Journal of the Korean Society of Mineral and Energy Resources Engineers ISSN:2288-0291(Print) 2288-2790(Online) 한국자원공학회지

Within the Boseong-Jangheung area of Chollanamdo-Province, several hydrothermal gold-silver quartz vein deposits occur. They have the characteristic features as follows : the gold-rich nature of electrums; the absence of Ag-Sb(-As) sulfosalt mineral; the massive and simple mineralogy of veins. They suggest that gold mineralization in this area is correlated with Jurassic to Early Cretaceous, mesothermal to hypothermal gold deposits in South Korea. Fluid inclusion data show that primary fluid inclusions in stage I quartz from all mines homogenize over a wide temperature range of 200o to 460oC with estimated salinities of 0.0 to 13.8 equiv. wt. NaCl. The homogenization temperature of primary fluid inclusions in stage II calcite ranges from 150o to 254oC with salinities of 1.2 to 7.9 equiv. wt. NaCl. This indicates a cooling of the hydrothermal fluid with time towards the waning of hydrothermal activity. Evidence of fluid boiling accompanying CO2 effervescence may indicate that pressures during entrapment of auriferous fluids in this area ranges from 90 to 770 bars. Calculated sulfur isotope composition of auriferous fluids (d34SSS = 0.2~3.3‰) may indicate an igneous source of sulfur in hydrothermal fluids.