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

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

ΤΗE PELAGONIAN NAPPE PILE IN NORTHERN GREECE AND FYROM. STRUCTURAL EVOLUTION DURING THE ALPINE OROGENY: A NEW APROACH

The geometry of kinematics and the deformation history of the Pelagonian nappe pile during the Alpine orogeny have been studied in Northern Greece and FYROM. Deformation was started in Middle-Late Jurassic time and was initially associated with ocean-floor subduction followed by ophiolites obduction, nappe stacking and duplication of the Pelagonian continent. The footwall Pelagonian segment from top to bottom was metamorphosed under greenschist to amphibolit facies conditions and a relative high pressure (T = 450o to 620o C and P = 12,5 to 8 kb). Blueschist facies metamorphic assemblages of Late Jurassic age are immediately developed between both hangingwall and footwall Pelagonian segments. Transgressive Late Jurassic-Early Cretaceous neritic limestones and clastic sediments on the top of the obducted ophiolites are maybe related to extension and basins formation simultaneously with the nappe stacking and metamorphism at the lower structural levels of the Pelagonian nappes. Contractional tectonics and nappe stacking continued during the Albian-Aptian time. Simultaneously retrogression and pressure decreasing taken place at the tectonic lower Pelagonian footwall segment. Low grade mylonitic shear zones, possible related to extension, are developed during Late Cretaceous time simultaneously with basins formation and sedimentation of neritic Late Cretaceous to Paleocene limestones and flysch. Intense shortening and imbrication under semi-ductile to brittle conditions occurred during Paleocene to Eocene time resulting the onset of the dome like formation of the footwall Pelagonian segment. The next stages of deformation from Oligocene to Quaternary are related to brittle extension and the final uplift and configuration of the Pelagonian nappe pile