Structural Complexity and Mineral Potential of Central Benue Trough, Using High Resolution Aeromagnetic Dataset
Keywords:Akwana, Wukari, aeromagnetic, first vertical derivative, analytic signal, exploration
Mineral mining is an important resource for economic development, and its mineralization is controlled by geology, structures and hydrothermal alteration within rock formations. For this reason, high resolution magnetic dataset covering parts of the Central Benue Trough was processed and filtered/enhanced using analytic signal, first vertical derivative and tilt derivative algorithms. Qualitative interpretation of the total magnetic intensity maps reveals numerous magnetic depletion zones defined as hydrothermal active areas within Dampar, Wuro Jam, Kishr, Yamere, Shnye, Jibu, Adi, Amafan, Akwana, Akahana, Ayere, Awe and Tunga. There is a major NE-SW trending low magnetic amplitude stretching from Ugba to Kwarata, which is interpreted as active zones at the contact between the Central Benue Trough and Eastern Nigerian Basement Complex, the zone is interpreted as a major area of interest, especially around intense structurally active areas at Wukari, Chonku, Ngbebe, Bayawai, Gidan Idi, Wamgbe, Gusawa, Anzwa and Gada Mayo. Derivative filters revealed majorly NE-SW trending structures within the Central Benue Trough, with minor NW-SE trends observed at the contact between the Central Benue Trough and Eastern Nigerian Basement Complex with the longest fault having a length of about 42 km, stretching from Sankara to Apar, Hundu area. Major folds are mapped at Dampar, Wuro Jam and Kishr area. Long stretched fault systems within the Central Benue trough is observed at Bangalala, Gwinwan, Amar, Yamere and Rufai, Uzam, Sojo area. The dominating series of high angle NE-SW trending faults and folds structure was defined to have resulted from two major regional series of deformation stages. Integration of geological information and geophysical interpretation defined Wukari, Chonku, Bayawai, Wamgbe, Gusawa, Anzwa, Dampar, Yamere, Akwana, Akahana, Bangalala, Gwinwan,and Tunga as area of highest potential of mineral deposits occurrences based on the geology, extensive alteration and structural complexity.
(2) Armstrong M, Rodeghiero A (2006). Airborne Geophysical Techniques in Aziz. Coal Operators' Conference (pp. 113-131). University of Wollongong and the Australasian Institute Mining and Metallurgy.
(3) Benkhelil J (1989) .The origin and evolution of the Cretaceous Benue Trough, Nigeria. J Afr Earth Sci 8:251– 282
(4) Benkhelil J, Robineau B (1983). Le fosse de la Benoue est il um rift? Centre Rech Eplor Prod Elf Aquitaine Bull 7:315–321
(5) Burke KC, Dewey JF (1972). Orogeny in Africa. In: Dessauvagie TFJ, Whiteman AJ (eds), Africa geology. University of Ibadan Press, Ibadan, pp 583–608
(6) Charles, O.O. (2007). Interpretation of aeromagnetic anomalies over the Lower and Middle Benue Trough of Nigeria. Geophysical Journal International. April 2007
(7) Connard, G., Couch, R., & Agemperle, M. (1983). Analysis of aeromagnetic measurements from Cascade Range in central Oregon. Geophysics,48, 376–390.
(8) Cratchley, C. R. and Jones, G. P. (1965). An interpretation of geology and gravity anomalies of the Benue valley, Nigeria Geophysics Paper, Overseas Geol. Surv. London, 1: 1-26.
(9) Effiong, C. I., Ekot, A. E., Bassey, C. E., & Udoh, A. C. (2017). Utilization of aeromagnetic and landsat data for structural interpretation: a case study of Ikom-Mamfe Embayment, southeastern Nigeria. American Journal of Engineering Research,6, 232–247.
(10) Essa, K. S., & Elhussein, M. (2017). A new approach for the interpretation of magnetic data by a 2-D dipping dike. Journal of Applied Geophysics,136, 431–443.
(11) Essa, K. S., Nady, A. G., Mostafa, M. S., & Elhussein, M. (2018). Implementation of potential field data to depict the structural lineaments of the Sinai Peninsula, Egypt. Journal of African Earth Sciences,147, 43–53.
(12) Fairhead JD, Blinks RM (1991). Differential opening of the Central and South Atlantic Oceans and the opening of the Central African Rift System. Tectonophysics 187:191–203
(13) Genik GJ (1993). Regional framework, structural and petroleum aspects of rift basins in Niger, Chad and Central African Republic (C.A.R.). Tectonophysics 213:169–185
(14) KelmaGeodynamics, (2019). Exploration and Ore targeting manual. Unpublished
(15) Luo, Y., Wang, M., Luo, F., Tian, S. (2011). Direct Analytic Signal Interpretation Of Potential Field Data Using 2-D Hilbert Transform. Chinese Journal of Geophysics Vol.54, No.4, 2011, Pp. 551 - 559
(16) Murphy BS (2007). Airborne geophysics and the Indian scenario. J. Ind. Geophysics Union, 11 (1), 1-28.
(17) Nabighian M. N., Grauch V. J. S., Hansen R. O., LaFehr T. R., Li Y., Peirce J. W., Phillips J. D., Ruder, M.E. (2005). The historical development of the magnetic method in exploration, Geophysics 70(6) 33 – 71.
(18) Ngama, E. J., & Akanbi, S. (2017). Qualitative interpretation of recently acquired aeromagnetic data of Naraguta area, north-central Nigeria. Journal of Geography, Environment and Earth Science International,11, 1–14.
(19) Nwajide, C. S. (2013). Geology of Nigeria’s Sedimentary Basins. CSS bookshops limited. Pp 290
(20) Nwosu, O. B. (2014). Determination of Magnetic Basement Depth over Parts of Middle Benue Trough by Source Parameter Imaging (SPI) Techniques using HRAM. Int. J. Sc. Tech. Res. 3 (1): 262-271.
(21) Obaje, N.G., (2009). Geology and Mineral Resources of Nigeria. Springer Publishers, Germany.
(22) Ofoegbu, C. O. (1984). Aeromagnetic anomalies over the Lower and Middle Benue Trough, Nigeria. J. Afr. Earth Sci., 3: 293-2.
(23) Oha, I. A., Onuoha, K. M., Nwegbu, A. N., & Abba, A. U. (2016). Interpretation of high-resolution aeromagnetic data over southern Benue Trough, southeastern Nigeria. Journal of African Earth Sciences,125, 369–385.
(24) Onyishi G.E., and Ugwu, G. Z. (2019). Source Parameter Imaging and Euler Deconvolution of Aeromagnetic Anomalies over Parts of the Middle Benue Trough, Nigeria. American Journal of Geophysics, Geochemistry and Geosystems Vol. 5, No. 1, 2019, pp. 1-9
(25) Phillips J.D. (2000). Locating magnetic contacts: A comparison of the horizontal gradient, analytical signal and local wavenumber methods: 70th Annual International Meeting, SEG, Expanded Abstracts 402 - 405.
(26) Rowland A.A., Nur, A. (2018). Interpretation of High Resolution Aeromagnetic Data for Hydrocarbon Potentials over Parts of Nasarawa and Environs North-
Central Nigeria. World Journal of Applied Physics 2019; 4(1): 1-11
(27) Selim, E. I., & Aboud, E. (2014). Application of spectral analysis technique on ground magnetic data to calculate the Curie depth point of the eastern shore of
the Gulf of Suez, Egypt. Arabian Journal of Geosciences,7, 1749– 1762.
(28) Telford, W. M., Geldart, L.P. and Sheriff, R.E. 1998. Applied Geophysics, (2nd Ed), Cambridge University Press, USA, 113 – 114.
(29) Thurston, J. B., & Smith, R. S. (1997). Automatic conversion of magnetic data to depth, dip, and susceptibility contrast using the SPI (TM) method. Geophysics,62, 807–813.
(30) Ugbor, C.C., Arinze, I.J. & Emedo, C.O (2020). Analysis of Aeromagnetic Data of Ikwo and Environs, Southeastern Nigeria: A Mineral and Hydrocarbon Exploration Guide. Nat Resour Res. https://doi.org/10.1007/s11053- 020-09633-3
(31) Ugwu, C. M., Ugwu, G. Z. and Alasi, T. K.(2018). Spectral analysis and source parameter imaging of aeromagnetic anomalies over Ogoja and Bansara areas of Lower Benue Trough, Nigeria. J. Geol. Min. Res., 10 (13): 28-38.