Geophysical investigation for delineating structures favorable to uranium mineralization in Al-Amerat, Sultanate of Oman

The Amdeh Formation near Al-Amirat area south west of Muscat, Sultanate of Oman is characterized by well-bedded quartzite exhibiting tabular cross-beds and contorted bedding structures were geophysically investigated initially with a gamma ray spectrometry technique. The spectroscopic results of acquired gamma ray has indicated moderately high concentration of radioactive minerals showing ∼100 ppm of uranium and ∼1000 ppm of thorium in the placer deposit. In order to identify the extension and structural parameters of the Formation, the area was further investigated with very low frequency electromagnetic (VLF-EM) and magnetic surveys along five profiles of approximately 200 m long 20 m apart (10 m measurement intervals). In-phase and quadrature components of the VLF-EM signal were recorded at two different transmitter frequencies (15.1 and 16.4 kHz) as well as total magnetic field. Spatial location by amplitude of analytical signal and the depth to targets by Euler deconvolution and spectral analysis in the case of total magnetic field and the Fraser and K-H filtering as well as EMD based Hilbert transform analysis in the case of VLF-EM signals have revealed the possible uranium bearing structures as deep as 5-20 m. The salient features of results are highlighted and discussed in this presentation.