Mineralogical investigation of the alteration aspects in Gabal El Sela area, South Eastern Desert, Egypt

Abstract

Kaolinitization, ferrugination, silicification, and illitization hematitization are the main alteration types recorded in the Gabal (G.) El Sela area, South Eastern Desert, Egypt. These altration zones occur in successive manar as supergene events along faults plane causing mineral redistribution. Uranium mineralization observed in the northern part of Gabal El Sela is mainly controlled by complicated structure regime: faulting, infrastructures, and shearing. So, the northern part of Gabal El Sela area is considered as the most significant and U-fertile part in the studied area. Visible secondary uranium minerals (uranophane and autunite) have been identified and are found to be related mainly to kaolinitized and ferruginated altered samples. Also, pyrite and chalcopyrite can be recorded as reduced Fe bearing minerals in fewer amounts than in hematite and goethite minerals. Finally, the present work confirms that G. El Sela granite is considered as one of the most promising granite plutons in Egypt. The fertility parts are mostly related to the extent of the overlap between the magmatic uranium enrichment, hydrothermal reworking through open fracture system, and suitable reservoir for the leached mineral. The U mineralization may be the result of all these reactions between the granite and the successive fluids.