INTEGRATION OF GAMMA-RAY SPECTROMETRIC AND ASTER DATA FOR URANIUM EXPLORATION IN QASH AMER-EL-SELA AREA, SOUTHEASTERN DESERT, EGYPT

The present work used the integrated remote-sensing and ground gamma-ray spectrometric data to
prospect of radioactive zones at Gabal Qash Amer–El-Sela area, Southeastern Desert of Egypt.
Geological interpretation of ASTER image correlated with field studies revealed that the study area
is mainly covered by intermediate metavolocanics, granodiorites, two-mica granites, biotite granites and
muscovite granites. These rocks were injected by pegmatitic and quartz veins and cutting by acidic and
basic dykes. The applied ASTER data enabled to identify uraniferous alteration zones hosted in the
granitic rocks through the use of band ratios b4/b6 and b5/b4 for clay and ferrous silicate alteration.
The band ratio combinations of b12/b13: b11/b12: b14/b13 as R:G:B and b4/b6:b2/b1:b4/b3 as R:G:B
were very useful for discriminate the granites from the metavolcanics and mapping different phases of the
granite in the study area.
Ground gamma-ray spectrometric survey data were applied to check the surface distribution of
radioactivity, which may ascertain its compatibility with surface structures, and delineate the suitable
locations for probable valuable mineralization.
The study revealed the existence of uranium mineralization in alteration zones associated with
granites, along ENE-WSW trending shear zones as well as other isolated alteration zones. Three
uranium-bearing alteration zones hosted in granities were detected. These zones are characterized by
ferrugination, silicification, grizenization and kaolinitization. The most promising alteration zones occur at
the northeastern part of El-Selashear zone. Another promising uranium anomaly is located to the west of
the main shear zone, as well as third anomaly, located at the southeastern part of Gabal Qash Amer. These
zones and individual anomalies are characterized by very high radioactive anomalies (up to 3700 ppm eU).
Other mineralized sites were detected in the south central part of Gabal El-Selaas well as in the eastern part
of the study area. The final result of this study confirms that El-Sela granite can be considered as one of the
most promising granite outcrops in Egypt, regarding its U-fertility.