Applied Geophysics
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Applied Geophysics
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Item Estimating the Heat Flow, Geothermal Gradient and Radiogenic Heat within the Young Granites of Jos Plateau North Central Nigeria(University of Tehran Press, 2024-02) Adetona, A. A; Rafiu, A. A; Aliyu, B. Sh; John, M. K; Kwaghhua, I. FBoth aeromagnetic and radiometric data were used to evaluate the Curie point depth and radiogenic heat production (RHP) of the young granitic regions of the Jos Plateau. An area of 55 by 110 square kilometers is bounded by latitude 9°30' to 10°00' N and longitude 8°30' to 9°30' E in central Nigeria. The magnetic data was subjected to spectral analysis to obtain the Curie depth, which was subsequently used to evaluate the geothermal gradient and heat flow for the area. Also, the concentration of radioelements (potassium, thorium and uranium) and the average density of the in-situ rock were used to estimate the radiogenic heat production at each point where the Curie point was evaluated. The heat flow in the study area ranges from 10 to 165.5 mW/m2 with an average value of 111.00 mW/m2. The regions with anomalous heat flow of 165.5 mW/m2 are located around Bowon Dodo, Dan Tsofo, Kadunu, Gimi, Kaura and Zankan in plateau state. The geothermal gradient values range from 5 to 68 °C/Km with an average of 26.16 °C/Km. The radiometric data analysis resulted in radiogenic heat values ranging from 0.4 µWm3 to 6 µW/m3 with an average radiogenic heat value of 3.36 µW/m3. Both analyses revealed that regions such as Ataka, Gimi, Jimjim and Pari could be investigated for geothermal energy potential. The high concentration of uranium, thorium and potassium associated with the study area is likely due to the weathering of the in-situ granitic basement rocks.Item Integrated Geophysical Investigation for Potential Gold Mineralised Zone within Lower Part of Zuru Schist Belts, NW Nigeria(Nigerian Institute of Physics, 2024) Augie, A. I; Salako, K. A; Rafiu, A. A; Jimoh, M. OThe study began with a reconnaissance survey that used high-resolution aeromagnetic data of the study area to identify suitable structure zones with the potential to trap mineral resources within the context of the gold exploration target. The findings of magnetic studies were followed up with detailed investigations using 2D electrical resistivity tomography (ERT) and induced polorisation (IP) techniques to reveal further details about gold mineral zones and other lithological boundaries. The airborne magnetic data of sheet 118_Yelwa was obtained from the NGSA; these datasets were processed and analyzed using Oasis Montaj's first vertical derivative (FVD) and center for exploration targeting (CET) techniques. Results of FVD and CET grid anomalies show that regions of major magnetic structures (lineaments) are associated with granite gneiss, migmatitic augen gneiss, and medium to coarse-grained biotite when compared to the geological settings of the area. The zones of major structures obtained in this study coincided with previous magnetic studies of the area, located in the eastern parts of Ngaski, Yauri (Yelwa), Shanga, Agwara, as well as Magama's northwest region. Some of the regions for lineament (in the eastern part of Ngaski/Yauri) were investigated further with 2D ERT and IP detailed geophysical methods in a dipole-dipole configuration. The results of geoelectric techniques along profiles 1, 2, and 3 identified the major gold mineralisation potential zones, which were labeled A1, A2, and A3. These regions have low/high resistivity (1.6 to 459 Ωm/1889 to 7773 Ωm) and chargeability signatures (≥ 20 msec), and could thus be interpreted as potential target zones for metallic mineral exploration, particularly gold mineralisation. The regions are located in the northern Mararraba and southwest of the Jinsani areas of Kebbi State. The results of integrated geophysical methods have produced updated structural features of the regions, as well as a database containing precise locations, lateral lengths, thicknesses, and depths for prospective gold mineralisation zones. This database could assist the miner/explorer in locating the potential zone of gold mineralisation.Item Integrated Geophysical Investigation using Aero-radiometric and Electrical Methods for Potential Gold mineralization within Yauri/Zuru Schist Belts, Kebbi State NW Nigeria(Unierasidad Naciona de Colombia, 2024) Abdulrahaman Idris Augie; Kazeem Adeyinka Salako; Andy Anderson Bery; Adewuyi Abdulwaheed Rafiu; Mufutau Owolabi JimohThis study used aero-radiometric, 2D electrical resistivity tomography (ERT), and induced polarization (IP) methods to delineate gold mineralization potential. The study also confirmed and followed-up on regions with major structural features identified in previous aeromagnetic studies in the area. A half-degree airborne radiometric data of sheet 118_ Yelwa from the NGSA, which contains three radioelements (%K, eTh, and eU) were used in this study. These datasets were processed and analyzed with Oasis Montaj Grid Math expression builder to obtain the %K_ratio_eTh and Ternary grid anomalies. The results identified zones E and F as hydrothermally altered regions that may harbour gold mineralization. These findings were consistent with the regions of major structural features identified in previous aeromagnetic studies in the area. The zones were located in the eastern parts of Ngaski, Yauri (Yelwa), Shanga, and Agwara, as well as Magama’s northwest region. However, zone F1 (the eastern portion of Ngaski/Yauri) has been further investigated using 2ERT and IP detailed geophysical methods in a dipole-dipole configuration. The results of geoelectric techniques along profiles 1, 2, and 3 identified the major gold mineralization potential zones, which were labeled A1, A, and C. These regions have low/high resistivity and chargeability signatures, and could thus be interpreted as potential target zones for metallic mineral exploration, particularly gold mineralization. The regions are located in the northern part of Mararraba and southwest of the Jinsani areas of Kebbi State.Item Groundwater investigation within the basement complex, North Central Nigeria, using magnetic and resistivity method(Arabian Journal of Geosciences, 2024) ADETONA, Adebayo Abbass, Shakira B. Aliyu1 · Fidelis I. Kwaghhua1 · Luka M. DamidamThe research focuses on using an integrated approach to locate viable locations for sitting boreholes within the Bosso local government area of Niger State. An area within the basement complex in North Central Nigeria is enclosed by longitudes 6.25′ to 6.31′ and latitudes 9.35′ to 9.45′, with a total area of 16 by 8 km2 . This work is central to employing both magnetic and electrical methods of exploration. The derivatives of residual magnetic intensity data for the area were employed to locate regions within the area that are fractured or faulted and could give access to the required underground water. This was followed by conducting Vertical Electrical Sounding (Schlumberger array) within two selected sites within the faulted area and one site outside the faulted area to serve as a control. First vertical derivative displayed lineaments labelled (A), (B), (C), (D), (F), and (G), which are mostly in the Northeast–Southwest (NE-SW) direction. Three sites were chosen for Vertical Electrical investigation for groundwater; sites A (on latitudes 9° 40′ 37.11″ to 9° 41′ 37.1″ N and longitudes 6° 29′ 52.64″ to 6° 30′ 51.56″ E) and B (latitudes 09° 40′ 37.17″ to 09° 41′ 37.15″ N and longitudes 06° 29′ 51.66″ to 06° 30′ 51.55″ E) are within the fractured zones and site C is outside the fractured zone which serves as a control. Thirty-six (36) VES points were sampled on each of the three sites measuring 500 by 500 m2 . Result of Vertical Electrical Sounding carried out indicated three geologic layers comprised of topsoil, intermediate clay formation, and weathered/fractured or fresh basement. The depth of the basement at VES points within sites A and B varies from 25 to 48 m; these are within the faulted zone, while depth of overburden in site C used for control varies from 6 to 18 m. Hence, VES points located within sites A (1) and B (2) are viable for groundwater exploration; points A2, A5, B4, B5, C2, C4, D4, D5, E1, E3, and F4 are high conductivity zone which are prolifc for groundwater potential. The depth range for aquifer potential zones is between 22.7 and 50.4 m. Result from site C equally shows two layers, more than 90% of the VES which are not viable for groundwater potential. This work thus recommends sitting of borehole within VES points on site A or B for good yield and authenticates the viability of integrated algorithms for groundwater exploration in the basement complex region.Item Assessment of Geothermal Potential of Parts of Middle Benue Trough, North-East Nigeria(Journal of the Earth and Space Physics, 2020) ADETONA, Adebayo Abbass, Salako K. A.Rafiu A.A., Alhassan U.D, Aliyu A and Adewumi TAbstract This research deals with assessment of geothermal potential in parts of middle Benue Trough, north-east of Nigeria. The study area lies within the Longitude 9°E – 10°E and Latitude 8°N – 9.50°N with an estimated total area of 18,150 km2 . Regional/Residual separation was performed on the total magnetic intensity using polynomial fitting. The residual map was divided into 14 overlapping spectral blocks, and the log of spectral energies were plotted against frequency. Centroid depth and depth to top boundary obtained were used to estimate the Curie point depth isotherm, which was then used to compute geothermal heat flow of the study area. The result shows that the geothermal heat flow varies between 50.02 and 85.1 mWm-2 with highest value in the southern part (Akiri and Ibi) and north-western part (Pankshin) of the area. The geothermal heat flow obtained from this study indicates that the study area possess a good source of geothermal potential. The aero-radiometric data covering the study area was also analysed to estimate the radiometric heat contribution. The analysis of aero-radiometric data shows that the area possesses high content of Uranium, Potassium and Thorium. The radioactive heat production values vary between 1.58 μW/m3 and 2.53 μW/m3 with an average of 2.21 μW/m3. Thus, harnessing the geothermal potential in this area would be of added values and advantage to power generation in NigeriaItem Preliminary Investigation of Seismicity in Parts of North Central Nigeria, Using High Resolution Aeromagnetic Data(Journal of Geography, Environment and Earth Science International, 2020) ADETONA, Adebayo Abbass. 13. A. Akali, D.U. Alhassan, O.U. Akpan,Qualitative analysis of Aeromagnetic data of parts of north central Nigeria had been carried out withthe aim to delineate seismic prone areas. The study area is bounded with latitude 9. 00o to 10. 00oNand longitude 7.00o to 9.00oE with an estimated total area of 24,200 km2. Vertical derivatives and upward continuation filters were used to enhances long wavelength anomalies which could givepreliminary information about the magnetic structures present in the study area. The total magneticintensity map shows both positive and negative anomalies with susceptibility ranging from 33487.7 nT to 33800.9 nT. The high magnetic susceptibilities dominated in the basement region around thenorth-eastern and north-western parts of the study area which corresponds to Naraguta, Jemma and Kafanchan area. Based on the geology of the area this is attributed to granite, schist and migmatite rocks. The low magnetic values are made of sediment deposition also dominates the south-western part of the study area, corresponding to Abuja and Gitata. The area with magneticsusceptibility values ranging between 33506.6 nT and 33653.8 nT indicates alluvium deposite around Bishini and Kachia area. Lineament from First Vertical Derivative trend in the northeastsouthwest and east-west directions, which is an extension from Romanche Fracture Zone. Majority of this lineament trends in the same directions as the Romanche Fault Line which continues at 25 km and 30 km into n inferred closure within the study area which is trending along north-west direction. This, closure occurs probably because of the existence of the paleo fracture zone Romanche Fracture Zone) within the study area. At 40 km and at 80 km a regional trend in the NESW direction in (porphyritic) basement rocks. At the northeast and southeastern part of the area which is made up of basement complex that corresponds to areas around Gitata, Kafanchaan and Jemma are prone to tectonic activities while the southwestern part of the area around Abuja is seismic free. It is suggested that those lineaments identified, most especially at the southeastern part could be the reason for the shaking of the subsurface which result into earth tremors.Item Edge Detection and Depth to Magnetic Source Estimation in Part of Central Nigeria(Physical Science International Journal, 2020) ADETONA, Adebayo Abbass, Mam D. Tawey, Usman D.Alhassan, Abdulwaheed A. Rafiu, Kazeem A. SalakoHigh-resolution aeromagnetic data covering an area of 24, 200 km2 in north central Nigeria has been acquired and analyzed with the aim of carrying out trend analysis, edge detection (structural delineation) and depth to magnetic source estimation using reduce to the pole (RTP), horizontal gradient magnitude (HGM), center for exploration targeting plug-in (CET), 3D Euler deconvolution and source parameter imaging (SPI) techniques. Trend analysis was applied to the RTP data to delineate structures that have dissected the area. The 3D Euler deconvolution and HGM were correlated by plotting the estimated Euler solutions for a structural index of one (SI=1) on HGM map and the resulting map produced have shown that both methods can contribute in the interpretation of the general structural framework of the study area. The structural delineation based on HGM and CET maps showed that two predominant trends (ENE-WSW) and (WNW-ENE) have affected the area. The trend/depth/contacts of these faults were classified into four groups: Faults <150 m, 150 m - 300 m, 300m - 450 m which are the most predominant fault system based on Euler solutions with a structural index of one (SI=1) and those deeper than 450 m while the result of source parameter imaging (SPI) revealed a depth to source varying from 58 m specificallyfor areas with shallow depth to the magnetic source to those from deeper source occurring at588.153m depth especially the south-central portion and the south-eastern portion of the study area. KItem GEOELECTRICAL INVESTIGATION OF THE SUBSURFACE LITHOLOGY AT THE PROPOSED INTERNATIONAL STADIUM, MINNA, NIGER STATE, NIGERIA(FUW Trends in Science & Technology Journal,, 2020) ADETONA, Adebayo Abbass, Jamiu Alani Sikiru, Jamilu Shehu and Aisha AlkaliGeoelectrical investigation was carried out to evaluate the viability and to determine the subsurface Lithology, depth to bedrocks as well as to establish prolific aquifers at the proposed Minna International Stadium, Niger State, Nigeria. The area is located at the Basement Complex of Nigeria which comprises of: Migmatites-Gneiss Complex, the Schist Belt, the older granites and undeformed acidic/basic dykes. Vertical electrical sounding (VES) surveys were conducted using a resistivity meter along six (6) profiles, at 50 m interval from each sounding point; and a total of 36 VES measurement were made. The results of the VES suggests that the entire subsurface of the proposed stadium, is made up of three (3) distinctive Lithologies; the First layer is Top Soil/Lateritic Particles with resistivity value between 20.38 and 272.8 Ω𝑚 it thickness is between 0.09 m to 5.84 m, the Second layer is a weathered/fractured basement with resistivity values variation between 45.15 and 1017 Ω𝑚, its thicknesses ranges between 2.54 m and 24.9 m and the Third layer is fresh basement with resistivity values from 1259 to 3606 Ω𝑚. The result of this work shows that the second layer is generally weathered Basement, it is therefore advisable for engineers to consider this in their design. The foundations should be situated towards the southeastern, southwestern and northern section of the site, where the bedrocks are shallow, uplifted and consolidated. The site is suitable and viable for the construction of the proposed stadium; the depth to bedrocks is more than 2.54 m from the surface. Borehole should be drilled on the following VES points; A6, B3, B4, C6, C1, C2, D1, D3, E2, E3, F2 and F1, these VES points depicts zones of good fracturesItem Analysis of Electrical Resistivity Survey Data for Aquifer Potential and Protective Capacity at Mararaba Dan-Daudu Minna, North Central Nigeria(Published by Science Publishing Group online, 2023) ADETONA, Adebayo AbbassAbstract: It is a fact that basement complex regions lacks sufficient overburden that can host sustainable water table, water bearing fractured/weathered rocks referred to as aquifers are usually identified via suitable geophysical methods to proffer solution to water challenges within these regions. This current study targets the exploration of groundwater potential within the Mararaba Dan-daudu community, a suburb of Minna metropolis. Electrical resistivity method was employed to delineate aquifer prospects and their protective capacity within the area of study. The data from thirty-six Vertical Electrical Sounding (VES) survey points were acquired and analysed. Survey points were aligned along six profiles (A – F) with six VES points per profile. Interpretation of VES points along profiles was helpful in determining the number of layers and thickness. The analysis revealed mainly three layers comprising of sand and fresh laterite at the first layer, fractured/weathered basement at the second layer and fresh basement at the third layer. Iso-resistivity mapping was also done at various depths (surface, 5 m, 10 m, 15 m, 20 m, 30 m and 40 m) respectively to investigate the lateral variations of resistivity over a horizontal plane. These showcased the electrical conductance sliced at the depths of interest. Thirteen VES points (A1, A5, A6, B1, B3, B6, C6, D6, E6, F1, F2, F4 and F5) were mapped as having good prospective aquifer properties. Longitudinal conductance was computed for the outlined VES points to determine their Aquifer Protective Capacity (APC). The result of (APC) rating for the 13 VES revealed the frequency and percentage of APC ranged as: 2 VES locations (15.4%) have good APC, 8 VES locations (61.5%) have moderate APC and 3 VES location (23.1%) have weak APC. with only 3 VES locations out of 13 VES locations in the study area revealed weak APC, the results proved that the groundwater potential of the study area has moderately good APC