Abstract Porphyry Cu deposits commonly contain critical and precious metal by-products, including the chalcophile and siderophile elements, Au, Pd, Pt, Ag, Te, Se, and Bi. These elements partition into residual sulfides during the partial melting of mantle wedge peridotite during subduction, potentially depleting the source magma for subduction-related porphyry Cu deposits. The chalcophile-rich residual sulfides in subduction-modified subcontinental lithosphere are thought to be the source of metals in postsubduction porphyry Cu deposits, and as such these deposits may be more enriched in chalcophile and siderophile elements than subduction-related porphyry deposits, although many postsubduction deposits have low Au grades. We test this by presenting whole-rock assay and PGE data with in situ LA-ICP-MS trace element data from sulfide minerals from three porphyry Cu deposits. The Skouries Cu-Au-(PGE) porphyry deposit, Greece, and the Muratdere Cu-Au-Mo porphyry deposit, Turkey are both postsubduction; these are contrasted with the El Teniente Cu-Mo porphyry deposit, Chile, which is a classic subduction-related system. By comparing these results with a newly compiled global dataset of trace element concentrations in sulfides from 18 other porphyry Cu deposits we show that postsubduction porphyry Cu deposit sulfides are relatively enriched in Bi, Sb, Te, and Se compared to sulfide minerals from subduction-related deposits. However, although some critical and precious metals (Ag, Bi, and Se) mainly reside in primary sulfide ore minerals, others (Au, Te, Pd, and Pt) are predominantly hosted in minor accessory minerals. Whole-rock data from mineralized samples show that although the Skouries and Muratdere deposits are enriched in Au compared with El Teniente, globally both subduction-related and postsubduction deposits can be precious and critical metal enriched, with metal endowment independent of tectonic setting. PGE-enriched porphyry Cu deposits are also enriched in Bi, Te, and Au, and semimetal melts are suggested to play an important role in PGE transport and concentration in porphyry Cu deposits.

Abstract Ore deposits form by a variety of natural processes that concentrate elements into a small volume that can be economically mined. Their type, character and abundance reflect the environment in which they formed and thus they preserve key evidence for the evolution of magmatic and tectonic processes, the state of the atmosphere and hydrosphere, and the evolution of life over geological time. This volume presents 13 papers on topical subjects in ore deposit research viewed in the context of Earth evolution. These diverse, yet interlinked, papers cover topics including: controls on the temporal and spatial distribution of ore deposits; the sources of fluid, gold and other components in orogenic gold deposits; the degree of oxygenation in the Neoproterozoic ocean; bacterial immobilization of gold in the semi-arid near-surface environment; and mineral resources for the future, including issues of resource estimation, sustainability of supply and the criticality of certain elements to society.