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Papers by Mohamed El-Sankary
Journal of African Earth Sciences, 2010
Kharga Oasis monumental sites are important to the cultural heritage in the South Western Desert ... more Kharga Oasis monumental sites are important to the cultural heritage in the South Western Desert of Egypt. These sites are scattered on the floor of the oasis representing ancient civilizations. The studied sites include the Hibis, EI-Nadura, EI-Ghueita and El-Zayyan temples as well as El-Bagawat Cemetery. The present study found that natural hazards have remarkable impacts on these sites. The impact of weathering processes, encroachment of sand dunes, stability of foundation beds and shallow groundwater seepage were documented. The present study found that humidity, temperature, sunlight and water content conditions seem to be favorable for biodegradation as evidenced by the presence of algae, bat blood and bird excretions. The radioactivity levels at the investigated sites are also measured via gamma-ray spectrometry. Sand dunes in the area pose a serious natural threat to the monumental sites. Active sand dunes are rapidly encroaching upon the components of these monuments, partially covering some monuments such as El-Ghueita Temple. These dunes load wind storms with fine sand particles. This causes wind erosion through sand blasting of these sites. Some monuments, such as EI-Nadura, EI-Ghueita and El-Zayyan temples were constructed on a suitable hard sandstone ground, whereas others, such as the Hibis Temple, were constructed on unsuitable soft shale ground in relatively topographically low area. The impact of the unstable foundation and shallow groundwater levels have caused severe structural damage as evidenced by tilted columns, cracked walls and salt-crystal growth in the porous building stones. These destructive elements threaten some other temples in Kharga Oasis and will eventually cause total physical collapse. Although rain is rare in this area, it can form a real threat to mud brick monuments such as El-Bagawat Cemetery. The natural radioactivity sources resulted in an annual effective dose equivalent values averaging 0.20, 0.13, 0.09 and 0.07 mSv/year for the monumental sites at Hibis, El-Nadura, El-Ghueita and El-Zayyan, respectively.
Report, 2005
This study is based on utilization of the color composite satellite images for preparation of pre... more This study is based on utilization of the color composite satellite images for preparation of preliminary photogeologic maps as base maps which have been modified to geologic maps after the performance of the field studies and laboratory investigations for the studied areas. These base maps have been used for collecting the field observations and define the interesting geologic features which have relations with the subject of this study. The collected field observations and studies are used in the preparation of geologic maps for some chosen monumental sites in both El Giza pyramids plateau and El Kharga Oasis. The studied geologic features, the other field observations and laboratory studies are used to define the natural hazards on the monumental sites and proposing the suitable recommendations for minimizing these hazards and a restoration plan for the studied monumental sites in El Giza Pyramids Plateau and E Kharga Oasis.
Journal of Environmental Sciences. Mansoura University
Anomalous uranium contents were recognized in the phosphatic beds of the Campanian-Maastrichtian ... more Anomalous uranium contents were recognized in the phosphatic beds of the Campanian-Maastrichtian Sudr Chalk of Wadi El-Quseiyib at the East Central Sinai. Microscopic examination, and scanning electron microscopy revealed the presence of carnotite patches disseminated in the studied Sudr Chalk phosphatic rocks. This mineral is recorded for the first time in the east central Sinai and it may be significant in discussing uranium prospection and the origin of secondary uranium deposits. The identification of this mineral directed the attention to study the natural radionuclides content which have been measured by gamma-ray spectrometry using a shielded HPGe detector. This study revealed that 238 U and some of its progenies were redistributed after subjection to several alteration processes. Petrographic study of Wadi El-Quseiyib phosphatic rocks revealed that they are consisted mainly of collophane pellets, bone and teeth fragments, which were diagenetically cemented by calcite, gypsum and quartz materials. The studied phosphatic microfacies was described texturally as pelphospharudite and pelphospharenite. X-ray diffraction analysis proved the presence of carbonate fluorapatite (francolite) as the dominant phosphatic mineral, while calcite, gypsum and quartz are the dominant non-phosphatic minerals with minor contents of bassanite and jarosite and siderotil. Averages of P 2 O 5 and uranium contents are 16.7 % and 70 ppm in the analyzed phosphatic rocks, respectively. Carnotite characteristics are identified by SEM/EDX in the studied phosphatic rocks which indicate that the uranium is leached out from the phosphatic materials and re-deposited as fine specks in open pores by circulating meteoric water. The leached uranyl ions together with vanadate ions are forming the identified carnotite under the influence of evaporation. The calculated annual effective dose equivalent values (AEDE) are 0.478 and 0.504 mSv/yr for the lower and upper phosphatic beds, respectively. The calculated radium equivalent activity values of (Ra eq) are 2319 and 2802 Bq/kg for the lower and upper phosphatic beds, respectively. Accordingly, although the estimated (AEDE) to the public is below the recommended limits, but the equivalent radium activity and the expected coincided radon gas emanation renders the phosphatic exposures in the study area classified unsafe for prolonged public activities.
Arabian Journal of Geosciences
International Geology Review
International Geology Review
International Geology Review
International Geology Review
Journal of African Earth Sciences, 2010
Kharga Oasis monumental sites are important to the cultural heritage in the South Western Desert ... more Kharga Oasis monumental sites are important to the cultural heritage in the South Western Desert of Egypt. These sites are scattered on the floor of the oasis representing ancient civilizations. The studied sites include the Hibis, EI-Nadura, EI-Ghueita and El-Zayyan temples as well as El-Bagawat Cemetery. The present study found that natural hazards have remarkable impacts on these sites. The impact of weathering processes, encroachment of sand dunes, stability of foundation beds and shallow groundwater seepage were documented. The present study found that humidity, temperature, sunlight and water content conditions seem to be favorable for biodegradation as evidenced by the presence of algae, bat blood and bird excretions. The radioactivity levels at the investigated sites are also measured via gamma-ray spectrometry. Sand dunes in the area pose a serious natural threat to the monumental sites. Active sand dunes are rapidly encroaching upon the components of these monuments, partially covering some monuments such as El-Ghueita Temple. These dunes load wind storms with fine sand particles. This causes wind erosion through sand blasting of these sites. Some monuments, such as EI-Nadura, EI-Ghueita and El-Zayyan temples were constructed on a suitable hard sandstone ground, whereas others, such as the Hibis Temple, were constructed on unsuitable soft shale ground in relatively topographically low area. The impact of the unstable foundation and shallow groundwater levels have caused severe structural damage as evidenced by tilted columns, cracked walls and salt-crystal growth in the porous building stones. These destructive elements threaten some other temples in Kharga Oasis and will eventually cause total physical collapse. Although rain is rare in this area, it can form a real threat to mud brick monuments such as El-Bagawat Cemetery. The natural radioactivity sources resulted in an annual effective dose equivalent values averaging 0.20, 0.13, 0.09 and 0.07 mSv/year for the monumental sites at Hibis, El-Nadura, El-Ghueita and El-Zayyan, respectively.
Report, 2005
This study is based on utilization of the color composite satellite images for preparation of pre... more This study is based on utilization of the color composite satellite images for preparation of preliminary photogeologic maps as base maps which have been modified to geologic maps after the performance of the field studies and laboratory investigations for the studied areas. These base maps have been used for collecting the field observations and define the interesting geologic features which have relations with the subject of this study. The collected field observations and studies are used in the preparation of geologic maps for some chosen monumental sites in both El Giza pyramids plateau and El Kharga Oasis. The studied geologic features, the other field observations and laboratory studies are used to define the natural hazards on the monumental sites and proposing the suitable recommendations for minimizing these hazards and a restoration plan for the studied monumental sites in El Giza Pyramids Plateau and E Kharga Oasis.
Journal of Environmental Sciences. Mansoura University
Anomalous uranium contents were recognized in the phosphatic beds of the Campanian-Maastrichtian ... more Anomalous uranium contents were recognized in the phosphatic beds of the Campanian-Maastrichtian Sudr Chalk of Wadi El-Quseiyib at the East Central Sinai. Microscopic examination, and scanning electron microscopy revealed the presence of carnotite patches disseminated in the studied Sudr Chalk phosphatic rocks. This mineral is recorded for the first time in the east central Sinai and it may be significant in discussing uranium prospection and the origin of secondary uranium deposits. The identification of this mineral directed the attention to study the natural radionuclides content which have been measured by gamma-ray spectrometry using a shielded HPGe detector. This study revealed that 238 U and some of its progenies were redistributed after subjection to several alteration processes. Petrographic study of Wadi El-Quseiyib phosphatic rocks revealed that they are consisted mainly of collophane pellets, bone and teeth fragments, which were diagenetically cemented by calcite, gypsum and quartz materials. The studied phosphatic microfacies was described texturally as pelphospharudite and pelphospharenite. X-ray diffraction analysis proved the presence of carbonate fluorapatite (francolite) as the dominant phosphatic mineral, while calcite, gypsum and quartz are the dominant non-phosphatic minerals with minor contents of bassanite and jarosite and siderotil. Averages of P 2 O 5 and uranium contents are 16.7 % and 70 ppm in the analyzed phosphatic rocks, respectively. Carnotite characteristics are identified by SEM/EDX in the studied phosphatic rocks which indicate that the uranium is leached out from the phosphatic materials and re-deposited as fine specks in open pores by circulating meteoric water. The leached uranyl ions together with vanadate ions are forming the identified carnotite under the influence of evaporation. The calculated annual effective dose equivalent values (AEDE) are 0.478 and 0.504 mSv/yr for the lower and upper phosphatic beds, respectively. The calculated radium equivalent activity values of (Ra eq) are 2319 and 2802 Bq/kg for the lower and upper phosphatic beds, respectively. Accordingly, although the estimated (AEDE) to the public is below the recommended limits, but the equivalent radium activity and the expected coincided radon gas emanation renders the phosphatic exposures in the study area classified unsafe for prolonged public activities.
Arabian Journal of Geosciences
International Geology Review
International Geology Review
International Geology Review
International Geology Review