RELATION BETWEEN GRANITE PLUTONISM, FAULTING AND URANIUM MINERALIZATION IN THE NORTHERN PART OF GABAL QATTAR AREA, NORTHERN EASTERN DESERT, EGYPT

Northern Gabal Qattar area is located in the Northern Eastern Desert and delineated by latitudes 27° 02 00 and 27° 08 00 N and longitudes 33° 14 00 and 33° 20 00 E. This area occupies the northern part of Gabal Qattar Batholith comprising Hammamat sedimentary rocks and younger granites. The Hammamat sedimentary rocks are composed of basal conglomerates, greywackes and siltstones. They are intruded by acidic, intermediate and basaltic dykes. The younger granites are leucocratic in composition formed of quartz, orthoclase perthite and subordinate plagioclase and biotite. Iron oxides, zircon, apatite and fluorite represent the accessory minerals. The younger granites of Gabal Qattar intruded the Hammamat sedimentary rocks with their extrusions of acidic and intermediate dykes.Primary and secondary structure features are represented in the studied area. Stratifications and sheetings represent the primary structures, while the secondary ones are folds, joints, faults and foliations. The NNE-SSW, NW-SE, WNW - ESE and NE-SW are the main fault trends controlling uranium mineralization.Radiometrically, the contact and around zones are enriched in uranium mineralization especially along the faults passing along NNE-SSW. The uranium content in some parts of their zones records up to 10000 ppm. The contact between Hammamat sedimentary rocks and the leucocratic granite is affected by reverse like fault trending WNW-ESE. The main alterations along this fault are hematitization, bleaching, episyenitization, kaolinitization, carbonitization, siliciflcation and fluoridation.According to this study it is concluded that the main sources of uranium mineralizations are related to the hydrothermal solutions injected along some deformed zones caused by the emplacement of the granite and later tectonic cycles