A PROCESS-BASED APPROACH TO ESTIMATING THE COPPER DERIVED FROM RED BEDS IN THE SEDIMENT-HOSTED STRATIFORM COPPER DEPOSIT MODEL

Most estimates of the total tonnage of copper metal leached from footwall red beds to form sediment-hosted stratiform copper deposits are based oil the amounts of copper at ppm levels that might have been derived from the volume of red beds underlying given sediment-hosted stratiform copper deposits. That static calculation is replaced here with a process-based approach in which the release of copper results from the progressive diagenetic alteration of the footwall aquifers by oxyen-rich meteoric water driven by topographic recharge in highlands adjacent to the intracontinental rift basins hosting these deposits. The total amount of liberated copper depends oil the volume of meteoric water, its oxygen content, and the duration of the diagenetic leaching of copper. Estimates suggest that adequate amounts of copper may be derived from footwall red beds within reasonable periods of early, and possibly more advanced, diagenesis.