scholarly journals Geological and petrographical studies around Um Taghir area, Сentral Eastern Desert, Egypt

2020 ◽  
Vol 1 (1) ◽  
pp. 7-25
Author(s):  
Hamdy Ahmed Mohamed AWAD ◽  
◽  
Aleksey Valer`evich NASTAVKIN ◽  
Keyword(s):  
Iron Oxides ◽  
Alkali Feldspar ◽  
Eastern Desert ◽  
Island Arc ◽  
The Other ◽  
The West ◽  
Central Eastern Desert ◽  
Hornblende Gabbro ◽  
Different Types ◽  
Mineral Compositions

Um Taghir area is located in the northern extreme boundary of Central Eastern Desert of Egypt at the west of Safaga City. Um Taghir is represented by island arc related rocks and late to post tectonic magmatism. The island arc related rocks are represented by metavolcaniclastic sequences and metagabrroic rocks. Metavolcanoclastic rocks are considered as the older rock units of the study are and intruded by the metagabbro. The late to post tectonic magmatism is represented by (dokhan volcanic, gabbro, tonalite-granodiorite, monzogranite, alkali feldspar granites and different types of dikes). Usually, the gabbroic rock is bearing ilmenite lenses or bands in the bottom of the layered; this is related to magma rich of iron oxides. Petrographically, island arc assemblage is classified in to actinolite hornblende schist and metagabbro that show quite different of their content in plagioclase, hornblende, augite, quartz and biotite. Occasionally, the late to post tectonic magmatism represented by andesite, gabbro, tonalite, granodiorite monzogranite, alkali feldspar granites and different types of dikes. Andesite consists of plagioclase, quartz, alkali feldspar and hornblende. Gabbroic rocks are represented by pyroxene hornblende gabbro and leucogabbro. They show quite different of their content in plagioclase, pyroxene and clear difference in the content of both olivine and hornblende in both of them. While tonalite and granodiorite show quite different of their content in plagioclase, quartz, hornblende, alkali felspar and biotite. On the other hand, monzogranite and alkali feldspar granite, they show plagioclase is varying from oligoclase to albite; K-feldspars, quartz and muscovite are relatively more abundant in the alkali feldspar granite. Finally, the different types of dikes classified into granite, andesite, rhyolite and basalt dikes consist of the different mineral compositions.

scholarly journals Geochemistry of the Um Had Plutonites, Central Eastern Desert, Egypt: Implications for Magma Evolution, and Tectonic Setting

2014 ◽  
Vol 6 (2) ◽  
pp. 36 ◽  
Author(s):  
Nedal Qaoud
Keyword(s):  
Tectonic Setting ◽  
Active Continental Margin ◽  
Eastern Desert ◽  
Island Arc ◽  
Water Vapour Pressure ◽  
Calc Alkaline ◽  
Magma Evolution ◽  
Basement Complex ◽  
Central Eastern Desert ◽  
Pan African

Geochemistry of gabbroid and granitoid plutonites from the Um Had area indicates island arc subalkaline basic magma with tholeiitic affinity and calc-alkaline, metaluminous and slightly peraluminous magma, respectively. Although different in age both plutonite types were emplaced under compressional regime, where subduction-related environment was dominant. They were formed under relatively low to moderate water-vapour pressure (1–5 k-bars) at moderate depths (20–30 km). Biotite granites were formed at a relatively high temperature range (800–840 °C), while biotite-muscovite granites were formed under relatively moderate temperature conditions (760–800 °C). These two units may represent evolution from island arc to active continental margin. It is suggested that island arc gabbros might have sourced the late subduction-related calc-alkaline granitoids during the waning stages of the pan-African orogeny. The I-type nature of the investigated plutonites in the study area and elsewhere suggests the juvenile character of the basement complex of the Eastern Desert of Egypt.

scholarly journals Thalassemia in the West Indies

Blood ◽  
1961 ◽  
Vol 17 (2) ◽  
pp. 166-181 ◽  
Author(s):  
L. N. WENT ◽  
J. E. MACIVER
Keyword(s):  
West Indies ◽  
Fetal Hemoglobin ◽  
Thalassemia Major ◽  
The Other ◽  
The West ◽  
Thalassemia Minor ◽  
High Incidence ◽  
Different Types ◽  
Mode Of Inheritance ◽  
Hemoglobin H Disease

Abstract Data are presented on seven cases of thalassemia major (six of whom were negroes) and 32 cases of thalassemia minor of whom eight had high levels (20-26 per cent) of fetal hemoglobin. Two families with hemoglobin H disease are presented, in whom the presence of thalassemia minor could be demonstrated. The mode of inheritance of hemoglobin H disease is discussed. Two families with an inherited double A2 fraction of hemoglobin are presented. In one of these thalassemia was also found, in the other elliptocytosis occurred concurrently. On the basis of these findings the existence of at least five different types of thalassemia is postulated. A study on 93 healthy students suggests a high incidence (above 3 per cent) of thalassemia minor in the West Indies.

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.

scholarly journals Mineralogical and geochemical studies of gabbroids in the East Central Desert, Egypt

2020 ◽  
Vol 59 (3) ◽  
pp. 41-51
Author(s):  
Hamdy Ahmed Mohamed AWAD ◽  
◽  
Aleksey Valer’evich NASTAVKIN ◽  
Keyword(s):  
Electron Microscope ◽  
Iron Oxide ◽  
Scanning Electron Microscope ◽  
Iron Oxides ◽  
Eastern Desert ◽  
Central Eastern Desert ◽  
Oxide Minerals ◽  
Central Eastern ◽  
Geochemical Studies ◽  
Scanning Electron

Relevance of the work. The study area is limited to the Central-Eastern Desert of Egypt, represented by various rock units in addition to the gabbro rock containing iron oxides. Research Objective. This work is devoted to detailed studies of the geology of gabbroid rock minerals and iron oxides. Methodology. This work includes both field work (creation of a new geological map for various rock units in the study area) and laboratory work (preparation of thin sections for petrographic and mineralogical studies using a polarizing microscope and a scanning electron microscope SEM). Results and their application. Exploration and extraction of ore deposits and minerals in the eastern desert of Egypt is one of the most important goals for increasing the rate of mining in the country, which leads to economic recovery and meeting the needs of society. Previous work has focused on evaluating and studying economically mineral resources in the Central-Eastern Desert of Egypt. This place is considered one of the most promising mineral deposits in addition to the available iron oxide minerals. Geological studies show that the mineralization of iron oxide in the study area is mainly associated with gabbroid rocks, which carry iron oxide minerals in the form of groups and lenses in the lower part of the Earth’s layers, which is associated with magma rich in iron oxides. According to field studies, we found that iron minerals are represented by lenses up to 3 m thick, alternating with rock. Conclusions. The chemical analysis of minerals based on iron oxides was discovered using a scanning electron microscope (SEM) used to determine the chemical composition of these minerals, which are classified as minerals such as ilmenite and magnetite. Actually geochemical studies have shown that they have a high content of total iron oxides.

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