Metal endowment and fertility of Andean porphyry-copper belts

Abstract

The Andes are among the richest copper-bearing regions globally, hosting significant porphyry copper deposits (PCDs). The Central Andes segment has become a focal point in global copper production, with substantial contributions from Cenozoic PCDs. This study provides an updated assessment of the copper endowment generated over the last 80 million years and its spatial–temporal distribution along the Andean orogen. The new estimates indicate that the total copper is about 1,300 Mt distributed within five major Andean PCD belts, emphasizing the importance of reassessing the region’s copper fertility.

Focus is placed on the younger and better-preserved Neogene PCD belts, which minimize preservation biases and allow for more accurate comparisons of their metallogenic fertility. The results highlight the heterogeneous distribution of copper, with significant disparities between the Northern and Central Andes despite their similar geodynamic settings. Notably, average copper productivity correlates strongly with PCD belt age in the Central Andes, suggesting a combination of preservation bias and increasing copper fertility with time.

This work also explores the relationship between slab flattening related to the subduction of buoyant oceanic anomalies and PCD formation. The findings underscore their role as critical geodynamic factors of metallogenic efficiency in Neogene PCD belts.

This study emphasizes the interplay between tectonic compression, magmatic productivity, and ore preservation, providing valuable insights for future target generation programs in the Andes and analogous subduction settings worldwide. By linking large-scale geodynamic processes to metallogenic outcomes, this work advances understanding of the factors governing copper endowment and fertility. It confirms the fertility of the Andean continental arc as a highly prospective target region for the future exploration of additional, but likely concealed, porphyry Cu systems.