New St Andrews Study Exposes Complexities of Rare Earth Extraction from Alkaline Rocks

Highlights

• Curtis James William Rooks’ study exposes the intricate mineralogical complexities of rare earth element extraction in alkaline silicate roof zones.
• Hydrothermal events significantly complicate REE recovery by remobilizing and stripping valuable light rare earth elements from primary mineral hosts.
• Western rare earth independence requires massive investment in specialized processing technologies beyond mere ore body mining.

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In a critical new study, Curtis James William Rooks of the University of St Andrews (Raising the Roof for Rare Metals: Controls on Rare Earth Mineralisation in Magmatic Roof-Zones, Motzfeldt, Southern Greenland, delivers a sobering scientific analysis that challenges simplistic assumptions about rapidly scaling rare earth element (REE) extraction from hard-rock sources. Funded by Elemental Rare Metals Ltd, the research reveals that while deposits in alkaline silicate “roof zones” such as Greenland’s Motzfeldt Sø Centre are richly endowed with REE, niobium, tantalum, and zirconium, unlocking these resources is far more complex than often portrayed by policymakers and industry headlines.

Using a combination of field studies, petrography, electron microscopy (EPMA), and laser ablation (LA-ICP-MS), Rooks systematically maps the mineralogical controls and hydrothermal overprints that complicate REE recovery.

Findings show that hydrothermal events remobilize rare earth elements (REEs), strip valuable light rare earth elements (LREEs) from primary hosts such as pyrochlore, and introduce structural complexity through secondary mineralization, including hydrothermal chimneys and anatectic melts. Critically, the study develops new methods for REE deportment modeling, identifying pyrochlore as the primary LREE carrier (~60%), and highlights significant processing challenges associated with secondary alteration phases.

While the research advances exploration models for alkaline systems worldwide, it also starkly illustrates why midstream and downstream rare earth capacity in the West remains so weak: simply mining ore bodies—even promising ones like Motzfeldt—is no shortcut to producing usable, high-purity REEs without highly specialized processing technologies, which are still severely lacking outside of China. Without massive investment in both processing R&D and infrastructure, Western aspirations for rare earth independence risk being built on geologically unstable ground.

DOI: 10.17630/sta/1301 (opens in a new tab))