Gold-Silver Mineralization of the Geojae Area

경남거제지역 金-銀鑛床들은 후기 백악기 안산암류와 화강섬록암(83 m.y.)내의 열극을 충진한 含金-銀 熱水脈狀 광체로 구성된다. 熱水鑛化作用은 구조운동에 의하여 시기적으로 3회에 걸쳐 진행되었다. 초기 제 370℃의 고온에서 후기 200℃에 이르는 제 I, II 鑛化期에서는 각기 상이한 熱水系에 의하여 석영, 유화물이 침전하였으며, 320℃를 전후로 하여 鑛化流體의 沸膽현상이 일어났다. 제 I, II 鑛化作用시의 압력은 <100기압이고, 심도는 500~1,250m였다.

The electrum-silver-sulfide mineralization of the Geojae island area was deposited in three stages (I, II, and carbonate) of quartz and calcite veins that crosscut Late Cretaceous volcanic rocks and granodiorite(83 m.y.). Stages I and II were terminated by the onset of fractunng and breCCIation events. Fluid inclusion data suggest that the gold-sulfide-bearing stages I and II each evolved from an initial high temperature( near 370℃) to a later low temperature(near 200℃). Each of those stages represented a separate mineralizing system which cooled prior to the onset of the next stage. The relationship between homogenization temperature and salinity in stages I and II suggests a complex history of boiling, cooling and dilution. Evidence of boiling indicates a pressure of < 100 bars, corresponding to a depth of 500 to 1,250m assummg hthostatlc and hydrostatic pressure regimes, respectively.