A GEO-DATA SCIENCE DRIVEN METHOD TO ASSESS REE OCCURRENCES IN UNCONVENTIONAL GEOLOGIC SYSTEMS

Rare-earth elements (REE) supply raw materials that constitute many of our modern critical infrastructure, defense, technology, and electrification needs. Despite REE accumulations occurring in conventional bedrock and ion-adsorption deposits, unconventional host material such as coal and related sedimentary strata have been identified as promising sources of REE to meet growing demand. We present an Unconventional Rare-earth and Critical minerals (URC) assessment method to predict and identify REE resource potential and occurrence in these unconventional systems. The method utilizes a geologic and geospatial data-driven approach, informed and guided by knowledge of REE enrichment processes, to systematically predict and identify areas of higher enrichment. A test case in the Powder River Basin is presented to demonstrate the method workflow and results. The key output is a Potential Enrichment (PE) score map reported with varying confidence levels based on the amount of supporting evidence. Results from the test case indicate several locations with promising potential for different types of coal-REE deposits, demonstrating the viability of the method for exploration and assessment of unconventional REE systems. The URC method is flexible by design and, with sufficient applicable knowledge, can be adapted for assessing other types of critical mineral occurrences in unconventional geologic systems.