Applied Geophysics
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Applied Geophysics
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Item Geoelectrical Investigation on Road Failure of part of London Road Minna, Nigeria(Dutse Journal of Pure and Applied Sciences (DUJOPAS), 2020) ADETONA, Adebayo Abbass, 31 Ndanusa H. H, Rafiu A. A, Salako K.A, Alhassan U,D,An electrical resistivity method involving Wenner technique was carried out at part of London Road Minna, Niger State. The aim of the study was to investigate the causes of road failure. Two profiles parallel to the road of the study area of 300 m in length were investigated using Wenner array electrical configuration method. The electrode spacing was at equal interval of 7.5 m and current was sent into the ground using both current electrodes while potential electrodes received the signal which is display by the terrameters in resistivity. A total of 42 electrodes were probed. The calculated apparent resistivity pseudo section of profile A shows low resistivity. At the distance between 205 - 250 m the material is of low resistivity which can also lead to failure of the road. Profile B shows some anomalies between the distances of 45-60 m which is likely to be clay.Item Application of Aeromagnetic Data to Assess the Structures and Solid Mineral Potentials in Part of North Central Nigeria(Journal of Geography, Environment and Earth Science International, 2020) ADETONA, Adebayo Abbass. 15. M.D. Tawey, D.U. AlhassanAssessment of the structures and solid minerals was carryout to investigate subsurface structural characteristics and mineralization potential zones within part of north-central Nigeria. The residual magnetic intensity data of the area was reduced to magnetic pole after which several source edge detection/interpretation with depth determination techniques including, analytic signal; tilt derivative; first and second vertical derivatives and Euler deconvolution were applied to the aeromagnetic data. From the analytic signal map, three magnetic zones were delineated. These are: low to relatively low magnetic zone (LM) with amplitude range from 0.003 to 0.009, moderate magnetic zone (MM) with amplitude 0.009 to 0.106 and those with amplitudes above 0.106 were products of later magmatic intrusions into host with fractures, faults and joints. Tilt derivative helped in delineating location and extent of edges of causative sources while Euler deconvolution helps in determination of boundary, depth and geometry of the structures. From first vertical derivative mapstructures were found to have high lineament density around the central portion of the area and span toward the western end of the map were delineated. The lineaments mapped trending in the ENE-WSW followed by WNW-ESE with some NE-SW, NNE-SSW and NNW-SSE trends. The second vertical derivative (SVD) map also helped in delineating structures and possible mineralization zones that are pronounced within the study area, around high analytic signal zones. Delineated possible and favorable mineralization zones from second vertical derivative map correlate with portion of the study area with rocks showing high analytic signal amplitude suggesting the rocks to be of later magmatic intrusions where mineralization fluids solidify within the host rocks.Item Structural Analysis and Interpretation of High Resolution Aeromagnetic data over the Southern Bida basin, North Central, Nigeria(Zuma Journal of Pure and Applied Sciences, 2020) ADETONA, Adebayo Abbass, Okwokwo O.IThis study focuses on the analysis and interpretation of high resolution aeromagnetic data over the southern part of Bida basin. The study covers an area of 24,200 km2 located between latitude 80 30′N and 90 30′N and longitudes 50 00′E and 70 00′E. Aeromagnetic data in grid format containing eight sheets in 1/2o by 1/2o (55 x 55 km) were analyzed and interpreted. This study employed several magnetic filtering methods to investigate lineaments and other structural features. The filtering methods used are: reduction to the magnetic equator, horizontal derivatives, vertical derivatives, analytical signal, and Centre for exploration targeting grid analysis. The reduced to magnetic equator shows variation in magnetic signatures ranging from-58.65nT-131.44nT. The results from first vertical derivative, second vertical derivative, horizontal derivatives and center for exploration targeting maps reveal that the major structures delineated, trend in NE –SW and NW-SE direction. Since minerals are structurally controlled, these structures delineated might host the economic mineralsin the study area. The second vertical derivative shows a major fault line cutting the area into two parts which is an extension of the Romanche fault. The CET grid analysis map reveals the geologic boundaries and fault lines within the basement rock.Item GEOELECTRICAL INVESTIGATION OF ROAD FAILURE ALONG MINNA-BIDA ROAD, NIGER STATE, NIGERIA(FUW Trends in Science & Technology Journal, 2020) ADETONA, Adebayo Abbass, 10. Rafiu A.A., T.A Adesete, Salako K. A., Alhassan U.D, Shehu JThe study is meant to reveal the horizontal and vertical geological discontinuities on the said road that has suffered repairs in the past. Probable zones of untimely failure along the road are then investigated by variation in resistivity. The resistivity values for profiles A, B, C, D and F range between 0.10 and 30.4 Ωm; indicating failed segments which are typical of fractured or fissured zone, as a result of clayey nature of the topsoil/sub-grade soil on which the road pavement is founded. The stable segment which is characterized by high ranging resistivity (16.4 – 4628 Ωm) shows no evidence of any major geologic feature such as fault and fractured zone that could have precipitated failure. The range of values characteristically places the regions in a basement complex area with the presence of clay-sandstone intercalation. The causes of road pavement failure on the studied road was found to be majorly as a result of a combination of clayey topsoil/sub grade soils, water-logged sands with characteristically low resistivity values and thin pavement unable to withstand pressure exerted on the roadItem Interpretation of Airborne Radiometric data for possible hydrocarbon presence over Bornu basin and its environs, Northeast Nigeria using Thorium normalisation method(Iranian Journal of Earth Sciences, 2021) ADETONA, Adebayo Abbass, Taiwo Adewuyi, Kazeem Adeyinka Salako, Usman Defyan AlhassanA new exploration technique called Thorium Normalisation Method has been applied on the airborne radiometric data of the Bornu basin and its environs to delineate favourable zones for hydrocarbon accumulations within the study area. This method is significant because it indicates the probable presence of hydrocarbon in a sedimentary basin. Separation of the radiospectrometric measurements over each lithologic unit and the estimation of the characteristic statistics of these units were carried out. The statistical treatment applied on the radioelements (K, eTh and eU) of the study area shows a relatively low coefficient of variability (CV%) value for K, eTh and eU signifying their high degree of homogeneity. The mean value of the radioelements (K ranging from 0.6 to 2.0 %; Th ranging from 9.6 to 15.9 ppm and U ranging from 2.2 to 3.8 ppm) obtained from the statistical analysis correlates with the mean of natural radioelement (K ranging from 0.1 to 2.7 %; Th ranging from 0.4 to 11.2 ppm and U ranging from 0.1 to 3.7 ppm) content of sedimentary rocks which corresponds to shale, the main source rock for hydrocarbon accumulation in the study area. The DRAD (delineation of radioactive anomalies) result ranges from -0.77 to 1.83. The positive values are indicators of favourable zones for the presence of hydrocarbon accumulations. These results suggest that the preliminary information obtained from the use of the thorium normalisation method will guide the exploration of hydrocarbon in the study area.Item INTERPRETATION OF MAJOR STRUCTURES WITHIN THE BASEMENT REGION OF BENUE-NIGER CONFLUENCE FROM AEROMAGNETIC AND RADIOMETRIC DATA KOGI STATE NIGERIA(Geological Behavior (GBR), 2021) ADETONA, Adebayo AbbassInterpretation of Aeromagnetic and Radiometric Data covering the basement region of Benue-Niger confluence was executed to delineate major structures and other geologic frame works of mineral interest. The study area which hosts the Benue-Niger confluence also encloses two major geologic units which are basement complex and sedimentary basins. The Aeromagnetic data set comprising sheet 227 (Koton-Karfe), 247 (Lokoja) and 267 (Idah) was enhanced to reveal geologic structures while radiometric data was analysed to map lithology and zones affected by hydrothermal alterations. A set of mathematical algorithms was used to enhance the data for interpretation. First Vertical derivatives, Analytical Signal and Euler deconvolution filters were applied to the Aeromagnetic data while Ratio and Ternary images of the three radiogenic elements were obtained for the radiometric data. Magnetic signatures from the TMI showed a mixture of high and low susceptibility below koton-karfe due to intrusion of oolitic iron ore within the sedimentary formation. Lokoja regions recorded highest susceptibility of 165 nT due to magnetic signatures emanating from exposed basement rocks. The southern Idah regions recorded relatively low susceptibility. Result of First Vertical Derivative revealed near surface mineral potent structures labelled F1 – F8, cringing surface features B1, B2 and B3. Analytical signal revealed high amplitudes range of 0.174 to 0.579 cycles for magnetic sources majorly at the basement regions, while low amplitude range of 0.021 to 0.157 cycles were recorded around the sedimentary regions. Euler depth analysis revealed shallower depth to sources in the basement and deeper depth to sources in the sedimentary regions due to thick overburden. Radiometric signatures from the K/Th ratio map revealed portions around Latitude 8°00’ NW and 7°30’ SW shaded in pink colour and having values above known threshold of 0.2 %/ppm to be hydrothermally altered. Mapping of lithology from Ternary map revealed K-Feldspar mineral bearing rocks dominated the NW and SW regions, while sandstones, ironstones, mudstones, shale, alluvium and other fluvial sedimentary lithologies dominated the sedimentary North-east and South-Eastern regions. The western regions (NW and SW) hosted the major structures in form of magnetic lineaments trending NE-SW and E-W which also coincided with regions delineated to be hydrothermally altered and apparently represents the most prospective regions of mineralisation in the study area.Item DR(2024) Adebayo ADETONA. AbbassBoth 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 thegeothermal 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 arelocated around Bowon Dodo, Dan Tsofo, Kadunu, Gimi, Kaura and Zankan in plateau state. The geothermalgradient 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/m with an average radiogenic heat valueof 3.36 µW/m. Both analyses revealed that regions such as Ataka, Gimi, Jimjim and Pari could be investigated for geothermal energy otential. 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.