The sigmoidal tension gashes are very important markers in the determination of deformation, which affected W. Belih area. They are markers for the determination of shear zone type (brittle shear zone). In addition, the tension gashes are used as strain markers for assessing strain localization in shear zones. The shear plane in association with its tension gashes determines the stress axes responsible for the formation of this tensile shear zone. W. Belih uranium mineralization in the area under consideration (G-V occurrence) is located along a tectonic shear contact zone between the Hammamat sedimentary rocks and younger Gattarian granites. The detailed structural analysis for this shear zone by using tension gashes indicated that the shear zone in association with its tension gashes gives an extension regime from NW-SE direction; this extension force is the main extensional force affecting the G-V mineralized shear zone and is responsible for distribution and localization of secondary uranium minerals along the contact shear zone. In addition, the strain analysis from a given tension gashes array indicates that the rate of dilatation relative to boundary-parallel shear is greatest as the finite strain is low (γ = 0.27), so that space is created rapidly for the precipitation of minerals.