Structural Geology and Mineralisation Controls in the Okene Iron Ore District, Kogi State

Iron ore mineralisation in the Okene District of Kogi State, North Central Nigeria, is structurally controlled by fold and fault systems developed during Precambrian orogenic events that concentrated magnetite and hematite ores within specific lithological and structural positions. This study investigates the structural controls on iron ore mineralisation in the Okene District through systematic structural geological mapping, geochemical sampling, and magnetic surveying. A detailed structural map was produced at a scale of 1:10,000, documenting fold axes, thrust surfaces, and ductile shear zones in relation to ore body outcrops. Ore channel samples collected at systematic intervals across documented ore bodies were analysed by X-ray fluorescence for total iron, alumina, silica, phosphorus, sulphur, and manganese to characterise ore grade variability. Ground magnetic surveys along profiles crossing identified ore lenses were used to extend structural interpretation into poorly exposed terrain. The study evaluates the spatial association between ore body plunges and fold hinge zones, interpreting this relationship in the context of tectonically controlled hydrothermal fluid focusing. A three-dimensional structural model incorporating surface mapping, magnetic data, and available drill hole information is presented to guide future resource definition drilling by the National Iron Ore Mining Company. Keywords: structural geology, iron ore, Okene District, Kogi State, mineralisation controls.