摘要
松辽盆地钱家店铀矿床含矿主岩为姚家组中的厚层砂岩。该砂岩上、下隔水层发育,局部夹较多不连续的泥岩透镜体,为辫状河流相沉积成因。平面上辫状河道周围为泛滥平原,以泥质沉积为主,在河道中间局部夹有河道间的沉积,其泥岩夹层多、厚度大,非均质性较强。通过与氧化带、铀矿化的对比分析,发现姚家组的岩相特征和砂体的非均质性对氧化带和铀矿化的分布、形态有明显的控制作用。河道间沉积及砂体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。砂体均质性较强的部位有利于氧化带的发育,而非均质性较强的部位则有利于铀成矿。
The host rocks of Qianjiadian uranium deposit in Songliao basin is composed of thick bed sandbodies, which are formed by braided stream sediment in Yaojia formation. The thick bed sandbody has favorable upper and lower waterproof layer, and has lenticular mudstone interlayer in some parts. On plane, the flood plain face locates around the braided stream face, which is mainly composed of sediments of argillaceous rock. In the middle of braided stream, distributes interchannel sediments, which has thicker mudstone interlayer and thinner sand bodies, and the sand body of these place is more heterogeous than others. Based on the analysis on oxidation zone and uranium mineralization, it is found that the distribution and configuration of oxidation zone and ore bodies are obviously controlled by the lithofacies characteristics and sandbody heterogeneity of Yaojia formation. The reason is that the movement of uranium-bearing oxidizing ground water can be obstructed by interchannel sediments and pelitic interbeds of host sandstones. As a result, the redox interface will be developed and uranium can be concentrated in neighbouring sandstones. The sandbodies with greater homogeneity are favorable for the formation of oxidation zone, and sandbodies with greater heterogeneity are favorable for the uranium mineralization.
出处
《铀矿地质》
CAS
CSCD
2007年第6期335-341,355,共8页
Uranium Geology
关键词
钱家店铀矿床
姚家组
岩相特征
铀成矿
砂体非均质性
Qianjiadian uranium deposit
Yaojia formation
lithofacies characteristics
uranium minerali- zation
sandbody heterogeneity
