Characterization of the sulfide deposits in the southeastern Nigeria using VLF method: insights from numerical modeling and field examples

D. E. Falebita (Department of Geology, Obafemi Awolowo University, Ile-Ife, Nigeria.)
O. Afolabi (Department of Geology, Obafemi Awolowo University, Ile-Ife, Nigeria.)
B. O Soyinka (Terracon, Seattle, Washington DC, USA.)
A. A. Adepelumi (Department of Geology, Obafemi Awolowo University, Ile-Ife, Nigeria.)

Abstract


A priori geologic and geophysical information has been used to construct conceptual VLF experiments on conductively and inductively coupled overburden geological models of the lead-zinc (Pb-Zn) mineralization zone found in southeastern Nigeria. This is based on the finite element approach to (1) simulate different geologic situations of overburden occurrence, (2) examine the roles played by overburden in modifying and masking VLF responses of a buried conductor target, and (3) confirm the effectiveness of VLF method in mapping lead-zinc lodes found in sedimentary terrains. The computed theoretical model curves and field examples are expected to serve as guide for VLF anomaly pattern recognition due to overburden thickness, resistivity and width of conductor in similar terrain as the study area.


Keywords


sulfide; conductor; VLF; overburden thickness; polarization parameters; Nigeria

Full Text:

PDF

References


[1]Abbas, A.M., Khalil, M.A., Massoud, U., Monterio-Santos, F., Mesbah, H. A., Lethy, A., Soliman, M., Ragab, E. S. A., 2012. The implementation of multi-task geophysical survey to locate Cleopatra Tomb at Tap-Osiris Magna, Borg El-Arab, Alexandria, Egypt “Phase II”. NRIAG J. Astron. Geophysics. 1, 1–11.

[2]Adelusi, A. O., Ayuk, M. A., Kayode, J. S., 2014. VLF-EM and VES: an application to groundwater exploration in a Precambrian basement terrain SW Nigeria. Annals of Geophysics, 57, 1, 2014, S0184; doi: 10.4401/ag-6291

[3]Adepelumi, A. A., Yi, M. J., Kim, J. H. and Ako, B. D. 2006. Integration of surface geophysical methods for fracture detection in crystalline bedrocks of southwestern Nigeria, Hydrogeology Journal, vol. 14, pp. 1284-1306.

[4]Akande, S. O., and Mucke, A., 1989. Mineralogical, textural and paragenetic studies of the Lead-Zinc-Copper mineralization in the lower Benue Trough (Nigeria) and their genetic implications. Journal of African Earth Science, 9, 23-29.

[5]Akande, S. O., and Mucke, A., 1993. Coexisting copper sulphides and sulphosalts in the Abakaliki Pb-Zn deposit, lower Benue Trough (Nigeria) and their genetic significance. Mineralogy and Petrology, Volume 47, Issue 2–4, pp 183–192.

[6]Al-Tarazi, E., Abu Rajab, J., Al-Naqa, A., El-Waheidi, M., 2008. Detecting leachate plumes and ground water pollution at Ruseifa municipal landfill utilizing the VLF-EM method. J. Appl. Geophysics 65, 121–131.

[7]Babu, V. R, Ram, S. and Sundararajan, N. 2007. Modeling and inversion of magnetic and VLF-EM data with an application to basement fractures: A case study from Raigarh, India. Geophysics, Vol. 72, No. 5; p. B133–b140.10.1190/1.2759921

[8]Bahri, A.S., Santoso, D., Kadir, W.G.A., Puradimedja, D. D., Tofan, R. M., Monteiro-Santos, F. A., 2008. Penerapan metoda Very Low Frequency-vertical Gradient (VLF-EM-vGRAD) untuk memetakan Sungai bawah permukaan di daerah karst. In: Proceedings of the 33rd Pertemuan Ilmiah Tahunan Himpunan Ahli Geofisika Indonesia (PITHAGI), pp.020.

[9]Bayrak, M., Şenel, L., 2012. Two-dimensional resistivity imaging in the Kestelek boron area by VLF and DC resistivity methods. J. Appl. Geophysics. 82, pp. 1–10.

[10]Beamish, D. 1998. "Three-dimensional modelling of VLF data", Journal of Applied Geophysics, vol. 39, pp. 63-76.

[11]Benkhelil, J. 1987. Cretaceous deformation, magmatism and metamorphism in the lower Benue Trough, Nigeria. Geological Journal, 22, 467-493.

[12]Cagniard, L., 1953. Basic theory of the magnetotelluric method of geophysical prospecting. Geophysics 18(3), 605-635.

[13]Coppo, N., Schnegg, P-A., Defago, M., and GSCB. 2006. Mapping a shallow large cave using a high-resolution very low frequency electromagnetic method. Proceedings of the 8th conference on limestone hydrogeology. Neuchatel Switzerland - Web edition, N. Goldscheider, J, Mudry, L. Savoy and F. Zwahlen (Eds), 268 pages

[14]Chung, S. H., Lee, S. H and Kim, J. H., 1990. Depth presentation of VLF-EM data using digital filtering. Geophysical exploration method development series KR-89-2D-2 of Korea institute of energy and resources, 97-115.

[15]Cratchley, C. R. and Jones, G. P. 1965. An interpretation of the geology and gravity anomalies of the Benue Valley, Nigeria. Overseas Geological Surveys (Great Britain) Geophysical Division, London, 26 pp.

[16]Eze, C. L., Mamah, L. I., and Israel-Cookey, C., 2004. Very low frequency electromagnetic (VLF-EM) response from a lead sulphide lode in the Abakaliki lead/zinc field, Nigeria. Intern. Journ. Applied Earth Observation and Geoinformation, 5, 159–163.

[17]EM2Dmodel, 2002. EM2Dmodel version 1.0, Processing and interpretation software for electrical resistivity data. KIGAM, Daejeon, South Korea.

[18]Etim, O.N., Louis, P., Maurin, J.C., 1988. Interpretation of electrical sounding on the Abakaliki lead–zinc and brine prospects, S.E. Nigeria: Geological and genetic implications. J. Afr. Earth Sci. 7 (5–6), 743–747.

[19]Gürer, A., Bayrak, M., Gürer, Ö. F., 2009. A VLF survey using current gathering phenomena for tracing buried faults of Fethiye–Burdur fault zone, Turkey. J. Appl.Geophys.68, 437–447.

[20]Jeng, Y., Lin, M-J., Chen, C-S., and Wang, Y-H. 2007. Noise reduction and data recovery for a VLF-EM survey using a nonlinear decomposition method. Geophysics, vol. 72, No. 5, September-October, pp. F223–F235.

[21]Joshi, M. S., Gupta, O. P., Negi, J. G., 1984. Scale-model response of a thin vertical conductor below a conductive, inductive, or laterally inhomogeneous over-burden layer. Geophysics 49, 2159–2165.

[22]Kaikkonen, P, 1980. Interpretation nomograms for VLF measurements. Acta Uni Oui, A. 92 Phys 17: 1- 48.

[23]Karous, M., Hjelt, S. E., 1983. Linear filtering of VLF dip-angle measurements. Geophysical Prospecting, 31, 782-794.

[24]Kaya, M.A., Özürlan, G., Şengül, E., 2007. Delineation of soil and groundwater contamination using geophysical methods at a waste disposal site in Çanakkale, Turkey. Environ.Monit.Assess.135, 441–446.

[25]Kayode, J. S., A.O. Adelusi, M.N.M. Nawawi, M. Bawallah, T.S. Olowolafe 2016. "Geo-electrical investigation of near surface conductive structures suitable for groundwater accumulation in a resistive crystalline basement environment: A case study of Isuada, southwestern Nigeria", Journal of African Earth Sciences, vol. 119, pp. 289-302.

[26]Lajoie, J. J., and West. G. F., 1976. The electromagnetic response of a conductive inhomogeneity in a layered earth. Geophysics, 41, 1133-1156.

[27]Lowrie, W., and West. G. F., 1965. The effect of conducting overburden on electromagnetic prospecting measurements. Geophysics, 30, 624-632.

[28]Mamah, L. I., Eze, L.C., 1988. Electromagnetic and ground magnetic survey over zones of lead-zinc mineralization in Wanakom (Cross River State). J Afr. Earth Sci. 7, 749–758.

[29]Monteiro-Santos, F. A., Mateus, A., Figueiras, J., Gonçalves, M. A. 2006. Mapping groundwater contamination around a landfill facility using the VLF-EM method – a case study. J. Appl. Geophysics. 60, 115–125.

[30]Neumann, T., Berner, Z., Stüben, D., Bahri, A. S., Jaya, M., 2009. Geowissenschaftliche Bewertung von Karsthöhlen für die asserbewirtschaftung in Gunung Sewu. Wasser Wirtsch. 7–8, 31–36.

[31]Olade, M. A and Morton, R. D. 1985. Origin of lead-zinc mineralization in the southern Benue trough, Nigeria. Fluid inclusions and trace element studies. Mineral Deposita, 20, 76-80.

[32]Ogilvy, R. D., and Lee, A. C., 1991. Interpretation of VLF-EM in-phase data using current density pseudosections. Geophysical Prospecting, 39, 567-580.

[33]Orajaka, S., Nwachukwu, S.O., 1968. Combined electromagnetic and geochemical investigations in Ameri lead-zinc area. Jour. Mining Geology, 3, 49–52.

[34]Paterson, N. R. and Ronka, V., 1971. Five years of surveying with the very low frequency electromagnetic method. Geoexploration, 9, 7-26.

[35]Phillips, W. J., and Richards, W. E., 1975. A study of effectiveness of the VLF method for the location of narrow-mineralised fault zones: Geoexploration, 13, 215-226.

[36]Poddar, M., 1982. Very low-frequency electromagnetic response of a perfectly conducting half-plane in a layered half-space. Geophysics, 47, 1059-1067.

[37]Saydam. A. S., 1981. Very low frequency electromagnetic interpretation using tilt angle and ellipticity measurements. Geophysics, 46, 1594-1605.

[38]Sharma, S. P., Anbarasu, K., Gupta, S., Sengupta, A., 2010. Integrated very low- frequency EM, electrical resistivity, and geological studies on the Lanta Khola landslide, North Sikkim, India. Landslides 7, pp. 43–53.

[39]Sinha, A. K., 1990. Interpretation of ground VLF-EM data in terms of vertical conductor models. Geoexploration, 26, 213-231.

[40]Smith, B. D., and Ward, S. H., 1974. On the computation of polarization ellipse parameters. Geophysics, 39, 867-869.

[41]Spies, B. R., 1989. Depth of investigation in electromagnetic sounding methods. Geophysics, 54, 872-888.

[42]Victor, O. M., Onwuemesi, A. G., Aniwetalu, E. U. 2015. Exploration of Lead-Zinc (Pb-Zn) mineralization using very low frequency electromanetic (VLF-EM) in Ishiagu, Ebonyi State. Journal of Geol. Geosci 4: 214. doi:10.4172/2329-6755.1000214

[43]Warnana, D. D., Bahri, A. S., 2004. On the use of resistivity and VLF method for profiling underground cave in Ngeposari, Semanu Gunung Kidul. In: Proceedings of the 1st International Seminar of Early Warning System. LPPM-ITS, Surabaya, pp. XX–XX.



DOI: https://doi.org/10.30564/jgr.v3i1.2809

Refbacks

  • There are currently no refbacks.
Copyright © 2021 D. E. Falebita, O. Afolabi, B. O Soyinka, A. A. Adepelumi Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.