Identification of Lateritic Nickel Deposits Potential in the Kokoe Area, Kabaena Island, Central Buton Regency, Southeast Sulawesi Province, Indonesia

Abstract

The study is situated in the Kokoe Region of Central Buton Regency, Southeast Sulawesi, specifically in the southern part of Kabaena Island. Its primary objective is to assess the potential of nickel laterite in the designated area. The research methodology involved microscopic analysis of bedrock using a polarizing microscope, examining the drilling data, including logging descriptions, and utilizing XRF geochemical analysis (Ni, Fe, Al2O3, Co, Mg, and SiO2) from 32 drilling sites. Both elementary grade and laterite profiles were visualized using Strater 5 software to simplify the representation of laterite profiles. Petrographic analysis divided the bedrock into two lithological units: serpentinized lherzolite and serpentinite. The laterite profiles in the study area were classified into four types: type A, type B, type C, and type D. Type A profiles consist of bedrock, saprolite, and limonite layers covered by clay and colluvium. Type B profiles lack limonite and instead exhibit saprolitic rock and rocky saprolite layers on top of the bedrock. Type C profiles comprise bedrock, saprolitic rock, rocky saprolite, limonite, and topsoil layers. Type D profiles contain three zones, namely bedrock, colluvium, and clay, but lack limonite and saprolite layers. Among the four profile types, type A and type C profiles show promising potential due to higher average grades of Ni and thicker saprolite zones compared to the type B and type D profiles.