屯田金鑛山 南鑛床의 鑛石과 流體包有物

Ores and Fluid Inclusions from South Ore Deposits of the Dunjeon Gold Mine

The south ore deposits of the Dunjeon gold mine is a fissure-filling vein emplaced in the granitoids, skarnized and hornfelsified rocks of Ordovician Dumudong formation. The vein mineral paragenesis is complicated by repeated fracturing but three distinct depositional stages can be recognized; (1) base metal sulfides stage, (2) base metal sulfides, antimony-bismuthsulfosalts and native metals stage, (3) barren carbonates stage. Gold was mainly deposited in stage II. Fluid inclusion data indicate that fluid temperatures were from 310℃ to 402℃ during stage I and then declined steadily to 148℃ in the closing late stage III. Salinities were in the range of 0.4 to 5.0 equivalent weight percent NaCl and do not reveals any systematic trend through stag I, II and III. Ore mineralogy suggests that temperatures and sulfur fugacities in the earlier stage II were in the range of 340℃ to 360℃, 10⁻⁸ to 10⁻⁹ atm. respectively and then declined steadily to the range of 185℃ to 200℃ and 10⁻¹⁷ to 10⁻¹⁹atm. in the later stage II.