Abstract

Quartz veins from the Jukwangri area of Hwawon-myeon are epithermal quartz veins that are filling the NW or NE-trending faults within Precambrian metasedimentary rocks. Based on their prolongation and ore grades, No.1 quartz vein can be traced for about 200 m and varies 0.1 to 3 m in thickness. Mineralization of No.1 quartz vein can be divided into hypogene and supergene stages. Hypogene stage is associated with hydrothermal alteration minerals(phyllic and argillic zones) such as illite, sericite and sulfides such as pyrite, arsenopyrite, sphalerite, chalcopyrite, galena, argentian tetrahedrite. Supergene stage is composed of Fe-Mn oxide, Zn-Fe oxide and Pb oxide. Fluid inclusion data indicate that homogenization temperature and salinity of hypogene stage range from 187 to 306^oC and from 0.0 to 6.2 wt.% eq. NaCl, respectively. They suggest that ore forming fluids were progressively cooled and diluted from mixing with meteoric water. Oxygen(-4.1~4.1 ‰) and hydrogen(-107~-88 ‰) isotope compositions indicated that hydrothermal fluids were derived from meteoric and evolved by progressive mixing with meteoric water during mineralization.

Keywords Jukwangri area, quartz vein, mineralization, fluid inclusion, stable isotope