Geoimaging of subsurface fabric in Awgbagba, Southwestern Nigeria using geomagnetic and geoelectrical techniques
DOI:
https://doi.org/10.11113/mjfas.v14n2.733Keywords:
Engineering activities, Geoimaging, Ground magnetic, Hydrogeological purposes, subsurface fabric, Vertical electrical sounding.Abstract
The heterogeneous nature of the earth has given rise to variations experienced in the subsurface. Some parts are good for hydrological exploration while others are good for civil engineering activities. These variations experienced in the subsurface could not be detected except through geophysical survey and analysis. Integration of ground magnetic and Vertical Electrical Sounding (VES) techniques were carried out in Awgbagba to image the subsurface fabric with a view to mapping subsurface geological features, such as the weak and competent zones, to determine the overburden thickness, and suitability of Awgbagba for civil engineering and hydrogeological purposes. Ten ground magnetic traverses were established in W-E and N-S azimuths. Twenty VES points were randomly sounded for the study in order to cover the entire study area. The magnetic residual field anomaly values ranged from -1, 600 to 700 nT. The study area is grouped into low, average, and high magnetic zones. The depth to magnetic sources ranged from 8.1 to 48.9 m with a mean value of 17.4 m. Three planar feature orientations in the study area are in NE-SW, NW-SE, and SE-NW orientations. VES results showed 7 QH-curve type, 6 HA-curve type, 4 KH-curve type, 1 AA-curve type, 1 HK-curve type and 1 QQ-curve type respectively. The ratio of thin-to-thick overburden and fresh-to-fractured bedrock are 3:7 and 2:3 respectively. It is concluded that the study area cannot withstand high-rise building constructions. However, the mapped fracture zones in the study area would serve as promising zones for borehole development.
References
Adagunodo, T. A., Sunmonu, L. A. 2012. Groundmagnetic survey to investigate on fault pattern of industrial estate Ogbomoso Southwestern Nigeria. Advances in Applied Science Research 3(5), 3142 – 3149.
Adagunodo, T. A., Sunmonu, L.A., Adabanija, M. A. 2015a. Geomagnetic signature pattern of industrial layout Orile Igbon. Advances in Architecture, City and Environment 1(3), 14 – 25.
Adagunodo, T.A., Adeniji, A.A., Erinle, A.V., Akinwumi, S.A., Adewoyin, O.O., Joel, E.S., Kayode, O.T. 2017. Geophysical investigation into the integrity of a reclaimed open dumsite for civil engineering purpose. Interciencia Journal 42(11), 324 – 339.
Adagunodo, T.A., Sunmonu, L.A., Adeniji, A. A. 2015b. An overview of magnetic method in mineral exploration. Journal of Global Ecology and Environment 3(1), 13 – 28.
Adagunodo, T.A., Sunmonu, L.A., Ojoawo, A., Oladejo, O.P., Olafisoye, E. R. 2013. The hydro geophysical investigation of Oyo State industrial estate Ogbomosho, Southwestern Nigeria using vertical electrical soundings. Research Journal of Applied Sciences, Engineering and Technology 5(5), 1816 – 1829.
Adagunodo, T.A., Sunmonu, L.A., Oladejo, O. P. 2014. Effect of constructing high-rise buildings without a geophysical survey. Nigerian Journal of Physics Special Edition September 2014, 91 – 100.
Adelusi, A.O., Akinlalu, A.A., Nwachukwu, A. I. 2013. Integration studies of buildings around school of science area, Federal University of Technology, Akure, Southwestern, Nigeria. International Journal of Physical Sciences 8(15), 657 – 669.
Adewoyin, O.O., Joshua, E.O., Akinwumi, I.I., Omeje, M. and Joel, E. S. 2017. Evaluation of geotechnical parameters using geophysical data. Journal of Engineering and Technological Sciences. 49(1), 95 – 113.
Al-Amoush, H. 2010. Integration of vertical electrical sounding and aeromagnetic data using GIS techniques to assess the potential of unsaturated zone and natural basalt caves for groundwater artificial recharge in NE-Jordan. Jordan Journal of Civil Engineering 4(4), 389 – 408.
Al-Garni, M. A. 2009. Geophysical investigations for groundwater in a complex subsurface terrain, Wadi Fatima, KSA: A case history. Jordan Journal of Civil Engineering 3(2), 118 – 136.
Al-Khafaji, W.M.S., Al-Dabbagh, H.A. Z. 2016. Visualizing geoelectric-Hydrogeological parameters of Fadak farm at Najaf Ashraf by using 2D spatial interpolation methods. NRIAG Journal of Astronomy and Geophysics 5(2), 313 – 322.
Carruthers, R. M. 1985. Review of geophysical techniques for groundwater exploration in crystalline basement terrain. British Geological Survey. Regional Geophysics Research Group,Report WK/RG/85/003, 30 pp.
Emenike, E. A. 2001. Geophysical exploration for groundwater in a sedimentary environment: a case study from Nanka over Nanka Formation in Anambra Basin, Southeastern Nigeria. Global Journal of Pure and Applied Sciences 7(1), 97 – 101.
WinGLink software. Version 1.62.08 – 20030519. January 10, 2008. Geosystem SRL. Via Clericetti 42a, 20133 Milan, Italy.
Hewaidy, A.G.A., El-Motaal, E.A., Sultan, S.A., Ramdan, T. M., El-Khafif, A. A., Soliman, S. A. 2015. Groundwater exploration using resistivity and magnetic data at the northwestern part of the Gulf of Suez, Egypt. Egyptian Petroleum Research Institute 24, 255 – 263.
Keller, G. V., Frishchnecht, F. C. 1966. Electrical methods in geophysical prospecting. New York: Pergamon Press, pp. 96.
Koefoed, O. 1979. Geosounding principles, 1. Resistivity measurements. Amsterdam, Netherlands: Elsevier Scientific Publishing, pp. 275.
Ojo, A.O., Omotoso, T.O., Adekanle, O. J. 2014. Determination of location and depth of mineral rocks at Olode village in Ibadan, Oyo State, Nigeria, using geophysical methods. International Journal of Geophysics Article ID 306862, 1 – 13.
Okwoli, E., Onaja, O. S., Udoeyop, U. E. 2014. Ground magnetic and electrical resistivity mapping for basement structures over charnokitic terrain in Ado-Ekiti area, Southwestern Nigeria. International Journal of Science and Technology 3(10), 683 – 689.
Olayanju, G.M., Adelusi,A.O., Adiat, K. A. 2015. Combined use of ground magnetic and electrical resistivity methods in bedrock mapping: case study of NTA premises Oba Ile area, South-western Nigeria. EJGE 20(15), 6591 – 6606.
Oyeyemi, K.D., Aizebeokhai, A.P., Adagunodo, T.A., Olofinnade, O.M.,
Sanuade, O.A., Olaojo, A.A. 2017. Subsoil characterization using geoelectrical and geotechnical investigations: implications for foundation studies. International Journal of Civil Engineering and Technology 8(10), 320 – 314.
Sunmonu, L.A., Adagunodo, T.A., Olafisoye, E. R., Oladejo, O. P. 2012. The groundwater potential evaluation at Industrial Estate Ogbomoso, southwestern Nigeria. RMZ – Materials and Geoenvironment 59(4), 363 – 390.
Surfer 11 software. Version 11.0.642. July, 2012. Golden Software, Inc., 809 14th street Golden, Colorado, 80401 – 1866, U.S.A.
Telford, W.M., Geldart, L. P., Sheriff, R. E. 1976. Applied Geophysics (2nd Ed.) Cambridge: Cambridge University Press.
Vander Velpen, B. P. A. 2004. WinRESIST Software Version 1.0. ITC, IT-RSG/GSD, Delft, Netherlands.
