内蒙古二连盆地早白垩世砂岩型铀矿目的层时代探讨  

DISCUSSION ON THE EARLY CRETACEOUS SANDSTONE-TYPE URANIUM DEPOSITS,ERLIAN BASIN,INNER MONGOLIA

作　　者：聂逢君[1] 陈安平 胡青华[1] 申科峰 秦明宽[3] 李满根[1] 姜美珠[1] 

机构地区：[1]东华理工学院,江西南昌330013 [2]核工业208地质大队,内蒙古包头014010 [3]核工业北京地质研究院,北京100029

出　　处：《地层学杂志》2007年第3期272-279,共8页Journal of Stratigraphy

基　　金：国家自然科学基金(No40376043)资助项目

摘　　要：赛汉高毕和巴彦乌拉地区是二连盆地两个新近突破的砂岩型铀矿区,分属于两个不同的二级构造单元,前者位于乌兰察布坳陷的东北角,后者位于马尼特坳陷的西南角,中间由贺根山断裂分隔。由于两个地区的含矿目的层的厚度、岩性、岩石颜色、沉积相和沉积环境等存在一定的差别,故而引起了两地的含矿目的层时代的争论。为了解决这一问题,在砂岩型铀矿区部分钻孔进行了古地磁采样、分析,结果表明:地磁极性序列变化基本相似,相当于国际标准年表的阿普第—阿尔必期。同时,在两个地区采集的部分孢粉样品分析结果显示,均获得较多早白垩世的标志分子,组合面貌与我国北方早白垩世赛汉塔拉组Cicatricosisporites-Disacciatrileti孢粉植物群的特征非常相符。古地磁和孢粉分析资料共同有力地证实了二连盆地的这两个地区砂岩型铀矿的目的层属于同一个层位,即下白垩统赛汉塔拉组。Saihangaobi and Bayanwula are two the Erlian rifted basin. They are located in two potential areas for the sandstone-type uranium deposits in different sub-tectonic units： the former in the Wulanchabu sub-basin and the latter in the Manite sub-basin, with the Hegenshan fault separating them. Since there are some differences in the thickness, lithology, color, sedimentary facies between the uranium deposits in these two areas, it has been debated whether these uranium deposits can be correlated. This study makes use of paleo-magnetic and sporopollen data to determine the age of the sandstone-type uranium deposits. Magnetostratigraphy indicates that the two deposits are of similar age, both belong to the Early Cretaceous Aptian-Albian stages. Palynological analysis indicates an Early Cretaceous Cicatricosisporites-Disacciatrileti age. A number of sporopollen species are characteristic of Early Cretaceous floras. Therefore, both paleo-magnetic and palynological data confirm that the sandstone-type uranium deposits in the study area are of Early Cretaceous （Aptian-Albian） age.

关 键 词：古地磁 孢粉 砂岩型铀矿 早白垩世 二连盆地 

分 类 号：P534.53[天文地球—古生物学与地层学]