摘要
通过前人资料二次开发利用,对赫尔洪德凹陷东南部伊敏组上段岩性-岩相特征及其对铀成矿的控制作用进行了综合分析。该区缓倾斜坡带主要发育辫状河三角洲-滨浅湖沉积体系,主砂体总厚10~80 m,单层砂厚3~12 m;岩性主要为灰色含砾中-粗砂岩、砂砾岩,其次为细砂岩,泥质胶结、疏松,孔渗性良好;碎屑成分以中酸性火山岩和石英为主,次为长石,内部铀源较好;砂体还原能力一般,肉眼可见还原介质主要为半炭化植物茎干,少量为炭屑和黄铁矿。铀矿化主要赋存于现存(水下)分流河道砂体中,受沉积微相和古潜水-层间氧化作用控制明显。总体上,研究区伊敏组上段岩性-岩相条件较良好,是寻找古潜水-层间氧化带型铀矿的有利远景区。
Based on the analysis of previous data,the lithological assemblage and sedimentary system of upper Member of Yimin Formation and their control on sandstone uranium mineralization have been comprehensively studied in the southeastern Herhonde sag.Results showed that the braided river delta and shore shallow lake depositional system was developed over the gently inclined slope zone of the eastern margin of the sag.The sand body,with the whole thickness varied from 10 to 80 m and the single thickness ranged from 3 to 12 m,mainly consist of gravel bearing medium-coarse sandstone and conglomerate,followed by fine sandstone.It is characterized by argillaceous cementation,good porosity and permeability.The detrital component is mainly composed of quartz,intermediate-acid volcanic rock debris and feldspar,which indicate that there is sufficient internal uranium source.The sand body generally contains some original reducing media,e.g.semi-carbonized plants,a small amount of carbon debris and pyrite,showing the medium reduction ability.Uranium mineralization,which has been obviously controlled by sedimentary microfacies and paleophreatic oxidation,mainly occurs in(distributary)channel sand body of the existing braided river delta.Therefore,it is a favorable prospect for the exploration of paleo-phreatic interlayer oxidation zone type uranium deposits in the study area owing to the fine lithologic and lithofacies conditions of upper Member of Yimin Formation.
作者
黄少华
周文博
周荣辉
刘彤
邓福理
HUANG Shaohua;ZHOU Wenbo;ZHOU Ronghui;LIU Tong;DENG Fuli(CNNC Key Laboratory of Uranium Resources Exploration and Evaluation Technology,Beijing Research Institute of Uranium Geology,Beijing 100029,China;Geologic Party No.243,CNNC,Chifeng,Inner Mongolia 024000,China)
出处
《世界核地质科学》
CAS
2020年第2期97-106,共10页
World Nuclear Geoscience
基金
中国核工业地质局地勘科研项目(编号:201911-02)
内蒙古海拉尔盆地铀矿资源调查评价项目(编号:201911)
中核集团启明星项目(编号:QNYC2018-1)
国家自然科学基金项目(编号:41902084)资助。
关键词
伊敏组上段
辫状河三角洲
砂体
铀矿化
赫尔洪德凹陷
upper Member of Yimin Formation
braided river delta
sand body
uranium mineralization
Herhongde sag
