Al-Azhar University, Faculty of Science (Boys)Al-Azhar Bulletin of Science1110-253522Issue 2-D20111201EVOLUTION OF THE TALC-CARBONATE ROCKS IN UMM RILAN OPHIOLITE, SOUTH EASTERN DESERT, EGYPT: IMPLICATION FROM MINERALOGY, PETROGRAPHY, GEOCHEMISTRY AND P-T CONDITIONS.132790810.21608/absb.2011.7908ENH.MEL-DESOKYDepartment of Geology, Faculty of Science, Al-Azhar University.A.EKHALILDepartment of Geology, National Research CenterJournal Article20110607Umm Rilan area is made up of talc-carbonate and talc serpentinite rocks of ophiolitic mélange, metavolcanics and granitoid rocks. The derivatives of ultramafic rocks as a result of metamorphism and the neighboring massive metavolcanic of the Late Proterozoic orogeny are related to a dismembered Pan-African ophiolitic mélange. In ultramafic rocks talc occurs as lenticular veins and along shear zone planes. Talc-carbonate rocks are whitish green, massive, slightly deformed, very fine- to fine-grained and composed of talc with carbonates as well as iron and manganese oxides as accessories. The talc carbonate rocks consist essentially of talc, malachite, dolomite, tremolite and magnesite. Geochemically, these rocks exhibit mafic-ultramafic cumulate ophiolite rocks of metamorphic peridotite and dunite in composition. The different variation diagrams indicate that these rocks are originated from cumulative komatiite with tendency to be tholeiitic magma and revealed that these rocks are formed in low Ti-ophiolites of tholeiitic environment. The scanning electron microscopic analysis detected that, the presence of Ta, Zn and Fe minerals in association with Cu, Ca and Mg mineralization. The contents of Cu, Zn and Pb show high tendency to be concentrated in the hydrothermally altered products associated with the sulfide minerals. The studied talc-carbonate rocks suffered low grade metamorphism in greenschist facies and was formed under medium pressure and low temperature of low Al<sub>2</sub>O<sub>3</sub>/CaO ratio related to the ultramafic rocks. Umm Rilan talc-carbonates are of hydrothermal origin. Tectonic activity plays a major role in the formation of Umm Rilan talc deposits by allowing fluids to penetrate the ultramafic rocks, creating a micro-permeability that facilitates reactions with the host rock (ultramafic-mafic rocks).
<strong> </strong>
https://absb.journals.ekb.eg/article_7908_0fc74bc50428a3de0fef02dc58ea9834.pdfAl-Azhar University, Faculty of Science (Boys)Al-Azhar Bulletin of Science1110-253522Issue 2-D20111201GEO-ENVIRONMENTAL STUDIES ON WADI QENA, EASTERN DESERT, EGYPT. BY USING REMOTE SENSING DATA AND GIS.3360790910.21608/absb.2011.7909ENE. K.EL-SAWYTechnical Training Department, Faculty of Earth Science, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia.M. H.BEKHIETGeology Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt.ABD EL-MOTAAL,E.Geology Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt.A. A.ORABIGeology Department, Faculty of Science, Al-Azhar University (Assiut branch), Assiut, Egypt.Journal Article20110612Geographic information system (GIS) and remote sensing data confirmed by field checks have been used to investigate the geoenvironmental characteristics at Wadi Qena area. The study area is mainly covered by sedimentary rock units (Paleozoic to Cenozoic) and a small basement exposure in its northeastern corner. It exhibits different types of structural elements represented by anticlines (Wadi Qena and Wadi Hamama) and synclines (El Serai and Abu Had) and four main fault trends (NE-SW, NW-SE, ENE-WSW and N-S). The basin analysis studies show that the most dangerous risk area is located at the southern part of the wadi drained by Wadi El-Jurdi and Wadi Shahdeen. Quantify the hydrogeologic situation, land-use map and a plane for flood risk protection of the investigated area are delivered to support the decision-making processes. However, many locations are suggested for new cities along Wadi Qena which accommodates the residential and the industrial activities required for developments. The most dangerous zones are located at the downstream of Wadi El-Jurdi and Wadi Shahdeen. So, the entire development plan should avoid this buffer zone. https://absb.journals.ekb.eg/article_7909_05bcc4ff29aa89d0ae8284a0c875efba.pdfAl-Azhar University, Faculty of Science (Boys)Al-Azhar Bulletin of Science1110-253522Issue 2-D20111201SUBSURFACE STRUCTURAL AND PETROPHYSICAL STUDY ON KARAMA FIELD, EAST BAHARIYA CONCESSION, WESTERN DESERT, EGYPT.6179791010.21608/absb.2011.7910ENM. H.BEKHIETGeology Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt.E. K.EL-SAWYGeology Department, Faculty of Science, Al-Azhar University (Assiut branch), Assiut, Egypt.H. E.EL-FOULYTPS Lead Geologist and Business Development Manager, Cairo, Egypt.M.FATHYGeology Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt.ABD EL-MOTAAL,EGeology Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt.R. M.KHALILBaker Hughes Company, Cairo, Egypt.Journal Article20110707Geophysical information in the form of seismic and well logging data are used to understand the structural elements, tectonic setting, stratigraphy and petrophysical characteristics of the upper Cretaceous rock units (Bahariya, Abu Roash and Khoman Formations) in the Karama field, northern part of the Western Desert. The interpretation of the available seismic data led to the identification of the reflectors under investigation as well as to map and determine the structural elements on the tops of the evaluated lithostratigraphic units. Seismic lines were used to make Four Two Way Time (TWT) structural contour map, reflection and four depth maps on the top of Khoman, Abu Roash "A", Abu Roash "G" and Upper Bahariya Formations reflecting the occurrence of major 11 normal faults in various directions (mainly NW-SE) forming different types of horst and graben structures. The structure of Karama-2 to Karama-4 wells is a stretched shoestring/oval shape E-W dipping against the dipping fault "F1", the resulting fold axis; however, is ENE-WSW with downthrown toward the southern part of the study area. The wire line log interpretations in 6 wells distributed in the study area have been used to evaluate the petrophysical parameters of the Abu Roash "G" Member, which is considered as an important reservoir in the study area. Computer-assisted log analyses have been used to evaluate all petrophysical interpretation such as effective porosity (ΦE), water saturation (Sw), hydrocarbon saturation (Sh). Horizontal distributions in forms of contour maps were constructed using computer software. Some vertical sections have been illustrated using IP (Interactive Petrophysics) program software output in order to show the vertical and lateral variations in reservoirs characteristics. The average values of effective porosity recorded among the studied wells range from 13% to 25% in the southern area toward the northeastern part of the study area. The shale volume generally is ranging from 24% at the southern part to 2% at the northeastern part of the area. The sand thickness of the net pay is ranging from 7% at the southern part to 25% at the eastern part of the study area.https://absb.journals.ekb.eg/article_7910_37dff56fb1e924c5f0e5326aeec08f8b.pdfAl-Azhar University, Faculty of Science (Boys)Al-Azhar Bulletin of Science1110-253522Issue 2-D20111201HEAVY MINERAL DIAGNOSIS OF RAS BAGHDADY BLACK BEACH SAND: ACCUMULATIONS AND SIGNIFICANCE81108791110.21608/absb.2011.7911ENSSAKRAl-Azhar Univ., Sci. Fac., Geology Dept.EL-AFANDYA. HEgyptian Nuclear materials authorityABU HALAWAA. F.Egyptian Nuclear materials authorityAWADM. EAl-Azhar Univ., Sci. Fac., Geology DeptJournal Article20110917A total of 30 samples each weighs 5 kg were collected from digging boreholes at 2 m depth at constant intervals across three profiles from Ras Baghdady beach sands, Red Sea coast, Egypt. Sieving, heavy mineral separation using Wilfy Shaked table and heavy liquid, magnetic separation using Lift type separator, mineral picking, mineral identifications, XRD, EDX and BSE have been performed to reveal the different mineral groups and the economic potentials. The separated grain size sub-samples arranged in their p order of abundance are 0.25-0.125 mm (10-60%), 0.5-0.25 mm (<10 to 20%), and 0.125-0.063 mm (<5 to 10%). Moreover, less than 1% to 10% are randomly distributed between grain size fractions < 0.063 and 1-0.5 mm. The most promising fraction based on the microscopic investigations containing mineral varieties and groups is very fine sand size. 60 gm of pure heavy minerals produced from 600 gm very fine sand size (0.125-0.063 mm). The light minerals are mainly detrital quartz grains and feldspars with mica flakes while the heavy minerals submitted to magnetic separation. Four separated magnetic sub-fractions (magnetite, ilmenite I, ilmenite II and ilmenite III) and one non-magnetic sub-fraction are obtained. The separated heavy minerals from Ras Baghdady very fine sand size (0.125-0.063 mm) contain 90 % of green silicates and 10 % of other heavy minerals in which ilmenite reaches 52 %, magnetite up to 15 %, garnet up to 11 %, goethite up to 11 %, zircon up to 5 %, rutile up to 3 %, sphene up to 3 % and other recorded traces of combined minerals up to 2 %. Based on the stereoscopic vision, XRD, BSE and SEM investigations, most of the studied heavy mineral grains are angular to sub-angular and homogenous in composition with a few variations to reflect short distance transportation and low energy deposition as depicted from the magnetically separated ilmenite grade III. The relative abundance and lateral distribution of the economic heavy mineral assemblages in the studied area are mainly controlled by hydraulic effects and beach topography. The estimated reserve of the economic heavy minerals within Ras Baghdady beach very fine sand can be summed up as follows; ilmenite 23490 tons, magnetite 6710 tons, garnet 5070 tons, goethite 5140 tons, zircon 2170 tons, rutile 1220 tons, sphene 1490 tons and leucoxene 10 tons. In addition to first record of ruby and sapphire, rare metal and radioactive bearing minerals such as monazite in which rare earth elements range is 61.2%, ~ 6.70 % Th, and ~ 5.4 % U as well as high content of Nd (17. 3%) and Sm (4.37%) are also recorded. Furthermore, the semi-quantitative EDX analyses of the picked uranothorite grains show high content of Th (40.12 %), U (11.77 %), and Y (11.9 %) while xenotime contains high content of Y2O3 (25.53 %), Yb2O3 (4.97 %), Nd2O3 (4.19 %) and Ce2O3 (3.46 %) as well.
<strong> </strong>https://absb.journals.ekb.eg/article_7911_ea7b2d001c0717617451fd3e6c2eac06.pdf