Structural and tectonic evolution of the Umm Gheig/El-Shush region, central Eastern Desert of Egypt

El Sibai gneissic complex, Central Eastern Desert, Egypt: Folded nappes and syn-kinematic gneissic granitoid sheets – not a core complex

“…The two dominant antiforms (Delihimmi and Higlig) have no special relationship to the gneissic association rocks and are separated by a series of lower amplitude antiforms and synforms. A somewhat similar combination of large and small amplitude folds characterizes the cross-sections provided by Ibrahim and Cosgrove (2001) and Abdeen (2003). The second point is that the main gneissic granitoids of the complex occupy an intermediate position, sandwiched between ophiolitic association units.…”

“…Fritz et al (2002) and Bregar et al (2002) referred to the close relationship between magmatism and buoyant rise of the El Sibai complex. Ibrahim and Cosgrove's (2001) structural model for the El Sibai complex returned to the idea that the boundary shear surrounding the El Sibai gneissic rocks is a folded thrust, and they questioned whether buoyancy processes may have been overstated in the origin of this structure. Recent resurveying of the eastern half of the CED by Akaad and Abu El Ela (2002) did not recognize the existence of basement versus cover rocks of the El Sibai complex and surroundings.…”

“…These structures consist of mainly granitoid and mafic orthogneisses, amphibolites and paragneisses divided into subunits by mylonite zones, and separated from overlying mainly lower greenschist facies metavolcanics, metasediments and ophiolitic mélanges by a mylonitic or sheared schistose carapace. The database for these structures has steadily increased since the 1980s, particularly with the wealth of data that has appeared on the Meatiq gneissic complex (Ries et al, 1983;Sturchio et al, 1983a,b;Habib et al, 1985;El Gaby et al, 1988;Wallbrecher et al, 1993;Fritz et al, 1996;Neumayr et al, 1998;Loizenbauer et al, 2001), the El Sibai gneissic complex (El Gaby et al, 1984Khudeir et al, , 1995Kamal El Din, 1993;Hamimi, 1996;Ibrahim and Cosgrove, 2001;Fritz et al, 2002;Bregar et al, 2002) and the Hafafit gneissic complex Greiling et al, 1984Greiling et al, , 1988Rashwan, 1991;El-Ramly et al, 1993;Krö ner et al, 1994;Fowler and El Kalioubi, 2002). The CED gneissic complexes are relatively small structures with simple outlines and well-preserved boundary relations with the surrounding low-grade rocks.…”

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

“…Several models have been postulated to explain the WHC four tectonic models were proposed to decipher their origin: (1) development of fault-bend fold "antiformal stacks" (e.g.Hafafit domal structure; Greiling et al,1988a), (2) orogen-parallel crustal extension (e.g. HaFafit, Sibai and Meatiq domal structures; Wallbrecher et al, 1993;Fritz et al, 1996Fritz et al, , 2002Bregar et al, 2002;Loizenbauer et al, 2001;Abdel Wahed, 2008;Khudeir et al, 2008), (3) emplacement within regional domal structures (Ibrahim and Cosgrove, 2001) followed by extension parallel to their fold axes (e.g. Sibai dome, Fowler et al, 2007), and (4) interpreted the WHC as a result of fold interference patterns involving multiply deformed sheath folds (Fowler and El Kalioubi, 2002).…”

Late Neoproterozoic basement rocks of Kadabora-Suwayqat area, Central Eastern Desert, Egypt: geochemical and remote sensing characterization

“…These rock assemblages were intruded by suites of mafic, syn-late to post tectonic volcanics and granitoids. Geological and tectonic setting of the basement rocks in the CED of Egypt particularly Umm Gheig-El Sibai area (north of the study area) has been the focus of many studies (e.g., El Ramly 1972;El Gaby et al 1984, 1994EGSMA 1992;Khudeir and Asran 1992;Kamal El Din 1993;Kamal El Din et al 1992;Khudeir et al 1992Khudeir et al , 1995Greiling et al 1994;Hamimi 1996;Fritz et al 1996Fritz et al , 2013Ibrahim and Cosgrove 2001;Abdeen and Greiling 2005;Fowler et al 2007;Johnson et al 2011;Abdeen et al 2014).…”