大華 및 敦山 重石ㆍ모리브덴 鑛床의 鑛石과 鑛物共生關係

Ore and mineral paragenesis of Daehwa and Donsan tungsten-molybdenum deposits

The Daehwa and Donsan tungsten-molybdenum deposits are composed of numerous fissure-filling veins developed in Precambrian gneiss and Cretaceous granite and quartz porphyry. K-Ar age of biotite in granite and that of muscovite in ore veins are 105±5 Ma and 88.2~88.6 Ma respectively. Occurrence of ore deposits shows that relevant igneous rock is possibly quartz porphyry rather than above mentioned granite in temporal view point. Vein structure and mineralogy suggest that ore veins were formed by continuous vein filling, not by repeated mineralization. Three distinct depositional stages with decreasing age can be devided on the basis of mineral paragenesis and fluid inclusion studies: Stage Ⅰ, deposition of oxides and silicates; stage Ⅱ, deposition of base-metal sulfides and sulfosalts with carbonates; stage Ⅲ, deposition of barren calcite and fluorite. Tungsten, molybdenum and tin mineralization occurred in stage Ⅰ.