Platinum group element mineralization at Musongati (Burundi): concentration and Pd-Rh distribution in pentlandite

Abstract

1. Introduction The platinum group elements (PGE: Ru, Rh, Pd, Os, Ir & Pt) are considered as critical metals (European Commission, 2014) and are highly valued for their high-tech applications. They are being recycled and intensely mined, but still deficits are experienced and expected in the coming years (European Commission, 2014). Since the large PGE deposits, such as the Bushveld Complex in South Africa and the Noril’sk-Talnakh deposits in Russia, will become depleted with time, new deposits need to be explored for their PGE potential, to sustain future demand. The mafic-ultramafic intrusions in Burundi, which are part of the Kabanga-Musongati alignment, are such potential deposits. They intruded the Mesoproterozoic rocks of the Karagwe-Ankole belt around 1375 Ma and form a SW-NE alignment of nine intrusions in Burundi, with further continuation towards Tanzania (Fig. 1; Fernandez-Alonso et al., 2012). Several drilling campaigns have been executed between 1970 and 1990 to explore the nickel and PGE potential of these intrusions (PNUD-UNDP, 1977; Exploration und Bergbau Gmbh, 1985;Deblond, 1994; Deblond & Tack, 1999). Although some limited data on the concentration of PGE in the boreholes of these campaigns is available (e.g. Klerkx, 1975, 1976), not much is known about the PGE distribution. In addition, the petrogenesis of the intrusions needs further elaboration, expanding on the work of e.g. Bandyayera (1997) and Duchesne et al. (2004). Figure 1. (A) Regional geology o