Identifying potential sources of critical minerals in mineral systems using the Critical Minerals in Ores (CMiO) database

Although critical minerals (CMs) are currently produced from existing mines, their distributions in many mineral systems are, in many cases, poorly known, raising the possibility that CMs are not fully recovered from some ores. The Critical Minerals in Ores (CMiO) database, compiled by Geoscience Australia, United States Geological Survey, Geological Survey of Canada, and Geological Survey of Queensland as part of the Critical Minerals Mapping Initiative, contains high-quality geochemical data from global ore deposits classified using a common framework, enabling global comparison. Using CMiO and other data, we have undertaken preliminary investigations on distributions of CMs in mineral systems including porphyry Cu (PCu), iron oxide-Cu-Au (IOCG), iron oxide-apatite (IOA), rare earth element (REE), and Zn-dominated systems. The PCu systems are enriched in Re, Pt, Pd, Se, and Te relative to the continental crust. At the Pebble (USA) PCu deposit, Re and Se are enriched in Cu ore zones; whereas Te is enriched immediately outside these zones. Although generally not recovered, alkalic PCu deposits (e.g., Galore Creek, Canada; Cadia, Australia) can be enriched in Pd and Pt. Cobalt and some REEs occur in IOCG systems, with Co enriched in magnetite-dominant IOCG systems (e.g., Ernest Henry, Australia; Kwyjibo, Canada), and REEs enriched in IOA (e.g., Pea Ridge, USA) and hematite-dominant IOCG systems (e.g., Olympic Dam, Australia). The enrichment of individual REEs depends strongly on mineral system type. In magmatic and metasomatic systems, light REEs (Ce to Sm) and Y are enriched in hematite-rich IOCG, IOA and carbonatite (e.g., Saint-Honoré, Canada) deposits, whereas heavy REEs (Eu to Lu) are enriched in deposits associated with peralkaline magmatism (e.g., Strange Lake, Canada). Unconformity-related REE (e.g., Maw, Canada; Wolverine, Australia) and ionic clay (e.g., Koopamurra, Australia) deposits also tend to be heavy REE-rich, whereas shale-hosted (e.g., SBH, Canada) and phosphorite (e.g., Ardmore, Australia) deposits can be enriched in heavy and/or light REEs. Zinc deposits are important sources of Ga, Ge, and In. Assessment of the distribution of these CMs in Zn deposits suggest that Ge is concentrated in deposits formed from low temperature, oxidized fluids (Mississippi Valley-type: Tres Marias, Mexico; sediment-hosted massive sulfides: Red Dog, USA), whereas In is enriched in deposits formed from higher temperature, reduced fluids (volcanic-hosted massive sulfide: Kidd Creek, Canada; skarn: Isabel, Australia). These examples demonstrate the utility of the CMiO and other datasets for characterizing CMs distribution in individual ore deposit and predicting CMs potentials of mineral systems. This abstract was presented at the Joint Annual Meeting of the Geological Association of Canada (GAC), Mineralogical Association of Canada (MAC) and Society for Geology Applied to Mineral Deposits, Sudbury, Canada May 2023