Pustaka Ilmiah Universitas Padjadjaran

Abstrak

Hydrothermal gold mineralization in island arc environment: case study in Western Java, Indonesia

Western Java area occupies a part of Sunda Banda magmatic belt. and is well known for the prevailed hydrothermal gold mineralizations where active gold mines of the Gunung Pongkor. and Cibaliung and formerly produced mines of the Cikidang the Cirotan and the Cikotok are located. And several other areas are under exploration such as Arinem, Cineam, Cipunagara, Ciemas and Gunung Subang. Hydrothermal gold ore deposits of western Java are mainly distributed along the NNE-SSW strike-slip faults cutting Miocene to Pliocene volcanic and plutonic formations. The ore veins are hosted mainly in calc-alkaline andesitic and dacitic volcanic breccia and tuff, less commonly in limestone, sandstone, claystone and microdiorite intrusive. Pervasive hydrothermal wall rock alterations are well developed in the mineralized area An intensive silicic, propylitic and argillic alterations are generally observed in the most of deposits, indicated by chlorite/smectite and/or illite/smectite, epidote, sericite, kaolinite and locally montmorillonite.