Drivers of critical metal enrichment in peralkaline magmas recorded by clinopyroxene zoning

Title	Drivers of critical metal enrichment in peralkaline magmas recorded by clinopyroxene zoning
Authors	Brenainn Simpson, Teresa Ubide, Carl Spandler
Magazine	Communications Earth & Environment
Date	02/10/2025
DOI	10.1038/s43247-025-02040-7
Introduction	Highly sodic peralkaline magmas can achieve significant enrichment in critical metals, including rare earth elements. This study examines clinopyroxene zoning to understand the evolution of these magmas and the processes leading to critical metal mineralisation, with a focus on the Mesozoic Benolong Volcanic Suite in eastern Australia. This area features a zirconium, hafnium, niobium, and tantalum mineralised subvolcanic sill. The analysis of major and trace elements in clinopyroxene reveals continuous magma differentiation from diopside-hedenbergite to aegirine, associated with the progressive enrichment of rare metals. Notably, aegirine in mineralised trachyte becomes sector-zoned and depleted in critical metals, which instead concentrate in eudialyte at later stages. The association with vesiculated sill portions suggests sector zoning results from undercooling possibly driven by degassing. Since volatiles enhance the solubility of critical metals in silicate magmas, the retention of volatiles and dynamic crystallisation conditions likely promote metal enrichment in the Toongi deposit. This research indicates that pyroxene chemistry and zoning can effectively track critical metal fertility in peralkaline magmas.
Quote	Brenainn Simpson, Teresa Ubide, Carl Spandler. Drivers of critical metal enrichment in peralkaline magmas recorded by clinopyroxene zoning. Commun Earth Environ. 2025. Vol. 6(1). DOI: 10.1038/s43247-025-02040-7
Element	Zirconium (Zr) , Hafnium (Hf) , Niobium (Nb) , Tantalum (Ta)
Materials	Rare Earth Metals
Topics	Energy Materials
Industry	Research & Laboratory