scholarly journals Some Mechanical and Physical Studies of Granitic Rocks in Um Taghir, Eastern Desert, Egypt

2021 ◽  
Vol 1945 (1) ◽  
pp. 012012
Author(s):  
H A M Awad ◽  
A V Nastavkin
Keyword(s):  
Eastern Desert ◽  
Granitic Rocks

scholarly journals Utilization of Space-Borne Imagery for Lithologic Mapping: A Case Study From Um Had Area, Central Eastern Desert, Egypt

2014 ◽  
Vol 6 (2) ◽  
pp. 113 ◽  
Author(s):  
Nedal Qaoud
Keyword(s):  
Remote Sensing Data ◽  
Principal Component ◽  
Eastern Desert ◽  
Granitic Rocks ◽  
Gray Scale ◽  
Band Ratio ◽  
Lithological Mapping ◽  
Central Eastern Desert ◽  
Dokhan Volcanics ◽  
Central Eastern

Remote sensing data are used to discriminate between the different lithologies covering the Um Had area, Central Eastern Desert of Egypt. Image processing techniques applied to the Enhanced Thematic Mapper (ETM+) data are used for mapping and discriminating the different basement lithologies of Um Had area. Principal component analysis (PCA), minimum noise fraction (MNF) transform and band rationing techniques provide efficient data for lithological mapping. The study area is underlain by gneisses, ophiolitic melange assemblage (talc-serpentinite, metagabbro, metabasalt), granitic rocks, Dokhan volcanics, Hammamat sediments and felsites. The resulting gray-scale PC2, PC3 and PC4 images are best to clearly discriminate the Hammamat sediments, amphibolites and talc-serpentinites, respectively. The gray-scale MNF3 and MNF4 images easily discriminate the felsites and talc-serpentinites, respectively. The band ratio 5/7 and 4/5 images are able to delineate the talc-serpentinites and Hammamat sediments, respectively. Information collected from gray-scale and false color composite images led to generation of detailed lithologic map of Um Had area.

scholarly journals Natural Radioactivity, Radiological Hazard and Petrographical Studies on Aswan Granites Used as Building Materials in Egypt

2021 ◽  
Vol 11 (14) ◽  
pp. 6471
Author(s):  
Nasser M. Moghazy ◽  
Amira M. El-Tohamy ◽  
Mona M. Fawzy ◽  
Hamdy A. Awad ◽  
Hesham M. H. Zakaly ◽  
...  
Keyword(s):  
Natural Radioactivity ◽  
Building Materials ◽  
Gamma Ray ◽  
Natural Radionuclides ◽  
Polarized Light ◽  
Environmental Parameters ◽  
Mineralogical Composition ◽  
Eastern Desert ◽  
Granitic Rocks ◽  
Gamma Ray Spectrometry

The present study was carried out on commercial types of Aswan granite used as building and decorative materials. Nearly 29 granitic rocks samples from 11 classes (black Aswan, red Aswan, dark Rosa, light Rosa, yellow Verdi, grey Shirka, Gandolla, Forsan, red Nefertiti, Royal, and white Halayeb) were collected from three stations near Aswan city for petrographical description and assessment of natural radioactivity. The petrographical study of granites was conducted by polarized-light microscope in order to determine their mineralogical composition and investigate their texture; the activity of the natural radionuclides 238U, Ra226, 232Th, and 40K was measured by gamma-ray spectrometry with a NaI(Tl) detector. The average values of the activities, 52.2 Bq kg−1, 57.8 Bq kg−1, 31.2 Bq kg−1, and 1055.7 Bq kg−1 of U-238, Th-232, Ra-226, and K-40, respectively, were higher than that the world average values of 35 Bq kg−1, 30 Bq kg−1 and 400 Bq kg−1 for 226Ra, 232Th, and 40K, respectively, according to the recommended levels from UNSCEAR reports. The minimum and maximum values obtained were compared with the value ranges from other locations in the Eastern Desert, highlighting the fact that that the maximum values obtained in this work are higher than those in other areas. According to the radiological hazards indices results, most samples lie in the permissible level ranges, suggesting their favorability for use as building materials. In contrast to that, some samples have some environmental parameters higher than the international levels, indicating their unsuitability as building materials.

scholarly journals An Overview on the Classification and Tectonic Setting of Neoproterozoic Granites of the Nubian Shield, Eastern Desert, Egypt

Geochemistry ◽  
2021 ◽  
Author(s):  
Gaafar A. El Bahariya
Keyword(s):  
Continental Crust ◽  
Tectonic Setting ◽  
Alkali Feldspar ◽  
Eastern Desert ◽  
Granitic Rocks ◽  
Rock Types ◽  
Nubian Shield ◽  
Magma Sources ◽  
Tectonic Settings ◽  
Ocean Ridge

Granites constitute the main rock components of the Earth’s continental crust, which suggested to be formed in variable geodynamics environments. The different types of granitic rocks, their compositional characteristics, tectonic settings and magma sources are outlined. Mineralogical classification of granites includes four rock types: tonalites, granodiorites, granite (monzogranite and syenogranites) and alkali-feldspar granites. Alphabetical classification subdivided granites into: I-type, S-type, A-type and M-type granites. Moreover, formation of granitic magmas requires distinctive geodynamic settings such as: volcanic arc granite (Cordilleran); collision-related granites (leucogranites); intra-plate and ocean ridge granites. The Eastern Desert of Egypt (ED) forms the northern part of Nubian Shield. Both older and younger granites are widely exposed in the ED. Old granites (OG) comprise tonalites and granodiorites of syn- to late-orogenic granitoid assemblages. They are calcalkaline, I-type, metaluminous and display island arc tectonic setting. Younger granites (YG) on the other hand, include granites, alkali-feldspar granites and minor granodiorites. They are of I- and A-type granites and of post-orogenic to anorogenic tectonic settings. The majority of the YG are alkaline, A-type granite and of within-plate tectonic setting (WPG). The A-type granites are subdivided into: A2-type postorogenic granites and A1-type anorogenic granites. Granite magma genesis involves: (a) fractional crystallization of mafic mantle-derived magmas; (b) anatexis or assimilation of old, upper crustal rocks (c) re - melting of juvenile mafic mantle – derived rocks underplating the continental crust. Generally, older I-type granitoids were interpreted to result from melting of mafic crust and dated at approximately 760–650 Ma, whereas younger granites suggested to be formed as a result of partial melting of a juvenile Neoproterozoic mantle source. Moreover, they formed from anatectic melts of various crustal sources that emplaced between 600 and 475 Ma.

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

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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