KARAKTERISTIK MINERALISASI ENDAPAN EMAS DAERAH TATELU, MINAHASA UTARA
Abstract
The research area of Tatelu, North Minahasa is located in the eastern part of north arm Sulawesi island. This area is a part of the North Sulawesi magmatic belts hosting potential ideal condition for occurrence of hydrothermal ore deposits. This study is aimed to identify geological condition that controlled vein-quartz mineralization pyrite, chalcopyrite, and magnetite mineralogy characteristic, and geochemical rocks induced the mineralization process. The methods applied in this research consists of petrographic analysis to identify microscopic lithology and hydrothermal alteration minerals, ore microscopy to identify types of ore minerals, ore geochemistry to determine elementals content and its correlation. Petrographic analysis indicated the lithology mainly composed by three main lithology; tuff, andesite, and breccia. Vein texture is mainly massive chalcedonic, crustiform, colloform and saccharoidal. Ore geochemistry shows base metal value relatively low: 1-20 ppm (Cu), 3-51 ppm (Pb), 4-101 ppm (Zn). Besides the base metal, the occurrence of precious metal indicated by various value of Au (1-35,50 ppm) and Ag (1-13 ppm). Au contents tend to have similar or increase trend if compare to Ag content. Identification and characterization of ore minerals show the presence of magnetite, hematite, chalcopyrite, and pyrite. Based on the characteristic of lithology, alteration, vein quartz, mineralogy and ore geochemistry, the mineralization in the research area is classified as a low-sulfidation epithermal.
Key words: Alteration, Mineralization, Tatelu
KARAKTERISTIK MINERALISASI ENDAPAN EMAS DAERAH TATELU, MINAHASA UTARA