Interpretation of aerospectrometric, aeromagnetic and geochemical data, Um-Alhuweitat basin area, Central Eastern Desert, Egypt.

This study presents the analysis of airborne gamma-ray spectrometry and aeromagnetic data to delineate the distribution of the radioactive elements and determine their anomalous zones, subsurface structures controlled mineralized zones, and 3D magnetic inversion to give a full view of basement relief. According to statistical treatment of airborne gamma-ray spectrometry measurements, the highest values of potassium and equivalent thorium associated with Nakhiel Formation are 3.2% and 12.8 ppm respectively. Meanwhile, the equivalent uranium associated with phosphate beds attains 19.1 ppm. The spatial distribution of the relatively high concentrations of eU, eU/K and eU/eTh are recorded in adjacent areas in Upper Cretaceous deposits as > 12, 25 ppm and 5 ppm for eU, eU/K and eU/eTh, respectively. According to field measurements, the highest values of eU associated with phosphate beds and black Shale are 117 ppm and 20 ppm respectively. Meanwhile, the highest value of potassium associated with Quaternary sediments is 2.9%. Moreover, the highest value of eTh associated with Taref Formation is 16.2 ppm. The geochemical studies of collected samples from the anomalous zones showed the presence of secondary uranium in addition to rare earth elements. Meanwhile, the black shale trace elements are measured and showed high concentrations of tungsten. The magnetic data analysis is performed using tilt derivative and 3D magnetic modeling methods. Most of the deduced structures are trending in NW-SE, and NE-SW directions. The depths to the basement rocks are ranged from 0.475 km to 1.07 km below the ground surface.