Origin of I- and A-type granitoids from the Eastern Desert of Egypt: Implications for crustal growth in the northern Arabian–Nubian Shield

Farahat, Esam S.; Mohamed, Hashim; Ahmed, Moustafa; Mahallawi, M.M. El

doi:10.1016/j.jafrearsci.2007.07.002

Cited by 117 publications

(69 citation statements)

References 71 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Assessment of the lithology of the clast population in the conglomerates indicates the presence of Dokhan volcanics, younger granite, and older metamorphosed suprastructural rocks. The younger granites consist chiefly of granite and syenogranite and have an age around 610-550 Ma (Fullager and Greenburg 1978;Beyth et al 1994;Jarrar et al 2003;Farahat et al 2007). The Dokhan volcanics at Gebel Dokhan have a Rb-Sr age of 592±26 Ma (Stern and Hedge 1985).…”

Section: Timing Of Basin Formation and Deformationmentioning

confidence: 99%

See 1 more Smart Citation

The role of the Najd Fault System in the tectonic evolution of the Hammamat molasse sediments, Eastern Desert, Egypt

El‐Wahed

2009

Arab J Geosci

View full text Add to dashboard Cite

The Hammamat molasse sediments of the Eastern Desert of Egypt were deposited in isolated basins formed during an initial stage of orogen parallel N-S extension (650-580 Ma) in the Neoproterozoic time. Supply of sediments to the molasse basins began after the eruption of Dokhan volcanics (602-593 Ma), exhumation of core complexes (650-550 Ma), and intrusion of late tectonic granites (610-550 Ma). The late Neoproterozoic structures in the molasse sediments include: (1) NNWdirected thrusts due to NNW-SSE shortening (650-640 Ma), indicated by the presence of NE-, ENE-, and WSW-trending folds and NNW-directed thrusts.(2) SWand NE-directed thrusts due to ENE-WSW constriction during oblique convergence and arc accretion at around 640-620 Ma. Many of the map-and mesoscopic-scale NWtrending folds in the core complexes, the molasse sediments, and the Neoproterozoic nappes in the Eastern Desert are related to this event. Sinistral shearing along the Najd Fault System (650-540 Ma) resulted in the development of subvertical foliation, subhorizontal stretching lineation, and NW-trending tight folds overprinting earlier folds. Stretched pebbles are oriented NW-SE and WNW-ESE in the molasse basins localized within the Najd Fault System, and NE-SW in the basins outside the influence zone of this NW-trending fault system. Strain estimated using pebbles from nine molasse basins indicate that the amount of strain differs from one basin to another and from one place to another within the same basin. Weak tectonic strain (Rs=2.16-2.24) is obtained from post-orogenic basins; moderate strains are reported from foreland basins (Rs=2.37-3.18), whereas moderate to high tectonic strains are recorded from the intermontane basins (Rs=2.40-4.36). The obtained tectonic strain and K values indicate that the flattening strain prevails in the post-orogenic and foreland basins, whereas as both constrictional and flattening strains are recorded in intermontane basins. Strain variation from one basin to another and within the individual basin is attributed to presence of thrust and sinistral shear zones. Away from the deformed zones, the pebbles show no significant stretching. Two phases of thrusting and an episode of transpressional sinistral shearing are the latest structure features of the East African orogeny in the Arabian-Nubian Shield.

show abstract

Section: Timing Of Basin Formation and Deformationmentioning

confidence: 99%

“…The molasse sediments constitute a sequence of immature, clastic sedimentary rocks which crop out sporadically throughout the central and northern parts of the Eastern Desert of Egypt. These are intruded by post-Hammamat felsites, young gabbros, late to post-tectonic granites, and postgranite dykes (Akaad and Noweir 1980;Noweir et al 1990;Farahat et al 2007). …”

mentioning

confidence: 99%

The role of the Najd Fault System in the tectonic evolution of the Hammamat molasse sediments, Eastern Desert, Egypt

El‐Wahed

2009

Arab J Geosci

View full text Add to dashboard Cite

show abstract

“…Following the previous tectonic schemes for the Pan-African crustal evolution (e.g., Stern 1994;Moghazi 2002;Farahat et al 2007), the studied older granitoids correspond to granites of collision stage. Field aspects and geochemical attributes indicate their I-type nature in the sense of White and Chappell (1977).…”

Section: Petrogenesis Of the Older Granitoidsmentioning

confidence: 86%

“…These arguments include (1) granite magmas derived from the extreme fractional crystallization of gabbroic melt are characterized by strong enrichment in the HFSE (Turner et al 1992), which is not recorded in the concerned rocks (Table 2); (2) if the metagabbro-diorite complexes and the studied rocks were related, collinear trend would exist between the two suites, but such trend does not occur as mentioned by Moghazi (2002) and Farahat et al (2007); and (3) in the north Eastern Desert of Egypt, huge granite batholiths occur with negligible metagabbro-diorite complexes.…”

Section: Petrogenesis Of the Older Granitoidsmentioning

confidence: 99%

Late Proterozoic older granitoids from the North Eastern desert of Egypt: petrogenesis and geodynamic implications

Mahallawi

Ahmed

2010

Arab J Geosci

View full text Add to dashboard Cite

Major, trace, and REE data for three localities of calc-alkaline older granitoid rocks exposed in the north Eastern Desert of Egypt are presented. These rocks were selected to cover wide compositional spectrum of the Egyptian older granitoid varieties. They are petrographically represented by granodiorite, tonalite, quartz-diorite, and quartz-monzodiorite. The rocks are comparable with the peraluminous, unfractionated calc-alkaline suites and fall within the volcanic arc and I-type granite fields. So, they can be regarded as belonging to the volcanic arc collision stage (665-614 Ma).

show abstract

“…Most of geochemical data came from granitoids in the ANS have indicated the early magmatic calc-alkaline granitoids are formed within evolving arc setting [6]. The youngest late-to postcollisional alkaline suite granitoids have formed during the decay of the previously consolidated orogon, possibly involving sub-continental lithospheric delamination [5] [7].…”

Section: Geological and Tectonic Settingmentioning

confidence: 99%

Geology, Geochemistry and Geochronology of the Kenticha Rare Metal Granite Pegmatite, Adola Belt, Southern Ethiopia: A Review

Mohammedyasin¹

2017

IJG

View full text Add to dashboard Cite

This work reviews the geology, geochemistry and geochronology and discusses the spatial and temporal relationship of the granite pegmatite and the rare metal mineralization of the Kenticha granite pegmatite, southern Ethiopia using published and unpublished works to give a comprehensive understanding about the formation of the mineral deposit. The Kenticha rare metal pegmatite belt comprises several groups of pegmatites which show a high magmatic fractionation, regional and compositional zoning, mineralogical assemblage, and secondary alterations. The internal zonation shows high degree of evolution from the border to the core zone during crystallization and solidification of the leucogranitic to pegmatitic melt. Tantalum mineralization at Kenticha includes zoned tantalite-(Mn) and columbite-(Mn), as well as microlite, pyrochlore, uranmicrolite, and rare tapiolite, ixiolite/wodginite and Ta-bearing rutile. The tectonic setting of the Kenticha granite pegmatite in the Within Plate Granite (WPG) to syn-Collisional Granite (syn-COLG) suites and probably sourced from extreme fractionation of syn-to late tectonic granites or anatexis process of the metasedimentary rocks in the area. The emplacement of the Kenticha pegmatite was at ca. 530 Ma and temporally related to the post-collisional phase of granitic magmatism at 570 -520 Ma, after the last tectonic stage of east African orogeny during the late stage of Gondwana assembly.

show abstract

Origin of I- and A-type granitoids from the Eastern Desert of Egypt: Implications for crustal growth in the northern Arabian–Nubian Shield

Cited by 117 publications

References 71 publications

The role of the Najd Fault System in the tectonic evolution of the Hammamat molasse sediments, Eastern Desert, Egypt

The role of the Najd Fault System in the tectonic evolution of the Hammamat molasse sediments, Eastern Desert, Egypt

Late Proterozoic older granitoids from the North Eastern desert of Egypt: petrogenesis and geodynamic implications

Geology, Geochemistry and Geochronology of the Kenticha Rare Metal Granite Pegmatite, Adola Belt, Southern Ethiopia: A Review

Contact Info

Product

Resources

About