Advanced Targeting of Rare Earth Elements in the Gabal Umm Naggat Pluton: A Combined Geophysical and Radiogenic Approach with Mineralization and Environmental Implications

Abstract

Abstract Investigating rare earth elements (REEs) has become growingly important due to their critical role in providing a sustainable supply of materials that support low-carbon and renewable-energy technologies. The Gabal Umm Naggat granite in Egypt’s central Eastern Desert forms an important, rare-metal-rich segment of the Arabian–Nubian Shield, evaluated using jointly interpreted high-precision airborne magnetic and radiometric data. Evolved albitized, alkali feldspar, and biotite granites are enriched in Nb, Ta, Zr, Hf, U, Th, and REEs, hosted mainly in the northern and central pluton and controlled by N–S-, NW-, NE-, E–W-, and ENE-trending structures; notably, this study first documented abundant N–S trends. Advanced aeromagnetic enhancement techniques outline shallow mineralized sources at 0–600 m and deeper tectonic features to ~ 1600 m, defining new targets along the northeastern, southeastern, and southwestern flanks adjacent to mafic–ultramafic belts. Radiometric (%K, eTh, eU), ratio (eTh/K%, eU/K%), ternary, and F-parameter maps reveal strong geochemical heterogeneity and zones highly enriched in U, Th, and REEs within albitized and alkali feldspar granites at major fault intersections. Radiological indices show U, Th, and related radionuclides exceeding global safety limits, classifying albitized granites as first-priority and alkali feldspar granites as second-priority radiological hazard zones, whereas surrounding mafic–ultramafic and metasedimentary rocks remain low risk. These results underscore the importance of ongoing radiological monitoring and careful land-use planning in areas of rare-metal exploration and mining. The integrated geophysical and geochemical approach effectively identifies rare-metal granites and evaluates environmental safety in high-radiation terrains.