The Tellus stream sediment and deep soil geochemistry data sets for Northern Ireland were used to locate four types of critical metals anomalies in granite bedrocks of the Mourne Mountains. A curvi-linear array of Nb, REE, Th and U soil anomalies across the eastern Mourne Mountains correlated with late-stage and eutectic temperature minerals in the roof zone of the most peralkaline F- and volatile-rich granite body, remobilized on micron to millimetre scales. Li, Be, B, As, Sn, Mn 3+ and Ce 4+ partitioned into pockets of late-stage heterogeneously distributed F-rich silicic residual melts and relatively oxidizing halide-rich magmatic fluids, resulting in drusy mineral and hydrothermal assemblages. Isolated soil anomalies correlated with amorphous Mn 3+ - and Ce 4+ -rich masses infilling drusy cavities, which resulted from short-distance percolation of small volumes of late-stage magmatic fluids. A significant As plume in stream sediments emanated from a greisen that hosted multiple critical and base metals including Sn, from reactions between large volumes of magmatic As + halide-rich fluids and mafic silicate + diverse accessory minerals on the metre- to kilometre-scale along geological structures. Diverse, small-scale REE anomalies in the soil data along structural features in the western Mournes correlate with vein mineralization resulting from episodic migration of hydrous fluids of variable composition, probably with a much smaller magmatic component than elsewhere. The regional geochemical dataset proved useful to develop a multi-stage model for enrichment of critical metals in the Mourne Mountains granites, which is analogous to the petrogenesis of some of the igneous-hosted economic deposits of critical metals. Thematic collection: This article is part of the energy-critical metals for a low carbon transition collection available at: https://www.lyellcollection.org/topic/collections/critical-metals
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