浅析贝尔凹陷伊敏组砂体沉积特征及铀矿成矿潜力  

A Brief Analysis of the Sedimentary Characteristics and Uranium Mineralization Potential of the Yimin Formation in the Beier Depression

作　　者：刘彤[1] 于赫楠[2] Tong Liu;Henan Yu(243 Team of Nuclear Industry, Chifeng Inner Mongolia;Institute of Disaster Prevention Science and Technology, Beijing)

机构地区：[1]核工业二四三大队,内蒙古赤峰 [2]防灾科技学院,北京

出　　处：《地球科学前沿（汉斯）》2018年第2期286-294,共9页Advances in Geosciences

基　　金：防灾科技学院精品建设课程基金项目(JPJS2016001);中央高校基本科研业务费专项资金创新团队资助计划项目(ZY20160109)联合资助。

摘　　要：贝尔凹陷属于海拉尔盆地的重要组成部分。其中伊敏组为区内主要找矿目的层,以湖沼相沉积为主,自下而上分为三段。其中伊敏组一、二段为泥、砂互层,不属于典型的“泥–砂–泥”结构的沉积建造,基本不具备铀矿成矿条件;而伊敏组三段顶板为新近系呼查山组泥岩,底板为伊敏组二段的泥岩,具备了稳定的“泥–砂–泥”结构,为铀成矿提供了良好的顶底板泥岩隔水层。通过对伊敏组三段取样并化验分析,表明沉积物分选一般,这与区内短物源,粗碎屑的特点关系较为密切。通过大量岩心编录,结合测井及分析化验资料,研究表明,贝尔凹陷下白垩统发育的沉积体系类型有冲积扇体系、扇三角洲体系、辫状河三角洲体系、曲流三角洲体系、湖泊体系和湖底扇体系。Beier depression is an important part of Hailar Basin. And Yimin Formation is the main prospecting stratum in the area, dominated by lacustrine facies sedimentation and divided into three sections from bottom to top. The first and second sections of the Yimin Formation are mud and sand interbeds, which do not belong to the sedimentary construction of the typical "mud-sand-mud"structure and basically do not have the metallogenic conditions for uranium deposits. The third section of the Yimin Formation is a Neogene system Huchanshan group mudstone, the bottom plate is the second section of the Yimin mudstone, with a stable “mud-sand-mud” structure, they provide a good roof and floor mudstone aquifuge for uranium mineralization. By sampling and analyzing the three sections of the Yimin Formation, it shows that the sediments are generally sorted, which is closely related to the characteristics of short source and coarse crust in the area. Based on a large number of core records, well logging and analysis, it shows that the sedimentary systems of the Lower Cretaceous in the Beier depression include alluvial fan system, fan delta system, braided delta system, meandering delta system, lake system and lake bottom fan system.

关 键 词：贝尔凹陷 伊敏组 砂体 沉积特征 

分 类 号：P61[天文地球—矿床学]