الفهرس 
TOPOGRAPHY AND GEOMORPHOLOGYOnly 14 pages are availabe for public view
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Abstract
Um Safi area is located in the southern part of the Central Eastern Desert of
Egypt, between latitudes 25° 1 56 & 25° 24 05 N and longitudes 34° 3 &
34° 15 E. It covers an area of about 340 square kilometers. Field investigations reveal that the basement rock units of Um Safi area, which were previously mapped, are serpentinite, metavolcanic, metagabbro - diorite complex, older granitoids, younger granites and Hammamat mollasse
sediments. These rocks are extruded by rhyolite stocks and trachyte plugs.
The airborne gamma-ray spectrometric survey data of Um Safi area have
been treated qualitatively and quantitatively and correlated with the geological map of the study area. The gamma-ray spectrometric survey shows some K, eU and eTh anomalies related to the younger granites and are structurally controlledby the dominated faults. As well as, eU and eTh anomalies associated with the rhyolite flow tuffs. This survey indicates that the study area possesses gamma
radiation ranging between 0.5 and 14 Ur as a total count, 0.1 to 3.8 % for K, to 7.4 ppm for eU and 0.9 to 15.7 ppm for eTh. As a result of the application of computed power spectrum technique to the total intensity magnetic map, the regional and residual magnetic component maps were separated at average depth of 756 m and 66 m respectively. The magnetic data interpretation shows that, the deepest faults in the study area are the NNWSSE,
WNW-ESE and E-W trending faults. where, their depths reaches to 3 km. meanwhile, the NW-SE and NNE-SSW trending faults are having depth reach up to 1000 m. The faults, which trend in NE-SW, ENE-WSW and N-S directions,
have depths ranging from 450 to 800m.
The integration of the results of magnetic and gamma ray-spectrometric
interpretation reveal that most of radiometric anomalies recorded in the study area lie over the younger granites which are distributed as isolated bodies aligned around the big mother batholith especially along the NW-SE, NE-SW and E-W faults.