Diagenetic Features at White Pine (Michigan), Redstone (N. W. Territories, Canada) and Kamoto (Zaire). Sequence of Mineralization in Sediment-Hosted Copper Deposits (Part 1)

Abstract

Disseminated copper and copper-iron sulfide mineralization at the White Pine (Michigan), Redstone (N.W. Territories, Canada) and Kamoto (Shaban Province, Zaire) deposits are interpreted to have been emplaced during early diagenesis by an influx of dissolved copper into initially pyritic basal units of grey-bed host rocks. This concept is supported by the position and configuration of the mineralized zones, by numerous textural features, by the zoning of Cu- and Fe- bearing sulfides as well as affiliated metals (e. g. Pb, Zn, Co and Mo), and by comparisons with modern analogs of strata hosting stratiform copper deposits. Most evidence supports an early diagenetic introduction of copper from underlying coarse-grained red beds. Plausible sources of copper include the red beds themselves, or pene-exhalative solutions which “exhale” into the red beds. Preliminary quantitative data now available suggest that the red beds may have provided sufficient copper to mineralize basal units of the overlying grey beds; the tectonic setting and timing of mineralization also encourage further research into the pene-exhalative model.

Contribution of the Mineral Exploration Research Institute, Montreal, Canada.