Um Samra-Um Bakra area located in the southern part of the Central Eastern Desert of Egypt and covered by; 1) ultramafic rocks and volcanogenic sediments), 2) igneous rocks (syn-orogenic granites, isotropic gabbros and post-orogenic granites and 3) post-granitic dykes (basic and intermediate) and veins (black-, red jasper and milky quartz). Um Samra-Um Bakra shear zone strikes N70°W - S 70°E and dipping 45°/SSW and ranges from 10 to 500 m in thickness and extends 10 km in length.
Three generations of silica veins differ in color, mineralization and age are intruded the shear zone. The milky quartz vein is the youngest silica phase, barren, running WNW and dipping 70°/ SSW direction .The red jasper (second phase) has N 60°-76° W trend, dipping 45°/SSW. The oldest phase is represented by black jasper trending N75°W and dipping 50°-65° /SSW .The black jasper veins richer in Ni, Cr, Zn, Cu, Au and Y than red one.
The mineralogical studies at Um Samra - Um Bakra shear zone confirm the presence of three mineralization stages through hydrothermal solutions .The first stage (high temperature) distinguishes by the formation of native Au associated with hypogene primary sulfide minerals such as pyrite, galena, sphalerite and nickel. The second stage (lower-temperature) illustrates by the formation of secondary minerals; uranium, copper minerals (atacamite, paratacamite, crysocolla and cuprite), zincite, cassiterite, wolframite, Ni-chromite and Cr-spinel. The third stage is related to carbonate facies (calcification, fluoritization) formed after the oxidation (supergene alteration).