Geological and Tectonic Setting of Andesitic Rock in Central Eastern Desert, Egypt

Objective. The current study aims to detect the geologic features, geochemical characteristics and tectonic setting of the investigated rock using field observations and geochemical analyses. Research methods. This work contains both field work (Collection samples and drawing of a new geological map) and laboratory work (preparation of thin sections for petrographic studies by polarizing microscope), X-ray Fluorescence analysis (XRF) in Institute of Biology, Southern Federal University and Mass-Spectrometer with Inductively Coupled Plasma (ICPMS) at the central Laboratory of Russian Geological Institute. Result. Investigated andesitic rock belongs to Dokhan volcanic that located in the Central Eastern Desert of Egypt a long Qena-Safaga Road. It is considered as one of the most important shear zones in Eastern Desert that includes distinctive rocks and economic mineral deposits. The investigated rock belongs to late to post tectonic magmatism of the East African Orogeny (EAO). Petrographically: Dokhan volcanic is represented by andesite according to petrographical studies. It consists of plagioclase, quartz, in addition to mafic minerals. Geochemically, the investigated andesite samples plotted in calk-alkaline nature. Conclusion. Tectonically, andesite samples fall in arc lava and continental fields. They are enriched in Ba, Sr, Rb, K, Nb and Ce with marked depletion in the most HFSEs like those of island arc calc-alkaline series.

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Geological and geochemical studies on El-Missikat granites, Central Eastern Desert, Egypt

News of the Ural State Mining University ◽

10.21440/2307-2091-2020-4-7-18 ◽

2020 ◽

pp. 7-18

Author(s):

Ibrahim m ABU EL-LEIL ALI ◽

◽

Abdellah Sadek TOLBA ◽

Hamdy Ahmed Mohamed AWAD ◽

Aleksey Valer’evich NASTAVKIN ◽

...

Keyword(s):

Tectonic Setting ◽

Eastern Desert ◽

Quartz Diorite ◽

Granitic Rocks ◽

Nile Valley ◽

Thin Sections ◽

Central Eastern Desert ◽

Different Types ◽

Central Eastern ◽

Geochemical Studies

Objective. The present work deals with the detailed investigations of the geology, geochemistry, and tectonic setting of the studied granitic rocks. Research methods. This work involves both field work (Collection samples and drawing of a new geological map) and laboratory work (preparation of thin sections for petrographic studies by polarizing microscope), Atomic absorption, X-ray Fluorescence analysis (XRF) in the Central Laboratories of the Acme in Canada and Mass-Spectrometer with Inductively Coupled Plasma (ICPMS). Result. The study area restricted in the Central Eastern Desert of Egypt between the Red sea and the Nile Valley. ElMissikat pluton is covered by island arc related rock (as xenolith), older granites, and younger granites, in addition to different types of dikes and veins swarms. Petrographically older granites are classified into quartz diorite, tonalite and granodiorite, whereas the younger granites are divided into monzogranite, syenogranite and altered granites. The geochemical studies suggest the granitic rocks are calc-alkaline affinity. The quartz diorite, tonalite and granodiorite are related to volcanic arc granites, while the monzogranite and syenogranite are similar to the infinity of the within plate granites behavior. The quartz diorite, tonalite, granodiorite and monzogranite are belonging to I-type granite, otherwise the syenogranite has A-type granites. Conclusion. According to geological and petrographical studies the investigated granites are represented by quartz diorite, tonalite and granodiorite, whereas the younger granites are divided into monzogranite, syenogranite and altered granites that are traversed by different types of dikes and veins swarms . Generally, the older granites have low content of LILE, most probably due to the relatively low content of K-feldspars and HFSE. The younger granites exhibit a fractionated pattern from LREE to HREE with negative Eu anomaly.

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Geochemical fingerprinting of Maastrichtian oil shales from the Central Eastern Desert, Egypt: Implications for provenance, tectonic setting, and source area weathering

Geological Journal ◽

10.1002/gj.3094 ◽

2017 ◽

Vol 53 (6) ◽

pp. 2597-2612 ◽

Cited By ~ 6

Author(s):

Douaa Fathy ◽

Michael Wagreich ◽

Rafat Zaki ◽

Ramadan S. A. Mohamed ◽

Susanne Gier

Keyword(s):

Tectonic Setting ◽

Source Area ◽

Eastern Desert ◽

Geochemical Fingerprinting ◽

Central Eastern Desert ◽

Oil Shales ◽

Central Eastern

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

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.11100 ◽

2017 ◽

Vol 47 (2) ◽

pp. 667 ◽

Cited By ~ 1

Author(s):

I. Thabet ◽

A. Kilias ◽

S. Kamh

Keyword(s):

Late Phase ◽

Strain Analysis ◽

Shear Zones ◽

Eastern Desert ◽

Fault System ◽

Transform Faults ◽

Central Eastern Desert ◽

South Central ◽

Deformation Event ◽

Central Eastern

The Wadi Hafafit Culmination (WHC) can be subdivided into two main units which are separated by Nugrus thrust shear zone. The WHC domes are occupies the southern part of the Central Eastern Desert of Egypt and is cored by five separated gneissic granitoids ranging in composition from tonalite to granodiorite having compositions consistent with hydrous partial melting of a mafic source suggesting subduction-related magmatism. The leucogranites along thrust zones is related to the late phase of metamorphism of Hafafit rocks. The five main domes of the WHC have been labeled A dome occupies the northern part of WHC, B and C domes occupies the central eastern part of WHC, D dome occupies the central western part of WHC and E dome occupies the southern part of WHC. The fourth domes A, B, C and E are affected by more than one deformation event but D dome is affected by one deformation event. The domes not uniform throughout the WHC according radial pattern of stretching lineation but these domes of WHC were subjected and affected by late-orogenic extension that was controlled by the Najd transform faults and that resulted in exhumation of the WHC domes are oriented NW-SE parallel to the trend of the left-lateral shear zones of Najd fault system.

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