Integrated Geophysical Study for Delineation of Structures Favorable to Uranium Mineralization in Al-Amerat, Sultanate of Oman

The spectroscopic results of the acquired Gamma-ray have indicated a moderately high concentration of radioactive minerals showing ~100 ppm of Uranium and ~1000 ppm of Thorium in the placer deposit in Amerat, near Muscat Sultanate of Oman. To identify the extension and structural parameters of the Formation, the area was further investigated with very low frequency electromagnetic (VLF-EM) and magnetics 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 kHz and 16.4 kHz) as well as the total magnetic field. Processing and interpretation were carried out by well-known methods such as Euler deconvolution, Fourier spectral analysis, and also by Hilbert transform technique. Magnetics data resulted in a depth in the range of 5-20 m by Euler deconvolution and 6-12 m by Fourier spectral analysis whereas the VLF-EM signals have resulted in a depth in the range of 7.2 m-10.4 m by Karous and Hajelt (KH) filtering. On the other hand, the Hilbert transform technique estimated both the depth and width of the subsurface source in the range of 9.2 – 24 m and 19.5 – 66.5 m respectively. Thus, the overall analyses of geophysical data have revealed the possible Uranium bearing structures as deep as 5-24 m from magnetics and VLF-EM methods.