International Journal of
Physical Sciences

  • Abbreviation: Int. J. Phys. Sci.
  • Language: English
  • ISSN: 1992-1950
  • DOI: 10.5897/IJPS
  • Start Year: 2006
  • Published Articles: 2569

Full Length Research Paper

A case study of aeromagnetic data interpretation of Nsukka area, Enugu State, Nigeria, for hydrocarbon exploration

Daniel N. Obiora
  • Daniel N. Obiora
  • Department of Physics and Astronomy, University of Nigeria, Nsukka, Enugu State, Nigeria.
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Mirianrita N. Ossai
  • Mirianrita N. Ossai
  • Department of Physics and Astronomy, University of Nigeria, Nsukka, Enugu State, Nigeria.
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Emmanuel Okwoli
  • Emmanuel Okwoli
  • Department of Physics, Kogi state University, Anyigba, Kogi State, Nigeria.
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  •  Received: 22 July 2015
  •  Accepted: 19 August 2015
  •  Published: 16 September 2015

Abstract

The aeromagnetic data of Nsukka area was interpreted qualitatively and quantitatively. Standard Euler deconvolution, Source Parameter Imaging (SPI), Forward and Inverse modeling techniques were employed in quantitative interpretation with the aim of determining depth/thickness of the sedimentary Basin, magnetic susceptibilities and type of mineralization prevalent in the area. Oasis montaj 6.4.2 software and potent Q 4.10.07 software were employed in the data analysis. Forward and inverse modeling estimated depths for profiles 1, 2, 3, 4 and 5 were 1644, 2285, 1972, 2193 and 1200 m respectively, with respective susceptibility values of 0.0031, 0.0073, 1.4493, 0.0069 and 0.0016 which indicate dominance of iron rich minerals like limonite, hematite,pyrrhotite and pyrite, and forms lateritic caps on sandstones. Results from SPI estimated depth ranges from 151.6 m (outcropping and shallow magnetic bodies) to 3082.7 m (deep lying magnetic bodies). Depths of shallow magnetic sources resulting from lateritic bodies in the outcrops within the study area as estimated by Euler depths for the four different structural index (SI = 0.5, 1, 2, 3) ranges from 7.99 to 128.93 m. 35 to 150 m depth are good potential water reservoirs for Nsukka and environs. Depths of 1644 to 3082.7 m show sufficiently thick sediments suitable for hydrocarbon accumulation.
 
Key words: Aeromagnetic data, Nsukka area, Source Parameter Imaging (SPI), Euler deconvolution, forward and inverse modeling, anomalous source.