摘要
研究砂岩型铀矿中的黏土矿物可以了解控制该矿床形成的沉积环境、成岩作用和成矿作用等。通过X射线衍射、扫面电镜等手段,对哈达图矿床含矿段赛汉组上段氧化还原带中黏土矿物特征展开研究。结果表明:该地区赛汉组上段岩石中黏土矿物组合主要为伊蒙混层(I/S)和伊利石(I),两者之和平均占黏土矿物总量94%,其中伊/蒙混层平均占61%,伊利石平均占34%,含少量高岭石及绿泥石,未发现蒙皂石;伊/蒙混层主要为完全无序型,是成岩期碱性环境下由蒙皂石转化形成的,高岭石是在成矿期氧化水渗入形成酸性流体作用下形成的,后期部分高岭石转化为伊利石;过渡带黏土总量相对最高,弱氧化带及还原带黏土总量略低,强氧化带黏土总量最低,这是导致强氧化带渗透性相对较高,更易被氧化,过渡带渗透性相对较差,进而成矿的一个重要原因;黏土矿物表面吸附有大量的超显微、显微状铀矿物。
Clay minerals study can beneficiate the understanding of the sedimentary environment and the ore-forming processes. In this paper, clay minerals in redox zone of upper member of Saihan Formation in Hadatu area were studied through XRD and SEM. Results showed that the main clay minerals are illite-smectite mixture and illite, they account for 94 % of the total amount of clay minerals, in which 61 % is illite-smectite mixture and 34 % illite, the minority are kaolinite and chlorite, no smectite was found.Illite-smectite mixture is completely disordered in structure which was transformed from smectite in alkaline environment during diagenesis. Kaolinite was generated via acid fluid due to the infiltration of oxidized water and later turned into illite partly under alkaline condition. The total amount of clay is relatively high in transition zone and slightly lower in weak oxidation zone and lowest in strong oxidation zone. Large amount of uranium are adsorbed on surface of clay minerals as ultromicro(<1 μm) and micro(1 μm^1.5 μm)uranium minerals.
作者
李伟涛
李子颖
李西得
刘武生
康世虎
吕永华
LI Weitao;LI Ziying;LI Xide;LIU Wusheng;KANG Shihu;LYU Yonghua(CNNC Key Laboratory of Uranium Resources Exploration and Evaluation Technology,Beijing Research Institute of Uranium,Beijing 100029,China;Geologic Party NO.208,CNNC,Baotou,Inner Mongolia 014010,China)
出处
《铀矿地质》
CAS
CSCD
2020年第2期96-103,共8页
Uranium Geology
基金
中核集团集中研发项目“二连基地砂岩型铀成矿环境和条件调查评价研究”(编号:地LCEQ01)
“二连基地砂岩型铀矿地质数字平台和大数据找矿预测”(编号:地LCEQ03)资助。
关键词
二连盆地
砂岩型铀矿
哈达图
黏土矿物
赛汉组上段
Erlian Basin
sandstone-type uranium deposit
Hadatu
clay minerals
Saihan Formation
