International Journal of Mining and Geo-Engineering

International Journal of Mining and Geo-Engineering

Structural interpretation of the Mangochi-Makanjira area (Southern Malawi) from an aeromagnetic analysis: Implications for gold exploration

Document Type : Research Paper

Authors
Joshua Chisambi 1
Joahua Chisambi 2
1 Department of Mining Engineering, School of Engineering, Malawi University of Business and Applied Sciences, Blantyre, Malawi.
2 Department of Mining Engineering, Malawi University of Business and Applied Sciences Private Bag 303
10.22059/ijmge.2023.354348.595026
Abstract
Malawi’s geology has not been mapped in detail and there is no detailed geological and structural assessment in relation to gold mineralization. Mangochi-Makanjira area in southern Malawi is endowed with abundant gold mineral resources but there is a scarcity of precise knowledge on the structures that control primary mineralization. This study used aeromagnetic data to provide a structural framework of the Makanjira area and delineated potential areas for further gold exploration. Many analytic approaches were applied to the aeromagnetic data, including reduction to the pole, Euler deconvolution, Tilt, and Vertical Derivatives filtering. Euler deconvolution was used to determine the depth of magnetic sources. Geophysical data interpretations identify the dominant linear trends present in the area to be faults, dykes and deep level basement shear zones as structures responsible for fluid flow and gold mineralization in the area.  Gold in this area is structurally controlled by N-S structures that were derived during the Pan African orogeny and it is during in this event that the area got mineralized. These fractures and faults served as channel ways for hydrothermal solutions, resulting in the emplacement of gold mineralization within the fractures. Mineralization occurs from the surface and goes deep and ranges in depth from 0.5 km to 2.4 km.  Exploration for gold should focus on these structures.
Keywords
Gold mineralization
Makanjira
Aeromagnetic anomaly
Mineral exploration
Subjects
  1. Kumah, “Sustainability and gold mining in the developing world.,” J Clean Prod, vol. 14, 2006, [Online]. Available: https://doi.org/10.1016/j.jclepro.2004.08.007.
  2. Amponsah-tawiah, “The Mining Industry in Ghana : A Blessing or a Curse.,” International Journal of Business and Social Sciences, 2(12), 62–69., 2011.
  3. Ministry of Mining, “Mines And Minerals Policy Of Malawi.,” 2013.
  4. S. Carter, “The Geology and Mineral Resources Of Malawi.” Government print, Zomba, Malawi, 1973.
  5. Bloomfield and M.S. Garson, “The Geology of the Kirk Range-Lisungwe Valley Area. Ministry of Natural Resources. Geological Survey Department. Bulletin No.17.,” The Government Printer, Zomba. Malawi, 1965.
  6. Khalifani, A. Bahroudi, S. Barak, and M. Abedi, “An integrated Fuzzy AHP-VIKOR method for gold potential mapping in Saqez prospecting zone, Iran,” Earth Observation and Geomatics Engineering, vol. 3, no. 1, pp. 21–33, 2019, doi: 10.22059/eoge.2019.263180.1027.
  7. Mami Khalifani, A. Bahroudi, F. Aliyari, M. Abedi, M. Yousefi, and M. Mohammadpour, “Generation of an efficient structural evidence layer for mineral exploration targeting,” Journal of African Earth Sciences, vol. 160, no. August, 2019, doi: 10.1016/j.jafrearsci.2019.103609.
  8. Mohammadpour, A. Bahroudi, and M. Abedi, “Automatic Lineament Extraction Method in Mineral Exploration Using CANNY Algorithm and Hough Transform,” Geotectonics, vol. 54, no. 3, pp. 366–382, 2020, doi: 10.1134/S0016852120030085.
  9. De Waele, J. Liegeois, A. A. Nemchin, and F. Tembo, “Isotopic and geochemical evidence of proterozoic episodic crustal reworking within the irumide belt of south-central Africa , the southern metacratonic boundary of an Archaean Bangweulu Craton,” Precambrian Res, vol. 148, pp. 225–256, 2006, doi: 10.1016/j.precamres.2006.05.006.
  10. De Waele, I. C. W. Fitzsimons, F. Tembo, and B. Mapani, “The geochronological framework of the Irumide Belt : A prolonged crustal history along the margin of the Bangweulu Craton,” Am J Sci, no. February, 2009, doi: 10.2475/02.2009.03.
  11. De Waele, A. B. Kampunzu, and F. Tembo, “The Mesoproterozoic Irumide belt of Zambia,” Journal of African Earth Sciences, vol. 46, pp. 36–70, 2006, doi: 10.1016/j.jafrearsci.2006.01.018.
  12. Boniface, V. Schenk, and P. Appel, “Mesoproterozoic high-grade metamorphism in pelitic rocks of the northwestern Ubendian Belt : Implication for the extension of the Kibaran intra-continental basins to Tanzania,” Precambrian Res, vol. 249, pp. 215–228, 2014, doi: 10.1016/j.precamres.2014.05.010.
  13. B. McConnell, Outline of the geology of Ufipa and Ubende. Bulletin of Geological Survey of Tanganyika. 1950.
  14. Ring, A. Kröner, and T. Toulkeridis, “Palaeoproterozoic granulite-facies meta-morphism and granitoid intrusions in the Ubendian-Usagaran Orogen ofnorthern Malawi, east-central Africa.,” Precambrian Reserch., vol. 85, 27–51., 1997.
  15. H. Ackermann, “Ein neuer Faltengürtel in Nordrhodesien und seine tektonische Stellung im Afrikanischen Grundgebirge.,” Geologische Rundschau, vol. 38, 24–39, 1950.
  16. H. Ackermann and A. Forster, “Grundzuge der Stratigraphie und Struktur des Irumide Orogen.,” 21st International Geological Congress,. pp. 182–192, 1960.
  17. Chisambi, T. Haundi, and G. Tsokonombwe, “Geologic structures associated with gold mineralization in the Kirk Range area in Southern Malawi,” Open Geosciences, vol. 13, no. 1, pp. 1345–1357, 2021, doi: 10.1515/geo-2020-0304.
  18. Chisambi and B. von der Heyden, “Primary gold mineralization in the lisungwe valley area, kirk range, southern Malawi,” South African Journal of Geology, vol. 122, no. 4, pp. 505–518, 2019, doi: 10.25131/sajg.122.0039.
  19. Bingen et al., “Geochronology of the Precambrian crust in the Mozambique belt in NE Mozambique , and implications for Gondwana assembly,” Precambrian Res, vol. 170, pp. 231–255, 2009, doi: 10.1016/j.precamres.2009.01.005.
  20. Boyd et al., “The Geology and Geochemistry of The East African Orogen In Northeastern Mozambique,” Geological Society of South Africa, vol. 113, pp. 87–129, 2010, doi: 10.2113/gssajg.113.1.87.
  21. Boyd et al., “The Geology and Geochemistry of The East African Orogen In Northeastern Mozambique,” Geological Society of South Africa, vol. 113, pp. 87–129, 2010, doi: 10.2113/gssajg.113.1.87.
  22. De Waele, I. C. W. Fitzsimons, F. Tembo, and B. Mapani, “The geochronological framework of the Irumide Belt : A prolonged crustal history along the margin of the Bangweulu Craton,” Am J Sci, no. February, 2009, doi: 10.2475/02.2009.03.
  23. Sommer and A. Kröner, “Lithos Ultra-high temperature granulite-facies metamorphic rocks from the Mozambique belt of SW Tanzania AR,” Lithos, vol. 170–171, pp. 117–143, 2013, doi: 10.1016/j.lithos.2013.02.014.
  24. J. Blakely, Potential Theory in Gravity and Magnetic Applications. Cambridge, England.: Cambridge University Press, 1996. doi: https://doi.org/10.1017/CBO9780511549816.
  25. Ates, F. Bilim, A. Buyuksarac, and Ö. Bektas, “A tectonic interpretation of the Marmara Sea, NW Turkey from geophysical data,” Earth, Planets and Space, vol. 60, no. 3, pp. 169–177, 2008, doi: 10.1186/BF03352780.
  26. Ateş, A. Büyüksaraç, F. Bilim, Ö. Bektaş, Ç. Şendur, and G. Komanovali, “Spatial correlation of the aeromagnetic anomalies and seismogenic faults in the Marmara region, NW Turkey,” Tectonophysics, vol. 478, no. 1–2, pp. 135–142, 2009, doi: 10.1016/j.tecto.2008.09.025.
  27. Rozimant, A. Büyüksaraç, and Ö. Bektaş, “Interpretation of magnetic anomalies and estimation of depth of magnetic crust in Slovakia,” Pure Appl Geophys, vol. 166, no. 3, pp. 471–484, 2009, doi: 10.1007/s00024-009-0447-8.
  28. L. Ekinci, A. Büyüksaraç, Ö. Bektaş, and C. Ertekin, “Geophysical Investigation of Mount Nemrut Stratovolcano (Bitlis, Eastern Turkey) Through Aeromagnetic Anomaly Analyses,” Pure Appl Geophys, vol. 177, no. 7, pp. 3243–3264, 2020, doi: 10.1007/s00024-020-02432-0.
  29. Ates, F. Bilim, A. Buyuksarac, A. Aydemir, O. Bektas, and Y. Aslan, “Crustal Structure of Turkey from Aeromagnetic, Gravity and Deep Seismic Reflection Data,” Surv Geophys, vol. 33, no. 5, pp. 869–885, 2012, doi: 10.1007/s10712-012-9195-x.
  30. Büyüksaraç, D. Jordanova, A. Ateş, and V. Karloukovski, “Interpretation of the gravity and magnetic anomalies of the Cappadocia region, Central Turkey,” Pure Appl Geophys, vol. 162, no. 11, pp. 2197–2213, 2005, doi: 10.1007/s00024-005-2712-9.
  31. B. Reid, J. M. Allsop, H. Granser, A. J. Millett, and I. W. Somerton, “Magnetic interpretation in three dimensions using Euler deconvolution,” Geophysics, vol. 55, no. 1, pp. 80–91, Feb. 2012, doi: 10.1190/1.1442774.
  32. B. Reid, J.M. Allsop, H. Granser, A.J. Millett, &I.W. Somerton, “Magnetic interpretation i n three dimensions using Euler deconvolution,” Geophysics, vol. v 55, 80-9, 1990.
  33. Ring, A. Kröner, and T. Toulkeridis, “Palaeoproterozoic granulite-facies meta-morphism and granitoid intrusions in the Ubendian-Usagaran Orogen of northern Malawi, east-central Africa.,” Precambrian Reserch., vol. 85, 27–51., 1997.
International Journal of Mining and Geo-Engineering
Volume 57, Issue 3
Summer 2023
Pages 275-281