钨锡矿床萤石的演化及稀土元素地球化学

本文对黄沙和珊瑚钨锡矿床的萤石进行了系统研究,随着成矿作用由早至晚成矿温度的逐渐降低,不同矿化阶段矿脉内和同一矿脉不同世代的萤石,其晶形和物理性质都具有相同的演化规律。产在硅铝质岩石中的充填型矿脉,其萤石的稀土模式与成矿母岩的相似,可以用来表征矿床的分带性和预测成矿母岩(花岗岩类)的成因类型;产于富含钙质围岩中的充填-交代型矿脉,其萤石的稀土模式不能表征成矿母岩的成因类型,但可以反映相应的成矿环境。

EVOLUTION AND REE GEOCHEMISTRY OF FLUORITES IN TUNGSTEN-TIN DEPOSITS

Fluorites in tungsten-tin deposits at Huangsha and Shanhu are systematically described in this paper. The results show that with decreasing formation temperature during mineralization from the early to the late stage, fluorites in ore veins at different mineralizing stages and of different generations from the single ore vein displayed the same evolution trend both in crystal form and in physical properties. The REE distribution patterns in fluorites present in the ore veins which filled in sialic rocks are similar to those in host granitold rocks, so they can be used to identify the zonation of ore deposits and to prognosticate the genetic types of host granitoid rocks associated with mineralization. On the other hand, the REE distribution patterns in fluorites present in filling-metasomatic ore veins in the country rocks rich in calcium cannot be used to identify the genetic types of host granitoid rocks, butthey may be able to characterize the ore-forming environment.