大華 重石輝水鉛鑛床産 鑛物中의 流體包有物에 關한 硏究

A study on the fluid inclusions in the minerals from the Dae Hwa tungsten-molybdenum deposits

Daehwa tungsten-molybdenum deposits is fissure filled quartz veins occurring in Precambrian granite gneiss adjacent to the contact with Mesozoic biotite granite mass. Essential ore minerals are molybdenum and wolframite accompaning scheelite, cassiterite chalcopyrite, pyrrhotite, pyrite and bismuthinites. Gangue minerals are quartz and little muscovte, fluorite, beryl and Carbonate minerals. Fluid inclusions in quartz, fluorite, beryl, scheelite and calcite have filling temperature ranges of 170-353℃. According to the studies of mineral paragenesis and filling temperature of fluid inclusion indicate that main tungsten and molybdnum mineralization have taken place with the minerals whose filling temperature ranges 205 to 353℃. Liquid CO₂ bearing fluid inclusions are characteristic in the quartz and early fluorite of tungsten and tungsten bearing molybdenum veins but hardly recognized from molybdemun veins. Estimated CO₂ concentration according to diagram proposed by the Takenouchi ranges from 10 to 20wt%. These facts suggest that tungsten mineralization may be related to the CO₂ content of the hydrothermal solution during the mineralizing period.