内蒙古贝尔湖坳陷目的层孢粉组合特征及其地质意义  

Characteristics and Geological Significance of Sporopollen Assemblages in the Target Layer of Beierhu Depression,Inner Mongolia

作　　者：东艳[1] 周文博[2] 刘彤[2] 许普林 黄少华[1] DONG Yan;ZHOU Wenbo;LIU Tong;XU Pulin;HUANG Shaohua(Beijing Research Institute of Uranium Geology,Beijing 100029,China;Geological Party No.243,CNNC,Chifeng,Inner Mongolia 024000,China;Research Institute No.270,CNNC,Nanchang,Jiangxi 330200,China)

机构地区：[1]核工业北京地质研究院,北京100029 [2]核工业二四三大队,内蒙古赤峰024000 [3]核工业二七○研究所,江西南昌330200

出　　处：《铀矿地质》2020年第4期261-267,279,共8页Uranium Geology

基　　金：中国核工业地质局铀矿地质科研项目(编号:地D1804);内蒙古海拉尔盆地铀矿资源调查评价项目(编号:201911)联合资助。

摘　　要：为精确厘定内蒙古海拉尔盆地贝尔湖坳陷砂岩型铀矿找矿目标层及其时代,采集了钻孔内灰色泥岩样品,并进行了孢粉化石分析鉴定。结果显示,区内目的层孢粉组合以桫椤孢属及无缝双囊粉类发育为特色,裸子类花粉占55.5%,蕨类孢子占44.5%,这与下白垩统伊敏组两段桫椤孢Cyathidites孢粉组合带较为相似,属于早白垩世巴列姆期。综合区域铀成矿地质条件认为,区内主要找矿目的层为下白垩统伊敏组,沉积时期为温暖湿润的热带古气候环境,泥-砂-泥地层结构稳定,砂体透水性好,本身还原容量较高,是一套有利的找矿目的层。In order to accurately determine the prospecting target layer and its age of the sandstone-type uranium metallizotion in the Beierhu depression of Hailaer Basin,Inner Mongolia,the gray mudstone samples in the borehole were collected systematically and analyzed for the sporopollen fossils.The results showed that the sporopollen assemblages of the target layer in the study area were characterized by the development of cyathidites and dissacciatrileti,with 55.5%of the nude sub-pollen and 44.5%of the fern spores,which are similar to the sporopollen assemblages of Cyathidites in the second section of the Lower Cretaceous Yimin Formation,belonging to the Early Cretaceous Barremian period.Based on the comprehensive study of geological conditions of uranium mineralization in the region,it was considered that the main ore-prospecting target layers are Yimin Formation deposited in the warm and humid tropical paleoclimate.The Yimin Formation is with good permeability,stable structure of the mud-sand-mud beds,and great reduction capacity,which are favorablefor the formation of sandstone-hosted deposit.

关 键 词：目的层时代 孢粉组合 伊敏组 砂岩型铀矿 贝尔湖坳陷 

分 类 号：Q914.8[天文地球—古生物学与地层学]