松辽盆地QJD铀矿床层间氧化带的展布特征及其与沉积相、铀成矿的关系

QJD铀矿床为一具有特殊形式的层间氧化带砂岩型铀矿床。经过对该矿床古气候、沉积作用等的分析以及钻孔剖面的对比,认为含矿砂岩原生色以灰色为主,红色和黄色砂岩均为后期氧化的结果,并绘制出了姚家组上、下段氧化带前锋线分布图。通过对氧化带前锋线与沉积相平面展布图的对比分析,发现河道间的细粒沉积对前锋线有明显的控制作用。河道间沉积及砂岩中的泥质夹层可以阻碍含铀含氧水的流动,在其附近形成氧化-还原过渡带和铀的富集。

Distribution characteristics of interlayer oxidation zone and its relationship with sedimentary facies and uranium mineralization in QJD uranium deposit, Songliao Basin, NE China

QJD uranium deposit is a sandstone-type uranium deposit with the special shape of the interlayer oxidation zone. After studying the palaeoclimate condition and sedimentation of host sandstones,contrasting drilling cross sections,this paper suggests that primary colors of host sandstones are mostly in gray,red and yellow colors of sandstones are the result of oxidation alteration. According to the positions of drill holes with red and yellow alteration sandstones,the plane distribution of oxidation roll fronts of the Upper and Lower Member of Yaojia Formation are delineated. By contrasting the plane distribution of oxidation fronts and sedimentary facies,it can be found that oxidation fronts are obviously controlled by interchannel fine-grained sediments. The movement of uranium-bearing oxidizing groundwater can be obstructed by interchannel sediments and pelitic interbeds of host sandstones. As a result,redox interface will be developed and uranium can be concentrated in neighbouring sandstones.