Geochemical Processes in the Arabian-Nubian Shield

The Arabian-Nubian Shield represents one of the most extensive juvenile Neoproterozoic crustal provinces, formed by successive accretion of island arcs, ophiolitic fragments and continental blocks during the assembly of Gondwana. Magmatic differentiation from mantle-derived melts produced a spectrum of lithologies from tholeiitic basalts to high-silica granites, while interaction with crustal melts yielded peraluminous and A-type granites. Hydrothermal fluids circulated along major shear zones and fractures, driving multi-stage alteration and remobilisation of rare- and radioactive-element assemblages. Surface weathering and sedimentation established volcanosedimentary basins that record cycles of exhumation and denudation, influencing element fluxes to shallow-marine and alluvial systems. These processes underlie the concentration of economically critical metals (gold, beryllium, uranium, thorium) and gemstones (emerald) and inform exploration models. The Shield thus offers a natural laboratory for linking crustal growth, fluid–rock interaction and ore-forming processes with broader geodynamic evolution.

Research from Nature Portfolio

Recent studies have applied high-resolution satellite imagery and targeted field sampling to map beryl-bearing bedrocks across South Sinai and the Eastern Desert. Quantitative assays show beryllium in host rocks ranges from 1 to 374 ppm, while groundwater concentrations remain well below regulatory thresholds. Concurrent gamma-spectrometry measurements of uranium and thorium isotopes have delineated the radiological footprint of granitic and pegmatitic units. These integrated remote-sensing and in situ geochemical approaches advance environmental risk assessments and resource evaluation by revealing spatial patterns of trace-element enrichment and natural radioactivity within key mineralised belts.

Geochemical Processes in the Arabian-Nubian Shield publication trend

The graph below shows the total number of articles in geochemical processes in the arabian-nubian shield across all publications each year (not limited to Nature Index journals).

Technical terms

Detrital zircon: Zircon grains eroded from source rocks whose U–Pb ages record provenance and depositional histories.

Juvenile crust: Newly formed crust derived from mantle melts with minimal older continental input.

Hydrothermal alteration: Chemical modification of rocks by high-temperature fluids mobilising and redepositing elements.

Leucogranite: Light-coloured, silica-rich granite typically formed in post-collisional settings.

Radionuclide: Radioactive isotope of an element emitting ionising radiation, used to assess radiological risk.

References

1. Orogen styles in the East African Orogen: A review of the Neoproterozoic to Cambrian tectonic evolution. Journal of African Earth Sciences (2013).
2. Volcanosedimentary Basins in the Arabian-Nubian Shield: Markers of Repeated Exhumation and Denudation in a Neoproterozoic Accretionary Orogen. Geosciences (2013).
3. Assessing environmental and radiological impacts and lithological mapping of beryl-bearing rocks in Egypt using high-resolution sentinel-2 remote sensing images. Scientific Reports (2023).
4. Chemistry of Hydrothermally Destabilized Rare-Metal and Radioactive Minerals in Deformed A-Type Granite in the Vicinity of Nugrus Shear Zone, South Eastern Desert, Egypt. Resources (2024).