义县萤石矿床稀土元素地球化学特征及其指示意义

为了研究辽西义县萤石矿床的成矿机理及成矿流体来源,文章对矿区萤石稀土元素进行了分析。结果表明:2种类型的萤石为同源不同阶段的产物,从成矿早期至晚期,LREE逐渐减少,Ce负异常由弱变强,Eu则均显明显的正异常;矿床成矿流体主要来源于中侏罗世髫髻山旋回岩浆热液;成矿过程为岩浆热液与围岩(主要为白云质灰岩和灰岩)的相互作用,并有天水的混入;成矿环境相对氧化。

REE geochemistry of fluorite from Yixian fluorite deposit and its geological implications

REE geochemistry of fluorite from the Yixian fluorite deposit in western Liaoning Province was systematically studied in order to probe into its metallogenic mechanism and the source of the ore-forming fluid. According to REE content, REE parameters and partition patterns, fluorites can be classified into LREE-flat and LREE-depleted types, with REE geochemical features of the two types varying regularly. The results indicate that the two types of fluorite were produced by the same source at different metallogenic stages. LREE content decreases gradually and negative Ce anomaly increases step by step from early to late ore-forming stages. The ore-forming fluid was magmatic hydrothermal fluid of Middle Jurassic Tiaojishan cycle, and mineralization took place in a re-lative oxidization environment.