Element mobility in the weathering environment and surface vectors to mineralisation-A case study from the Mashitu South Cu-Co deposit, Katanga, Democratic Republic of Congo

Of the major and trace elements which are known to be associated with hypogene mineralisation at Mashitu South, Cu, Ni, S and Zn are depleted in the near-surface environment, whereas Co, Bi, V, Mo, As and Fe experienced residual enrichment due to supergene alteration. Indeed, Bi and V exhibit an even greater degree of residual enrichment than Co, which is known as a surface pathfinder to Cu deposits in Katanga. It is suggested that Bi, V and Co would make effective surface vectors to Katangan Cu-Co deposits that have experienced a high degree of leaching; deposits which may evade detection by exploration solely for Cu surface anomalies. The average-normalisation technique utilised by this study can be used to identify immobile surface vectors to any polymetallic deposit which has been significantly affected by chemical weathering.