Ground Based Gravimetric for the Detection and Depth Mapping of Subsurface Geological Features of Ilesha, Southwest Nigeria

Document Type : Research Article


1 Senior Lecturer, Department of Physics, Federal University of Agriculture, Abeokuta, Nigeria

2 M.Sc. Student, Department of Physics, Federal University of Agriculture, Abeokuta, Nigeria

3 Assistant Lecturer, Department of Physics, Federal University of Agriculture, Abeokuta, Nigeria

4 Undergraduate, Department of Physics, Federal University of Agriculture, Abeokuta, Nigeria


This paper presents the analysis and interpretation of ground gravity data of Ilesha and its environs in southwest Nigeria. The work is aimed at complementing researches done in this locality with magnetic survey for both ground and airborne data. The ground gravity data of the area within latitude (7o30ˈ - 8o00ˈ) N and longitude (4o30ˈ - 5o00ˈ) E was acquired from the Nigerian Geological Survey Agency (NGSA). The data set was interpreted qualitatively and quantitatively to derive information about the structural features of the subsurface. The qualitative analysis was carried out by filtering techniques and interpreted by making visual inspection of grids to map low and high-density regions. Equally, the quantitative interpretation employed were Euler 3-D deconvolution and Source Parameter Imaging (SPI) methods, which revealed the boundary, location and depth of gravity sources defining the study area. The minimum and maximum depths of anomalous sources obtained are 781.43 m and 4,208.85 m, while the average depth to the target is 2,537.215 m. The average depth of gravity anomalous sources estimated predicted the area to hold a worthy prospect for the accumulation of near surface rock minerals.


Main Subjects

Abraham, E.M., Lawal, K.M., Ekwe, A.C., Alile, O., Murana, K.A. and Lawal, A.A., 2014, Spectral analysis of aeromagnetic data for geothermal energy investigation of Ikogosi warm spring – Ekiti State, southwestern Nigeria. Geothermal Energy, 2(6), 1–21.
Adegoke, J.A. and Layade, G.O., 2019, Comparative depth estimation of iron-ore deposit using the Data-Coordinate Interpolation Technique for airborne and ground magnetic survey variation. African Journal of Science, Technology, Innovation and Development. 11(5), 663-669, doi: 10.1080/20421338. 2019.1572702.
Barnes, G.J., Lumley, J.M., Houghton, P. and Gleave, R., 2011, Comparing gravity and gravity gradient surveys, Geophysical Prospecting, 59, 176–187, doi:10.1111/j.1365-2478.2010.00900.x.
Blakely, R.J., 1995, Potential theory in gravity and magnetic applications. Cambridge University Press.
Briggs, I. C., 1974, Machine contouring using minimum curvature. Geophysics 39(1), 39-48.
Chemin, J.Y.,  Desjardin, B., Gallagher, I. and Greneir, E., 2006, Mathematical geophysics: an introduction to rotating fluids and the Navier-Stokes equation. Oxford lecture series in mathematics and its applications. Oxford University Press London, 9-12.
Cyril, C.O., 2019, Delineation of High-Resolution Aeromagnetic Survey of Lower Benue Trough for Lineaments and Mineralization: A Case Study of Abakaliki sheet 303.        Malaysian Journal of Geosciences, 3(1), 51-60.
Dobrin, M.B., 1976, Introduction to Geophysical Prospecting, 3rd Edition: McGraw-Hill Book Co., Inc, New York.
Elueze, A.A., 1988, Geology of the Precambrian Schist belt in Ilesha area Southwestern Nigeria.
Fieberg, F.C., 2002, Ground Magnetic Investigation for Gold Prospecting in South-Western Nigeria. Abstract Presentation at 62nd Meeting of German Geophysical Society, Hannover, 20p.
Hammer, S., 1939, Terrain corrections for gravimeter stations. Geophysics, 4, 184–194, doi:10.1190/1.1440495.
Hansen, R.O. and Simmonds, M., 1993, Multiple-source Werner deconvolution. Geophysics, 58, 1792-1800.
Hartman, R.R., Tesky, D.J. and Friedberg, J.L., 1971, A system for rapid digital aeromagnetic interpretation. Geophysics, 36, 891-918.
Hesham, S.Z. and Hesham, T.O., 2016, Application of High-Pass Filtering Techniques on Gravity and Magnetic Data of the Eastern Qattara Depression Area, Western Desert, Egypt. National Research Institute of Astronomy and Geophysics, 5, 106-123.
Houghton, P., Bate, D., Davies, M. and Lumley, J., 2007, Using gravity gradiometry as a blueprint for exploration in thrust and fold belts, First Break, 25, 105–112.
Johnson, W.W., 1969, A least - Squares method of interpreting magnetic anomalies caused by Two- Dimensional structures. Geophysics, 34, 65-74.
Kayode, J.S., Adelusi, A.O. and Nyazebe, P.K., 2013, Interpretation of Ground Magnetic Data of Ilesha, Southwestern Nigeria for Potential Mineral Targets. Advances in Applied Science Research, 4(1), 163-172.
Keary, P. and Brooks I., 1984, Introduction to petroleum geology and geophysics.
Kevin, M., 1997, Gravity method overview. Department of Geosciences, Southwest Missouri State University, Springfield, MO 65804.
Mendonca, C.A. and Silva, B.C., 1995, Interpolation of potential-field data by equivalent layer and minimum curvature: A comparative analysis: Geophysics, 60, 399–407, doi:10.1190/1.1443776.
Ngozi, A.O., Ezemmah K.C. and Igwe E.A., 2019, Euler Deconvolution and Source Parameter Imaging of Aeromagnetic Data of Guzabure and Gudumbali Regions, Chad Basin, Northeastern Nigeria. IOSR Journal of Applied Physics, 11(3), 1-10.
Nicolas, O.M., 2009, The Gravity Method. Exploration for Geothermal Resources, pp. 1-9.
Nigerian geological Survey Agency, 2009, Geological Map of Nigeria, scale: 1:2,000,000.
Nwosu, O.B., 2014, Determination of Magnetic Basement Depth Over Parts of Middle Benue Trough By Source Parameter Imaging (SPI) Technique Using HRAM. International    Journal of Scientific and Technology Research, 3(1), 262-271.
Obaje, N.G., 2009, Geology and mineral resources of Nigeria. Lecture Note in Earth Science Series, Vol. 120. Geo. surv. Nig., 77 – 82.
Olurin, O.T., 2017, Interpretation of High resolution airborne magnetic data (HRAMD) of Ilesha and its environs, Southwest Nigeria, using Euler Deconvolution method. Materials and Geoenvironment, 64(4), 227-241.
Ozebo, V.C., Ogunkoya, C.O., Layade, G.O., Makinde, V. and Bisilimi, A.I., 2017, Evaluation of Aeromagnetic Data of Ilesha Area of Oyo State Nigeria using Analytical Signal (ASM) and Local wavenumber (LWN). J. Appl. Sci. Environ. Manage, 21(6), 1151-1161.
Ozebo, V.C., Ogunkoya, C.O., Makinde, V. and Layade, G.O., 2014, Source Depth Determination from Aeromagnetic Data of Ilesha, Southwest Nigeria, using Peter's Half Slope Method. Earth Science Research, 3(1), 41-49.
Pajot, G., de Viron, O., Diament, M., Lalancette, M.F. and Mikhailov V.O., 2008,Noise reduction through joint processing of gravity and gravity gradient data: Geophysics, 73(3), I23–I34, doi:10.1190/ 1.2905222.
Parasnis, D.S., 1986, Principles of applied geophysics (4th edition) chapman and Hall, London.
Rahaman, O.J., 1976, Review of Basement Geology of Smith, Western Nigeria.
Reeves, C., 2005, Aeromagnetic Surveys; Principles, Practice and Interpretation. GEOSOFT, 155.
Reid, A.B., Allsop, J.M., Granser, H., Millett, A.J. and Somerton, I.W., 1990, Magnetic interpretation in three dimensions using Euler deconvolution. Geophysics, 55, 80-99.
Reynolds, M.J., 1997, Introduction to Applied and Environmental Geophysics. John Wiley and Sons, New York USA.
Roest, W.R., Verhoef, J. and Pilkington, M., 1992, magnetic interpretation using 3-D analytic signal. Geophysics, 57, 116-125.
Salako, K.A., 2014, Depth to Basement determination using Source Parameter Imaging (SPI) of Aeromagnetic Data: An application to upper Benue Trough and Borno Basin, Northeast, Nigeria. Academic Research International (AR Int.), 5(3), 74-80.
Telford, W.M., Geldart, L.P., Sheriff, R.E., and Keys, D.A., 1976, Applied Geophysics: Cambridge University Press.
Thompson, D.T., 1982, A new technique for making computer-assisted depth estimates from magnetic data. Geophysics, 47(1), 31-37.
Thurston, J.B. and Smith, R.S., 1997, automatic conversion of magnetic data to depth, dip and density contrast using the SPITM method. Geophysics, 62(3), 807-813.
Whitehead, N. and Musselman, C., 2005, MontajGrav/Mag interpretation: Processing, analysis and visualization system for 3D inversion of potential  field data for Oasis montaj v6.1. Geosoft Inc. ON, Canada.