Investigation of gold mineralization along the Al Amar Fault Zone using integrated geophysical and remote sensing methods in the Saudi Arabian Shield

Abstract

The study of gold mineralization along the Al Amar Fault Zone, Saudi Arabian Shield, Ar Rayn and Ad Dawadimi terranes is undertaken using an integrated multi-method approach. The research effort aims to improve geological mapping of lithology, structure, and hydrothermal alteration by integrating Landsat-8 multispectral imagery, aeromagnetic geophysical data, and targeted field validation to overcome the limitations posed by remote, inaccessible desert terrain. Advanced image processing techniques, such as principal component analysis and Logsigm Function (LSF), enable precise discrimination of major rock units, thrust contacts, and zoned hydrothermal alteration systems (phyllic-argillic, propylitic, and iron oxide assemblages) associated with mineralization. Automated lineament extraction and aeromagnetic analysis imply multi-phase, depth-dependent structural controls, with NNE-NE and NW-trending faults and shear zones serving as major conduits for hydrothermal fluids and gold deposition. Fieldwork supports a spatial association between high lineament density and intense alteration with known mineral occurrences, especially in the Al Khunayqiyah and Al Amar mine sectors, highlighting the significance of structural permeability in mineralization localization. Gold in the Al Amar area is mainly found in structurally controlled quartz veins, breccia zones, and stockworks, often at volcanic-intrusive contacts. Here we present results that illustrate the complicated tectonic evolution of the Al Amar Fault Zone with multiple episodes of deformation and magmatism and the variety of types of mineral deposits that formed in response, including epithermal, VMS, and IOCG systems. Overall, the study demonstrates that integrating remote sensing, geophysical, and field data provides a robust three-dimensional exploration framework that improves understanding and targeting of gold mineralization in the structurally complex terranes of the Arabian Shield.