노화납석광산에서 산출되는 명반석대에 대한 지구화학적 연구

A geochemical study on the alunite zone of the Nohwa pyrophyllite deposits

Ores of the Nohwa Pyrophyllite Deposits are composed mainly of pyrophyllite, kaolinite (dickite), quartz, pyrite, alunite and diaspore, etc. Alunite ore zone is located in the middle-lower parts of the deposits. Alunite ore zone with thickness of 20~30 cm is divided into two parts according to alunite contents: reddish and white greyish zone in the upper and lower parts, respectively. And the reddish alunitic ore has higher contents Al₂O₃, K₂O, Na₂O and Ig. loss than the white greyish alunitic ore. Perhaps alunitization of the deposits occurred in the vicinity of paleo-ground water table. EPMA data shows that sodium replaces potassium considerably in alunite structures and that the hydrothermal solution probably contains considerable amounts of sodium.