Microstructural finite strain analysis of the Hafafit granitoids domes South Central Eastern desert of Egypt

Résumé

The Wadi Hafafit Culmination (WHC) can be subdivided into two main units which are separated by Nugrus thrust shear zone. The WHC domes are occupies the southern part of the Central Eastern Desert of Egypt and is cored by five separated gneissic granitoids ranging in composition from tonalite to granodiorite having compositions consistent with hydrous partial melting of a mafic source suggesting subduction-related magmatism. The leucogranites along thrust zones is related to the late phase of metamorphism of Hafafit rocks. The five main domes of the WHC have been labeled A dome occupies the northern part of WHC, B and C domes occupies the central eastern part of WHC, D dome occupies the central western part of WHC and E dome occupies the southern part of WHC. The fourth domes A, B, C and E are affected by more than one deformation event but D dome is affected by one deformation event. The domes not uniform throughout the WHC according radial pattern of stretching lineation but these domes of WHC were subjected and affected by late-orogenic extension that was controlled by the Najd transform faults and that resulted in exhumation of the WHC domes are oriented NW-SE parallel to the trend of the left-lateral shear zones of Najd fault system.