(编号:地HSL1403-3)
中核集团第四批青年英才项目(编号:QNYC2102)联合资助。
关键词
成矿条件与特征
板状铀矿体
成矿模式
超覆层
钱家店矿田
松辽盆地
metallogenic conditions and characteristics
tabular uranium ore body
ore-forming model
overlying deposition
Qianjiadian ore field
Songliao Basin
作者简介
黄少华(1989—),男,高级工程师,博士,从事砂岩型铀矿成矿机理及成矿规律研究。E-mail:huangshaohua20@126.com;通信作者:秦明宽(1968—),男,高级工程师(研究员级),博士,从事盆地砂岩型铀矿研究。E-mail:qinmk9818@163.com。
