PETROLOGY AND URANIUM DISTRIBUTION IN THE YOUNGER GRANITES OF GABAL ABU DIAB AREA, EASTERN DESERT, EGYPT

The area of Gabal Abu Diab (about 92.5km²) is located between latitudes 25º 11` and 25º 16`N and longitudes 34º 11` and 34º 17` E.  The younger granites of G. Abu Diab are classified on petrographic and geochemical bases as monzogranites, syenogranites and alkali-feldspar granites. They originated from peraluminous, cal-alkaline magma. This magma was derived from crustal sialic materials during post-orogenic magmatism. The field observations, the petrographic characteristics and the geochemical features may suggest that the studied younger granites intruded in successive pulses started with monzogranites and ended with alkali-feldspar granites.
The enrichment of uranium in the alkali-feldspar granites is related to magmatic processes, except minor locations, which suffered secondary processes and limited redistribution of uranium. These secondary processes have leached uranium from the country rocks and even the monzogranites and syenogranites themselves and added it within the microfractures of the alkali-feldspar granites.