Preliminary comparison of diagenetic stratiform copper mineralization from Redstone, NW Territories, Canada,and Kamoto, Shaban copperbelt, Zaire

Abstract

Recent studies of stratiform copper mineralization in the Redstone copperbelt of the NW Territories, Canada, indicate analogies with sediments of modern intertidal and supratidal environments. Textural analyses show that mineralization occurred in microbial-laminated carbonate units during diagenesis following initial enrichment of the carbonates in iron sulphides and evaporitic sulphates. Similar features have been described for the dolomitic beds hosting the well-known Kamoto ores of the Shaban copperbelt. The present work gives a brief comparison of the Redstone and Shaban host-rocks and their mineralization. Similarities include the interpreted shallow marine/red-bed sequence and the presence of stromatolitic and microbial-laminated structures in the carbonates. However, the Shaban host-rocks are more magnesian than those at Redstone, and silicification in Shaba surpasses the more normal diagenetic silification seen at Redstone. The copper, copper-iron and iron sulphides of Redstone and Shaba exhibit similar peneconcordant arrays across their respective basal carbonate horizons, but cobalt is important only in the Shaban mineralization. A more detailed comparison of host-rocks and mineralization in these two copperbelts is currently in progress.