Geology and hydrothermal alteration in cibeber prospect, Banten: A preliminary study on Au-Ag-base metal sulfide deposit

The research area is located in Neglasari, Cibeber, Lebak, Banten. As we know that western Java has a big potential in mineral deposits especially epithermal deposits and one of them was found in this studied area. This study aims to understand the geological and hydrothermal alteration as well as the mineralization characteristic in studied area. Surface geological mapping is used to know the geological condition including lithologies and structural geology also hydrothermal alteration distribution. Five representative ore vein samples were analyzed using FA-AAS method to determine the grade of precious and base metal contents. The lithologies found in this area can be divided into 3 unit stratigraphically that is sandstone unit, tuff breccia unit and andesitic lava unit while the structural geology are strike slip fault, normal fault and some joints. There are 4 alteration zone that is silification zone, clay-silica zone, clay zone and chlorite-epidote zone. The mineralization mostly found as hydrothermal veins which can be divided into two type that is precious metal bearing vein or usually called as low sulfidation type and base metal bearing vein or usually called as intermediate sulfidation.