GEOPHYSICAL SURVEYS FOR DEFINING FAVORABLE STRUCTURES FOR URANIUM REMOBILIZATION IN WADI YOIDER, SOUTH EASTERN DESERT, EGYPT | ||
| Journal of Egyptian Geophysical Society | ||
| Volume 14, Issue 1, 2016, Pages 149-163 PDF (4.9 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/jegs.2016.385666 | ||
| Author | ||
| I.M. Gaafar | ||
| Nuclear Materials Authority, Cairo, Egypt. | ||
| Abstract | ||
| Geophysical data integration was used for delineating the structural controlling U-remobilization in Wadi Yoider area, south eastern desert, Egypt. The area was studied using detailed ground gamma ray spectrometric, magnetic and VLF-EM surveys. The interpretation of the obtained ground gamma ray spectrometric maps clearly reflects the sharp increase of eU content. The eU/eTh ratios correlate positively with eU concentrations and negatively with eTh concentrations associated with the ENE-WSW trending shear zone indicating an increase in the U-potentiality than the surrounding granite. The N-S trending shear zone displays eU content ranging from 10 to 110 ppm. The ENEtrending shear zone is characterized by elongated uranium anomalies which values attaining up to 750 ppm. This study follows the expected subsurface geometry of the shear zone. 3-D Euler deconvolution method was applied to estimate source depths from the ground total magnetic-intensity data. The calculated source depths are in the range of 20 to 150 m. The shallow structures follow the ENE-WSW direction located mostly in the eastern part of the studied area. The major structures trending in the NNW-SSE direction have depths of up to150 m and are associated mainly with its western part. The filtered VLF-EM maps of the two used frequencies (17.1 and 17.4 kHz) show an excellent agreement indicating that the shear zone is elongated in an ENE-WSW trend for about 600m in the E-W direction and distinguished with relatively high electrical conductivity. Most of the NW-SE trending faults suggest discontinuities in depth due to their left-lateral strike-slip displacements. The interpreted faults, with an ENE-WSW trend represent the main trend of the shear zone, through which hydrothermal solutions flowed causing high alteration and uranium mineralization. | ||
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