The geophysical analysis and interpretation of magnetic data to characterize subsurface has been on the increase with Peter’s half slope method being one of the earliest quantitative techniques of depth determination. This was used with varying structural indices of 1.2, 1.6 and 2.0 on a digitized aeromagnetic map for Ogbomoso area with sheet number 221 within longitudes 4000/ E and 4030/E and latitudes 8000/ N and 8030/ N, covering the total area of 55 km by 55 km (3025 km2). The data was gridded and delineated into profiles at 100 m interval. Filtering process was applied to remove the regional gradient and other possible magnetic noises, subsequently various geological bodies’ size and depth to the top of the magnetic source were calculated. The result of the selected profiles revealed different ranges of depth depending on the basement indicator considered. The depth range are 750 m-2333.3 m for very thin body, 562.5 m -1750.0 m for Intermediate thickness, and 450 m – 1400 m for very thick body respectively.The overall result from all the analyses indicate the presence of magnetic mineral resources in the locality which spread across the surveyed region of the earth crust.
