Felsic granites of G.Abu Harba, G.Dara and G. Hamrat Al Jirjab areas are characterized by the presence of radioactive shear zones.
The radioactive minerals occurrence at G.Abu Harba area and G. Dara area are recorded along normal fault zone or shear zone trending in the same direction (N15ºW) with same dips of about 86º. The gamma radioactivity measured over these anomalies ranges between 1800 ppm to 2400 ppm; while the occurrence of the radioactive mineral at G. Hamrat Al Jirjab is along sinistral strike slip fault trending N50°W with a dip equal 70° to NE. The gamma radioactivity reaches 2200 ppm.
shear stress required initiating slip on both G. Abu Harba and G. Dara radioactive shear zones is directed in the same trend(N-S) direction; while G.Hamrat Al Jirjab radioactive shear zone is directed NNW-SSE direction. The shear strain on both G. Abu Harba and G. Dara mineralized shear zones is also the same ( pitches by 87º and 82º respectively the same direction E); while G.Hamrat Al Jirjab mineralized shear zone pitches by different amount equal 42º to W.
The mineralogical study revealed that the uranium minerals are the main detected radioactive minerals at G.Dara and G. Abu Harba areas while the thorium minerals are the main detected radioactive minerals at G. Hamrat Al Jirjab area.