Geo-Investigations on the Qarat Kibrit Salt Dome Faulting System South of Adam, Oman—In Search of Anomalies Favorable for Uranium and Associated Minerals

Abstract

The development of salt domes, often arising from depths of some 10 km or more, causes intense faulting of the surrounding host rocks (salt tectonics). The fractured rocks then present ideal space for oil that can migrate and get trapped. If such moving of hydrocarbons passes uranium-carrying rock units (e.g., shales), uranium is collected and enriched by organic carbon compounds. Brines from the salt body is also ideal carriers for oxidized uranium species and will further dislocate uranium when in contact with uranium-enriched oils. Uranium then has the potential to mineralize in the vicinity of the dome (blue halite is evidence for radiation having affected salt deposits). Based on this, the Qarat Kibrit salt dome was investigated by very low-frequency electromagnetic (VLF-EM) and magnetic surveys along five traverses approximately 250 m in length (10 m intervals) in order to identify subsurface fault systems. In-phase and quadrature components of the VLF-EM signal were recorded at two transmitter frequencies (24.0 and 24.9 kHz) along with the total magnetic field. The Karous-Hjelt current density pseudo section delineates the subsurface faults at depths between 10 and 40 m which is substantiated by the Hartley spectral depth from the total magnetic field. The stacked profiles of the line joining the Fraser peaks have brought out two plausible trends/directions of faults. Furthermore, the in situ XRF measurements that were carried out in the field are unable to establish any possible uranium enrichment within the salt-tectonic system, and there seems to be no evidence for an enrichment of uranium.