Perpustakaan Digital ITB

Research location located in Kertajaya Village, Cigaru, Sukabumi, West Java, has so many active local gold mines until now. Gold mineralization in this area is part of Jampang complex, southern Bayah Dome and one of southern West Java gold mineralizations. The purposes of the research is to know the characteristic of gold mineralization based on vein samples, country rock samples, and tailing sample from amalgamation in local mine openings that got from field work. The thickness of Cigaru veins varies from 3 cm to 30 cm. Cigaru veins show N320E — N345E orientation and 75 — 90 dips. Ouartz veins show colloform and hydrothermal breccias textures. Main alteration minerals dominated are montmorilonite, illite, and clinochlore. Pyrite assemblage is abundant, and then base metal minerals dominated are chalcopyrite, sphalerite, tetrahedrite, galena, and covellite. All of minerals are found as coarse grain sized 100-500 um. Digenite and tennantite are minor minerals. In some samples, there are identified massicot, minium and gold. Gold is inditified as free grain and associated with other minerals, like pyrite and galena. Fluid inclusions result show two phases dominated (vapor and liguid). Homogenization temperature is 200C — 280C and salinity range from 0.2 to 0.8 wtYs NaCI eg. Based on those analysis, it is considered that mineralization in Cigaru area is divided into two arcas. The locations are the base metal Pb, Cut Zn mineralization and precious metal mineralization. Both of the mineralizations are epithermal low sulphidation system.