الفهرس 
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Abstract
The present study deals with the geological, geochemical and mineralogical studies of uraniferous granites from Abu Hadedah area which locates in the southern part of the Northern Eastern Desert. The studied area is bounded by longitudes 33o 44` 06``and 33o 47` 42`` E and latitudes 26o 42` 54``and 26o 45` 36``N. The area covers about 26 km2 and occupied by Precambrian basement suites.
Field investigation shows that the exposed rock units are represented by older granitoids, younger gabbros, younger granites moreover basic and acidic dykes. The older granitoids ranges from quartz-diorite– tonalites – granodiorites followed by younger granite monzogranites and alkali-feldspar granite with emphasis on the microgranite offshoots as a target of study. The microgranite offshoots occur as swarms of abnormal radioactivity and poly mineralization. They are restricted in a highly deformed, faulted, sheared narrow zone. They are equigranular, fine grained rocks, compact and silicified in some areas. They show color varying from buff, pink, dark red and brown. Microscopically, they consist of K-feldspar, quartz and plagioclase together with subordinate biotite and muscovite. Zircon, fluorite and apatite are accessories. Also, secondary uranium minerals are recorded in some sample such as uranophane and kasolite. They show highly alteration processes such as hematitization, silicification, kaolinization, sericitization and carbonization that are affecting on the rocks with different degrees of intense..
The geochemical investigations of the studied microgranite offshoots samples revealed that they plot in the granites field and they evolved from magma with subalkaline characters. The uraniferous granites from Abu Hadedah plot in the high K-calc alkaline field. The studied samples lie in the peraluminous field belong to Atype granite. The microgranite offshoots are enriched in rare metals (Zr, Y, Nb and Hf) and alkali earths such as Ba and Sr. Similarly, the heavy metals; Pb and Zn, increase. The alteration improves the total REE budget, but with preferential enrichment of the HREE over the LREE. In light of the uraniferous microgranites,. it is found that the area have background values higher than the corresponding Clark value, it was also observed
that, U, Th, Nb, Pb, Y and Zr have abnormal contents. These dykes hosting or acting as a source for uranium, and heavy rare earths mineralization. They could be used to delineate the most suitable locations for the surface and probable hidden mineralization
The mineralogical studies of the studied rock units illustrate that the common heavy minerals of W. Abu Hadedah can be classified to: a) secondary uranium minerals (kasolite and uranophane), b) thorium minerals (thorite, uranothorite and orangite), c) niobium - tantalum minerals (fregusonite, samarskite, ferro-columbite, urano-polycrase, ashanite and ixioite), d) base metals minerals (wolframite, franklinite, molybdenite, danalite, mimetite, cassiterite and pyrite and minor amounts of gold detected by ESEM) and e) accessory minerals (zircon, fluorite, monazite, xenotime, apatite, titanite). The secondary uranium mineralization occurs as microfractures infilling or coating on joint surfaces. Nb-Ta mineralization and zircon is the most common heavy minerals in the study area. The examined granitic rocks of Abu Hadidah area are characterized by their high content of Zr (up to 2000 ppm) and Nb concentration reaches up to (1850ppm) and Ta contents reaches up to 185 ppm.
The radiometric investigation suggested that the studied granites can be classified as uraniferous granites because they host the most radioactive anomalies in the study area and the highest dose rate values recorded in uraniferous microgranites. The pre-existing primary uranium minerals are the source of the present secondary uranium minerals by the action of oxidizing fluids, mobilization of uranium and then re-deposition in other forms. Redistribution by circulating meteoric waters might have taken place. They possess the highest contents of eU, eTh, and ratio of eU/eTh. They suggest enrichment in uranium which related to post-magmatic processes and the leaching of uranium from surrounding country rocks. from the D-factor of the studied uraniferous microgranites, it is clear that chemical uranium is greater than the radiometric uranium in all of the samples, which reflects disequilibrium due to the addition of uranium. The relation between U and Th (ppm) contents is examined by plotting the U contents against Th contents. It shows strong positive correlation between both U and Th indicating their enrichment of U with magmatic differentiation.