SUBSURFACE GEOLOGIC STUDIES OF GEBEL EL-EREDIY A URANIUM OCCURRENCE, CENTRAL EASTERN DESERT, EGYPT
ALI AHMED OMRAN;
Abstract
A drilling program is carried out by the Nuclear Materials Authority of Egypt to follow the extension of surface U-mineralization in deep levels below the mine floor at EL-Ereydiya uranium occurrence in the Eastern Desert. The present thesis is concerned with the study of lithology, petrography, radiometry and geochemistry of the core samples recovered from the first bore hole (Er-1) drilled in EL-Erediya u- occurrence.
The recovered core samples have been grouped according to the degree of alteration into three main types Fresh granite (GF). moderately altered granite (GM) and highly altered granite (GH) The highly altered granite has been subdivided into 5 varieties (from GH 1 to GHs) according to the type of alterations.
Petrographically, the fresh granite is essentially composed of alkali feldspars, quartz and plagioclase with subordinate amount of biotite. Zircon, sphene, apatite and opaques (mainly magnetite. pyrite and radioactive minerals) are the main accessories. The altered granites revealed vanous degrees of alterations, including silicification, kaolinization, sericitization. albitization, ferrugination, carbonatization and chloritization.
Gamma-ray logging and quantitative analysis of U and Th contents indicate the presence of pronounced radioactive anomaly associated with the upper shear zone (from 16.5 to 17.5 ms drilling
length). This prom1smg anomaly (max: 460 eU ppm) is related to thesilicified granite intersected by jasperoid veins.
The study of geochemistry revealed that there are pronounced fluctuations of major and trace element contents which are related mainly· to the various alteration varieties rather than depth. There is a pronounced enrichment of Si02, Ah03 and F 03 and a depletion of Ti02, FeO, Mn02, MgO, CaO, Na20, K20 and P20 5 in the silicified granite On the other hand, there are enrichment in Y, Nb, Ba, Pb, Cu, Ni, Co, V, Zn and Ga and depletion in Zr, Sr and Cr. In the kaolinized granite there is enrichment in Ah03, K20 and MgO, addition in L.O.l. and depletion in FeO, CaO. Na2 0 and Zr. The upper shear zone is characterized by the
highest range of the mentioned fluctuation in major and trace elements, /
besides the intense silicification and kaolinization.
The study of the uranium and thorium distribution and their ratios, the relations of the uranium to some trace elements, besides the petrography and geochemistry revealed that radioelement distribution is at least in part governed by magmatic processes, and in other part redistribution of U is closely associated with the shear zones and the intense alterations. This means that uranium and thorium are mainly partitioned in the liquid phase and are taken by late crystallizing phases such as biotite, epidote, zircon. sphene, apatite and iron oxides from which (except zircon) the uranium
The recovered core samples have been grouped according to the degree of alteration into three main types Fresh granite (GF). moderately altered granite (GM) and highly altered granite (GH) The highly altered granite has been subdivided into 5 varieties (from GH 1 to GHs) according to the type of alterations.
Petrographically, the fresh granite is essentially composed of alkali feldspars, quartz and plagioclase with subordinate amount of biotite. Zircon, sphene, apatite and opaques (mainly magnetite. pyrite and radioactive minerals) are the main accessories. The altered granites revealed vanous degrees of alterations, including silicification, kaolinization, sericitization. albitization, ferrugination, carbonatization and chloritization.
Gamma-ray logging and quantitative analysis of U and Th contents indicate the presence of pronounced radioactive anomaly associated with the upper shear zone (from 16.5 to 17.5 ms drilling
length). This prom1smg anomaly (max: 460 eU ppm) is related to thesilicified granite intersected by jasperoid veins.
The study of geochemistry revealed that there are pronounced fluctuations of major and trace element contents which are related mainly· to the various alteration varieties rather than depth. There is a pronounced enrichment of Si02, Ah03 and F 03 and a depletion of Ti02, FeO, Mn02, MgO, CaO, Na20, K20 and P20 5 in the silicified granite On the other hand, there are enrichment in Y, Nb, Ba, Pb, Cu, Ni, Co, V, Zn and Ga and depletion in Zr, Sr and Cr. In the kaolinized granite there is enrichment in Ah03, K20 and MgO, addition in L.O.l. and depletion in FeO, CaO. Na2 0 and Zr. The upper shear zone is characterized by the
highest range of the mentioned fluctuation in major and trace elements, /
besides the intense silicification and kaolinization.
The study of the uranium and thorium distribution and their ratios, the relations of the uranium to some trace elements, besides the petrography and geochemistry revealed that radioelement distribution is at least in part governed by magmatic processes, and in other part redistribution of U is closely associated with the shear zones and the intense alterations. This means that uranium and thorium are mainly partitioned in the liquid phase and are taken by late crystallizing phases such as biotite, epidote, zircon. sphene, apatite and iron oxides from which (except zircon) the uranium
Other data
| Title | SUBSURFACE GEOLOGIC STUDIES OF GEBEL EL-EREDIY A URANIUM OCCURRENCE, CENTRAL EASTERN DESERT, EGYPT | Other Titles | دراسات جيولوجية تحت سطحية لموقع اليورانيوم بجبل العرضية بواسطة الصحراء الشرقية | Authors | ALI AHMED OMRAN | Issue Date | 1999 |
Attached Files
| File | Size | Format | |
|---|---|---|---|
| ALI AHMED OMRAN.pdf | 1.46 MB | Adobe PDF | View/Open |
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