GEOLOGY AND STRUCTURAL CONTROL ON ALTERATION AND MINERALIZATION IN DOUP AND SURROUNDINGS AREA, KOTABUNAN SUB-DISTRICT, EAST BOLAANG MONGONDOW DISTRICT, NORTH SULAWESI PROVINCE

• Main Author: David Suhendi, Dirga
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/69651
• Institution: Institut Teknologi Bandung

The research area is located in Doup and surroundings area, Kotabunan Sub-District, Bolaang Mongondow Timur District, North Sulawesi Province. It’s located in PT. J Resources exploration area in Doup within an area of 7,5 km2 (3 x 2,5 km) and geographically located in 90750-93750 mU and 681500–684000 mT (UTM WGS84 51 N Zone). Lithotectonically, the research area is included in North Sulawesi magmatic arc. It has a lot of hills morphology which can be divided into 5 geomorphological units, that is Benteng Intrusion Hills Unit, Bakan Lava Flow Hills Unit, Tungow Folded Hills Unit, Batu Pinupul Intrusion Hill Unit, and Ongkobu Alluvium Plain Unit. Stratigraphy in research area consists of 10 main units from oldest to youngest, that is Calcareous Sandstone-Siltstone Unit, Hornblende-Pyroxene Andesite Intrusion Unit, Porphyry Andesite Intrusion Unit, Hornblende-Quartz Andesite Intrusion Unit, Microdiorite Intrusion Unit, Conglomerate-Sandstone Unit, Tuff Unit, Dacite Lava Unit, Pyroclastic Breccia Unit, and Alluvium Unit. The research area is an area which has phorpyry mineral deposit system overprinted by intermediate sulphidation system. It’s consists of 5 alteration zone, that is Potassic, Propylitic, Sub-Propylitic, Phyllic, and Argilic Zone. Alteration and mineralization in research area is controlled by NW-SE strike-slip faults which appeared because of North Sulawesi subduction and East Sangihe subduction.