Delineation of shear zone-hosted mineral targets within the Arabian-Nubian Shield, Egypt, using aeromagnetic data

This study presents a pre-field airborne magnetic interpretation designed to delineate priority targets and guide subsequent ground-based exploration in the underexplored southern Eastern Desert of Egypt, a key sector of the Arabian-Nubian Shield. The analysis utilizes regional-scale airborne magnetic data (2-arc-minute grid resolution, acquired at ~4 km altitude) obtained from the National Oceanic and Atmospheric Administration (NOAA), and the National Centers for Environmental Information (NCEI) database. Multiple enhancement and interpretation techniques were applied to extract maximum structural information from the magnetic data. These included Centre for Exploration Targeting (CET) porphyry analysis, Source Edge Detection (SED) filtering, Euler deconvolution, and power spectral analysis, along with derivative filters (tilt, vertical, and horizontal gradients). Integration of these products enabled delineation of subsurface structures and estimation of depths to magnetic source ensembles. The interpretation reveals three major shear systems governing regional deformation: the interested Kharit-Hodein Megashear Zone (KHSZ), the Nugrus Shear Zone (NSZ), and the Allaqi-Heiani Shear Zone (AHSZ). These features, concentrated south of the Hafafit Core Complex (HCC), around Nugrus, and within the attentive Wadi Kharit depocenters, coincide with prominent magnetic anomalies and fault-controlled structures linked to the Upper Cretaceous Rift System. Euler deconvolution and power spectral analysis provide depth estimates to magnetic source ensembles, interpreted as lithological contacts, intrusive bodies, and basement structures, and magnetic source clusters ranging from near-surface to approximately 18 km, with quantified uncertainties of ±15–20% for spectral analysis and ±10–15% for Euler solutions. These depths represent centroids of magnetic source distributions, interpreted as crustal interfaces and intrusive complexes, rather than discrete body tops, and are consistent with regional crustal thickness estimates. Integration of magnetic anomaly patterns, structural lineaments, and porphyry signatures defines distinct high-, moderate-, and low-prospectivity zones. The convergence of high magnetic intensities and CET-derived porphyry signatures pinpoints the concerned Wadi Kharit depocenter and the Hafafit Core Complex margins as priority exploration targets for gold (orogenic and intrusion-related), copper (Volcanogenic Massive Sulfide (VMS) and porphyry-style), and rare earth element (REE) potential mineralization. This study establishes a data-driven predictive framework for subsequent ground validation and architecture, delineates structurally complex zones, and demonstrates the value of airborne magnetic surveys as a cost-effective first step for mineral exploration in complex shield terrains globally.