I am a professor of Stratigraphy and Paleontology in fayoum University. I am interested in Micropaleontology, Paleoecology, Paleoclimatology and Paleoenvironmental interpretations. Recent ostracoda and Foraminifera, their distribution and environmental relations is also a part of my experience. Address: Egypt
Fourty six surface samples representing the recent marine sediments in the mangrove ecosystem of ... more Fourty six surface samples representing the recent marine sediments in the mangrove ecosystem of the Egyptian Red Sea are treated for their Ostracoda content. These samples are collected from Wadi Gemal and Abu Ghoson areas. Fourty eight ostracode species have been identified, belonging to twenty eight genera and fourteen families. The percentages of the most common Ostracoda genera are Xestoleberis (42.11% at Wadi Gemal& 29.6% at Abu Ghoson respectively), Ghardaglaia (11.1% and 24.23%), Loxoconcha (9.57% and 11.88%), Quadracythere (11.4%and 8.43%), Hiltrmannicythere (2.5% and 5.82%) and Loxocorniculum (6.59% and 2.23%). These genera represent more than three quarters of the whole present assemblage in the sites. The studied fauna show a clear Indo-Pacific affinity with rare Mediterranean and cosmopolitan elements. The presence of such species is attributed to passive migration.
ABSTRACT The distribution of recent shallow marine species of Ostracoda was recorded from 46 bott... more ABSTRACT The distribution of recent shallow marine species of Ostracoda was recorded from 46 bottom samples collected from two mangrove ecosystems along the Egyptian Red Sea coast, i.e., the regions Wadi El Gemal and Abu Ghoson. Four communities of Ostracoda were determined and examined, recorded from recent intertidal, lagoon, swamp, and downstream sediments, respectively. The distribution patterns of the Ostracoda are affected primarily by the conditions of the vegetation and the bottom. Areas with dense vegetation and/or muddy sand bottoms contain the more abundant and more diverse assemblages. Statistical analysis showed three clusters of species at each site. These results coincide with the observed physiographic assemblages, except at Wadi El Gemal where we have three clusters of species and only two communities. This can be explained through the more dense growth of mangroves in the southeastern and southwestern parts, as well as the fact that the substrate there is muddy sand instead of the sandy substrate found in the northern parts. La répartition des espèces marines récentes d'Ostracodes d'eaux peu profondes a été étudiée à partir de 46 échantillons du fond collectés dans deux écosystèmes de mangrove de la côte égyptienne de la mer Rouge, Wadi El Gemal et Abu Ghoson. Quatre communautés d'Ostracodes ont été déterminées et examinées, en provenance d'intertidal actuel, de lagune, de marais et de sédiments aval, respectivement. Les modèles de distribution d'Ostracodes sont affectés principalement par la végétation et le type de fond. Les zones à végétation dense et/ou à fond de sable vaseux contiennent les assemblages les plus abondants et les plus diversifiés. L'analyse statistique a montré trois groupes d'espèces à chaque site. Ces résultats coïncident avec les assemblages physiographiques observés, sauf à Wadi El Gemal où nous avons trois groupes d'espèces et seulement deux assemblages. Ceci peut s'expliquer par la croissance plus dense des mangroves dans les parties sud-est et sud ouest, ainsi que par le fait que le substrat est du sable vaseux alors qu'il est sableux dans les régions septentrionales.
Contamination and health risk assessment of heavy metals in beach sediments of Red Sea and Gulf of Aqaba, Egypt, 2022
The Egyptian beaches on the Red Sea and the Gulf of Aqaba in Sinai are a destination for internat... more The Egyptian beaches on the Red Sea and the Gulf of Aqaba in Sinai are a destination for international tourism throughout the year. Therefore, assessing the concentration levels of heavy metal pollutants and identifying the extent of their impact on human health is important. Single and integrated pollutants indices have been used to assess the risks of these elements. The results of single indices proved that the study area contain Fe and Zn came mostly from natural source while Cu, Pb, Cd and Hg originated from anthropogenic sources. However, the integrated pollutants indices revealed that this area is not polluted with heavy metals. On the other hand, the hazard index, and the carcinogenic risk over the lifetime coefficients proved that the beach sand of the study area is completely safe and does not have additional health risks to children or adults, where LCR < 10 − 6 .
Helal, S. A. and Abd El-Wahab, M.,2004, Recent ostracodes from marine sediments of Safaga Bay, Re... more Helal, S. A. and Abd El-Wahab, M.,2004, Recent ostracodes from marine sediments of Safaga Bay, Red Sea, Egypt. Egypt. ABSTRACT This work is the first attempt to throw some light on the ostracodes from the recent marine environment in the Safaga bay along the Red Sea coast, Egypt. Thirty surface bottom sediment samples were collected from the study area, and treated for their Ostracoda content. Identification, taxonomy, occurrence, ecology, and zoogeographic aspects were carried out on the ostracode assemblages. Twenty–three ostracode species belonging to 21 genera, and 13 families are recorded. Three biofacies were determined covering the area under study. A shallow, warm ,slightly alkaline, hypersaline, oxidizing marine environment was determined for the living medium of the present ostracode assemblages. Beside the main Indian fauna, some Mediterranean and cosmopolitan faunal elements were recoded. KEY WORDS Ostracodes – Recent marine sediments – Safaga bay- Red Sea-Egypt.Jour. Pa...
Foraminiferal assemblages from 4 sections (total-ling 158 samples) were quantitatively analysed t... more Foraminiferal assemblages from 4 sections (total-ling 158 samples) were quantitatively analysed to reconstruct paleoenvironmental changes in inner to outer shelf, tropical epicontinental sea of the southern Peritethys area around the middle Eocene climatic optimum. In comparison with bathyal oceanic sites, shelf assemblages from Fayoum area are strongly influenced by climatically forced sea-level oscillations and aridification in cooling post-MECO interval. Pre-MECO interval can be characterized by gradual deepening and hypoxic, eutrophic bottom water. The maximal deepening during the temperature peak was associated with destruction of hypoxic bottom water. Sea-level fall, nutrient decrease and salinity increase in marginal part of basin due to decreased continental runoff caused by aridification was suggested for post-MECO cooling interval. Clastic-carbonate system of the warming period and thermal maximum was changed to only carbonate system of cooling post-MECO period.
Environmental Science and Pollution Research, 2021
Benthic ostracods are deemed as one of the most useful micro-fauna for biomonitoring in shallow m... more Benthic ostracods are deemed as one of the most useful micro-fauna for biomonitoring in shallow marine ecosystem, which are sensitive to environmental changes that can be reflected by their diversity and abundances. The pollution leads to high dominance index and low abundance ostracod communities. Therefore, eighteen sediment samples were collected from Ras Gharib and Quseir sites, along the Red Sea coast, to assess the ostracods response toward the anthropogenic environmental disturbances. Jugosocythereis borchersi, Alocopocythere reticulata, and Loxocorniculum ghardaqensis are the most abundant ostracods in the study localities. To evaluate the linkage between ostracods and contaminated sediments, metal concentrations in the sediments were measured using inductively coupled plasma optical-emission spectrometry (ICP-OES). We observed a significant spatial difference in elemental distribution in sediment samples, and some elements are of higher contributions than the average marine sediment composition. The quantitative analysis of benthic ostracod associations was processed statistically with geochemical data and differentiated the study area into two environments, based on the degrees of contamination. Quseir is encompassing the most contaminated stations. It is characterized by sediments richer in heavy metals, higher silt, and higher organic matter contents. Contaminated environments favor the presence of pollution-tolerant species (e.g., J. borchersi, C. torosa, L. ghardaqensis, G. triebeli, M. striata, A. reticulata, and partly, C. dimorpha). Conversely, Ras Gharib is less polluted with metals and organic matter, and is characterized by pollution-sensitive species (X. rhomboidea). Noteworthy, a low density of ostracods was observed at the expense of the diversity around contaminated stations of the Quseir site.
This paper describes for the first time the dentary of the Masracetus markgrafi collected from th... more This paper describes for the first time the dentary of the Masracetus markgrafi collected from the Late Middle Eocene (Late Bartonian) Gehannam Formation at Qaret umm Regl section, north of Lake Qaroun, Fayoum, Egypt. These teeth are found as isolated, well preserved elements among and beneath the remnants of the eroded and deformed vertebrae, ribs and other elements of the Masracetus markgrafi skeleton in calcareous mudstone layer. These teeth are similar in shape and ornamentation to those of the Basilosauridae, especially Basilosaurus isis and Dorudon atrox, but differ in their sizes. These specimens are represented by the upper and lower teeth of incisors, canine, premolars and molars. The internal structure of the teeth is studied in the thin section of the lower incisor of the Masracetus markgrafi.
Fifth International Conference on the Geology of th e Tethys Realm, South Valley University, January 2010, P. 55-70, 2010
Fourty six surface samples representing the recent marine sediments in the mangrove ecosystem of ... more Fourty six surface samples representing the recent marine sediments in the mangrove ecosystem of the Egyptian Red Sea are treated for their Ostracoda content. These samples are collected from Wadi Gemal and Abu Ghoson areas. Fourty eight ostracode species have been identified, belonging to twenty eight genera and fourteen families. The percentages of the most common Ostracoda genera are Xestoleberis (42.11% at Wadi Gemal& 29.6% at Abu Ghoson respectively), Ghardaglaia (11.1% and 24.23%), Loxoconcha (9.57% and 11.88%), Quadracythere (11.4%and 8.43%), Hiltrmannicythere (2.5% and 5.82%) and Loxocorniculum (6.59% and 2.23%). These genera represent more than three quarters of the whole present assemblage in the sites. The studied fauna show a clear Indo-Pacific affinity with rare Mediterranean and cosmopolitan elements. The presence of such species is attributed to passive migration. INTRODUCTION Mangrove forests are important environmental element and ecologically significant habitat. Two species of mangrove trees have been recorded from the Egyptian Red Sea coast; Avicennia marina and Rhizophra mucronata (Zahran, 1965). The former one dominates the study area. The mangrove represents mosaic habitats containing both hard and soft ones. So, it provides living space in many parts of the world for more than 2,000 species of fish, invertebrates and epiphytic plants (Hamilton & Snedaker, 1984). The present work aims to study the Recent Ostracoda, as a part of the invertebrate community, from mangrove environment of the Egyptian Red Sea coast. This study is mainly directed to: 1. Explore the Ostracoda population in the mangrove ecosystem. 2. Identify and systematic study of the recovered Ostracoda, as this work is the first in this item along the Egyptian Red Sea coast. 3. Throw some light on the environmental relations and probable role of Ostracoda in the mangrove ecosystem. 4. Study the zoogeography of the Ostracoda faunal assemblage. The study area comprises two mangrove sites which is the largest occurrences of mangrove trees along the Egyptian Red Sea coast (Fig. 1). The first one, Wadi El Gemal Site, is situated in the south of Marsa Alam at lat. 24° 40 \ 37\\ to 24° 41 \ 13\\ N and Long. 35° 05 \ 18\\ to 35° 04 \ 57\\ E. The second one, Abu Ghoson area (El Qalaan site), is located at 40 Km south Wadi El Gemal between lat. 24° 21 \ 29 \\ to 24° 21 \ 32 \\ N and Long. 35° 18 \ 23 \\ to 35° 18 \ 13 \\ E.
The sequence stratigraphic framework of the Cenomanian Galala Formation (north Eastern Desert, Eg... more The sequence stratigraphic framework of the Cenomanian Galala Formation (north Eastern Desert, Egypt) is estimated on the basis of the Sedimentological and obtainable biostratigraphic data, in addition to the regional correlation of the studied sections. Five sequence boundaries are identified. The first sequence boundary separates between the Galala and Malha formations. The second, third and fourth sequence boundary exhibit a differentiated nature. It is noticed that such sequence boundaries in Gebel El-Zeit are mainly represented by paleosols and caliche, while those of the Northern Galala, Gebel Ataqa and Gebel Shabraweet are mostly typified by emergence horizons of dolomites and dedolomites. The fifth (last) sequence boundary separates the Galala Formation from the overlying El-Khashm Formation at Gebel El-Zeit, the Northern Galala and Gebel Ataqa and from Maghra El-Hadida Formation at Gebel Shabraweet. The Galala Formation in the study area is subdivided into four depositional sequences, which are built up of three systems tracts; the lowstand (LST), transgressive (TST) and highstand (HST) systems tracts. The LSTs are realized only from Gebel El-Zeit, where they are made up of clastic facies organized in coars-ening-and fining-upward parasequences. The TSTs form a series of aggradational-retrogradational, shal-lowing-upward parasequences, which transgress across the ramp till the point of maximum flooding is reached. The HSTs are built up of aggradational-progradational, shallowing-upward parasequences of shallow subtidal to peritidal facies.
The present study was undertaken for assessing the level of heavy metals such as iron,
manganese,... more The present study was undertaken for assessing the level of heavy metals such as iron, manganese, zinc, copper, nickel, cadmium, lead, and cobalt in recent sediment samples of Safaga Bay, Egypt. Concentration of heavy metals in sediments shows significant variability and ranges from 863.37 to 1144.93 ppm for Fe, 64.29–586.8 ppm for Mn, 2.7–12.68 ppm for Zn, 3.01–7.2 ppm for Pb, 1.53–3.29 ppm for Ni, 0.55–1.57 ppm for Co, 0.16–1.37 ppm for Cu, and 0.22–0.4 ppm for Cd. Sediment pollution assessments were carried out using an enrichment factor and geoaccumulation index. The calculation of enrichment factor showed that Cd is enriched by 4.1 due to phosphate sources in Safaga Bay. The Geoaccumulation index results revealed that there are positive and negative correlations between Fe, Zn, Mn, Pb, Ni, Cu, Co, and Cd indicating that these metals have complicated geochemical behaviors. Keywords Egypt, enrichment factor, geoaccumulation index, heavy metals, Safaga Bay, sediments
The distribution of recent shallow marine species of Ostracoda was recorded from 46 bottom sample... more The distribution of recent shallow marine species of Ostracoda was recorded from 46 bottom samples collected from two mangrove ecosystems along the Egyptian Red Sea coast, i.e., the regions Wadi El Gemal and Abu Ghoson. Four communities of Ostracoda were determined and examined, recorded from recent intertidal, lagoon, swamp, and downstream sediments, respectively. The distribution patterns of the Ostracoda are affected primarily by the conditions of the vegetation and the bottom. Areas with dense vegetation and/or muddy sand bottoms contain the more abundant and more diverse assemblages. Statistical analysis showed three clusters of species at each site. These results coincide with the observed physiographic assemblages, except at Wadi El Gemal where we have three clusters of species and only two communities. This can be explained through the more dense growth of mangroves in the southeastern and southwestern parts, as well as the fact that the substrate there is muddy sand instead of the sandy substrate found in the northern parts. RÉSUMÉ La répartition des espèces marines récentes d'Ostracodes d'eaux peu profondes a été étudiée à partir de 46 échantillons du fond collectés dans deux écosystèmes de mangrove de la côte égyptienne de la mer Rouge, Wadi El Gemal et Abu Ghoson. Quatre communautés d'Ostracodes ont été déterminées et examinées, en provenance d'intertidal actuel, de lagune, de marais et de sédiments aval, respectivement. Les modèles de distribution d'Ostracodes sont affectés principalement par la végétation et le type de fond. Les zones à végétation dense et/ou à fond de sable vaseux contiennent les assemblages les plus abondants et les plus diversifiés. L'analyse statistique a montré trois groupes d'espèces à chaque site. Ces résultats coïncident avec les assemblages physiographiques observés, sauf à Wadi El Gemal où nous avons trois groupes d'espèces et seulement deux assemblages. Ceci peut s'expliquer par la croissance plus dense des mangroves dans les parties sud-est et sud ouest, ainsi que par le fait que le substrat est du sable vaseux alors qu'il est sableux dans les régions septentrionales.
The Early and Middle Eocene rocks at Assiut-Minia stretch are shallow marine limestones. These ro... more The Early and Middle Eocene rocks at Assiut-Minia stretch are shallow marine limestones. These rocks consist of three rock units namely, Drunka, Minia and Samalut formations. Four algal and larger foraminiferal zones are recorded from these rocks namely in stratigraphic order Ovulites pyriformis/Ovulites arabica, Nummulites planulatus, Alveolina oblonga/Orbitolites complanatus and Nummulites gizehensis zones. Also, these rocks are characterized by high-diversified green algal floras (both Bryopsidales and Dasycladales). Nine Dasycladales taxa are identified (six of species-level and three of genus-level). They are Belzungia silvestrii (Pfender) Massieux, Cymopolia elongata (Defrance), Furcoporella diplopora Pia, Niloporella subglobosa Dragastan & Soliman, Clypeina cf. rotella Yu-Jing, Acicularia robusta Dragastan & Soliman, Dissocladella sp., Cymopolia sp. and Neomeris sp. A total of nine Bryopsidales (seven of species-level and two of genus-level) are recorded. They are represented by Ovulites pyriformis Schwager, Ovulites arabica (Pfender), Ovulites morelleti Elliott, Ovulites marginulata (Lamarck), Ovulites elongata Lamarck, Halimeda nana Pia, Halimeda praemonilis Morellet, Halimeda sp. and Ovulites sp. The paleoecological importance of the described algae is also discussed and deduced.
Foraminiferal assemblages from 4 sections (total-ling 158 samples) were quantitatively analysed t... more Foraminiferal assemblages from 4 sections (total-ling 158 samples) were quantitatively analysed to reconstruct paleoenvironmental changes in inner to outer shelf, tropical epicontinental sea of the southern Peritethys area around the middle Eocene climatic optimum. In comparison with bathyal oceanic sites, shelf assemblages from Fayoum area are strongly influenced by climatically forced sea-level oscillations and aridification in cooling post-MECO interval. Pre-MECO interval can be characterized by gradual deepening and hypoxic, eutrophic bottom water. The maximal deepening during the temperature peak was associated with destruction of hypoxic bottom water. Sea-level fall, nutrient decrease and salinity increase in marginal part of basin due to decreased continental runoff caused by aridification was suggested for post-MECO cooling interval. Clastic-carbonate system of the warming period and thermal maximum was changed to only carbonate system of cooling post-MECO period.
The Cenomanian Galala Formation is composed of a thick mixed siliciclastic-carbonate facies outcr... more The Cenomanian Galala Formation is composed of a thick mixed siliciclastic-carbonate facies outcropping in the north Eastern Desert, Egypt. It was deposited on a passive continental margin of southern Tethys. It displays a lateral facies changes in the form of a homoclinal ramp that is divided into two environmental settings; proximal and middle ramp. The proximal ramp is characterized by the silicclastic-dominanted coastal marine shoreface to peritidal facies and the mixed siliciclastic-carbonate intertidal-supratidal facies. The middle ramp includes three facies types; the peritidal, shallow subtidal and deep subtidal facies. The facies distribution on the middle ramp points out to that the ramp was drowned under the effect of local tectonic subsidence due to the east-west Tethyan tectonic movements during the Jurassic rifting forming an intra-ramp basin at the Southern Galala. The dominance of the carbonate facies in the northern part of the study area reflects that it was subjected to structural uplifting under the effect of the Syrian Arc System to form a carbonate buildup at Gebel Ataqa.
Fourty six surface samples representing the recent marine sediments in the mangrove ecosystem of ... more Fourty six surface samples representing the recent marine sediments in the mangrove ecosystem of the Egyptian Red Sea are treated for their Ostracoda content. These samples are collected from Wadi Gemal and Abu Ghoson areas. Fourty eight ostracode species have been identified, belonging to twenty eight genera and fourteen families. The percentages of the most common Ostracoda genera are Xestoleberis (42.11% at Wadi Gemal& 29.6% at Abu Ghoson respectively), Ghardaglaia (11.1% and 24.23%), Loxoconcha (9.57% and 11.88%), Quadracythere (11.4%and 8.43%), Hiltrmannicythere (2.5% and 5.82%) and Loxocorniculum (6.59% and 2.23%). These genera represent more than three quarters of the whole present assemblage in the sites. The studied fauna show a clear Indo-Pacific affinity with rare Mediterranean and cosmopolitan elements. The presence of such species is attributed to passive migration.
ABSTRACT The distribution of recent shallow marine species of Ostracoda was recorded from 46 bott... more ABSTRACT The distribution of recent shallow marine species of Ostracoda was recorded from 46 bottom samples collected from two mangrove ecosystems along the Egyptian Red Sea coast, i.e., the regions Wadi El Gemal and Abu Ghoson. Four communities of Ostracoda were determined and examined, recorded from recent intertidal, lagoon, swamp, and downstream sediments, respectively. The distribution patterns of the Ostracoda are affected primarily by the conditions of the vegetation and the bottom. Areas with dense vegetation and/or muddy sand bottoms contain the more abundant and more diverse assemblages. Statistical analysis showed three clusters of species at each site. These results coincide with the observed physiographic assemblages, except at Wadi El Gemal where we have three clusters of species and only two communities. This can be explained through the more dense growth of mangroves in the southeastern and southwestern parts, as well as the fact that the substrate there is muddy sand instead of the sandy substrate found in the northern parts. La répartition des espèces marines récentes d&#39;Ostracodes d&#39;eaux peu profondes a été étudiée à partir de 46 échantillons du fond collectés dans deux écosystèmes de mangrove de la côte égyptienne de la mer Rouge, Wadi El Gemal et Abu Ghoson. Quatre communautés d&#39;Ostracodes ont été déterminées et examinées, en provenance d&#39;intertidal actuel, de lagune, de marais et de sédiments aval, respectivement. Les modèles de distribution d&#39;Ostracodes sont affectés principalement par la végétation et le type de fond. Les zones à végétation dense et/ou à fond de sable vaseux contiennent les assemblages les plus abondants et les plus diversifiés. L&#39;analyse statistique a montré trois groupes d&#39;espèces à chaque site. Ces résultats coïncident avec les assemblages physiographiques observés, sauf à Wadi El Gemal où nous avons trois groupes d&#39;espèces et seulement deux assemblages. Ceci peut s&#39;expliquer par la croissance plus dense des mangroves dans les parties sud-est et sud ouest, ainsi que par le fait que le substrat est du sable vaseux alors qu&#39;il est sableux dans les régions septentrionales.
Contamination and health risk assessment of heavy metals in beach sediments of Red Sea and Gulf of Aqaba, Egypt, 2022
The Egyptian beaches on the Red Sea and the Gulf of Aqaba in Sinai are a destination for internat... more The Egyptian beaches on the Red Sea and the Gulf of Aqaba in Sinai are a destination for international tourism throughout the year. Therefore, assessing the concentration levels of heavy metal pollutants and identifying the extent of their impact on human health is important. Single and integrated pollutants indices have been used to assess the risks of these elements. The results of single indices proved that the study area contain Fe and Zn came mostly from natural source while Cu, Pb, Cd and Hg originated from anthropogenic sources. However, the integrated pollutants indices revealed that this area is not polluted with heavy metals. On the other hand, the hazard index, and the carcinogenic risk over the lifetime coefficients proved that the beach sand of the study area is completely safe and does not have additional health risks to children or adults, where LCR < 10 − 6 .
Helal, S. A. and Abd El-Wahab, M.,2004, Recent ostracodes from marine sediments of Safaga Bay, Re... more Helal, S. A. and Abd El-Wahab, M.,2004, Recent ostracodes from marine sediments of Safaga Bay, Red Sea, Egypt. Egypt. ABSTRACT This work is the first attempt to throw some light on the ostracodes from the recent marine environment in the Safaga bay along the Red Sea coast, Egypt. Thirty surface bottom sediment samples were collected from the study area, and treated for their Ostracoda content. Identification, taxonomy, occurrence, ecology, and zoogeographic aspects were carried out on the ostracode assemblages. Twenty–three ostracode species belonging to 21 genera, and 13 families are recorded. Three biofacies were determined covering the area under study. A shallow, warm ,slightly alkaline, hypersaline, oxidizing marine environment was determined for the living medium of the present ostracode assemblages. Beside the main Indian fauna, some Mediterranean and cosmopolitan faunal elements were recoded. KEY WORDS Ostracodes – Recent marine sediments – Safaga bay- Red Sea-Egypt.Jour. Pa...
Foraminiferal assemblages from 4 sections (total-ling 158 samples) were quantitatively analysed t... more Foraminiferal assemblages from 4 sections (total-ling 158 samples) were quantitatively analysed to reconstruct paleoenvironmental changes in inner to outer shelf, tropical epicontinental sea of the southern Peritethys area around the middle Eocene climatic optimum. In comparison with bathyal oceanic sites, shelf assemblages from Fayoum area are strongly influenced by climatically forced sea-level oscillations and aridification in cooling post-MECO interval. Pre-MECO interval can be characterized by gradual deepening and hypoxic, eutrophic bottom water. The maximal deepening during the temperature peak was associated with destruction of hypoxic bottom water. Sea-level fall, nutrient decrease and salinity increase in marginal part of basin due to decreased continental runoff caused by aridification was suggested for post-MECO cooling interval. Clastic-carbonate system of the warming period and thermal maximum was changed to only carbonate system of cooling post-MECO period.
Environmental Science and Pollution Research, 2021
Benthic ostracods are deemed as one of the most useful micro-fauna for biomonitoring in shallow m... more Benthic ostracods are deemed as one of the most useful micro-fauna for biomonitoring in shallow marine ecosystem, which are sensitive to environmental changes that can be reflected by their diversity and abundances. The pollution leads to high dominance index and low abundance ostracod communities. Therefore, eighteen sediment samples were collected from Ras Gharib and Quseir sites, along the Red Sea coast, to assess the ostracods response toward the anthropogenic environmental disturbances. Jugosocythereis borchersi, Alocopocythere reticulata, and Loxocorniculum ghardaqensis are the most abundant ostracods in the study localities. To evaluate the linkage between ostracods and contaminated sediments, metal concentrations in the sediments were measured using inductively coupled plasma optical-emission spectrometry (ICP-OES). We observed a significant spatial difference in elemental distribution in sediment samples, and some elements are of higher contributions than the average marine sediment composition. The quantitative analysis of benthic ostracod associations was processed statistically with geochemical data and differentiated the study area into two environments, based on the degrees of contamination. Quseir is encompassing the most contaminated stations. It is characterized by sediments richer in heavy metals, higher silt, and higher organic matter contents. Contaminated environments favor the presence of pollution-tolerant species (e.g., J. borchersi, C. torosa, L. ghardaqensis, G. triebeli, M. striata, A. reticulata, and partly, C. dimorpha). Conversely, Ras Gharib is less polluted with metals and organic matter, and is characterized by pollution-sensitive species (X. rhomboidea). Noteworthy, a low density of ostracods was observed at the expense of the diversity around contaminated stations of the Quseir site.
This paper describes for the first time the dentary of the Masracetus markgrafi collected from th... more This paper describes for the first time the dentary of the Masracetus markgrafi collected from the Late Middle Eocene (Late Bartonian) Gehannam Formation at Qaret umm Regl section, north of Lake Qaroun, Fayoum, Egypt. These teeth are found as isolated, well preserved elements among and beneath the remnants of the eroded and deformed vertebrae, ribs and other elements of the Masracetus markgrafi skeleton in calcareous mudstone layer. These teeth are similar in shape and ornamentation to those of the Basilosauridae, especially Basilosaurus isis and Dorudon atrox, but differ in their sizes. These specimens are represented by the upper and lower teeth of incisors, canine, premolars and molars. The internal structure of the teeth is studied in the thin section of the lower incisor of the Masracetus markgrafi.
Fifth International Conference on the Geology of th e Tethys Realm, South Valley University, January 2010, P. 55-70, 2010
Fourty six surface samples representing the recent marine sediments in the mangrove ecosystem of ... more Fourty six surface samples representing the recent marine sediments in the mangrove ecosystem of the Egyptian Red Sea are treated for their Ostracoda content. These samples are collected from Wadi Gemal and Abu Ghoson areas. Fourty eight ostracode species have been identified, belonging to twenty eight genera and fourteen families. The percentages of the most common Ostracoda genera are Xestoleberis (42.11% at Wadi Gemal& 29.6% at Abu Ghoson respectively), Ghardaglaia (11.1% and 24.23%), Loxoconcha (9.57% and 11.88%), Quadracythere (11.4%and 8.43%), Hiltrmannicythere (2.5% and 5.82%) and Loxocorniculum (6.59% and 2.23%). These genera represent more than three quarters of the whole present assemblage in the sites. The studied fauna show a clear Indo-Pacific affinity with rare Mediterranean and cosmopolitan elements. The presence of such species is attributed to passive migration. INTRODUCTION Mangrove forests are important environmental element and ecologically significant habitat. Two species of mangrove trees have been recorded from the Egyptian Red Sea coast; Avicennia marina and Rhizophra mucronata (Zahran, 1965). The former one dominates the study area. The mangrove represents mosaic habitats containing both hard and soft ones. So, it provides living space in many parts of the world for more than 2,000 species of fish, invertebrates and epiphytic plants (Hamilton & Snedaker, 1984). The present work aims to study the Recent Ostracoda, as a part of the invertebrate community, from mangrove environment of the Egyptian Red Sea coast. This study is mainly directed to: 1. Explore the Ostracoda population in the mangrove ecosystem. 2. Identify and systematic study of the recovered Ostracoda, as this work is the first in this item along the Egyptian Red Sea coast. 3. Throw some light on the environmental relations and probable role of Ostracoda in the mangrove ecosystem. 4. Study the zoogeography of the Ostracoda faunal assemblage. The study area comprises two mangrove sites which is the largest occurrences of mangrove trees along the Egyptian Red Sea coast (Fig. 1). The first one, Wadi El Gemal Site, is situated in the south of Marsa Alam at lat. 24° 40 \ 37\\ to 24° 41 \ 13\\ N and Long. 35° 05 \ 18\\ to 35° 04 \ 57\\ E. The second one, Abu Ghoson area (El Qalaan site), is located at 40 Km south Wadi El Gemal between lat. 24° 21 \ 29 \\ to 24° 21 \ 32 \\ N and Long. 35° 18 \ 23 \\ to 35° 18 \ 13 \\ E.
The sequence stratigraphic framework of the Cenomanian Galala Formation (north Eastern Desert, Eg... more The sequence stratigraphic framework of the Cenomanian Galala Formation (north Eastern Desert, Egypt) is estimated on the basis of the Sedimentological and obtainable biostratigraphic data, in addition to the regional correlation of the studied sections. Five sequence boundaries are identified. The first sequence boundary separates between the Galala and Malha formations. The second, third and fourth sequence boundary exhibit a differentiated nature. It is noticed that such sequence boundaries in Gebel El-Zeit are mainly represented by paleosols and caliche, while those of the Northern Galala, Gebel Ataqa and Gebel Shabraweet are mostly typified by emergence horizons of dolomites and dedolomites. The fifth (last) sequence boundary separates the Galala Formation from the overlying El-Khashm Formation at Gebel El-Zeit, the Northern Galala and Gebel Ataqa and from Maghra El-Hadida Formation at Gebel Shabraweet. The Galala Formation in the study area is subdivided into four depositional sequences, which are built up of three systems tracts; the lowstand (LST), transgressive (TST) and highstand (HST) systems tracts. The LSTs are realized only from Gebel El-Zeit, where they are made up of clastic facies organized in coars-ening-and fining-upward parasequences. The TSTs form a series of aggradational-retrogradational, shal-lowing-upward parasequences, which transgress across the ramp till the point of maximum flooding is reached. The HSTs are built up of aggradational-progradational, shallowing-upward parasequences of shallow subtidal to peritidal facies.
The present study was undertaken for assessing the level of heavy metals such as iron,
manganese,... more The present study was undertaken for assessing the level of heavy metals such as iron, manganese, zinc, copper, nickel, cadmium, lead, and cobalt in recent sediment samples of Safaga Bay, Egypt. Concentration of heavy metals in sediments shows significant variability and ranges from 863.37 to 1144.93 ppm for Fe, 64.29–586.8 ppm for Mn, 2.7–12.68 ppm for Zn, 3.01–7.2 ppm for Pb, 1.53–3.29 ppm for Ni, 0.55–1.57 ppm for Co, 0.16–1.37 ppm for Cu, and 0.22–0.4 ppm for Cd. Sediment pollution assessments were carried out using an enrichment factor and geoaccumulation index. The calculation of enrichment factor showed that Cd is enriched by 4.1 due to phosphate sources in Safaga Bay. The Geoaccumulation index results revealed that there are positive and negative correlations between Fe, Zn, Mn, Pb, Ni, Cu, Co, and Cd indicating that these metals have complicated geochemical behaviors. Keywords Egypt, enrichment factor, geoaccumulation index, heavy metals, Safaga Bay, sediments
The distribution of recent shallow marine species of Ostracoda was recorded from 46 bottom sample... more The distribution of recent shallow marine species of Ostracoda was recorded from 46 bottom samples collected from two mangrove ecosystems along the Egyptian Red Sea coast, i.e., the regions Wadi El Gemal and Abu Ghoson. Four communities of Ostracoda were determined and examined, recorded from recent intertidal, lagoon, swamp, and downstream sediments, respectively. The distribution patterns of the Ostracoda are affected primarily by the conditions of the vegetation and the bottom. Areas with dense vegetation and/or muddy sand bottoms contain the more abundant and more diverse assemblages. Statistical analysis showed three clusters of species at each site. These results coincide with the observed physiographic assemblages, except at Wadi El Gemal where we have three clusters of species and only two communities. This can be explained through the more dense growth of mangroves in the southeastern and southwestern parts, as well as the fact that the substrate there is muddy sand instead of the sandy substrate found in the northern parts. RÉSUMÉ La répartition des espèces marines récentes d'Ostracodes d'eaux peu profondes a été étudiée à partir de 46 échantillons du fond collectés dans deux écosystèmes de mangrove de la côte égyptienne de la mer Rouge, Wadi El Gemal et Abu Ghoson. Quatre communautés d'Ostracodes ont été déterminées et examinées, en provenance d'intertidal actuel, de lagune, de marais et de sédiments aval, respectivement. Les modèles de distribution d'Ostracodes sont affectés principalement par la végétation et le type de fond. Les zones à végétation dense et/ou à fond de sable vaseux contiennent les assemblages les plus abondants et les plus diversifiés. L'analyse statistique a montré trois groupes d'espèces à chaque site. Ces résultats coïncident avec les assemblages physiographiques observés, sauf à Wadi El Gemal où nous avons trois groupes d'espèces et seulement deux assemblages. Ceci peut s'expliquer par la croissance plus dense des mangroves dans les parties sud-est et sud ouest, ainsi que par le fait que le substrat est du sable vaseux alors qu'il est sableux dans les régions septentrionales.
The Early and Middle Eocene rocks at Assiut-Minia stretch are shallow marine limestones. These ro... more The Early and Middle Eocene rocks at Assiut-Minia stretch are shallow marine limestones. These rocks consist of three rock units namely, Drunka, Minia and Samalut formations. Four algal and larger foraminiferal zones are recorded from these rocks namely in stratigraphic order Ovulites pyriformis/Ovulites arabica, Nummulites planulatus, Alveolina oblonga/Orbitolites complanatus and Nummulites gizehensis zones. Also, these rocks are characterized by high-diversified green algal floras (both Bryopsidales and Dasycladales). Nine Dasycladales taxa are identified (six of species-level and three of genus-level). They are Belzungia silvestrii (Pfender) Massieux, Cymopolia elongata (Defrance), Furcoporella diplopora Pia, Niloporella subglobosa Dragastan & Soliman, Clypeina cf. rotella Yu-Jing, Acicularia robusta Dragastan & Soliman, Dissocladella sp., Cymopolia sp. and Neomeris sp. A total of nine Bryopsidales (seven of species-level and two of genus-level) are recorded. They are represented by Ovulites pyriformis Schwager, Ovulites arabica (Pfender), Ovulites morelleti Elliott, Ovulites marginulata (Lamarck), Ovulites elongata Lamarck, Halimeda nana Pia, Halimeda praemonilis Morellet, Halimeda sp. and Ovulites sp. The paleoecological importance of the described algae is also discussed and deduced.
Foraminiferal assemblages from 4 sections (total-ling 158 samples) were quantitatively analysed t... more Foraminiferal assemblages from 4 sections (total-ling 158 samples) were quantitatively analysed to reconstruct paleoenvironmental changes in inner to outer shelf, tropical epicontinental sea of the southern Peritethys area around the middle Eocene climatic optimum. In comparison with bathyal oceanic sites, shelf assemblages from Fayoum area are strongly influenced by climatically forced sea-level oscillations and aridification in cooling post-MECO interval. Pre-MECO interval can be characterized by gradual deepening and hypoxic, eutrophic bottom water. The maximal deepening during the temperature peak was associated with destruction of hypoxic bottom water. Sea-level fall, nutrient decrease and salinity increase in marginal part of basin due to decreased continental runoff caused by aridification was suggested for post-MECO cooling interval. Clastic-carbonate system of the warming period and thermal maximum was changed to only carbonate system of cooling post-MECO period.
The Cenomanian Galala Formation is composed of a thick mixed siliciclastic-carbonate facies outcr... more The Cenomanian Galala Formation is composed of a thick mixed siliciclastic-carbonate facies outcropping in the north Eastern Desert, Egypt. It was deposited on a passive continental margin of southern Tethys. It displays a lateral facies changes in the form of a homoclinal ramp that is divided into two environmental settings; proximal and middle ramp. The proximal ramp is characterized by the silicclastic-dominanted coastal marine shoreface to peritidal facies and the mixed siliciclastic-carbonate intertidal-supratidal facies. The middle ramp includes three facies types; the peritidal, shallow subtidal and deep subtidal facies. The facies distribution on the middle ramp points out to that the ramp was drowned under the effect of local tectonic subsidence due to the east-west Tethyan tectonic movements during the Jurassic rifting forming an intra-ramp basin at the Southern Galala. The dominance of the carbonate facies in the northern part of the study area reflects that it was subjected to structural uplifting under the effect of the Syrian Arc System to form a carbonate buildup at Gebel Ataqa.
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Papers by Sobhi A. Helal
manganese, zinc, copper, nickel, cadmium, lead, and cobalt in recent sediment samples
of Safaga Bay, Egypt. Concentration of heavy metals in sediments shows significant
variability and ranges from 863.37 to 1144.93 ppm for Fe, 64.29–586.8 ppm
for Mn, 2.7–12.68 ppm for Zn, 3.01–7.2 ppm for Pb, 1.53–3.29 ppm for Ni,
0.55–1.57 ppm for Co, 0.16–1.37 ppm for Cu, and 0.22–0.4 ppm for Cd.
Sediment pollution assessments were carried out using an enrichment factor and
geoaccumulation index. The calculation of enrichment factor showed that Cd is enriched
by 4.1 due to phosphate sources in Safaga Bay. The Geoaccumulation index results
revealed that there are positive and negative correlations between Fe, Zn, Mn, Pb, Ni,
Cu, Co, and Cd indicating that these metals have complicated geochemical behaviors.
Keywords Egypt, enrichment factor, geoaccumulation index, heavy metals,
Safaga Bay, sediments
manganese, zinc, copper, nickel, cadmium, lead, and cobalt in recent sediment samples
of Safaga Bay, Egypt. Concentration of heavy metals in sediments shows significant
variability and ranges from 863.37 to 1144.93 ppm for Fe, 64.29–586.8 ppm
for Mn, 2.7–12.68 ppm for Zn, 3.01–7.2 ppm for Pb, 1.53–3.29 ppm for Ni,
0.55–1.57 ppm for Co, 0.16–1.37 ppm for Cu, and 0.22–0.4 ppm for Cd.
Sediment pollution assessments were carried out using an enrichment factor and
geoaccumulation index. The calculation of enrichment factor showed that Cd is enriched
by 4.1 due to phosphate sources in Safaga Bay. The Geoaccumulation index results
revealed that there are positive and negative correlations between Fe, Zn, Mn, Pb, Ni,
Cu, Co, and Cd indicating that these metals have complicated geochemical behaviors.
Keywords Egypt, enrichment factor, geoaccumulation index, heavy metals,
Safaga Bay, sediments