Applied Geophysics
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Applied Geophysics
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Item Analysis of Electrical Resistivity Survey Data for Aquifer Potential and Protective Capacity at Mararaba Dan-Daudu Minna, North Central, Nigeria(Science Publishing Group, 2023-10-28) Alfa Idris Alhaji; Salako Kazeem Adeyinka; Rafiu Abdulwaheed Adewuyi; Udensi Emmanuel Emeka; Adetona Abbas Adebayo; Jamilu ShehuIt 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.Item Integrated 2D Geoelectric Prospecting for Gold Mineralization Potential Within Southern Part of Kebbi NW Nigeria(ANAS Transactions, Earth Sciences, 2024) Augie A. I; Salako K.A; Rafiu A. A; Jimoh M.OThis is a detailed geophysical research into the anomalous zones identified by pre vious aeromagnetic studies in the area. Integrated 2D geoelectric prospecting methods involving ERT, IP and SP techniques were used to delineate subsurface structure suitable for gold mineralization potential in parts of the Yauri, Shanga, and Magama areas of the states of Kebbi and Niger in the northwest Nigeria. The ERT, IP and SP measurements were carried out with a dipole-dipole configuration and the SuperSting resistivity meter. The research results revealed regions with low/high resistivity, high chargeability, and high SP values, which were identified as mineral potential zones. The ERT technique has helped to delineate regions with low resistivity anomalous which correspond to oxidized rocks associated with granite/quartzite veins. High resistivity range could exist over dyke structures associated with partially decomposed granite and quartzite, as in dicated by the geological setting and borehole log of the area. The IP technique revealed a high chargeability (≥ 20 milliseconds) in the study area, possibly due to the accumulation of metallic minerals in host rocks, such as gold. The SP technique has also helped to identify regions with high SP anomalies (≥20 mV), which are characterized by vein-bearing ore minerals. The integration of ERT, IP, and SP results revealed oxidized rock zones, dyke subsurface structures of decomposed quartzite, granite, gneiss, and ore mineral veins. These zones are located in the northwest Mararraba, the southwest Jinsani, and the southern Sabon Gari in Niger and Kebbi states. The areas could be considered a potential pathway for gold exploration and exploitation.Item Application of High-Resolution Aeromagnetic Data for Structural Frame Work of Zamfara Basement Complex,North Western Nigeria.(Federal University Dutse, Jigawa State – Nigeria, 2024) A.M. Narimi; A.A Rafiu; U.D. AlhassanZamfara state, located in the northwest of Nigeria, is regarded as one of the richest states in terms solid mineral abundance in Nigeria. Unofficial artisanal miners have found over 120 mining sites in the state. However, there is Insufficient knowledge of local and regional geology in the research area. High resolution aeromagnetic data were utilized to determine the depth of magnetic sources and basement tectonics. Clarifying the tectonic distribution of the basement complex and small portion of Sokoto sedimentary sequence within the research area is the aim of this investigation. Furthermore, this elucidation will help to differentiate the region's causative sources, which include contacts, faults, fractures, silk and dykes. Three approaches were compared for estimating the depth to magnetic sources namely: upward continuation, source parameter imaging, and Euler deconvolution. Euler deconvolution was upward continued to a distance of 1 km for (structural indexes 0 and 1, i.e., for contact and dyke) respectively. The map from these structural indexes exhibits similar patterns in terms of magnetic intrusive geological structures. Most magnetic structures and intrusive depth sources diminish at shallower range < 500 m while deeper sources > 1 km and 1.5 km were still present. The source parameter imaging produces the depth to the magnetic source, which ranges from 85.42 nT, which indicates a basement complex, to 1088.21 nT, which indicates a sedimentary basin. In addition to the subsurface geologic conditions, Visual inspection of the total horizontal derivative (THD), and tilt derivative (TD) revealed swift variations in the lithologic features and tectonic inferences as well as the subsurface geologic conditions. Three primary magnetic lithologic zones were identified from the analytical signal map classification: strong (> 0.051 nT/m), intermediate (0.016 to 0.051 nT/m), and low magnetic zones (< 0.016 nT/m). The lineament map, tilt derivative, and horizontal tilt derivative all showed the amplifications of various structural features (faults, fractures, and folds). These demonstrate the structural control of minerals in this research area.Item Delineating and Interpreting the Gold Veins Within Bida and Zungeru Area, Niger State Nigeria, Using Aeromagnetic and Radiometric Data(Pakistan Journal of Geology, 2021) Aliyu, Shakirat Bukola; Adetona, Abbass. Adebayo,; Rafiu Abdulwaheed Adewuyi; Ejepu Jude; Adewumi, TaiwoBoth Airborne Magnetic and Radiometric datasets were employed to interpret the geology and geological structures that serve as host to gold and associated minerals within the Bida and Zungeru, Niger State, Nigeria. An area of 55 by 110km2, contained within the cretaceous sediments of Bida Basin and the meta- sediments of Zungeru-sarkin-pawa schist belt. Data interpretation involve the application of a mathematical algorithm for data enhancing such as, Reduce to the Equator, Analytical signal, First Vertical Derivative, and Centre for Exploration Targeting (CET) to the magnetic data, and Ternary imaging to the radiometric data, with a sole aim of mapping geological structures such as faults fracture folds joints and geological boundaries and possible gold mineralization veins that arise from hydrothermally altered zones. Two major geological units inhibit the study area, the cretaceous sediment, and the meta-sediments, major feature identifies within the Cretaceous sediment are the folds majority of which are located within the contacts. The result of the 1VD display is the vivid picture of the observed structural features such as faults fractures folds’ contacts labeled F1 to F8 both within the high region of magnetic susceptibility (in red) and low regions (in blue) geology contacts (yellow), folds (bold yellow) all across the field. Prominently at the North-Western corner of the study area are sets of linear structure that trend NE-SW, located within the contacts between the mylonites and the amphibolites and the belt-type meta- sediments located around Katakwo, Gindei, Kwange, Gabas and Akusu villages. Equallyworth mentioning are sets of lineament (in blue) trend E-W all across the mid-region of the study area, precisely at the Eastern corner within and below the Federal University of Technology Minna around Kata-eregi, Sabon- Dagan, Kakaki down Minkwoigi, Sunbwagi, Kakagi, Sabon dagga, and Bobo-shiri towns, where the majority of volcanic activities must have been recorded. The airborne radiometric show mobilization of the immobile thorium Th, concentration, and this also indicated hydrothermally altered zones. The increase in potassium concentration and decrease in K/Th relation observed from radiometric interpretation are very pinpointing of hydrothermal activities within the study area. The gold mineralisations are found within this vein and in the adjacent, highly deformed host rock located below the Federal University of Technology Minna Campus. The deformation seems to comprise principally of pebbly schist, amphibolites along fine-grained and magnetite.Item 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, A. Akali, D.U. Alhassan, O.U. Akpan, K.A. SalakoQualitative analysis of Aeromagnetic data of parts of north central Nigeria had been carried out with the aim to delineate seismic prone areas. The study area is bounded with latitude 9. 00o to 10. 00o N and longitude 7.00o to 9.00o E with an estimated total area of 24,200 km2 . Vertical derivatives and upward continuation filters were used to enhances long wavelength anomalies which could give preliminary information about the magnetic structures present in the study area. The total magnetic intensity 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 the north-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 Aeroradiometric Data Assessment of Hydrothermal Alteration Zones in Parts of North Central Nigeria(Asian Journal of Geological Research, 2021) ADETONA, Adebayo Abbass, Mam D. Tawey, Usman D.Alhassan, Abdulwaheed A. Rafiu, Kazeem A. Salako and Emmanuel E. UdensiThis work aims to map radioelement distribution, delineate hydrothermal alteration areas, and produce a surface geologic map of the area using recently acquired high-resolution aeroradiometric data covering parts of north-central Nigeria with estimated area coverage of 24, 200 Km2 . Radioelement maps, ratio maps, and composite radioelement maps were produced to accomplish this goal. The spatial distribution and occurrence of each radioelement were determined using the radioelement maps, and hydrothermal alteration zones that fell within the north, northeast, northwest, southwest, and eastern portions of the study area were delineated using the percentage potassium (% K)-equivalent Thorium (eTh) ratio (K/eTh) map. Some of these altered zones have one or more structural associations, implying that the structures serve as channels (pathways) for migrating hydrothermal fluids that reacted with rock formations that were later altered. The coincidences in these alteration zones with high lineaments densities areas discovered by previous work in this area suggest a high likelihood of the occurrence of prospective mineralization within these locations. The composite maps aided in the production of the studyarea's surface geology map, while the paleostructure trending NE-SE revealed in previous work within the study area based on aeromagnetic data analysis was delineated using both radioelement and composite radioelement (ternary) maps.Item Delineating and Interpreting the Gold Veins Within Bida and Zungeru Area, Niger State Nigeria, Using Aeromagnetic and Radiometric Data(Sciendo, 2021) ADETONA, Adebayo Abbass, Aliyu Shakirat Bukola,, Rafiu Abdulwaheed Adewumi ,Ejepu jude and Adewumi TaiwoAbstract: Both Airborne Magnetic and Radiometric datasets were employed to interpret the geology and geological structures that serve as host to gold and associated minerals within the Bida and Zungeru, Niger State, Nigeria. An area of 55 by 110km2, contained within the cretaceous sediments of Bida Basin and the metasediments of Zungeru-sarkin-pawa schist belt. Data interpretation involve the application of a mathematical algorithm for data enhancing such as, Reduce to the Equator, Analytical signal, First Vertical Derivative, and Centre for Exploration Targeting (CET) to the magnetic data, and Ternary imaging to the radiometric data, with a sole aim of mapping geological structures such as faults fracture folds joints and geological boundaries and possible gold mineralization veins that arise from hydrothermally altered zones. Two major geological units inhibit the study area, the cretaceous sediment, and the metasediments, major feature identifies within the Cretaceous sediment are the folds majority of which are located within the contacts. The result of the 1VD display is the vivid picture of the observed structural features such as faults fractures folds’ contacts labeled F1 to F8 both within the high region of magnetic susceptibility (in red) and low regions (in blue) geology contacts (yellow), folds (bold yellow) all across the field. Prominently at the North-Western corner of the study area are sets of linear structure that trend NE-SW, located within the contacts between the mylonites and the amphibolites and the belt-type metasediments located around Katakwo, Gindei, Kwange, Gabas and Akusu villages. Equallyworth mentioning are sets of lineament (in blue) trend E-W all across the mid-region of the study area, precisely at the Eastern corner within and below the Federal University of Technology Minna around Kata-eregi, SabonDagan, Kakaki down Minkwoigi, Sunbwagi, Kakagi, Sabon dagga, and Bobo-shiri towns, where the majority of volcanic activities must have been recorded. The airborne radiometric show mobilization of the immobile thorium Th, concentration, and this also indicated hydrothermally altered zones. The increase in potassium concentration and decrease in K/Th relation observed from radiometric interpretation are very pinpointing of hydrothermal activities within the study area. The gold mineralisations are found within this vein and in the adjacent, highly deformed host rock located below the Federal University of Technology Minna Campus. The deformation seems to comprise principally of pebbly schist, amphibolites along fine-grained and magnetiteItem Interpreting the magnetic signatures and radiometric indicators within Kogi State, Nigeria for economic resources(ELSEVIER, 2022) ADETONA, Adebayo AbbassThe mineral and geothermal potentials of part of Kogi State was investigated through the interpretation of aeromagnetic and radiometric data of the study area. The analysis targeted bridging the gap of insufficient geophysical information of sub-crustal resources that could be of economic value within the area of study. Vertical derivatives, analytical signal and spectral depth analysis were used for the interpretation of the aeromagnetic data while the concentration and ternary images of the three radiogenic elements were used for the interpretation of the radiometric data. The result of first vertical derivative was helpful in delineating mineral potent lineaments labelled F1 to F8. The lineaments were seen trending E-W and NE-SW direction. A principal fault line F6 tends to separate the regions of sediments to the south-east and basement geologic formations to the south-western regions. Result of the analytical signal amplitude revealed regions with shallow intrusive magnetic rocks having high amplitudes ranging from 0.152 to 0.557 nT/m, while regions with magnetic rock intruding into sedimentary formations at greater depths, have medium to low amplitudes ranging from 0.014 to 0.136 nT/m. Regions delineated to be altered through hydrothermal process coincided with areas of major magnetic lineaments. The lineaments which could be fractures, faults or shear zones usually serve as conduits for mineral deposits during hydrothermal process. Result of potassium_thorium ratio map showed evidence of hydrothermal alteration in the NW and SW regions of study area. These regions of alterations also corresponds to regions where major lineaments were mapped and thus represent regions with significant potency for mineralisation. Result of spectral depth analysis on the aeromagnetic data showed that peak values of geothermal gradient and Heat flow were 27°C/km and 68 mW/m2, respectively, the values were recorded at the North-eastern part of study area, at the lower end of Koton-Karfe and part of Lokoja where the shallowest Curie point depth of 24 km also occurred. The estimated values of heat flow falls below the range of 80 to 100 mW/m2 recommended as threshold for a good source of geothermal energy, hence the region will not be prospectively good for a cost effective geothermal energy exploration. In order to assess the heat production within the study area due to activities of radioelements, a comparative analysis of the concentration of the three radiogenic elements was carried out. A relatively high radiogenic heat production (RHP) value of 3.4 µW/m3 was recorded at the North-western region indicating high occurrence of radioactivity within the granitic rocks. The (RHP) value of 3.4 µW/m3 is slightly below 4.0 µW/m3 which is a recommended value for a good source of geothermal energy. Graphical abstractItem Effect of High Concentration of Equivalent Thorium (eTh) And Uranium (eU) Within Part of North Central Nigeria on Geothermal Parameters(2024) ADETONA, Adebayo AbbassA high amount of heat flow from a shallow curie depth is essentially related to a promising geothermal resource. This work explores the depth of demagnetisation due to high radiogenic heat content of the basement rocks. The Total Magnetic Intensity and the radiometric data, consisting of the Potassium count, the Uranium and Thorium equivalents, were employed for the research work. Sheet 145 (Kajuru) and 146 (Geshere) both on latitude 10°00'N to 10°30'N and longitude 7°30'E to 8°30'E covering 6,050 km2 within Kaduna State of Central Nigeria is an area with notedly high concentrations of these radionuclide by previous researchers. A shallow Curie point depth of 12.00 km was observed below Wugana while heat flow values ranging from 30.00 mW/m2 to 160 mW/m2 was estimated with an average of 80.60 mW/m2. Also, the geothermal gradients varied from 8.00 to 50.00 °CKm-1, with an average value of 25.50 °CKm-1. The effect of heat generated from the Potassium count, equivalent concentrations of Uranium and Thorium indicated the Northern end down to the Mid-western end displays medium to high radiogenic heat production (3.6 – 4.5 μW/m3). In conclusion, areas with low Currie depth that coincide with relatively high radiogenic heat production are located within Wugana, New Kwasan, and down to Ron villages, which are generally located at the Mid-North and Mid-Western areas with intrusive granitic rocks