Browsing by Author "Lawal, T.O."

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    Estimation of Depth to Magnetic Sources Using Gradient Inversion Method: A Case of Aeromagnetic Field of Binji, North-Western Nigeria
    (Al-Hikmah Journal of Pure & Applied Sciences, 2016-09-01) Nwankwo, L.I.; Akinmadeyan, O.C.; Lawal, T.O.; Ige, S.O; Saleh, A.
    The depth to magnetic sources has been estimated from gradient inversion analysis of the acquired aeromagnetic magnetic data of Binji, north-western Nigeria. The study area is bounded by Longitude 4° 30’ E and 5° E and Latitude 13° N and 13°30’ N. The total magnetic field was separated into regional and residual fields using least squares polynomial fit, while twenty two (22) profiles of the residual magnetic fields were subsequently used to determine depth to magnetic sources. The depths vary from 0.22 km to 2.19 km with an average of 1.26 km. Since estimation of depth to magnetic sources is also regarded as a proxy for sedimentary thickness; the results showed that the sedimentary layer is not thick enough for hydrocarbon prospect and therefore confirm that petroleum exploration may not be plausible in the study area.
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    Geophysical Investigation of Groundwater Contamination in a Solid Waste Disposal Site
    (Al-Hikmah Journal of Pure & Applied Sciences, 2017-07-26) Lawal, T.O.; Orosun, M.M.; Ige, S.O.; Sunday, J.A.; Shehu, A.T.; Bello, S.A.; Nwankwo, L.I.
    A geophysical investigation of groundwater contamination within the solid waste disposal site was carried out at Tanke Tipper Garage, a typical non-controlled open dumpsite located in Ilorin, Nigeria. The aim of the investigation is to study the spatial distribution of contaminant plumes in the groundwater and ascertain if areas that can be free from contaminants are available in the study area. In view of this, four (4) vertical electrical soundings (VES) methods employing Half Schlumberger electrode array were conducted due to limited space in the area with maximum electrode spacing of 50 m. The field data were processed and Interpreted Resistivities Values were obtained by iterative computer modeling of the apparent resistivity data. The interpreted resistivity value showed that contaminant plumes at low zones with values ranging between 30.2 and 81.5 ohm-m extending from the surface down to the aquifer of shallow groundwater of less than 15 m. The hydraulic conductivity of the subsurface layers of interpreted VES points was also calculated and values ranging between 0.076 m/s and 0.418 m/s were obtained respectively. In order to complement the result of geophysical data, a physiochemical analysis of water samples from the existing hand dug well within the premises of the dumpsite was also conducted and high values of measured parameters were observed. This is an indication of groundwater contamination resulting from the solid waste leachate accretion found within the shallow aquifer zones.