Identification of nickeliferous laterite zone thickness distribution based on satellite gravity and coring data: A case study in Morowali Regency, Central Sulawesi, Indonesia

Geophysical exploration can be performed efficiently using open-source satellite data. This research used GGMPlus2013 satellite gravity data for nickeliferous laterite exploration in Morowali Regency. Processed and analysed satellite gravity data generated a residual gravity anomaly map that could be compared with the nickeliferous laterite thickness distribution map produced by coring data. Thinner nickeliferous laterite distributions (< 13 meter) are associated with higher gravity anomaly values ranging from 0 to 1.2 mGal. Thicker nickeliferous laterite distributions (15.5 to 32.7 meter) are associated with lower gravity anomaly values ranging from -1 to 0 mGal. The composition of low-density mineral, 1.6 gr/cc for limonite and 1.9 gr/cc for saprolite influence the lower gravity anomaly values of nickeliferous laterite. This approach of using open-source data could be expanded with other open-source data such as satellite geomagnetic, topography, and other remote sensing data for initial identification of mineral distribution or structure before in-site measurements being conducted.