Ground Magnetic Survey for the Investigation of Iron Ore Deposit at Oke-Aro in Iseyin East, South-Western Nigeria

Abstract

A ground magnetic survey was carried out to investigate the presence of iron ore at a location (Lat. 7.99883°N to Lat. 7.99933°N, Long. 3.57900°E to Long. 3.57990°E) in Iseyin, Oyo State, South-western Nigeria. Ten magnetic traverses each 100 m long at a separation of 5 m were run West-East. Magnetic intensity was taken at intervals of 10 m along each traverse line using the proton precession magnetometer (G-856 AX). The measured magnetic field data were corrected for drift and were presented as profiles. The profiles were interpreted by calculating the depth to the top of anomalies. The data obtained were used to construct magnetic anomaly maps in 2D and 3D. The magnetic survey results delineated this location into some high and low magnetic field intensity regions. The regions of high magnetic field anomaly indicated the presence of materials with high susceptibility which was suspected to be iron compounds. The quantitative and qualitative analyses on interpretations of field data collected were given, while these results provided values for the total component measurements of ground magnetic anomaly that widely ranged between a maximum positive peak result of 8 nT and to a minimum negative peak result of —6 nT. Using Peter’s half slope technique, depth to the basement was assessed, which actually provided a maximum depth to basement of 6.25 m. From the knowledge of the geology of the area and also, the magnetic survey employed information, therefore, we can finally conclude that, the study area is under laid by geologic structures which favour the accumulation of iron-ore minerals deposit at Oke-Aro area in Iseyin.