Tectonic evolution of the Meatiq infrastructure, Central Eastern Desert, Egypt

Abstract

The Pan‐African basement exposed in the Meatiq area, Central Eastern Desert, Egypt, was found to possess tectonic styles belonging to infrastructure, transition and super‐structure levels. Tectonic style of the infrastructure was developed during an old orogeny in the Lower Pan‐African, and overprinted by those of the transition and superstructure levels of a younger orogeny in the Middle and Upper Pan‐African, respectively. In the Lower Pan‐African, old sequences of sediments and volcanics, together with ophiolitic rocks, were intensely deformed and regionally highly metamorphosed into gneisses and amphibolites. In the infrastructure level such rocks were migmatized, plastically deformed and intruded by synkinematic granitoid (diorite to alkali granite) lenses, sheets and plutons which were probably crystallized as amphibolite‐facies gneisses. Later on, these infrastructural rocks were cut by mafic to intermediate dykes and sills, isostically uplifted and cratonized. Parts were exposed to erosion. In the Middle Pan‐African the cratonized rocks sank into a transition tectonic level where they underwent large‐scale thrusting, varying degrees of cataclasis and mylonitization, and low‐ to medium‐grade regional metamorphism. An episode of plutonism guided by thrusts followed, mainly in the form of synkinematic intrusion of tonalite, granodiorite and quartz monzodiorite. In the Upper Pan‐African, isostatic uplift occurred and the mylonitic rocks attained the superstructure level. There they were subjected to two main phases of folding resulting in the major Meatiq domal structure. Subsequently, the folded rocks were intruded by a postkinematic quartz monzonite pluton.

Structural constraints on the evolution of the Meatiq Gneiss Dome (Egypt), East-African Orogen

“…Habib et al (1985a) identified and described several thrust sheets structurally above the Um Báanib Orthogneiss, including the Abu Fannani Thrust Sheet. In the description and discussion which follows we have adopted the Abu Fananni Thrust Complex, as a term for all the five thrust sheets (Fiadiya-, Gabal-Meatiq-, Abu Zohleiga-, Um Esh Hamra-and Abu Fannani thrust sheets).…”

Lithological Mapping in the Eastern Desert of Egypt,wadi Um Gheig Area, Using Landsat Enhanced Thematic Mapper (Etm+)

“…The studied rock units have pre Pan-African and Pan-African age by many authors (e.g. El Gaby, 1983;Asran, 199;Khudeir et al, 1995;Kamal El-Din, 1993;Ragab et al, 1993 andHabib et al, 1985). Recent studies suggest the Neoproterozoic age for the investigated rocks (e.g.…”

Mineralogy of a rare Ediacaran epidote‐bearing trondhjemitic complex from the Nubian Shield: Insights into P‐T conditions of magma emplacement

“…This assemblage occurs essentially as tectonically dismembered sheets, blocks, and fragments embedded in a metasedimentary succession. Host rocks of the FIC were extensively investigated by numerous authors (e.g., Akaad & Shazly, 1975; Andresen, El‐Rus, Myhre, Boghdady, & Corfu, 2009; Fritz et al, 2014; Habib, Ahmed, & El Nady, 1985; Loizenbauer et al, 2001; Neubauer, 1962; Neumayr, Hoinkes, Puhl, Mogessie, & Khudeir, 1998). Thus, in‐depth geochronological, metamorphic, structural, and tectonic studies on rock units hosting the TTG suite of the FIC (the Fawakhir and Meatiq rocks) have been carried out.…”

“…Thus, in‐depth geochronological, metamorphic, structural, and tectonic studies on rock units hosting the TTG suite of the FIC (the Fawakhir and Meatiq rocks) have been carried out. These studies showed that the Fawakhir ophiolitic mélange (736.5 Ma; Andresen et al, 2009) occurring within the eugeoclinal thrust sheet formed in a fore‐arc setting, whereas the Meatiq dome (630.8 Ma; Andresen et al, 2009) is a younger structural feature interpreted to have formed as a result of NE‐SW tectonic shortening occurred during an oblique collision of East and West Gondwana (e.g., Akaad & Shazly, 1975; Andresen et al, 2009, 2010; Habib et al, 1985; Loizenbauer et al, 2001; Neumayr et al, 1998; Schuermann, 1966). The Meatiq dome is made‐up of high‐grade granitic orthogneiss occurring at the structurally lowest part that is overlain by a dominant metasedimentary succession consisting of quartz‐rich schists intercalated with metapelitic schists.…”