Abstrak 
Arinem Gold And Basemetal Mineralization West Java Indonesia
E. T. Yuningsih, H. Matsueda, E.P. Setyaraharja, M.F. Rosana
Universitas Padjadjaran, Proceedings PIT IAGI Lombok 2010 The 39th IAGI Annual Convention And Exhibition
Inggris
Universitas Padjadjaran, Proceedings PIT IAGI Lombok 2010 The 39th IAGI Annual Convention And Exhibition
Arinem, electrum, enargite, fluid inclusion., hessite, quartz vein, sulphide, tennantite
Arinem area is located at the south of Mt. Papandayan active volcano at western Java, Indonesia. The main mineralization in the area is represented by Arinem vein zone with total length about 5,900m, including unexposed vein zone at the south. The host rocks of mineralization consist of volcanic rock groups such as tuff, tuffaceous breccia and andesitic lava of Jampang Formation. The volcanic host rock suffered of propylitic and argillic alteration and they are characterized by the occurrences of chlorite, sericite, kaolinite, smectite and in place by carbonate. The mineralized quartz vein has colloform, crustiform, comb, vuggy, massive and brecciated textures and some of bladed quartz also observed. Outcrop and drill holes data indicate that the occurrences of gold-silver is intimately associated with basemetal minerals of copper, lead and zinc. Three stages of mineralization was recognized as vuggy-massivecrystalline quartz-sulfide, banded-brecciated sulphide-quartz and massive-crystalline barren quartz. The ore mineral assemblage of the deposit consists of sphalerite, galena, chalcopyrite, pyrite, marcasite, arsenopyrite with little amount of pyrrhotite, argentite, electrum, chalcocite, hematite, bornite, covellite, hessite, tetradymite, altaite, petzite, stutzite, enargite and tennantite. The results of measurements from primary fluid inclusions in quartz from different level indicate that homogenization temperatures at stage I is in range of 176.6-325.1ºC, stage II is 156.9-311.8ºC and stage III is 165.1-236.1ºC. Measurement from sphalerite and calcite from substage IIA and IIIB give a results of 152.7-218.0ºC and 140.4-217.1ºC, respectively. The salinities of fluid inclusions in quartz, sphalerite and calcite determined by freezing point measurements are less than 4.34 wt% NaCl equiv.. So far, Raman spectroscopic analyses of CO, H2S and CH4 performed on selected fluid inclusions, detected no volatile component other than HO. Based on the K-Ar dating on hydrothermal sericite associated with quartz vein the age of mineralization is around 8.8 ± 0.3 Ma.