One important factor that influences the optimization of the formation of nickel laterite deposits is the slope of a region's topography. The Mangguruh area in Sebuku Island in South Kalimantan is composed of ultramafic rocks on a gently flat topography but forms laterite deposits of varying thickness. Based on the exploration data from 33 drilling points and field data acquisition, this study aims to: 1) create topographic slope groups with varying ranges to determine the range most suited to real conditions in the field, 2) determine the laterite thickness, 3) analyze the concentration of Ni and Fe in limonite and saprolite layers, 4) analyze the effect of topographic slope to the laterite thickness. The method used is the measurement of topographic slope in the field with compass and using ArcGIS software applications in preparing the maps, analyzing laterite profiles from the drilling data and sampling rocks and ores. The study performed a laboratory analysis consisting of petrographic analysis and X-ray Fluorescence testing of the elements. The result revealed that the appropriate topographic slope groups in the study area were 0-5%, 5-10%, 10-15% and ≥ 15%. The laterite thickness of > 10m lied on the slope of 0-5% and 5-10% and contains a moderate-high nickel content of 1.2% -> 1.4%. This indicates that laterite nickel enrichment is influenced by topography. While the distribution of iron ore with medium and high levels of concentration (45-50% and > 50%) has commonly occurred in each topographic slope group indicating that topography is less influential on the distribution of iron ore. Earlier research has indicated that effect of topography on different morphologies is clear and many of the studies were conducted on a regional scale, but interestingly in Sebuku area, the topography is gently flat but the thickness and nickel content is varied. So the results of this study can be applied to slightly flat slope areas and therefore needs more detailed mapping.

The profile of laterite nickel deposits following mining operations can be determined using a geoelectric method, which is crucial information for exploration as well as sustainability. The purpose of this research is to ascertain the physical properties and thickness profile of laterite nickel deposits in the subsurface following mining. The geoelectric method used is resistivity to map variations in the apparent resistivity values of rocks. This value reflects the different types of rock layers in the subsurface. Through the use of two electrodes, an electric current was introduced into the earth, and the potential difference that resulted from this injection was then measured. Based on the configuration of the electrodes utilized, the apparent resistivity value can be determined. The profile of laterite nickel deposits in the Motui post-mining area includes three layers, red limonite, yellow limonite, and bedrock, with resistivity values ranging from 17.0 to 1572 Ωm. The resistivity of the red limonite layer ranges from 17.0 to 1572 Ωm, and its depth is 0 to 10 meters. The yellow limonite layer is between 10 and 20 meters thick and has a resistivity range of 17.0 to 31.8 m. The resistivity of bedrock, on the other hand, ranges from 84.2 to 1572 Ωm at depths between 20 and 70 meters.

The research conducted in the Lapaopao area focuses on analyzing the process of serpentinization in ultramafic rocks and its impact on the formation of nickel laterite. Ultrabasic rocks containing olivine and pyroxene minerals undergo hydrothermal metamorphism, resulting in the formation of serpentine minerals. The research purposed to understand effect of serpentinization process to development of nickel laterite. Various samples were taken on location to see the correlation in both the Lapaopao sub-block and Babarina sub-block. There are two (2) types of samples were taken, including fresh rock (bedrock samples) and laterite samples (limonite and saprolite material). All samples were analyzed using methods such as XRF, thin section, and XRD. Bedrock samples were analyzed using the thin section method, while laterite samples (limonite and saprolite) were analyzed using XRF and X-RD analyzing methods. The serpentinization process in the Babarina sub-block is generally medium to high level, while in the Lapaopao sub-block low to moderate level. The enrichment of nickel (Ni) in the supergene zone is dominantly influenced by Ni’s ability to replace magnesium (Mg) in weathered serpentine minerals.

This study aims to determine the characteristics of hydrothermal alteration and the mineralization of sulfide deposits in the Sasak area. The method used is field research which includes observations of lithology, geomorphology, and geological structures and subsurface data collection with geomagnetic and polarization induction (IP), laboratory analysis methods in the form of petrographic, mineragraphy, AAS, and Fire Assay. The alteration characteristics start from strong intense potassic, argillic, and intense silicification to strong intense prophylitic. The mineralization is sulfide consisting of galena (PbS), sphalerite (ZnS), chalcopyrite (CuFeS2), and covellite (CuS) as well as a small amount of chalcocite (CuS2). Limonite, magnetite, and quartz are the dominant accompanying minerals, while gold-silver (Au-Ag) tends to be associated with limonite or quartz. Covellite tends to exist on the surface of chalcopyrite. Galena, sphalerite, chalcopyrite, and covellite are complexly bound to pyrite minerals or between the three minerals in fine sizes, there is even superfine galena as inclusions in pyrite. Based on the characteristics of alteration and mineralization indicates a porphyry-type deposit.

The mining sector is a vital component of the Indonesian economy. Nickel laterite mining operations result in the discharge of metals such as iron (Fe), nickel (Ni), and chromium (Cr) into the surrounding environment. This has serious consequences for the environment and the health of the local population. The geomedical evaluation study was conducted by combining the ISFAR DEM mapping method, metal measurements in the air through gravimetric tests and sediment measurements with AAS tests and an integrated public health factor determinant survey. This was achieved by conducting observations with validated instruments on 99 respondents with 10% precision. The observation data was then analysed using correlation ( X ² ) and risk magnitude (OR) tests in the South Konawe Regency. The study’s findings indicated that the Laeya District area is characterised by silicic rock formations spanning from the Middle Miocene to the Late Miocene periods. The study also reported PM 2.5 dust measurements of 56.7 µ g/m ³ and PM 10 levels of 79.9 µ g/m ³ , both of which exceed the established threshold value. Meanwhile, the results of the odds ratio statistical test demonstrated that the presence of mining variables resulted in a risk magnitude of 7.643 times greater than other variables for the occurrence of ARI. Tinanggea District, which is located in the ultramafic complex area and young alluvial sedimentary rocks, showed that the results of the inlet and outlet sediment examination were below the threshold value, with the odds ratio statistical test showing that consumption patterns had a risk magnitude of 6.218 times greater than other variables for the occurrence of diarrhea. The study’s findings demonstrate a significant correlation between mining activities in specific geographical regions and an elevated risk of acute respiratory infections (ARI) and diarrhea. This observation underscores the necessity for government policies aimed at mitigating dust exposure and sediment pollution in areas dedicated to laterite nickel mining.