GEOLOGY, ALTERATION, AND MINERALIZATION OF LUNYUK AREA, SUMBAWA REGENCY, WEST NUSA TENGGARA

• Main Author: Faisal , Dendi
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/26476
• Institution: Institut Teknologi Bandung

The research area is located in Lunyuk Area, Sumbawa Regency, West Nusa Tenggara Province with area 51.48 km2. It is located in 8°54’19” S-8°57’54” S and 117°11’14” E-117°15’23” E. This area belongs to PT Aneka Tambang, Tbk. The objectives of this research are to study the geological arrangement, characteristic of rock alteration, and type of mineralization in Lunyuk area. Geomorphologically, this study area consists of volcanic denudational hills, volcanic denudational plain, lava domes, intrusion hill, pyroclastic flow plain, and alluvial plain that were controlled by structural geology. Geologically, the study area consists of Pyroclastic Breccia Unit, Tuff Unit, Diopside Andesite Lava Unit, Dasite Lava Unit 1, Augite Andesite Lava Unit, Dacite Lava Unit 2, Reef Limestone Unit, Diorite Intrusion Unit, and Alluvium Unit. Structures geology in this area are northwest-southeast and northeast-southwest lateral fault because deformation that cut trough all lithology. Hydrothermal alteration in this research area have weak until strong intensity with alteration zone are Vuggy Quartz ± Kaolinite ± Dickite Alteration Zone, Kaolinite - Dickite Alteration Zone, Chlorite - Smectit ± Epidote Alteration Zone, and Biotite - K-feldspar - Chlorite ± Epidote Alteration Zone. Mineralization of research area consists of enargite, pyrite, chalcopyrite, covelite, bornite, and magnetite which indicate epithermal high sulfidation and porhyry copper system that were controlled by lithology type and structural geology. Potential area of high epithermal sulfidation mineralization occured on Plara and potential area of porphyry copper mineralization occured on Loak River and Batumonyok River.