الفهرس 
Introduction
Gneisses and migmatitesOnly 14 pages are availabe for public view
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Abstract
The present study deals with the geological, radioactivity and mineralogical studies of the younger granite of Wadi Um Hamd environs. The studied area is delineated by the following coordinates; Longitudes 33o 16 / and 33o 28 / E, Latitudes 28o 52 / and 29o 00 / N. The studied younger granites are divided into two phases, monzogranite and syenogranite. Acording to geochemical data the studied younger granite are belong to syncollision, Itype and withinplate granite. Mineralogical studies of the younger granites revealed to the presence of secondary uranium minerals, e.g. kasolite and uranophane minerals. Radioactivity studies of the younger granites revealed to that the averages of U and Th of the studied younger granites are higher than those reported by Rogars and Adams (1969) and lower Th/U ratio for granites. The studied younger granite plutons have average uranium and thorium content more than two folds of the Uclarke value (4ppm), accordingly these granites are considered as uraniferous ones. The presence of U and Th may be attributed to a mineralization stage, which took place contemporaneously with the formation of granite or may be related to post magmatic stage such as small veins of fluoritebearing quartz which contain fluorite and secondary uranium minerals.