Applied Geophysics

Permanent URI for this collectionhttp://197.211.34.35:4000/handle/123456789/95

Applied Geophysics

Browse

Search Results

Now showing 1 - 10 of 18
  • 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. F
    Both 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. O
    The 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 Jimoh
    This 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. Damidam
    The 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
    GEOPHYSICAL INVESTIGATION OF WESTERN PART OF FEDERAL UNIVERSITY OF TECHNOLOGY, GIDAN KWANO CAMPUS, MINNA, NIGER STATE, USING ELECTRICAL AND SEISMIC REFRACTION METHODS
    (Natural and Applied Sciences Journal, 2010) ADETONA, Adebayo Abbass, Salako, K .A., Abdulrashid, U.A; Rafiu, A.A., Ofor, N.P., Alhassan D.U. and Jonah S.A.
    A geophysical survey of western part of Federal University of Technology, Gidan Kwano Campus, Minna, was carried out using Electrical Resistivity (VES) and Seismic refraction methods. The aim of this survey was to determine the ground water potentials of the area and to also locate those areas that could be useful for civil engineering purposes. Careful interpretation of the seismic data obtained shows two geologic sections within the survey area. The first layer has an average seismic velocity value of 1237.86 ms-1 . The second layer is the refractor layer whose seismic velocity average is 4581.67 ms-1 and has an average depth of 4.74m. The results obtained from the electrical resistivity method also shows that the survey area consists of three geoelectric/geologic layers. The first layer has resistivity values between 20m and 200m, which represents topsoil the second layer has resistivity value ranging from 200m to about 900m and typifies weathered and fractured basement. The fresh basement forms the third layer with resistivity value above 1000m. The results obtained from both methods shows that the area appropriate for ground water development were found in the north-east and north-central portion of the survey area with aquifer systems of 100m in width and depth between 3.8m and 25m. Similarly the site most appropriate for civil engineering purpose could be located at the southern part of the survey area where the fresh basement is shallow.
  • Item
    PRELIMINARY ASSESSMENT OF GROUNDWATER POTENTIAL AND STRUCTURAL DEVELOPMENT AT POMPOM VILLAGE, MINNA, NORTH CENTRAL NIGERIA USING ELECTRICAL PROFILING METHOD
    (Journal of Science, Technology, Mathematics and Education (JOSTMED), 2012-04) ADETONA, Adebayo Abbass, 10. Rafiu A.A., T.A Adesete, Salako K. A., Alhassan U.D,
    The result of preliminary study of ground water assessment and structural development at Pompom village is presented. The profiling data were collected over a total number of sixty-six (66) VES points covering 500m by 1km, using Werner configuration method. The field was divided into two measuring 500m by 500m and the data collected were analyzed separately. The profiling data were analyzed using both Surfer 8 and Microsoft Excel package. The results of the analyses shows that the areas identified as suitable for ground water exploitation are northeast and southern parts of the study area where resistivity values are relatively low. Areas or points identified for civil engineering development are areas identified with relatively high resistivity values, these areas correspond to VES: B2, C1, C2, C4, D3, F3, F4 C’4 and F’1.
  • Item
    2-DIMENTIONAL MODELS OF THE STRUCTURAL FEATURES WITHIN THE LOWER BENUE AND UPPER ANAMBRA BASINS NIGERIA, USING (2009) AEROMAGNETIC DATA
    (Journal of Science, Technology, Mathematics and Education (JOSTMED),, 2015-08) ADETONA, Adebayo Abbass, ABU Mallam
    Analysis base on the CET shows that the basement rocks to the North and Southern edge of the study area intrude into the sedimentary formation. At the lower (middle-portion) of the study area (within Angba and Otukpo sheets) are structures that are Basaltic rocks that intrude into the basement. It is believed that these structures must have predated the depositional period of the sedimentary formation. Several fracture and fault lines are detected on the CET map, most prominent among is that which start from the Eastern end (latitude 7.450 and longitude 8.300 ) and ends at the Southern end (Latitude 7.000 longitude 7.450 ).cutting the South Western corner of the study area diagonally. Secondly is that which runs vertically and is parallel to the course of River Niger within this area, supporting the assertion that the River Niger is structurally controlled. The 2-dimentional models of the six profiles revealed sedimentary formations whose susceptibility values are zero (0). Maximum depth of about ten (10) kilometers was obtained within the Southern end of the study area, but a maximum thickness of sedimentation of about four (4) kilometers was observed on profile six within Nkporo formation. The basement susceptibility varies from 0.002 to 0.004 but in some places it is as high as 0.007. Structural, 2-dimensional, Exploration Targeting, Total Magnetic Intensity
  • Item
    Interpretation of Aeromagnetic data over parts of Bida Basin, north Central, Nigeria.
    (2017) ADETONA, Adebayo Abbass, 37 Alkali A., Salako, K.
    This study focuses on the analysis and the qualitative and quantitative interpretation of aeromagnetic data over the southern part of Bida basin. The study area covers an area of 24,200 km2 located between latitude 80 30ꞌN and 90 30ꞌN and longitudes 50 00ꞌE and 70 00ꞌE. Aeromagnetic data in grid format containing eight sheets were analysed and interpreted. This study employed several magnetic filtering methods to investigate lineaments and other structural features; reduction to the equator, horizontal derivatives, upward continuation, vertical derivatives, analytical signal, and Centre for exploration targeting grid analysis. Depth estimates using Source parameter Imaging and Euler Depth determination method reveal a maximum depth of 4.2 km around Mokwa and batati areas. Shallow sources also exist around pategi, paiko, Izom and Lapai areas with an average depth ranging from 107.74 m to about 514.82 m. A maximum thickness of sedimentation of 4.0 km was obtained along the modelled profile trending NE-SW. The regional fields of the study area have a trend of NW-SE with some minor structures trending in the NE-SW direction. The study area was found to have a good potential for mineral and hydrocarbon exploration.
  • Item
    DETERMINATION OF DEPTH TO MAGNETIC BASEMENT OVER BIU PLATEAU AND YOLA SUB-BASIN, NORTHEASTERN NIGERIA, USING SOURCE PARAMETER IMAGING (SPI) AND EULER DECONVOLUTION TECHNIQUES
    (Nigerian Journal of Physics, 2018) ADETONA, Adebayo Abbass, 34 Bello Sani, Udensi, E, E., Salako K.A.
    Quantitative analysis of aeromagnetic data covering total area of 48,000 km2 on latitude 11.000 N to 13.000 N and Longitude 9.000 E to 11.000 E, which corresponds to Basement Complex part of upper Benue trough northeastern, Nigeria was carried out with the aim of estimating the sedi mentary thickness using Source parameter imaging and Euler deconvolution. The study area is c overed by sixteen (16) aeromagnetic data sheet. Aeromagnetic data were analysed using the Oasi s Montaj 8.3 software. The total magnetic map was reduced to magnetic equator with geomagnet ic inclination of -4.3° and geomagnetic declination of -1.0o so as to get the actual position of the anomalies. The pre-processed grids dx, dy and dz from the reduced to magnetic equator map wer e used as input grids to calculate the source parameter imaging and Euler deconvolution. The res ults from the total magnetic intensity (TMI) and TMI - RTE shows that magnetic intensity values range from -94.1 nT to 235.5 nT and -80.261 nT to 234.153 nT respectively. The results indicate a dominant NE-SW, NW – SE and E – W orientation of faults and were also identified mostly at the edges of sediments-basement contacts. The result from SPI ranges from 0.110 km (shallow magnetic bodies) is observed at the northeast part of the study area which is made of crystalline rocks to 3.243 km (deep lying magnetic bodies) is observed at the Northwest, Southeast and Sou thwest part of the study area. The depths of the magnetic source bodies estimated from Euler dec onvolution for the structural index SI = 1 ranges from 0.094 km (out cropping magnetic bodies) t o 3.32 km (deep lying magnetic bodies). The shallower magnetic anomalies are as a result of bas ement rocks which intruded into the sedimentary rocks while the deeper magnetic anomalies are associated with magnetic basement surface and intra basement discontinuities like faults and frac tures. The maximum sedimentary thickness of about 3.24 km and 3.32 km from SPI and Euler d econvolution respectively might be sufficient for hydrocarbon maturation in the area.
  • Item
    INVESTIGATING THE GEOTHERMAL POTENTIAL WITHIN BENUE STATE, CENTRAL NIGERIA, FROM RADIOMETRIC AND HIGH RESOLUTION AERO MAGNETIC DATA
    (Nigerian Journal of Physics, 2018) ADETONA, Adebayo Abbass, Akinnubi, Tunde Daniel
    The study focuses on the analysis of high resolution Aeromagnetic data for the estimation of geot hermal potential within the eastern part of Lower Benue Basin and correlating the results from th e analysis of radiometric concentration data of the study area. The study area covers a total area o f 18,150 km2 , six aeromagnetic sheets cover the area, major towns are Markudi, Gboko,Otukpo, Agena, Akwana and Katsina-Ala, it is bounded by latitude 7.000 and 8.000 and longitude 8.000 a nd 9.500 . The aeromagnetic data was subjected to Fourier analysis and then spectral analysis of 12 sub sections was carried out. From the spectral analysis, the depth to the top of magnetic sourc es varies from 0.28 Km to 0.36 Km while the depth to the bottom of magnetic sources varies fro m 5.52 Km to 9.63 Km. The modified Curie depth method was employed in evaluating the Curie point depth, heat flow and geothermal gradient were also obtained. The region found to have a sh allow Curie depth of 9 km at the south-western and south-eastern part of the study area has an av erage geothermal heat flow 103.98 Wm-2. The geothermal gradient also has a value of 62Ԩ/km a nd 30Ԩ/km respectively with an average value of 41.59 oC/km, anomalous high heat flow of 153. 35, and 135.62 Wm-2 was obtained within around Katsina- Ala and Oturkpo respectively. Correlat ing this result with the analysis of the radiometric values covering the study area, the ternary map shows that potassium and thorium radioactive content is noticeably high within these areas wher e relatively high heat flow values were obtained, The radioactive heat production within the two e xothermally active areas was estimated to be1.47 μW/m3 and 2.21 μW/m3 respectively this can be associated with the occurrence of these elements.