An interpretation of Airborne Magnetic data to characterize Nickel-Copper mineralization over Mpemba Hill, Blantyre Malawi
Subject Areas :
Economic Geology
Joshua Chisambi
1
,
Tiyamike Haundi
2
1 - Department of Mining Engineering, Malawi University of Business and Applied Sciences, Blantyre, Malawi.
2 - Department of Mining Engineering, Malawi University of Business and Applied Sciences, Blantyre, Malawi.
Received: 2022-03-13
Accepted : 2022-07-25
Published : 2023-07-01
Keywords:
Geophysical Survey,
Nickel- Copper,
Drilling,
Disseminated sulphides,
Ore type,
Mpemba,
Abstract :
The present study seeks to characterize Ni-Cu mineralization at Mpemba hill in Blantyre, southern Malawi by using aeromagnetic and drill hole data. The area has been under-explored for this im-portant economic commodity and as such not much is known regarding its mineralization poten-tial. The minimal curvature gridding technique was utilised to grid the aeromagnetic data, and a grid cell size of 50 m was employed. The Ni-Cu host lithologies are characterized by high mag-netism, and are mostly ultramafic rocks. Drilling results indicates that the mineralization starts at depths from 50m and remains open. The area is associated with disseminated and blebby type of mineralization and the mineralization is associated with high magnetic signatures in ultramafic meta pyroxenite bodies yielding high base metal values. Euler model depths analysis of the mag-netic sources is deep, lies at 3.2 km depth and the shallower magnetic bodies lie between 100 m and 1km. The depth estimates show that the mineralization is near surface and goes deep, so fur-ther exploration should not be limited to shallow depth. The ultramafic rocks are potential sites for Ni-Cu mineralization in the area and Mpemba hill has a huge potential to find economic min-eralization suitable for mining.
References:
Aitken ARA, Betts PG (2009) Multi-scale integrated structural and aeromagnetic analysis to guide tectonic models: An example from the eastern Musgrave Province, Central Australia, Tectonophysics 476(3–4): 418–435.
AlSaud MM (2008) Structural mapping from high resolution aeromagnetic data in west central Arabian Shield, Saudi Arabia using normalized derivatives, Arabian Journal of Geosciences 1(2): 129–136.
Ates A, Bilim F, Buyuksarac A, Bektas Ö (2008) A tectonic interpretation of the Marmara Sea, NW Turkey from geophysical data. Earth, Planets and Space 60(3): 169–177.
Ates A, Bilim F, Buyuksarac A, Aydemir A, Bektas O, Aslan Y (2012) Crustal Structure of Turkey from Aeromagnetic, Gravity and Deep Seismic Reflection Data, Surveys in Geophysics 33(5): 869–885.
Ateş A, Büyüksaraç A, Bilim F, Bektaş Ö, Şendur Ç, Komanovali G (2009) Spatial correlation of the aeromagnetic anomalies and seismogenic faults in the Marmara region, NW Turkey, Tectonophysics 478(1–2): 135–142.
Aziz AM, Sauck WA, Shendi EA, Rashed MA, Abd El-Maksoud M (2013) Application of Analytic Signal and Euler Deconvolution in Archaeo-Magnetic Prospection for Buried Ruins at the Ancient City of Pelusium, NW Sinai, Egypt: A Case Study, Surveys in Geophysics 34(4): 395–411.
Barnes SJ, Cruden AR, Arndt N, Saumur BM (2016) The mineral system approach applied to magmatic Ni–Cu–PGE sulphide deposits, Ore Geology Reviews 76: 296–316.
Barnes SJ, Mole DR, Hornsey R, Schoneveld LE (2019) Nickel-copper sulfide mineralization in the Ntaka Hill ultramafic complex, Nachingwea region, Tanzania. Economic Geology 114(6): 1135–1158.
Bloomfield K, Garson MS (1965) The Geology of the Kirk Range-Lisungwe Valley Area. Ministry of Natural Resources, Geological Survey Department. Bulletin No.17. The Government Printer, Zomba. Malawi.
Briggs I (1974) Machine Contouring Using Minimum Curvature, Geophysics 39(1):39-48
British Geological Survey. (2009). Mineral potential of Malawi (Issue January).
Büyüksaraç A, Jordanova D, Ateş A, Karloukovski V (2005) Interpretation of the gravity and magnetic anomalies of the Cappadocia region, Central Turkey, Pure and Applied Geophysics 162(11): 2197–2213.
Chernicoff CJ, Richards JP, Zappettini EO (2002) Crustal lineament control on magmatism and mineralization in northwestern Argentina: Geological, geophysical, and remote sensing evidence, Ore Geology Reviews 21(3–4): 127–155.
Chisambi J, Haundi T, Tsokonombwe G (2021) Geologic structures associated with gold mineralization in the Kirk Range area in Southern Malawi, Open Geosciences 13(1): 1345–1357.
Cooper SM, Liu T (2011) Journal of African Earth Sciences A magnetic and gravity investigation of the Liberia Basin, West Africa, Journal of African Earth Sciences 59(2–3): 159–167.
Diakov S, West R, Schissel D, Krivtsov A, Kochnev-Pervoukhov V, Migachev I (2019) Recent Advances in the Noril’sk Model and Its Application for Exploration of Ni-Cu-PGE Sulfide Deposits.
Drury S (2001) Image interpretation in geology. Blackwell science; Nelson Thornes.
Ekinci YL, Büyüksaraç A, Bektaş Ö, Ertekin C (2020) Geophysical Investigation of Mount Nemrut Stratovolcano (Bitlis, Eastern Turkey) Through Aeromagnetic Anomaly Analyses, Pure and Applied Geophysics 177(7): 3243–3264.
Evans DM (2011) Geodynamic setting of Neoproterozoic nickel sulphide deposits in eastern Africa, Applied Earth Science 120(4):175–186.
Evans DM, Boadi I, Byemelwa L, Gilligan J, Kabete J, Marcet P, Sy A (2000) Kabanga Magmatic Nickel Sulphide Deposits, Tanzania:Morphology and Geochemistry of Associated Intrusions, Journal of African Earth Sciences 1;30(3):651-74.
Fichler C, Rundhovde E, Olesen O, Sæther BM, Rueslåtten H, Lundin E, Doré AG (1999) Regional tectonic interpretation of image enhanced gravity and magnetic data covering the mid-Norwegian shelf and adjacent mainland, Tectonophysics 306(2): 183–197.
Ge T, Qiu L, He J, Fan Z, Huang X, Xiong S (2020) Aeromagnetic identification and modeling of mafic-ultramafic complexes in the Huangshan-Turaergen Ni-Cu metallogenic belt in NW China: Magmatic and metallogenic implications, Ore Geology Reviews 127: 103849.
Geophysics S (2013) Data Processing Report High Resolution Airborne Magnetic and Gravity Survey : The Comprehensive Countrywide Airborne Geophysical Survey for The Government of The Republic of Malawi , The Ministry of Mining.
Geosoft (2008) Oasis montaj Viewer 7.0 The core software platform for working with large volume spatial data quick starttm tutorial.
Hutchins DG, Reeve, CV (1980) Regional Geophysical Exploration of the Kalahari in Botswana, Tectonophysics 69: 201–220.
Jafari HR, Yazdi A (2014) Radioactive Anomalies in 1: 50000 Dehbakri Sheet, South of Kerman Province, Iran, Open Journal of Geology, 04(08): 399-405.
Kis KI (1990) Transfer properties of the reduction of magnetic anomalies to the pole and to the equator, Society of Exploration Geophysics 55(9): 1141–1147.
Kohanpour F, Lindsay MD, Occhipinti S, Gorczyk W (2018) Structural controls on proterozoic nickel and gold mineral systems identified from geodynamic modelling and geophysical interpretation, east Kimberley, Western Australia, Ore Geology Reviews 95: 552–568.
Li C, Zhang Z, Li W, Wang Y, Sun T, Ripley EM (2015) Geochronology, petrology and Hf-S isotope geochemistry of the newly-discovered Xiarihamu magmatic Ni-Cu sulfide deposit in the Qinghai-Tibet plateau, western China, Lithos 1;216: 224-40.
Li X (2008) Magnetic reduction-to-the-pole at low latitudes: Observations and considerations, The Leading Edge 27(8): 990–1002.
MacLeod IN, Jones K., Dai TF (1993) 3-D Analytic signal in the interpretation of total magnetic field data at low magnetic latitudes. Explo-annotated, Exploration Geophysics 993;24(4): 679-88
Reid AB, Allsop JM, Granser H, Millett AJ, Somerton IW (1990) Magnetic interpretation i n three dimensions using Euler deconvolution, Geophysics 55(1): 80-91.
Rozimant K, Büyüksaraç A, Bektaş Ö (2009) Interpretation of magnetic anomalies and estimation of depth of magnetic crust in Slovakia, Pure and Applied Geophysics 166: 471-84.
Yazdi A, Ziaaldini S, Dabiri R (2015) Investigation on the Geochemical Distribution of REE and Heavy Metals in Western Part of Jalal-Abad Iron Ore Deposit, Zarand, SE of Iran, Open Journal of Ecology 5 (09): 460-476.
