Papers by Nurudeen Olasunkanmi
Journal of the Nigerian Society of Physical Sciences, Apr 21, 2024
This study explores the extent of leachate contamination and groundwater vulnerability in urban d... more This study explores the extent of leachate contamination and groundwater vulnerability in urban dumpsites, with a specific focus on the Ipata area in Ilorin, Nigeria. The study employs a combination of 2D Electrical Resistivity Tomography (ERT), soil classification, and physicochemical analyses to investigate the percolation of leachate into groundwater and its potential environmental and health implications. The ERT data unveiled subsurface layers, highlighting the presence of decomposed topsoil down to approximately 1.2m. Beneath this layer, a low-resistivity zone (6.53 to 10.7 Ωm) indicated the potential risk of leachate percolation into groundwater. Soil classification revealed a shallow topsoil layer with insufficient clay content to hinder leachate penetration, emphasizing the need for enhanced containment measures. Physicochemical analysis of leachate, well water, and soil displayed variations in key parameters such as pH, electrical conductivity, total dissolved solids, and anion concentrations. Leachate exhibited high pH and electrical conductivity, suggesting elevated total dissolved solids, while well water remained within acceptable pH limits for drinking water. Heavy metal concentrations exceeded permissible WHO limits in topsoil, leachate, and well water, with cadmium presenting a high ecological risk. The absence of persistent organic pollutants (POPs) in the samples indicates a current focus on heavy metals as a primary concern. In conclusion, this study underscores the urgent need for proactive pollution abatement measures in urban dumpsites like Ipata. Regular monitoring of surface and groundwater quality is essential to safeguard public health and the environment.
International Letters of Natural Sciences, Oct 27, 2013
The results of a magnetic study of the Okenugbo Area of Ago-Iwoye, Southwestern Nigeria are prese... more The results of a magnetic study of the Okenugbo Area of Ago-Iwoye, Southwestern Nigeria are presented for the evaluation of the geostructural settings in the area to determine the competency of the basement for building constructions. The study area lies within Longitude N 06°55.389̕-N 06°55.384̕ and Latitude E 003°55.001̕ and E 003°54.959̕ in the basement complex of Nigeria. Three magnetic profiles were established for the evaluation and the magnetic anomaly map, the regional geology and its analytic signal amplitude helped in identifying the nature and depth of the magnetic sources in the study region. The magnetic residual values range from-2400 nT to +1800 nT. The area shows magnetic closures of various sizes at the Western part of the study area trending West with prominence at the center and distributed East-West which has been interpreted as fractured or faulted zones. The depth estimate revealed the apparent depth to the causative body from the surface and the basement depth range from 4.3 to 21.3 m which agrees with other literatures. The study has revealed that the area is generally competent for high rise structures and industrial site while the faulted/fractured zones are prospective better locations for hydrogeological purposes.
Academic Journal of Interdisciplinary Studies, Oct 1, 2013
The results of a magnetic study of the Okenugbo Area of Ago-Iwoye, Southwestern Nigeria are prese... more The results of a magnetic study of the Okenugbo Area of Ago-Iwoye, Southwestern Nigeria are presented for the evaluation of the geostructural settings in the area to determine the competency of the basement for building constructions. The study area lies within Longitude N 06°55.389̕-N 06°55.384̕ and Latitude E 003°55.001̕ and E 003°54.959̕ in the basement complex of Nigeria. Three magnetic profiles were established for the evaluation and the magnetic anomaly map, the regional geology and its analytic signal amplitude helped in identifying the nature and depth of the magnetic sources in the study region. The magnetic residual values range from-2400 nT to +1800 nT. The area shows magnetic closures of various sizes at the Western part of the study area trending West with prominence at the center and distributed East-West which has been interpreted as fractured or faulted zones. The depth estimate revealed the apparent depth to the causative body from the surface and the basement depth range from 4.3 to 21.3 m which agrees with other literatures. The study has revealed that the area is generally competent for high rise structures and industrial site while the faulted/fractured zones are prospective better locations for hydrogeological purposes.
Journal of Nigerian Society of Physical Sciences, May 2, 2023
Thermo-electric (TE) material applications reduce reliance on traditional energy resources by con... more Thermo-electric (TE) material applications reduce reliance on traditional energy resources by converting heat to electric energy. We have studied, for the first time, the thermo-electric properties of Rb 2 SeX 6 (X Br,Cl). Using norm-conserving pseudo potentials in a plane wave basis set of Quantum Espresso code, the optoelectronic, elastic and thermo-electric properties of Rb 2 SeX 6 (X Br,Cl) have been investigated using density functional theory. Generalized Gradient Approximation of Perdew Burke Ernzerhof (GGA-PBE) and Generalized Gradient Approximation of Perdew Burke Ernzerhof adapted for Solid (GGA-PBESol) exchange correlation functionals were employed in all calculations. The band structure plots suggest that the studied double perovskites have indirect band gaps. Rb 2 SeBr 6 band gap values of 1.7574/ 1.569 eV (using GGA-PBE/PBEsol) are remarkably similar to that of two effective inorganic/organic perovskites FAPbI 3 and MAPbI 3. Maximum peaks generated from refractive index results indicate possible solar cell uses of the materials because they are in the visible and ultraviolet ranges. The results of other optical properties such as absorption coefficients, electron energy loss, conductivity, and reflectivity concludes that Rb 2 SeX 6 (X Br,Cl) have good values for electron generation, high potential for applications in the optoelectronic industry and are semiconductor in nature. The calculated shear anisotropy values of Rb 2 SeBr 6 /Cl 6 are 3.09/1.71, suggesting that they are isotropic materials. With calculated Poisson's ratio of 0.32 and 0.26, the materials are predicted to be ductile in nature. The two materials are appropriate for thermo-electric applications since their thermal to electrical conductivity ratio are small (the order of 10 −5). The calculated minimum values of Seebeck coefficient values of 0.198 × 10 3 / 0.166 × 10 3 (m V/K) at 750 K, for Rb 2 SeBr 6 /Cl 6 are positive, indicating that they have p-type conduction. Figure of merit values at all temperature range considered are greater than one (ZT > 1) for both Rb 2 SeBr 6 and Rb 2 SeCl 6 , suggesting that they are good thermo-electric materials. The results of the calculations provide the basis for the industrial application of Rb 2 SeBr 6 /Cl 6 as solar cells.
International journal of engineering research and technology, Oct 26, 2013
The digitized aeromagnetic data of Ibadan obtained from the Nigeria Geological Survey Agency NGSA... more The digitized aeromagnetic data of Ibadan obtained from the Nigeria Geological Survey Agency NGSA has been analysed for the purpose of delineating the geostructural settings of the area. Ibadan is located in present Oyo State, South Western Nigeria underlain by basement complex rocks of the Precambrian age and bounded within longitude 3 0 30'E to 4 0 00'E and latitude 7 0 00' to 7 0 30' N. The aeromagnetic anomaly map, its analytic signal amplitude, its vertical gradient magnitude, the Euler solutions and residual magnetic intensity map helped in identifying the nature and depth of the magnetic sources in the study region. The residual magnetic intensity map shows areas of magnetic highs and magnetic lows. The NorthWestern part shows prominent magnetic clusters trend, relatively prominent along the South East and the North central trending North, which signify areas of magnetic conductive materials which could be higher magnetite (a common magnetic rock) intrusion, buried metallic materials or areas of thin overburden. The depth estimate from analytic signal amplitude revealed magnetic depth range from 0.26-4.28 km while the results from the vertical gradient revealed minimum and maximum limit on source depth to be 0.16 km and 2.87 km respectively. The Euler Deconvolution overestimated the shallow depth to top of the magnetic source and the magnetic basement depth ranging from 0.02 km to 6.78 km respectively. The result obtained from the enhancement techniques used shows the shallow magnetic source depth values in the range 0.263 km to 0.881 km while the magnetic basement depth values are in the range 0.02 km to 6.78 km.
IOP conference series, Jul 1, 2018
High resolution aeromagnetic data that covers Igbeti-Moro area, within southwestern Nigeria, has ... more High resolution aeromagnetic data that covers Igbeti-Moro area, within southwestern Nigeria, has been subjected to data enhancement processes and interpreted to establish significant geologic features associated with occurrence of marble, gabbro and muscovite mineralization in the area. These were established by applying 2D Fast Fourier transform filters for reduction to equator (RTE), lineament enhancement of vertical and total horizontal gradient, edge detection of analytic signal amplitude (ASA), and magnetic source depth parameter imaging (SPI) and average power spectrum (APS); using Oasis Montaj software. The RTE residual magnetic intensity of the area ranged between-338.3 nT to-2.4 nT, 9.9 to 27.7 nT and 32.1 to 208.0 nT for low, intermediate and high magnetic susceptibility respectively which indicate contrasting basement rocks (namely; granite-gneiss) and intrusion of quartz and amphibolite schists. The lineament development and its disjoint revealed fractures and faults associated with emplacement of the quartz-schist and muscovite-schist, which would have formed synchronously with isoclinal fold and hosts marble, gabbro, amphibolites and muscovite mineralogy at shallow depth that ranges from 0 to 200 m in the northeastern, western, north central sections of the area. The geologic features observed in the study area have been established to be associated with the solid minerals that can be of social-economic benefit.
Advances in science, technology & innovation, 2019
In an attempt to establish the geologic structures in connection with the assessment of groundwat... more In an attempt to establish the geologic structures in connection with the assessment of groundwater resources within Igbeti crystalline basement complex terrain, Landsat 8 and aeromagnetic data were analysed using various sub-menus of Geographic Information System (GIS) and 2D Fast Fourier transform filters, respectively. Visual and automated models of the landform types and relief, the range of color composition of the Landsat 8 data controlled by the climato-morphogenic processes and alternating positive and negative magnetic anomalies revealed the contrasting lithologic units in the basement rock of the area. Lithologic contacts were developed with a vertical gradient while the linear features decipher the fracture orientation in concordance with a northeast-southwest low gradient trend. The associated groundwater flow direction revealed catchment in the northern, northwestern and southern parts of the area and indicated low run off, more infiltration time and better recharge potential for these regions, while zones of high degree indicated otherwise. The hydrology potential for groundwater development in the area should be targeted at geologic deformation.
Arabian Journal of Geosciences, Mar 27, 2023
Environmental Earth Sciences, May 1, 2023
Journal of environment and earth science, 2018
Integrated geophysical methods involving VLF-electromagnetic, magnetic intensity and electrical r... more Integrated geophysical methods involving VLF-electromagnetic, magnetic intensity and electrical resistivity (ER), were employed to investigate the probable internal seepage at University of Ilorin Dam, Kwara State, Southwestern Nigeria. Five (5) profiles were established in the south-north and west-east orientations, along the dam and reservoir axis. VLF-em conductivity response from-65 % to 50 % with estimated average anomalies of-7.5 % and; magnetic susceptibility distribution range between 2.27 nT and 756.24 nT, with average response of 163.6 nT suggests resistive basement rock contrasts in the area. Twenty seven (27) vertical electrical sounding (VES) points using the schlumberger array configuration were distributed along the profile lines. The lithologic units delineated with geo-electric sections established; 22 % wet/gravelly topsoil and 78% hard lateric pangranitic outcrop having resistivity variation between 28.8 Ωm and 2612.8 Ωm with average response of 870 Ωm and thickness range of 0.8 m to 2 m; straddled with 22 % clayey-sand and 78 % sandy-clay, having resistivity distribution between 63.2 Ωm and 316 Ωm with average response of 148 Ωm and thickness range of 3.4 m to 8 m and; fresh bedrock. The area is underlain by fairly thin superficial soil (overburden) materials with an average thickness of 6.5 m which shows that the bedrock is close to the surface and serves as support to the dam. The clay materials which could serve as conduit, exist within the shallow overburden and has been excavated during construction. It is therefore concluded that the dam retains its strength and the observed reduction in reservoir water level could be a result of other environmental factors.
kuwait journal of science, Jul 2, 2020
To establish significant geologic features associated with marble, gabbro, and muscovite minerali... more To establish significant geologic features associated with marble, gabbro, and muscovite mineralization in the Igbeti-Moro area of southwestern Nigeria, high-resolution aeromagnetic data were subjected to data enhancement processes and interpretation. The reduced-to-magnetic equator (RTE) anomaly map was subjected to various normalized (vertical, tilt and total horizontal) derivatives for lineament enhancement, edge detection of analytic signal (AS) amplitude and depth estimation techniques of source parameter imaging (SPI), averaged power spectrum and Euler deconvolution at different spectral indices. The range of RTE residual magnetic intensity from 338.3 nT to-2.4 nT (low), 9.9 to 27.7 nT (intermediate) and 32.1 to 208.0 nT (high) suggests contrasting basement lithologies in the area (viz; granite-gneiss) and the intrusion of quartz and amphibolite schists. The prominent NE-SW lineament revealed regional structural grains such as fractures and faults in these rocks associated with emplacement of the quartz-schist and muscovite-schist. This would have formed contemporaneously with isoclinal fold and host marble, gabbro, amphibolites, and muscovite mineralogy at a shallow depth range from 0 to 200 m in the western, north-central and northeastern parts of the area. The significant geologic features and their geometry of occurrences have been established as a prospect for solid minerals in the area. However, a geochemical investigation is encouraged to determine the economic value of the minerals.
International Letters of Natural Sciences, Oct 1, 2013
The results of a magnetic study of the Okenugbo Area of Ago-Iwoye, Southwestern Nigeria are prese... more The results of a magnetic study of the Okenugbo Area of Ago-Iwoye, Southwestern Nigeria are presented for the evaluation of the geostructural settings in the area to determine the competency of the basement for building constructions. The study area lies within Longitude N 06°55.389̕-N 06°55.384̕ and Latitude E 003°55.001̕ and E 003°54.959̕ in the basement complex of Nigeria. Three magnetic profiles were established for the evaluation and the magnetic anomaly map, the regional geology and its analytic signal amplitude helped in identifying the nature and depth of the magnetic sources in the study region. The magnetic residual values range from-2400 nT to +1800 nT. The area shows magnetic closures of various sizes at the Western part of the study area trending West with prominence at the center and distributed East-West which has been interpreted as fractured or faulted zones. The depth estimate revealed the apparent depth to the causative body from the surface and the basement depth range from 4.3 to 21.3 m which agrees with other literatures. The study has revealed that the area is generally competent for high rise structures and industrial site while the faulted/fractured zones are prospective better locations for hydrogeological purposes.
IOP conference series, Feb 1, 2021
Natural radionuclides content of 238U, 232Th and 40Kfor water and sediment samples collected from... more Natural radionuclides content of 238U, 232Th and 40Kfor water and sediment samples collected from Asa-dam Ilonn. Nigeria weremeasured using Nal(TI) detector. The mean activity concentration in the water samples were 6.05, 3.23 and 9.65 Bql−1 for 238U, 232Th and 40Krespectively. The mean activity concentration of 238U, 232Th and 40Kmeasured in the sediment samples were 7.57, 8.19 and 73.48 Bql−1 respectively. Theactivity concentration of 40Kwas higher than that of 238U and 232Thfor the water and sediment samples. All measured activity concentration and estimated radiological parameters were below world permissible limit values. Therefore, there may be no serious immediate radiological health burden on the environment and the people using the dam.
Cracks on concrete and walls could be bothersome for quality of life and for property claims. Geo... more Cracks on concrete and walls could be bothersome for quality of life and for property claims. Geophysical investigations was carried out around Faculty of Science and BACOSA buildings of Bowen University Temporary site, Iwo with a view to establish the possible cause(s) of failure of buildings within the study area. The geophysical methods used for the investigation were the Very Low Frequency Electromagnetic (VLF-EM) and the Electrical Resistivity (ER) methods. The VLF-EM measurements were taken at an interval of 10m along six traverse lines in the E-W and S-N directions. From the result of the VLF-EM, six VES stations were occupied in the study area involving Schlumberger configuration with half current electrode separation (AB/2) varying from 1 to a maximum of 65m. The 2-D VLF-EM models generated showed a network of suspected linear (geological) structures such as fractures, faults and contacts within the study area. The VES curve types obtained in the area include HA, KH, QH and AA with HA type curve dominating. Four subsurface geologic layers were delineated in the study area. These include the topsoil, weathered layer, clayey sand and fresh basement with resistivity ranging from 121.3 to 771.2 ohm-m, 134.4 to 595.8 ohm-m, 81.6 to 951.9 ohm-m and 1474.7 to 5134.4 ohm-m respectively. The thickness range from 0.5 to 2.4m, 1.8 to 9.8m and2.7 to 24.5m. Depths to the bedrock are generally less than 40m. The resistivity of the weathered layer beneath the topsoil in which the foundation is seated was found to be low within the study area, ranging from 134.4 to 595.8 ohm-m typical of clayey materials. From the models generated from VLF-EM and resistivity data, the distressed structures were found to be situated within the areas with a fairly high concentration of fractures, faults and contacts and relatively low resistivity values(less than 1000 ohm-m) typical of incompetent clayey formation.
Arabian Journal of Geosciences, Dec 1, 2017
This report details the result of geophysical exploration for iron ore; which involved vertical m... more This report details the result of geophysical exploration for iron ore; which involved vertical magnetic intensity (ΔZ) and gravity measurements, to delineate the geometry and depth extent of the deposit and acquiring quantitative and qualitative information for pre-drilling purposes in Agbado-Okudu. It is located about 3 km from Jakura along Lokoja-Jakura marble quarry and within low latitude precambrian basement complex district of Kogi State, Nigeria. A total of 517 magnetic measurement points along 16 traverses and 330 gravity reading along 11 profiles on the deposit in northeast-southwest azimuth were undertaken. The magnetic and gravity data enhancement involved linear regression curve fitting and fast Fourier transform, which were used to construct residual magnetic (RM) and gravity (RG) anomalies, analytic signal amplitude, Euler deconvolution at varying spectral indices (SI), power spectrum, and source parameter image (SPI), using the submenu of Geosoft Oasis Montaj software. Interpretation of the RM and RG anomalies revealed a primary causative body which perfectly correlates the positive anomalies and iron ore deposit, in form of a horizontal or gently dipping dyke with strike length of 600 m and average width of 110-130 m, within the gneiss complex in the north and trending south of the area. A secondary causative body associated with the negative anomalies and inferred as a vertical/near vertical thin sheet striking northeast-southwest coincided with the granitic and quartzitic intrusion. The NW-SE and E-W lineament trend conformed Kibarian and Liberian orogeny cycles of generally known structural trends in Nigeria, which shows that the iron ore deposit is structurally controlled. Depths to sources were estimated within range ≤ 2-24 m and 37.5-60 m, regarded as shallow and relatively deep depths, respectively. Ten vertical boreholes ranging in depth between 50 and 100 m are recommended, five of which require a priority attention to ascertain the thickness of the primary causative body.
Environmental Earth Sciences
Arabian Journal of Geosciences
IOP Conference Series: Earth and Environmental Science, 2021
Natural radionuclides content of 238U, 232Th and 40Kfor water and sediment samples collected from... more Natural radionuclides content of 238U, 232Th and 40Kfor water and sediment samples collected from Asa-dam Ilonn. Nigeria weremeasured using Nal(TI) detector. The mean activity concentration in the water samples were 6.05, 3.23 and 9.65 Bql−1 for 238U, 232Th and 40Krespectively. The mean activity concentration of 238U, 232Th and 40Kmeasured in the sediment samples were 7.57, 8.19 and 73.48 Bql−1 respectively. Theactivity concentration of 40Kwas higher than that of 238U and 232Thfor the water and sediment samples. All measured activity concentration and estimated radiological parameters were below world permissible limit values. Therefore, there may be no serious immediate radiological health burden on the environment and the people using the dam.
Academic Journal of Interdisciplinary Studies, 2013
The results of a magnetic study of the Okenugbo Area of Ago-Iwoye, Southwestern Nigeria are prese... more The results of a magnetic study of the Okenugbo Area of Ago-Iwoye, Southwestern Nigeria are presented for the evaluation of the geostructural settings in the area to determine the competency of the basement for building constructions. The study area lies within Longitude N 06°55.389̕-N 06°55.384̕ and Latitude E 003°55.001̕ and E 003°54.959̕ in the basement complex of Nigeria. Three magnetic profiles were established for the evaluation and the magnetic anomaly map, the regional geology and its analytic signal amplitude helped in identifying the nature and depth of the magnetic sources in the study region. The magnetic residual values range from-2400 nT to +1800 nT. The area shows magnetic closures of various sizes at the Western part of the study area trending West with prominence at the center and distributed East-West which has been interpreted as fractured or faulted zones. The depth estimate revealed the apparent depth to the causative body from the surface and the basement depth range from 4.3 to 21.3 m which agrees with other literatures. The study has revealed that the area is generally competent for high rise structures and industrial site while the faulted/fractured zones are prospective better locations for hydrogeological purposes.
SN Applied Sciences, 2019
This study aims at estimating depths and boundaries of magnetic source bodies, in order to provid... more This study aims at estimating depths and boundaries of magnetic source bodies, in order to provide an indirect insight into subsurface geologic features within Danko area of Kebbi state. The study area is located within low magnetic latitude. Hence, the total magnetic intensity anomaly map was reduced to the magnetic equator. This is to center magnetic anomalies over their respective magnetic source bodies, which equally makes the interpretation of sources easier. Matched filtering of the reduced-to-equator (RTE) magnetic anomaly map indicates that the anomalies could be represented by two equivalent layers with some additional noise. The estimated mean depths of burial for the regional and residual sources are 1000 m and 500 m, respectively. Horizontal gradient magnitude and tilt derivative methods carried out on the RTE aeromagnetic anomaly map facilitated the identification of two distinct geologic trends bounded by a prominent fault suspected to be the documented Yelwa fault. Furthermore, the analytic signal map showed magnetic basement depth values between 50 and 900 m with an average value of 475 m, indicating a compelling alignment of results with the 500 m depth value for the residual matched filter layer. Several mineral occurrences have been found within the outcropping basement rocks of the study area. Hence, the combined appraisal of source edge locations and magnetic basement depth estimates offers useful information of the underlying basement configuration, which is highly essential for mineral exploration targets that are mostly obscured by regolith cover.
Uploads
Papers by Nurudeen Olasunkanmi