Unconformity-related rare earth element mineral potential of Australia

Arianne Ford , Jessica Walsh, Michael Doublier, Antony Burnham, Jonathan Cloutier, Geoff Fraser, Charles Magee, Karol Czarnota

Heavy rare earth elements are critical for the transition to net zero in addition to being key to manufacturing defence technologies. Unconformity-related rare earth element (REE) deposits represent an important source of heavy rare earth elements (HREE), including key elements such as dysprosium (Dy) and terbium (Tb). Given the strategic importance of these critical minerals to the national economy, a national-scale mineral potential assessment has been undertaken to evaluate the geological potential for unconformity-related REE mineral systems in Australia.

Leveraging previous research into the formation of unconformity-related REE mineral systems in Australia, a new mineral system model has been developed based on an existing mineral systems framework. The deposits form as a result of crustal- to deposit-scale processes that operate under favourable spatial and temporal conditions. This study demonstrates how a mineral system that is lacking comprehensive understanding can be used as the basis for predictive modelling through the novel use of datasets not typically utilised in broad-scale mineral potential assessments.

Both a knowledge-driven and data-driven approach have been used to generate national-scale mineral potential maps that reduce the exploration search space for unconformity-related REE mineral systems in Australia by up to 95%. In addition to predicting known mineralised regions, the model also demonstrates high prospectivity in parts of Australia where no unconformity-related REE mineralisation has previously been identified, particularly on the margins of Precambrian basins in northern Australia.