SUBSURFACE IMAGING OF SOME PARTS OF AGO-IWOYE USING GEOPHYSICAL MAGNETIC METHOD

Abstract

Near Surface characterization of some parts of Ago-Iwoye was carried out using magnetic method with the aim of evaluating the magnetic depth variation to basement rock and geologic structures and lineament. Magnetic data survey was carried using a Magnetometer on a lateral and horizontal spacing, starting at a base point and intervals of 10m. The coordinate of each point was obtained with the aid of a digital GPS. The acquired data was processed using OASIS Montaj with view to obtain the Total Magnetics Intensity (TMI), Reduction to Magnetic Equator (RTE), Source Parameter Imaging (SPI), Analytic Signal (AS) and Total Horizontal Derivative (THDR). The result shows that the amplitude of total magnetic strength obtained ranges from - 541.3 nT to 493.4 nT depicting low and high magnetic points respectively. The RTE Map corroborated that the amplitude of the magnetic intensity ranges from -353.2 nT to 488.3 nT describing the study area with varying magnetic intensity. This shows that geologic lineament and structures were delineated within the area which trends NW-SE, NE-SW and EW-NS. The imaging obtained from SPI showed clear variation to the magnetics basement within the area. These areas are associated with low magnetic and high magnetics basement. Different fault lines were unraveled in the study area which are capable to be groundwater recharge channel thereby producing high yield of groundwater. The study area is found to be rich in rock minerals for future exploitation. The study suggests further investigation in the area to obtain the bulk density of the rock minerals. Also this act will assist further elucidation of the geotechnical properties of the area for future engineering construction. However, the study has established the basic information about the area for the miners, building engineers and academic environment