Prospectivity Mapping Using Stream Sediment Geochemistry along the Orange River Catchment for Base Metal, Prieska, Northern Cape, South Africa

Abstract

The Areachap Terrane, which is part of the Namaqua Sector of the Namaqua-Natal Belt in the Northern Cape Province, host volcanic-hosted Zn-Cu deposits at volcanic centres. The primary objective was to map Volcanogenic Massive Sulphide (VMS) mineralisation, determine the heavy metal contents of sediments, locate the source of anomalies and delineate targets for follow-up studies. Nine thousand three hundred and fourteen stream sediments samples collected were analysed using XRF. The element associated with their respective lithostratigraphy was calculated using spatial joint analysis tool. ArcGIS was used to display uni-elements maps and relevant multi-element maps. The delineated potential VMS mineralisation target is considered for further follow-up study. The M23 and M24 anomalies are delineated for Cu_Ni mineralisation. M23 and M24 anomalies are sourced from ultramafic debris transported from the Ghaap Group; however, this potential target will require follow-up studies for verification. The correlation between the Cu-Pb-Zn anomaly with alkali elements (Nb, Zr, Th, and U) and REEs (in Table 9) suggests there is a possibility that the M26–M29 anomaly is alkali-granitic genetic origin. The As, Ba, Ce, Cr, Cu, Hf, Nd, Ni, Rb, Sr., S, V, Zr and Zn contents showed a heterogeneous spatial distribution, reflected by high coefficient of variation and large standard deviation.