Uranium distributions in the mineral constituents of granitoid rocks and the associated pegmatites at Wadi Abu Had, north eastern desert, Egypt

Wadi Abu Had area is located at the northern part of the Eastern Desert of Egypt. It covers about 55 km2 of the crystalline basement rocks stretching between latitudes 28o 15'- 28o 25' N and longitudes 32o 25' - 32o 35' E. Abu Had younger granites are fertile (uraniferous) granites as they possess U-contents greater than 11 ppm. Their associated pegmatites show higher U-contents than those of granitoid rocks and hosting secondary uranium minerals. Numerous unzoned and zoned pegmatite pockets are associated with the marginal parts of granodiorite and within younger granites. Zoned pegmatites are the most radioactive ones. They are composed of extremely coarse-grained milky quartz core, intermediate zone of mica and wall zone of feldspars. An alteration zone with secondary uranium minerals (uranophane and beta-uranophane) is found at the contact between quartz core and the intermediate zone.