An interpretation of Airborne Magnetic data to characterize Nickel-Copper mineralization over Mpemba Hill, Blantyre Malawi

Subject Areas : Economic Geology

Joshua  Chisambi ¹ (Department of Mining Engineering, Malawi University of Business and Applied Sciences, Blantyre, Malawi.)
Tiyamike  Haundi 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.

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