Integrating multi-source remote sensing, field work, and petrography for automatic lithological mapping and...

The Gabal El-Faraid Group, in the Egyptian Southeastern Desert, comprises Neoproterozoic lithologies and structurally controlled mineralization zones that require an integrated exploration approach. This study integrates multi-source remote sensing data with detailed field observations, structural analysis, and petrographic investigations to improve lithological differentiation and delineate mineralization-related structures. Results indicate a potential structural-control spatial association among shear zones, hydrothermal alteration zones, and mineralization, suggesting their potential role in controlling mineralization. Support Vector Machine (SVM) and Random Forest (RF) algorithms have been used to best delineate lithological rock units of the study area. Accurate lithological mapping was achieved using an SVM applied to combined Sentinel-2 and ALOS PALSAR datasets, yielding an overall accuracy of 92.67%, a Kappa coefficient of 0.8928, and an F1-score of 88.64%. Six spectral mineral indices, like argillic, clay, ferrous silicates, ferrugination, hydroxyl, and phyllic alterations, have been emphasized using the hyperspectral PRISMA dataset. Exposed rocks comprise metavolcanics, metagabbro-diorite, tonalite-granodiorite, monzogranite, syenogranite, pegmatite, and late basic dikes, representing a multiphase magmatic sequence spanning arc-related to post-collisional stages. Structural investigations indicate a polyphase deformation history comprising four major events (D1-D4). The earliest phase (D1) is characterized by penetrative foliation, stretching lineation, and low-angle thrusting associated with nappe transport during intra-oceanic arc accretion. D2 reflects large-scale folding and regional shortening related to arc-to-continent collision. The D3 phase records transpressional strike-slip shearing, reactivating earlier structures and facilitating magma ascent, whereas D4 is marked by brittle faulting and jointing linked to post-orogenic uplift and extensional tectonics. Lineament analysis from PALSAR data highlights dominant NW-SE and NE-SW trends that closely correspond to field-measured fabrics and shear zones. Integration of field and remote sensing datasets demonstrates that late-stage deformation (D3-D4) exerted strong structural control over pegmatite emplacement, quartz veining, and hydrothermal alteration, with a main set trending WNW to NW and a less prominent set with pronounced ENE and NNW trends, emphasizing the role of inherited Pan-African structures in localizing mineralization. High-priority prospective zones in the studied granites were derived from integrated datasets, which were systematically combined in ArcGIS using a fuzzy-logic overlay. The detected zones are labeled as very high, high, moderate, low, and very low based on their potential for rare-metal mineralization. The integrated datasets can be applied to similar areas in the Eastern Desert of Egypt and across the entire Arabian-Nubian Shield (ANS).