Wadi El-Gemal Research Articles

Geochemistry and mineral chemistry of granitic rocks from west Wadi El Gemal area, southern Eastern Desert of Egypt: Indicators for highly fractionated syn- to post-collisional Neoproterozoic felsic magmatism

Geochemistry and mineral chemistry of granitic rocks from west Wadi El Gemal area, southern Eastern Desert of Egypt: Indicators for highly fractionated syn- to post-collisional Neoproterozoic felsic magmatism

Assessing the Heavy Metals in Surface Sediments of Wadi El-Gemal Island, Red Sea, Egypt: Pollution Levels, Sources, and Associated Risks

Assessing the Heavy Metals in Surface Sediments of Wadi El-Gemal Island, Red Sea, Egypt: Pollution Levels, Sources, and Associated Risks

Petrogenesis and possible fingerprints of the Najd shear system on the evolution of deformed granitic rocks in the west Wadi Nugrus area, Egypt

In this paper, we present petrological constraints on the geodynamic evolution of deformed granitic rocks in the west Wadi Nugrus area, south Eastern Desert of Egypt. The deformation belt trends NW-SE forming the so-called “Nugrus Shear Zone (NSZ)” a major tectonic feature in the Arabian-Nubian Shield (ANS) at the junction between Wadi El Gemal and Wadi Hafafit areas, namely “Site I″ and “Site II”. The deformed granitic rocks comprise highly sheared arc granitoids and post-collisional to within-plate younger granites. Although the investigated granitic rocks are highly deformed, they show no signs of metamorphism and retain their primary igneous minerals. The melts from which the investigated granitic types originated experienced considerable degrees of partial melting in the transitional lower crust/upper lithospheric mantle as indicated by the contents of incompatible and rare-earth elements (REEs). Typical A-type granites developed before deformation and during emplacement in a continental environment. Zircon has ThO2/UO2 > 0.1, which is typical of igneous zircon, which sometimes experiences little recrystallization during the late magmatic deuteric stage, either pre-or syn-deformational due to circulation of fluids along the shear zone. It is believed that the deformation of all granitic rocks in the west Wadi Nugrus area is possibly synchronous and related to the Najd Fault System (NFS). The (NFS) extends from the western Arabian Peninsula to develop the NW-trending Nugrus Shear Zone (NSZ) in the south Eastern Desert. Sub-magmatic, solid-state, and sub-solidus deformational microstructures are evidence for the deformation related to the (NFS). Chessboard patterns in quartz and sub-magmatic fractures in plagioclase indicate deformation at high temperatures (T > 650 °C) in the presence of melt, which demonstrate the shearing during granitic cooling. On the other hand, quartz grain boundary migration and sub-grain recrystallization are two examples of solid state-related high-temperature deformation-related microstructures (T > 450 °C). Mica kinks along feldspar twinning and bending planes refer to low-temperature sub-solidus microstructures (T < 450 °C).

Dolphin-shaped island: Exploring the natural resources and radiological hazards of Wadi El Gemal Island

The objective of this study is to assess the natural resources and radiological risks of Wadi El Gemal Island by examining its topography, mineralogy, geochemistry, and radioactive distributions. This island, which is situated at the outlet of Wadi El Gemal in Egypt's southeastern Desert, has a unique shape resembling a dolphin based on Landsat imagery. It's a part of the Wadi El Gemal-Hamata Protectorate and is notable for its diverse environmental, geological, economic, and archeological features, including recent reefs, sandy deposits, Quaternary carbonate sediments, and mangroves. The main natural resources on the island are fauna, mangrove forests, and flora. Samples collected from the island were analyzed using a NaI detector to measure the concentrations of radionuclides such as 238U, 232Th, 226Ra, and 40K, which were found to be within acceptable levels according to UNSCAR guidelines. The radionuclide 238U, 232Th, 226Ra, and 40K activity concentrations of the collected samples were 32.55 ± 9, 12.63 ± 4, 12.49 ± 4, and 325 ± 34 Bq/kg, respectively. Regarding radiological hazard indices, the values of absorbed gamma dose rate (36.06 ± 5.42 nGy/h), radium equivalent activity (73.88 ± 14.4 Bq/kg), annual effective dose indoor (0.18 ± 0.03 mSv/y) and outdoor (0.04 ± 0.01 mSv/y), internal (0.29 ± 0.05) and external (0.2 ± 0.03) indices, and excess lifetime cancer index (0.15 ± 0.05 × 10−3).This is suggest that there is no significant risk associated with these sediments.

New insights into chemical and spectroscopic characterization of beryl mineralization related to leucogranites in the west Wadi El Gemal area, southern Eastern Desert of Egypt

Our combined mineral chemistry and spectroscopic studies enabled us to envisage details about composition and genesis of beryl from the Eastern Desert of Egypt. Two types of beryl were investigated including emerald from ancient workings in the schist-related type whereas the other type is non-gem and granite-related. On the basis of FeOt-Cr2O3-MgO ternary classification, the Wadi El Gemal emeralds (alkali-type, sodic) are Mg-bearing while the Mikpid-Akarem beryls (normal-type) are Fe2+-bearing. Intense green colour of emerald results in a 323 cm−1 Raman shift due to ∼0.77 wt% Cr22O3 derived from serpentinite. In the Mikpid-Akarem district (belonging to the granite-related type), beryls are either faint blue or white and lack Cr, Mg and AlIV. On the other hand, they are relatively enriched in Fe and AlVI compared with the Wadi El Gemal emeralds (up to 0.13 & 1.97 apfu and 0.04 & 1.68 apfu, respectively), which is a function of the peraluminous composition of the granite host. Al3+ is substituted in the Y-site by di- to tetravalent cations (Mg2++Fe2++Cr3++Ti4+) and this is paired with a vacancy substitution by Na+. The Wadi El Gemal emeralds have H2O & K+ in the 2a-site and H2O & Na+ in the 2b-site. The latter site is vacant in the Mikpid-Akarem beryls.The FTIR spectra of our beryls and emeralds show a series of stretching and bending vibrations due to the presence of type I H2O (OH-Na band at 3657 cm−1) and type II H2O (stretching at 3591–3657 cm−1 & bending at 1631 cm−1). Lacking of Li+ leads to the absence of OH-Li band that is indicative of type III H2O. Hypothetical H2O in the Wadi El Gemal emerald (green beryl) amounts 2.24–2.92 wt% whereas it amounts 1.21–1.25 wt% in the Mikpid-Akarem non-green beryl. The asymmetric stretching vibration at 2921–2923 cm−1 is related to CH due to the presence of CH4, and possibly CO2, in the fluid inclusions trapped in the analyzed crystals. Some beryls, e.g. the Um Kabu emerald, has a Raman shift at 672 cm−1, which indicates maximal cation substitutions in the octahedral sites and minimal H2O in the channel sites. An uncommon shift at 147 cm−1 can be attributed to defect structure due to presence of radioactive zircon and monazite inclusions. Fe2+ substitution in the octahedral sites is appreciable and results in an UV–Vis-NIR band at 836 nm.

ASSESSMENT OF THE CORAL REEF HABITATS, DAMAGE INDICATORS AND CORALS-REEF FISH RELATIONSHIP IN WADI EL-GEMAL NATIONAL PARK, RED SEA, EGYPT

Because of the pivotal role of the substrate composition in the ecological state of coral reef communities, the present study was attempted to investigate the substrate cover, coral reefs, and reef fishes in the marine ecosystem of the Wadi El-Gemal National Park (WGNP), Red Sea, Egypt. The surveys were conducted in the Spring and Autumn of 2015 by SCUBA diving and/or snorkeling. We applied the Point, Line, and Belt Intercept Transect (PIT, LIT and BLT) methods, to assess the state and forms of the substrate, through a quantitative assessment of the fundamental components of the benthic cover. A quantitative assessment was conducted on five main benthic categories at WGNP; hard corals, soft corals, dead corals, sand, and rocks. Six invertebrate groups; banded coral shrimp, sea urchin, sea cucumber, the crown of thorn, giant clam, and Drupella sp. were also investigated. The study showed that, while there was no significant difference between sites in the benthic structure and cover, sites were different in the cover of hard coral, the abundance of benthic invertebrates, and the abundance of reef fishes. We also, assessed the status of eight impact indicators of reef damage (or damage indication categories); old dead, recently dead, total bleached, partial bleached, diseased, broken, fragments, and recruitments of corals at the marine protected area as well as investigated the coral reef/reef fish community relationship. Among the eight reef impact indicators that were assessed in the current study, the old dead corals showed the highest cover of the substrate. In the same context, the cover of the diseased colonies was lower than other categories in the area of the study. The study also indicated that increasing hard coral cover in the study area had strongly affected the abundance of reef fishes. Nevertheless, the abundance of reef fishes was found to be increased with the increase of the hard coral cover (P &lt; 0.05, r = 0.8), and this trend was attained by all reef fish families, the highest sites in coral cover and fish abundance were: Hnakourab, Wadi Lahmy and Sharm El-Luli (32, 28 and 25%, and 9, 11 and 6 mean number of fish/20 m transect), respectively. Positive correlation between the hard coral cover and fish abundance was detected as well. Acanthuraidae displayed the highest mean number of individuals (53.25/20 m belt transect). The study concluded that there is a need to perform a periodic assessment of the benthic cover of the main components of coral reef communities. Also, the study emphasized the role of benthic substrate structure and cover in the reef fish ecology.

Comparative Studies on Hydrometallurgy and Pyrometallurgy to the Extraction of Beryllium from Decrepitated Beryl from Wadi El Gemal Region, Eastern Desert, Egypt

Comparative Studies on hydrometallurgy and pyrometallurgy to the extraction of beryllium from decrepitated beryl from Wadi El Gemal Region, Eastern Desert, Egypt are carried out in this work in short, useful summary. Beryl is one of the important ore mineral constituents of the mineralized zones at Wadi El Gemal area, Eastern Desert, Egypt. Extraction of beryllium from beryl ore involves both (a) pyrometallurgical techniques through roasting of beryl with Na2SiF6 followed by leaching of roasting beryl with commercial (dilute) H2SO4 (b) hydrometallurgical processing techniques of beryl through direct leaching with H2SO4 to produce directly sulfate liquor. 88% of beryllium was extracted by roasted beryl with Na2SiF6 at 850°C for 1.5 hours and leaching the roasted product with 25% H2SO4 AT 85 ° C for 3/4 hour. On the other hand, 95 % of beryllium was extracted directly after 20 minutes by direct leaching at 280°c with 10 mol/liter H2SO4. Therefore, this work sheds light on the study of the factors affecting both forms of beryllium extraction.

In situ laboratory for plastic degradation in the Red Sea

Degradation and fragmentation of plastics in the environment are still poorly understood. This is partly caused by the lack of long-term studies and methods that determine weathering duration. We here present a novel study object that preserves information on plastic age: microplastic (MP) resin pellets from the wreck of the SS Hamada, a ship that foundered twenty-nine years ago at the coast of Wadi el Gemal national park, Egypt. Its sinking date enabled us to precisely determine how long MP rested in the wreck and a nearby beach, on which part of the load was washed off. Pellets from both sampling sites were analyzed by microscopy, X-ray tomography, spectroscopy, calorimetry, gel permeation chromatography, and rheology. Most pellets were made of low-density polyethylene, but a minor proportion also consisted of high-density polyethylene. MP from inside the wreck showed no signs of degradation compared to pristine reference samples. Contrary, beached plastics exhibited changes on all structural levels, which sometimes caused fragmentation. These findings provide further evidence that plastic degradation under saltwater conditions is comparatively slow, whereas UV radiation and high temperatures on beaches are major drivers of that process. Future long-term studies should focus on underlying mechanisms and timescales of plastic degradation.

Which is a stronger predictor of the abundance of Dorcas Gazelle, Gazella dorcas in the Eastern desert of Egypt: human or natural factors?

The Dorcas Gazelle, Gazella dorcas, has lost 86% of its global historical range, and is regionally categorized as endangered by the IUCN. The factors that caused this decline have never been quantified. In this work, field and remotely sensed data were used to examine the ecological and anthropogenic factors affecting the abundance of Dorcas Gazelle within Wadi El-Gemal Protected Area in the Eastern desert of Egypt, using Generalized Linear Mixed Models (GLMM). The species’ abundance is shaped by anthropogenic activities (number of car trails and proximity to the coastal road) more than ecological factors (vegetation and wetness indices). Dorcas Gazelle is avoiding more humid and greener areas because of human disturbance. Such suitable habitats may be perceived by gazelles as too dangerous, and the animals therefore prefer less suitable but safer habitats that are further away or less frequented by humans. Moreover, an easy to conduct, cheap monitoring tool, the Kilometric Abundance Index (KAI), was devised and implemented for baseline information to be used for future monitoring of Dorcas Gazelle.

Petrology, REE Geochemistry and Tetrad Effect of Some Muscovite Granites at Wadi El Gemal Area, South Eastern Desert, Egypt

The muscovite granites at the study area are being emplaced into biotite granites and ophiolitic mélange settings. They occur in four exposures namely; Umm Seleimat, Sikait, Umm El Kheran and Umm Addebaa exposure. The presence of garnet and muscovite flakes may reflect the peraluminous nature of the studied muscovite granites. Petrographically, the studied granites are mostly subsolvus and consist of plagioclase, K-feldspars, quartz, muscovite and biotite. Garnet, zircon, allanite and opaques are accessories. The textural features of these granites are expressed by bent plagioclase lamellae, distorted microcline twinning, deformed mica flakes and development of myrmekite and recrystallization of feldspars into fine-grained aggregates. Umm Seleimat and Sikait exposures are more differentiated due to the presence of high content of K-feldspar and LREEs. The REE budget decreased from Umm Seleimat-Sikait exposures to Umm El Kheran-Umm Addebaa exposures as (514.5 - 495.6) to (195.9 - 197.7), respectively. Umm Seleimat-Sikait exposures have lower HREE/LREE (0.12 - 0.67), relative to Umm El Kheran-Umm Addebaa exposures (0.99 - 2.06). The studied granites revealed that the chondrite normalized REE patterns are the normal M-type of tetrad effect, where TE1,3 tetrad effect is higher than 1 in all samples which implies that there was an interaction between melt and water-haloid-rich fluid when these granites are crystallized from magma. Spectrometric values of Umm Seleimat and Umm Addebaa indicate that U content is more than Th content. Applying the U mobilization equation proved that the studied granites have been originated from a late magmatic phase of magma very rich in radioelements, also the majority of measurements lie above the zero line indicating that the studied granites affected with hydrothermal solutions rich in uranium than thorium which indicates uranium addition.

Expression of some salt tolerance genes isolated from Egyptian gray mangrove (Avicennia marina)

Mangroves are well-adapted halophytes that thrive in coastal saline environments. They live under difficult environmental conditions, such as high light intensity and external salt concentrations, as well as low-oxygen environments, such as water-logged muck, that are typically inappropriate for the survival of other plants. Salinity is a major abiotic factor that affects plant growth, productivity, and dispersal in tropical and semitropical intertidal areas. Furthermore, it affects approximately 20% of all cultivable land and 50% of all irrigated land on the planet. Mangroves have developed a sophisticated salt filtration mechanism and a complicated root structure to withstand salty water exposure and tidal movement. The expression patterns of five salt tolerance genes (amFer1, amDhna, amSod1, amCat1, and amUbc2) in the Egyptian gray mangrove (Avicennia marina Forssk.) grown under different environmental conditions in South Sinai protectorates (Nabq, Ras Mohamed, Safaga, and Wadi El-Gemal), Egypt, were investigated in this study. This study aimed to assess and examine the genetic behavior of mangroves in response to salinity by using quantitative real-time PCR. Findings revealed differences in the expression patterns of the investigated genes under various conditions, showing that salinity influences plant genetic response. Ferritin gene expression was high in all locations, indicating that ferritin represents an essential component of the mangrove response mechanisms.

Geomatics approach to assess nesting habitat of green turtles Wadi El Gemal, Red Sea, Egypt

Long-term wave action, sea level rise, climate change, human activities, pollutants, sea surface temperature SST, are causative factors for deterioration and changes in natural ecosystems. The current study aims to assess environmental deterioration that disturbs turtles and their nesting grounds at Wadi El Gemal National Park (WGNP), using modern remote sensing techniques and ecological investigations. Nesting area mapping and change detection were found to be precise and clear in the current investigation. The true nests recorded from WGNP during the current survey were Wadi El Gemal Delta (3), Torfa (10), Elshiekha Sabieha (2), Hankorab (14), Umm Alabas, Wadi El Gemal Island (1) and Syial Island (1). The concentration of some heavy metals in eggshells were positively correlated with their concentrations in sand (p ≤ 0.01), while heavy metals in nesting sands were negatively correlated with grain size (p < 0.05). On the other hand, the distance from vegetation and SST found to interact with the number of nests. Wadi El Gemal Island declined from 1984 to 1990 at a rate of (0.861 %), from 1990 to 2003 at (2.093 %), and (4.059 %) between 2003 and 2016. According to the shift detection review, Syial Island was reduced in area from 1973 to 1984 (−12,523 m2). Wadi El Gemal shoreline accretion was about (16,777 m2) from 1973 to 1984, while erosion was about (16,777 m2) during the same period (393.754 m2). For the entire period (42 years), the overall shift in accretion area was (362,175 m2), while the erosion area was approximately (724.269 m2).

Local participation in the management of protected areas: legitimate claims and unfulfilled promises: a case study of Wadi El Gemal Protected Area in Egypt

In Egypt, there has been an increasing recognition that the establishment of protected areas (PAs) alone cannot safeguard perpetuation of biodiversity, and local community participation is a viable strategy for reducing local costs of PAs, while improving their management performance. Here, the emphasis is on the local community perceptions of the practices and challenges of grassroots community participation in the management process of Wadi El Gemal Protected Area (WGPA), which is inhabited by the local community of Ababda tribe and heavily relies on the natural resources for their livelihood. The study revealed that the current participatory approach in the WGPA resembles in many aspects manipulative and passive-receptive participation, where people are involved by being told what is going to happen or what has already happened. This type of local participation in the WGPA does not identify local communities as managers and decision makers, rather as law abiders and in best cases as passive consultees.

Local participation in the management of protected areas: legitimate claims and unfulfilled promises: a case study of Wadi El Gemal Protected Area in Egypt

Local participation in the management of protected areas: legitimate claims and unfulfilled promises: a case study of Wadi El Gemal Protected Area in Egypt

Resilience drivers in some coral reef sites in Wadi El-Gemal marine protected area, Southern Egyptian Red Sea

Resilience drivers in some coral reef sites in Wadi El-Gemal marine protected area, Southern Egyptian Red Sea

Obstacles of Geotourism in Egypt as applied to Wadi El Gemal National Park

This research aims to explore the obstacles of Geotourism in Wadi El Gemal National Park as a potential model for Geo-tourism in Egypt. The research relied on the descriptive approach to describe and analyze the phenomenon, and it relied on collecting primary data on survey forms that were directed to the managers of tourism companies in the region of the South Red Sea. The importance of research emerges in providing a vision for Geo-tourism development by exploring the obstacles that prevent developing Geo-tourism activities in the study area. The research pointed to obstacles related to several axes, including organizational obstacles, obstacles related to government tourism policy, and obstacles related to international tour operators.

New Occurrence of Gold Mineralization at the Eastern Part of Wadi El Gemal, South Eastern Desert, Egypt

The basement rock units of the study area are represented by metasediments-metavolcanics association, diorite rocks, granodiorites and syenogranites. The whole sequence is cut by basic dykes, pegmatites and different quartz (jasper) veins. Metasediments-metavolcanics association is represented by hornblende schist and metadacite respectively. There is visible sulfides mineralization in hornblende schist, metadacite and diorite rocks at their contacts at the wadi level. So, polished sections were prepared to study opaque minerals under the ore microscope, which reveals the presence of gold, pyrite and goethite. The radioactivity of this area is weak, where the average eU contents in metasediments-metavolcanics association, diorites, granodiorites, syenogranites, pegmatites and jasper veins are 2.8 ppm, 1.9 ppm, 3.26 ppm, 4.91 ppm, 4.32 ppm and 6.7 ppm respectively. The intrusion of granodiorite rocks may act as a source for hydrothermal solutions ascending along fractures of all older rocks. During this stage, a chemical reaction of hydrothermal fluids with metasediments-metavolcanics association and diorite rocks lead to forming sericite and enrichment of silica content. The enrichment of silica content led to the formation of quartz-diorite. Also, iron derived from the host rocks and sulfur from the hydrothermal fluids could have formed pyrite while the gold was precipitated at the contact between metasediments-metavolcanics association and diorite rocks.

Geology, mineralogy and mineral chemistry of the NYF-type pegmatites at the Gabal El Faliq area, South Eastern Desert, Egypt

The Gabal El Faliq area is located in the Eastern Desert of Egypt and belongs to the Wadi Hafafit–Wadi Ghadir fold belt. Lenses and dykes of rare metal-bearing pegmatites occur along major weak zones in the area (Wadi El Gemal strike-slip and its Riedel shears), by which they are structurally controlled. These pegmatites are mineralogically complex. Moreover, they are zoned, and the intermediate zones of the pegmatite varieties contain high amounts of zircon, fergusonite-(Y), columbite-(Fe), allanite-(Ce), xenotime-(Y), monazite-(Ce and Nd), thorite and gummite. These minerals carry Zr, rare earth element (REE), Nb, Ta, Th, U >Ta, F, and they are classified into rare-metal pegmatites, specifically, the niobium, yttrium and fluorine (NYF) enrichment family. The geochemistry aspects of these pegmatites indicate Zr up to 28,984 ppm, Hf up to 1171 ppm, REE up to 19,206 ppm, Nb up to 9962 ppm, Ta up to 152 ppm, U up to 565.5 ppm, Th up to 850 ppm and Ga up to 90 ppm. They were formed under an intracontinental tectonic setting from a basaltic magma similar to the oceanic island basalts (OIBs) contaminated with the crust. Consequently, this study could be used as a guide for the exploration of rare metals in similar regions of the world.

First Report on the Reptile Diversity of Wadi El Gemal National Park, Eastern Desert, Egypt

The herpetofauna of Wadi El Gemal National Park, Eastern Desert, Egypt currently includes 28 reptile species. Three large wadies, Wadi El Gemal, Wadi Abu Ghusoun and Wadi Sartout, were observed as a model of the species composition within the national park. Species assemblages, taxonomic and ecological diversity, and the biogeographical affinities of reptiles in the specific environment of the hyperarid desert are discussed.

Sensitivity of WRF microphysics schemes: case study of simulating a severe rainfall over Egypt

In this work, sensitivity of ten microphysics schemes of Weather Research and Forecasting model were compared to determine which is more accurate. A case study of heavy rains over the Red Sea coast of Egypt on 26th October 2016 that caused damaging floods is the subject of this study. Three coastal areas were chosen, the city of Ras Ghareb, Wadi Elgemal National park, and Elba National park. The output precipitation from the model was compared to the satellite data obtained from Tropical Rainfall Measuring Mission (TRMM). Our analysis showed that the model has the capability to simulate the rainy events spatially and produce the cloud pattern. The results showed also that the model generally tends to overestimate the precipitation for all the ten schemes compared to TRMM data.