ESTIMATION OF THE MAGNETIC DEPTH FROM QUANTITATIVE INTERPRETATION OF AEROMAGNETIC ANOMALY OVER ILORIN, NORTHCENTRAL NIGERIA

Total field aeromagnetic anomalies over Ilorin (bounded by longitude 4030’- 5030’ E and latitude 80 - 8030’ N) have been interpreted using Fast Fourier Transform method in order to estimate the sedimentary thickness. Aeromagnetic data of the area (sheet 223) were acquired, digitized and analyzed. The result obtained reveals two depth sources in the study area: the depth to the shallow magnetic sources which is averagely 0.415 km and the depth to the deeper magnetic sources which is averagely 1.294 km. These depths are relatively shallow; hence, hydrocarbon exploration is not recommended in the area owing to the low thickness of sediment on the average. The shallower sources are probably due to the presence of igneous intrusives and/or magnetized bodies within the sedimentary cover. The lithology of the basement structure was also modelled in contour and 3D surface map. All deductions made from this study were reached after due consideration of the quantitative interpretations supported by geological information of the area.