Investigation of Magnetic Anomalies and Depth to Magnetic Sources Over Igboho Area Using High Resolution Aeromagnetic Data
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Abstract
The availability of geophysical Information about the presence of magnetic minerals can further showcase the location and depth of suspected minerals, the use of aeromagnetic data over a study area for Investigation of magnetic mineral can provide more information about subsurface geology of the area. Aeromagnetic dataset of Igboho acquired from the Nigeria Geological Survey Agency (NGSA), was processed to map out the geological structures of the area and determine the basement depth to magnetic sources in the study area. Regional correction based on the IGRF value of the study area was carried out on the Total Magnetic Field Intensity (TMFI) values which generates the residual map of the study area. The magnetic enhancement filters including Reduction to Magnetic Equator (RTME), Analytic Signal Amplitude (ASA), and Total Horizontal Derivative (THDR) were further applied to residual total magnetic field intensity data so as to further define the lithological boundaries and magnetic structure locations. This is followed by determination of basement depth to magnetic sources using Euler deconvolution (ED) and Source Parameter Imaging (SPI) techniques. The results of the RTME map generates magnetic anomalies’ amplitude ranging from -37.577 nT to 27.398 nT, the northwest, southeast through southern part of the study area are dominated by high magnetic anomaly. However the definite lithological boundaries and geological structures result generated from THDR is similar to the one obtained from ASA technique. The structural trends observed were in NW, NS and SW directions. The SPI results shows 126.383 m as the shallowest depth to basement magnetic anomalous structures and 1834.659 m for the deepest depth to basement magnetic structures with calculated average depth of 981 m. The results of the Euler Deconvolution shows an undulating structural basement with estimated depth between -474.253 m and 1266. 027 m. The results also suggested the basement relief of...
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