Radioactivity and aeromagnetic of magmatic suites, Arabian Nubian Shield: Petrological and health risk characteristics

Abstract

This study attempts to assess radiation doses in the El Maghrabiya- Ria Elgarra granitic phases and elucidate the subsurface structural influences on mineralization employing sophisticated airborne magnetic data processing and interpretation methods. The granitic phases include granodiorite, monzogranites, syenogranites, and altered granites (which are frequently visible along shear zones). The former rocks show a small amount of ²³⁸U (21.70 ± 11.87 Bqkg⁻¹), ²³²Th (20.20 ± 12.78 Bqkg⁻¹), and ⁴⁰K (305.18 ± 168.1 Bqkg⁻¹) employing the NaI (Tl) spectrometer. Monzogranites contain ²³⁸U (43.40 ± 41.13 Bqkg⁻¹), ²³²Th (29.29 ± 5.08 Bqkg⁻¹), and ⁴⁰K (1169.84 ± 79.45 Bqkg⁻¹), while syenogranites include high amounts of ²³⁸U (121.52 ± 46.73 Bqkg-1), ²³²Th (96.15 ± 12.58 Bqkg⁻¹), and ⁴⁰K (1315.23 ± 146.62 Bqkg⁻¹). Furthermore, the altered granites had the greatest activity of ²³²Th (105.04 ± 65.73 Bqkg⁻¹), ⁴⁰K (683.91 ± 333.34 Bqkg⁻¹), and ²³⁸U (1674.00 ± 1275.25 Bqkg⁻¹), alongside the total quantity (avg. 1842.90 ± 871.02 Bqkg⁻¹). Several radiological elements have been utilized to assess the risk inherent with these rocks. Granodiorite and monzogranite results are consistent with established global standards, however syenogranites and altered granites exhibited elevated metrics. Therefore, granodiorite and monzogranite are suitable for use in the construction sector, whereas syenogranites and altered granites are unsuitable due to their elevated natural gamma radiation emissions. Upward continuation was subsequently applied to RTP aeromagnetic data at four discrete levels (0.5 km, 1 km, 2 km, and 3 km), corresponding to average source depths, to image subsurface geological structures. Based on automated lineament extraction methods and rose diagrams, the principal structural directions are N-S, NNW-SSE, and E-W. The identification of these trends as the dominant structural trends is not just a descriptive finding; it reveals the fundamental plumbing system of the region. These trends are the highways and intersections along which mineralizing fluids traveled and where they were most likely to deposit their economic metal load.