Magmatism and Related Mineralizations in Wadi Hammad, North Eastern Desert, Egypt

: Mineralization in the Wadi Hammad area is represented by polymetallic vein-type and occurs in four modes, they are mineralized main quartz vein, silicified shear zone, associated hydrothermal alterations, and breccia zones. They mainly occur in the contact between Dokhanvolcanics and Younger granites and are confined to and controlled by the Wadi Hammad shear zone. The study revealed that Dokhan volcanics have adakitic nature and are formed by slab melt. Accordingly, these rocks are favorable sites for the formation of Au-(Cu)deposits. Hammad granite rocks are characterized bymetaluminous to weakly peraluminous, span the boundary between the ilmenite-magnetite series, transitional between moderately and strongly oxidized granites, situated a relatively shallow to moderate depths (20 to 30 km), and started to crystallize at temperatures around 800 °C. It is suggested that mineralization in WadiHammad formed due to intrusion of the strongly oxidizing, water-and volatile-rich, and alkaline to alkalie-calcic magma into the adakiticDokhan volcanic leads to circulation of these fluids in the latter leaching the available metals (Au and base metals). The leached metals are deposited in preexisting open fissures at the cold end of convective cells near the surface form Au (Cu)-rich quartz veins.