下庄铀矿田中基性脉岩地球化学特征及其控矿作用

The Geochemical Character of Intermediate-basic Dikes and Its Control on Uranium Deposits in Xiazhuang Ore Field

研究下庄铀矿田中基性脉岩的地球化学特征发现,其Fe3+、Fe2+、K2O、Na2O和Al2O3等的含量与SiO2呈线性关系,铀矿化与硅化和碱交代关系密切,而与其他常量化学组分的关系并不明显。对流体作用敏感的U/Th、Pb/Ce、Ba/La、Cs/Rb特征值和对流体作用不敏感的Ce/Yb值,为中基性脉岩后期存在的流体作用提供了佐证。研究结果显示,中基性脉岩对铀成矿的控制作用主要是通过对构造裂隙的控制来实现;所谓的"交点"控矿,本质上是硅化带型铀矿化以"界面效应"控矿方式呈现的特殊表现形式。

Geochemical study of major element in intermediate - basic dikes in Xiazhuang uranium orefiled found that the content of Fe3＋ , Fe2＋ , K2 O, Na2O Al2 O3 is in liner realtion with SiO2, uranium mineralization is closely related to silicification, but has less realtion to other major elements. Research on fluid sensitive U/Th, Pb/Ce, Ba/La and Cs/Rb ratio and non-sensitive, Ce/Yb ratio provides the evidence for the later fluid action of intermediate - basic dikes. The results showed that the control effect of intermediate - basic dikes to uranium ore formation was by controlling the fracture fissures, the so -called ＂ intersection＂ controll of mineralization is fundamentally a special silieification zone type uranium mineralization controlled by ＂ the effect of interface ＂ .