The emplacement and exhumation of gneissic domes of continental lithospheric fragments within the Pan-African oceanic crust in the Arabian-Nubian shield have been subjects of debate in the recent literature. The Wadi Hafafit culmination is one of the largest metamorphic dome complexes, not only in the Eastern Desert, but also in the Arabian-Nubian shield. The culmination forms a northwest-trending folded belt including five individual gneissic domes that show complex interference fold patterns, bounded by northwest- to west-northwest–trending marginal shear zones (the Nugrus and Hafafit shear zones), which belong to the late Proterozoic Najd fault system in the Eastern Desert of Egypt. The Hafafit metamorphic dome forms a positive flower structure that is characterized by a vertical stretch in the central part with subvertical foliation at the individual dome peripheries, subhorizontal flattening in the roof, and near simple shear at the complex margins defined by the Nugrus and Hafafit shear zones. This study presents arguments concerning the folding pattern and exhumation of the culmination and its relation to sinistral, transpressional kinematics along the branches of the Najd fault system. The folded axial surfaces of the gneissic domes are interpreted in terms of interference of two fold generations: (1) an early fold generation that developed east-northeast–trending axial surfaces, which may have formed during late Pan-African northwestward nappe stacking, and (2) a late fold generation that developed north-south–trending fold axes that deformed the axial surfaces of the first fold generation, and probably associated with sinistral shearing on the Nugrus and Hafafit shear zones. The fold interference patterns associated with exhumation of the Hafafit gneissic domes are consistent with published geochronological data and the tectonic evolution of the Arabian-Nubian shield.

You do not currently have access to this article.