This report outlines the methodology and results of a targeting exercise in Queensland for three key mineral deposit types that are globally significant hosts for indium, gallium and germanium, and which have high potential for discovery in Queensland. Indium, gallium and germanium are high-value critical metals that currently have restricted global production, but demand is forecast to increase with new high technology applications. The study outlines 41 discrete areas across Queensland considered as having high prospectivity for new resources of these metals, with accompanying rationale and data provided in both this hardcopy report and in digital format.

The three key deposit types considered include volcanic-hosted massive sulphide (VHMS) deposits, epithermal deposits, and granite-related deposits. All three types are related to igneous systems and share somewhat similar theoretical and mappable criteria that can be applied in targeting. Significant examples of all three mineral deposit types are present in Queensland, most particularly in northeast Queensland. The targeting study has combined the relatively well-documented mineral systems models for these deposit types with an overlay of In-Ga-Ge geochemistry derived from two key datasets; the mineral occurrence dataset (MinOcc) and the fine-fraction basin drainage data from the National Geochemical Survey of Australia (NGSA).

Indium, gallium and germanium are known to be variably enriched in sediment-hosted Zn-Pb-Ag, bauxite and coal deposits. The mineralogy and occurrence of indium, gallium and germanium in these deposit types are discussed in this report, but given the large existing resource base for these deposit types in Queensland they have not been considered as part of this prospectivity analysis.