The significance of gneissic rocks and synmagmatic extensional ductile shear zones of the Barud area for the tectonics of the North Eastern Desert, Egypt

Fowler, Abdel-Rahman; Ali, Khaled G.; Omar, Sayed M.; Eliwa, Hassan A.

doi:10.1016/j.jafrearsci.2006.04.011

Cited by 48 publications

(22 citation statements)

References 42 publications

(75 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These masses striking E-W parallel to the planes of schistosity in the enveloping basaltic metaandesite and dacitic metatuffs. The sheared metavolcanics are tectonically intercalated with bands of iron-rich horizons such as those reported by Bishara and Habib (1973) from Gabal Semna (30 km south of the Barud area at 26°26′ N, 33°34′ E) and the banded quartz-magnetite rocks recorded in the Abu Furad amphibolites (20 km south of the Barud area at Wadi El Bula; Fowler et al 2006). They are intruded in the east and west by post-tectonic granites of Abu Hamr and Umm Inab, respectively (Fig.…”

Section: Location and Pervious Workmentioning

confidence: 51%

“…The southern part of the Barud belt, to the south of Qena-Safaga road, was structurally investigated by Abd El-Wahed and Abdeldayem (2002) and they reported three phases of deformation and two phases of metamorphism and migmatization. Fowler et al (2006) concluded that the amphibolites, schists, and migmatites of Barud area (to the south of Qena-Safaga road) were formed by extensional shearing of previous arc metavolcanics. Many geochemical studies on the syntectonic and post-tectonic granitoids have been reported by Abdel Aal (1995), Ahmed (1995), Abu El-Maaty et al (1998, Ahmed et al (1998), Hassan (1999, Mahmoud (2004), and Helmy et al (2004).…”

Section: Location and Pervious Workmentioning

confidence: 99%

“…This batholith is a huge igneous mass traversed by Qena-Safaga road. It was the subject of many contributions especially its central and southern parts (e.g., Habib 1972Habib , 1987Akaad et al 1973;Abu El-Ela 1979;El-Gaby and Habib 1982;Kamal El-Din and Asran 1994;Masoud 1997;Abd El-Wahed and Abdeldayem 2002;Fowler et al 2006). The Barud batholith exhibit distinct intrusive features to the Fatira sheared metavolcanics and also to metavolcanics and amphibolites around Qena-Safaga road (Abd ElWahed and Abdeldayem 2002;Fowler et al 2006), and not an autochthonous igneous body separated from a remobilized granitized pre-Pan-African basement (Fowler et al 2006), as proposed by Akaad et al (1973), El-Gaby and Habib (1982), Habib (1987), El-Gaby et al (1990), El-Gaby (1994), andEl-Shazley andEl-Sayed (2000).…”

Section: Barud Tonalite-granodioritementioning

confidence: 99%

“…This thrust uplifted the NED in relation to CED and put the continental basement in the front of ensimatic cover rocks. Fowler et al (2006) stated that the thrusting at the southern margin of the NED is not responsible for the ∼620-600 Ma uplift of the NED because the thrusts are related to the earlier event of arc accretion.…”

Section: Introductionmentioning

confidence: 99%

“…The second model argues against the presence of core complexes in the Eastern Desert of Egypt and explains the development of gneiss-cored domes by an overlap between NW-SE complex folding and NW-SE extension parallel to the fold hinges (e.g., Fowler and Osman 2001;Fowler et al 2007;Andresen et al 2008). This model diminished and ignored the role of the NFS in the tectonic history of the Egyptian Eastern Desert and ascribed the evolution of gneisses, migmatites, and the major ductile shear zones to extensional tectonics (e.g., Greiling et al 1988;Fowler et al 2006;Fowler and Hassan 2008;Fowler and Osman 2008).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Synoblique convergent and extensional deformation and metamorphism in the Neoproterozoic rocks along Wadi Fatira shear zone, Northern Eastern Desert, Egypt

El‐Wahed

Anbar

2008

Arab J Geosci

View full text Add to dashboard Cite

The Wadi Fatira area occurs at the southern margin of the Northern Eastern Desert (NED) of Egypt and is occupied by highly sheared metavolcanics tectonically alternated with banded iron formations and intruded by Barud tonalite-granodiorite, post-tectonic gabbroic and granitic intrusions. Detailed structural investigation showed that the schists and migmatitic amphibolites are formed by shearing in metavolcanics and syntectonic Barud tonalitegranodiorite due to movement along the Wadi Fatira shear zone (WFSZ). This shear zone starts as a NW-SE striking fault along Wadi Barud Al Azraq and the Eastern part of Wadi Fatira and turns to a E-W trending fault to the north of Wadi Fatira. Microstructural shear sense indicators such as asymmetric geometry of porphyroclasts such as σ-type and asymmetric folds deforming fine-grained bands which are frequently found around porphyroclasts indicate sinistral sense of shearing along the WFSZ. This shear zone is characterized by transitions from local convergence to local extension along their E-W and NW-SE trending parts, respectively. The NW-SE part of the WFSZ is of about 200 m in width and characterized by synmagmatic extensional features such as intrusion of synkinematic tonalite, creation of NE-SE trending normal faults, and formation of migmatitic amphibolites and schlieric tonalites. This part of the shear zone is metamorphosed under synthermal peak metamorphic conditions (725°C at 2-4 kbar). The E-W compressional part of the WFSZ is up to 3 km in width and composed of hornblende, chlorite, actinolite, and biotite schists together with sheared intermediate and acidic metatuffs. Contractional and transpressional structures in this part of the WFSZ include E-W trending major asymmetrical anticline and syncline, nearly vertical foliation and steeply pitching stretching lineations, NNE dipping minor thrusts, and minor intrafolial folds with their hinges parallel to the stretching lineation. P-T estimates using mineral analyses of plagioclase and hornblende from schists and foliated metavolcanics indicate prograde metamorphism under medium-grade amphibolite facies (500-600°C at 3-7 kbar) retrogressed to low-grade greenschist facies (227-317°C). The foliation in Barud tonalite-granodiorite close to the E-W part of the WFSZ runs parallel to the plane of shearing and the tonalite show numerous magmatic flow structures overprinted by folding and ductile shearing. The WFSZ is similar to structures resulted from combined simple shear and orthogonal shortening of oblique transpressive shear zones and their sense of movement is comparable with the characteristics of the Najd Fault System.

show abstract

Section: Location and Pervious Workmentioning

confidence: 51%

Section: Location and Pervious Workmentioning

confidence: 99%

Section: Barud Tonalite-granodioritementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Synoblique convergent and extensional deformation and metamorphism in the Neoproterozoic rocks along Wadi Fatira shear zone, Northern Eastern Desert, Egypt

El‐Wahed

Anbar

2008

Arab J Geosci

View full text Add to dashboard Cite

show abstract

Egyptian Hammamat molasse basins and their relations to arc collision stages: Implications for radioactive elements mineralization potential

2018

View full text Add to dashboard Cite

Our understanding of the formation style and tectonic setting of Hammamat molasse sedimentary rocks (HMSR) as well as their chronological situation in the legend of the geologic maps is as yet deficient. The purpose of the work is to decipher the misinterpretation of the HMSR genesis. As such, we present a new classification for HMSR that provides answers about its significant field relationships with the mature island arc volcanics that obviously explains the changes in the depositional environments of HMSR, tectonic setting in addition to the shape and type of their constituents. In the light of our suggested thematic evolution model, the HMSR have been deposited in 3 different tectonic settings: (a) fore‐arc, intra‐arc, and back‐arc basins during pre‐collision stage; (b) fore‐arc basins and low land basins in accretionary prism during syn‐collision stage; and (c) low land and intramontane basins during late‐collision stage. The characteristics of HMSR in each stage differ according to the shape and type of basin and the source of sediments supplying. Thus, they show different types and sizes of clasts, mineralization, and radioactivity. The low radioactive potentiality of HMSR is entirely related to their composition, nature, and source of sediments. Generally, any radioactive anomalies are not related to HMSR themselves, but to the surrounding U‐rich rocks and/or the hydrothermal and super‐heated solutions. Siltstones of HMSR with their recognizable low permeability could be a good barrier for solutions carrying uranium and probably form visible uranium mineralization. Spots of visible uranium mineralization are scattered at the contact between HMSR and late‐collision granites within the southern periphery of Um Tawat Basin and at the contact between trachytes and HMSR within Wadi El Kareim Basin; the extension of this mineralization does not exceed more than few centimetres away from the contact.

show abstract

Structural and Tectonic Framework of Neoproterozoic Basement of Egypt: From Gneiss Domes to Transpression Belts

Fowler

Hamimi

2019

The Geology of Egypt

View full text Add to dashboard Cite

The significance of gneissic rocks and synmagmatic extensional ductile shear zones of the Barud area for the tectonics of the North Eastern Desert, Egypt

Cited by 48 publications

References 42 publications

Synoblique convergent and extensional deformation and metamorphism in the Neoproterozoic rocks along Wadi Fatira shear zone, Northern Eastern Desert, Egypt

Synoblique convergent and extensional deformation and metamorphism in the Neoproterozoic rocks along Wadi Fatira shear zone, Northern Eastern Desert, Egypt

Egyptian Hammamat molasse basins and their relations to arc collision stages: Implications for radioactive elements mineralization potential

Structural and Tectonic Framework of Neoproterozoic Basement of Egypt: From Gneiss Domes to Transpression Belts

Contact Info

Product

Resources

About