Analysis of Heavy Mineral Placer Deposits Along the Coastline of Ondo State, South West Nigeria

Coastal placer deposits hosting heavy minerals including ilmenite, rutile, zircon, and monazite represent potential valuable resources along the Atlantic coastline of Ondo State, South West Nigeria, yet their economic viability has not been evaluated using modern resource estimation methods. This study analyses the distribution, grade, and economic potential of heavy mineral placer deposits along a 60-kilometre coastal segment of Ondo State. A systematic sampling programme was conducted using hand auger and vibrocoring equipment at 200-metre intervals along shore-parallel transects at three distances from the shoreline. Heavy mineral concentrate recovery was assessed by panning, and individual mineral proportions determined by automated mineralogy. Chemical analysis of zircon and monazite separates assessed rare earth element and radioactive element content for regulatory classification. Resource estimation using indicator kriging provided grade and tonnage estimates at multiple cut-off grades. Results indicate economically significant concentrations of ilmenite averaging 4.2 percent and zircon averaging 0.8 percent in heavy mineral concentrate within a 15-kilometre coastal segment, with total heavy mineral resource estimated at 18 million tonnes above 1.5 percent total heavy mineral cut-off. Radioactive thorium content in monazite fractions requires special licence considerations under the Nigerian Nuclear Regulatory Authority framework. This research provides a resource development-ready dataset and identifies regulatory requirements for project advancement. Keywords: heavy mineral placer, coastal deposits, Ondo State, resource estimation, ilmenite.