STUDY OF THE DISTRIBUTION OF BRAVO ROMEO'S PIT NICKEL ORE IN LALOMERUI, ROUTA, KONAWE, SOUTHEAST SULAWESI

• Main Author: Hotman Marnaek Samosir, Daniel
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/78867
• Institution: Institut Teknologi Bandung

Indonesia is a country with a tropical climate, where climate is an important factor in determining the level of chemical weathering. This chemical weathering will play a direct role in the formation of laterite nickel ore. Indonesia is also one of the world's largest reserves of nickel (Ni) laterite ore. Sulawesi itself is an area that has large potential for laterite nickel ore in Indonesia. This is due to the control of morphology, bedrock and geological structure which are important factors in the formation of good laterite nickel ore. In the Lalomerui area, there is still little research regarding geological control of the formation of laterite nickel ore. Therefore, research on the distribution of laterite nickel ore in the Lalomerui Area is needed. This research aims to determine the zoning characteristics of laterite nickel deposits and the distribution of ore in the research area and determine the controlling factors for the distribution of laterite nickel ore in the research area. The data used is primary data in the form of 5 rock samples and petrographic and geological structures in the form of 35 joints. Apart from that, there is secondary data in the form of geochemical data from 121 drill points, drill core photos from 1 drill point, Digital Elevation Model (DEM), and geological maps. Based on analysis of the characteristics of laterite nickel deposits, the laterite profile is divided into limonite, saprolite and bedrock zones. The Ni element in laterite nickel deposits is enriched in the saprolite zone and leaching occurs in the limonite layer. The elements Fe, Al, Co, Cr, and Mn experience residual enrichment in the limonite layer. The elements Si and Mg experienced leaching from the bedrock to limonite and there was deposition of silica in the limonite to saprolite zone at several points. In addition, the research area is dominated by medium grade limonite ore and high grade saprolite ore. Ore thickness was dominated by ore thickness above 12 m and 2 drill points were found that did not contain ore out of 121 drill points. The topographic formation of the research area based on slope slope is divided into flat slope, slight slope, intermediate slope and ridge. The analysis results show that the highest ore thickness is at the ridge, while the relationship between morphology and Ni content of the ore shows less significant results. The bedrock in the research area has a less significant correlation with the Ni content of the ore in the research area, which is possibly that the types of both bedrock are actually the same. In addition, the influence of the serpentinization level which is dominated by mediumhigh serpentinization levels results in less significant control of the bedrock on the Ni content of the ore. The structure in the research area is thick and there are indications of a reverse fault (N 142o E/85). The area around the thrust fault in the central part of the study area has quite high levels of Ni ore. The fault structure also influences the elevation of the bedrock.