Regolith-Hosted Rare Earth Deposits

Hamed Pourkhorsandi – 23.01.2023 – 11:00

Regolith-Hosted Rare Earth Deposits and the Potential of Radiogenic and Stable Isotopes in Understanding their Genesis

Abstract: Rare Earth Elements (REE) are used widely in advancing technologies, in particular the renewable energy sector and are considered critical metals at the highest risk of supply by the EU. In addition to primary magmatic REE deposits such as those in carbonatite and alkaline complexes, REE are also extracted from weathered deposits. Formed as the result of intense chemical weathering of magmatic rocks such as granites. These regolith-hosted deposits typically have a greater proportion of heavy to light REE and a mineralogy that is easier to process, facilitating economic REE extraction.
During intense chemical weathering, primary minerals in rocks transform to secondary products, resulting in the REE mobility and fractionation and in the case of regolith-hosted deposits their adsorption on the surface of weathering products such as clays. However, involvement of different mechanisms during intense chemical weathering has made predicting REE mobility, fractionation and understanding formation of these deposits challenging. In addition to elemental behavior, even to a greater degree, the isotopic dynamics of the REE during weathering and formation of these deposits remain poorly understood.
In this seminar, I will discuss the ore geology of REE, particularly the formation of regolith-hosted deposits, and will explore the possibility of using isotopic tracers to understand their formation. In addition, I will discuss the possibility of using these deposits as natural laboratories to understand isotopic behavior of the REE during intense chemical weathering.