Distribution of porphyry Au-Cu systems in the Ordovician Macquarie Arc of NSW, Australia

摘要

The Ordovician Macquarie arc has emerged in recent years as a significant porphyry Au-Cu province. The deposits are not uniformly distributed throughout the volcanic belts and extreme clustering is evident at all scales. The location of the known systems is heavily skewed toward four productive districts. These districts occupy approximately 11% of the explored volcanic belts but contain 92% of the known systems. Two of the districts contain all of the known economic and feasibility stage systems. These districts can be distinguished to a certain extent from much of the remaining Macquarie arc, but no single or combination of features can definitively distinguish them. Although the Macquarie arc remains highly prospective for porphyry systems this prospectivity lies overwhelmingly within the known districts. Further exploration in the Macquarie arc outside the defined Porphyry Districts has a much lower probability of success.