Geological Models of Platinum Group Elements (PGE) Depletion in Metamorphosed Ultramafic Rocks of the Nyong Series, Southeast Cameroon
T.A.Ako1,A.Vishiti2,C.E.Suh3,A.C.Kedia4,B.O.Omang5
Citation :T.A.Ako,et.al, Geological Models of Platinum Group Elements (PGE) Depletion in Metamorphosed Ultramafic Rocks of the Nyong Series, Southeast Cameroon International Journal of Mining Science 2017,3(4) : 52-63
Meta-ultramafic rocks in the Paleoproterozoic Nyong Series (SE Cameroon) which occur as intrusions within the metasedimentary and meta-igneous units have been studied. The aim was to study the concentration of platinum group elements (PGEs) within the layered sequence and suggests models of their depletion relevant to the rocks. Twenty-seven samples of the ultramafic rocks were collected from the different layers of the sequence and analysed for their Ni, Cu, Au and PGE contents. Ni, Cu, Au, Pt and Pd were analysed by ICP-MS while Ir, Os, Rh and Ru were analysed by INAA. Results of the analyses show that the concentrations of Cu, Au, PGE and SPGE are very low throughout the cliff face while Ni concentrations are high and variable. The effect of alteration of the rocks has resulted in the low PGE concentration due to remobilization. It is also suggested that the rocks are PGE-depleted due to low degree of partial melting or depleted mantle source and various models have been used to explain this depletion as related to the Nyong Series.