Magnetic modeling of ophiolites in NW Saudi Arabia for natural hydrogen exploration

Western Saudi Arabia presents significant potential for natural hydrogen exploration due to the extensive presence of serpentinized ophiolitic rocks within the Precambrian Arabian Shield, particularly in the western and northwestern regions. This study focused on two ophiolitic suites in northwest Saudi Arabia by analyzing airborne magnetic data to model their geometry and burial depths. Advanced edge-detection algorithms were applied to the magnetic data, enabling the identification of lineaments associated with lithological contacts and tectonic structures. These features were further integrated to construct a comprehensive lineament density map of the broader region. The 3D geophysical modeling reveals the subsurface tectonic regime and identifies highly fractured areas that may act as conduits for rainwater infiltration and aquifer formation within the ophiolitic masses, enhancing the region's hydrogeological potential. Laboratory measurements of the magnetic susceptibility of ophiolitic rock samples from these areas provided constraints for refining the inversion process, ensuring more accurate 3D subsurface models. The study also explores the implications of serpentinization processes within these ophiolitic masses. At depths exceeding 7 km and temperatures above 200 ^οC (conditions present in the study area), serpentinization can create pathways for the vertical migration of hydrogen. The latter can accumulate in structural traps such as fault zones or contacts with overlying sedimentary layers. By integrating geological and geophysical insights, this research underscores the potential of ophiolitic massifs in the Arabian Shield as viable targets for natural hydrogen exploration. It also contributes to the growing recognition of natural hydrogen as a clean and sustainable energy source, aligning with broader efforts to diversify energy resources in the Middle East region.