LA-ICP-MS trace element geochemistry of chalcopyrite from Tenke Fungurume, Central African Copperbelt

Tenke Fungurume is one of the world's premier sediment-hosted copper and cobalt mining districts located in the northwestern part of the Central African Copperbelt. The ore-forming processes for this giant district are subdivided into disseminated, nodule type, a burial (stylolite-related), a pre-folding, a syn-folding, and a post-folding vein I and vein II mineralization stages. This study presents new LA-ICP-MS trace element data on chalcopyrite that shows distinct trace element distributions between the different stages. The stylolite-related veins and nodule type chalcopyrite data are quite consistent, i.e. both are rich in redox sensitive elements (V, Mo, Sb). Both stages are regarded to be of diagenetic origin as proposed for the Kamoto and Luiswishi Cu-Co deposits in the Democratic Republic of Congo. Pre-folding and syn-folding chalcopyrite also share similarities in their trace element distribution, but the former is generally richer for most elements. This could indicate higher precipitation temperature for the pre-folding chalcopyrite, since this latter tends to host more trace elements. The post-folding veins I and II show distinct trace element distributions, which could correspond to different deformation stages. Vein II chalcopyrite is extremely rich in Ge, which could be linked to the post-orogenic fluid forming the Cu-Zn-Pb (Ge, Ag) Kipushi deposit.