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Sample records for western desert egypt

  1. The corrosive well waters of Egypt's western desert

    USGS Publications Warehouse

    Clarke, Frank Eldridge

    1979-01-01

    The discovery that ground waters of Egypt's Western Desert are highly corrosive is lost in antiquity. Inhabitants of the oases have been aware of the troublesome property for many decades and early investigators mention it in their reports concerning the area. Introduction of modern well-drilling techniques and replacements of native wood casing with steel during the 20th century increased corrosion problems and, in what is called the New Valley Project, led to an intense search for causes and corrective treatments. This revealed that extreme corrosiveness results from combined effects of relatively acidic waters with significant concentrations of destructive sulfide ion; unfavorable ratios of sulfate and chloride to less aggressive ions; mineral equilibria and electrode potential which hinder formation of protective films; relative high chemical reaction rates because of abnormal temperatures, and high surface velocities related to well design. There is general agreement among investigators that conventional corrosion control methods such as coating metal surfaces, chemical treatment of the water, and electrolytic protection with impressed current and sacrificial electrodes are ineffective or impracticable for wells in the Western Desert's New Valley. Thus, control must be sought through the use of materials more resistant to corrosion than plain carbon steel wherever well screens and casings are necessary. Of the alternatives considered, stainless steel appears to. be the most promising where high strength and long-term services are required and the alloy's relatively high cost is acceptable. Epoxy resin-bonded fiberglass and wood appear to be practicable, relatively inexpensive alternatives for installations which do. not exceed their strength limitations. Other materials such as high strength aluminum and Monel Metal have shown sufficient promise to. merit their consideration in particular locations and uses. The limited experience with pumping in these desert

  2. Volatiles in the Desert: Subtle Remote-sensing Signatures of the Dakhleh Oasis Catastrophic Event, Western Desert, Egypt

    NASA Technical Reports Server (NTRS)

    Haldemann, A. F. C.; Kleindienst, M. R.; Churcher, C. S.; Smith, J. R.; Schwarcz, H. P.; Osinski, G.

    2005-01-01

    Over the past decade members of the Dakhleh Oasis Project have studied enigmatic signatures in the Pleistocene geologic record of portions of the Dakhleh oasis and palaeo-oasis in Egypt's Western Desert [1,2]. In particular, Si-Ca-Al rich glass melt (Dakhleh Glass, Fig. 1) points to a catastrophic event between c.100,000-200,000 years ago [3] in this well-studied African savannah and freshwater lake Middle Stone Age environment [4,5].

  3. Geological heritage of the Bahariya and Farafra oases, the central Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Plyusnina, Ekaterina E.; Sallam, Emad S.; Ruban, Dmitry A.

    2016-04-01

    Archaeological and cultural heritage of Egypt is world-known, but its geological heritage is yet to be revealed. Investigations in the central Western Desert of Egypt permitted finding a lot of unique features that can be assigned to this heritage. In the Bahariya Oasis, 10 geological heritage types are established, namely stratigraphical, paleontological, sedimentary, igneous, mineralogical, economical, paleogeographical, geomorphological, hydrological and hydrogeological, and pedological types. In the Farafra Oasis and vicinities, only geomorphological and hydrological and hydrogeological types are found. On the area between these oases, sedimentary, mineralogical, paleogeographical, and geomorphological features are established. Chalk and nummulitic limestones, invertebrate and dinosaur localities, paleoreefs and paleokarst, iron ore deposit, and peculiar landforms occur on the study territory. Taken together, these features constitute a highly diverse geological heritage that can be judged global (even if the rank of individual objects is often relatively low). This heritage is well suitable for the purpose of geotourism; for instance, thematic excursions explaining the geological evolution during the last 100 Ma are possible. Participants of such excursions can also see different facies. A geopark in the central Western Desert of Egypt would facilitate geoconservation and geotourism activities.

  4. Integrated geophysical study to delineate the subsurface structures in Siwa Oasis, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Khalil, Ahmed; Abd El All, Esmat; Rabeh, Taha; Osman, Salah

    2015-04-01

    Siwa Oasis is located within the Western Desert of Egypt and is a potential candidate for the development. It represents one of the most interesting and distinct region of Egypt. The main goal of the present work is to study the subsurface structures in Siwa Oasis area, Western Desert, Egypt and to determine their effects on surface geologic structures. To achieve this, two geophysical methods (magnetic and geothermal) have been used in this study. A detailed land magnetic survey was performed. The necessary reduction concerning daily variation, the regional gradient and time variation observation were applied. The measured total magnetic field was corrected and reduced to the north magnetic pole. Data analysis was performed using trend analysis, Euler deconvolution, high pass filter, analytical signal. The results indicate that the area is affected by tectonic forces in the NE-SW, NW- SE and E-W directions. Geothermal studies in some places in Siwa Oasis were carried out using the device of thermo-physical properties (Isomet-104) for measuring the subsurface temperature contour map (30 meters below the earth's surface). This map illustrates that there are good geothermal regions have hot groundwater reservoir. The measurements of geothermal properties of some rock samples such as thermal conductivity, thermal diffusivity, volume capacity and thermal values gave us an indication about the geothermal of rocks in the subsurface. Also, geothermal studies gave us an idea about the heat flow and the increasing of the energy and chemical of properties of the predominant subsurface rocks in the study area.

  5. Application of LANDSAT satellite imagery for iron ore prospecting in the Western Desert of Egypt

    NASA Technical Reports Server (NTRS)

    Elshazly, E. M.; Abdelhady, M. A.; Elghawaby, M. A.; Khawasik, S. M.

    1977-01-01

    Prospecting for iron ore occurrences was conducted by the Remote Sensing Center in Bahariya Oasis-El Faiyum area covering some 100,000 km squared in the Western Desert of Egypt. LANDSAT-1 satellite images were utilized as the main tool in the regional prospecting of the iron ores. The delineation of the geological units and geological structure through the interpretation of the images corroborated by field observations and structural analysis led to the discovery of new iron ore occurrences in the area of investigation.

  6. Morphologic characteristics and migration rate assessment of barchan dunes in the Southeastern Western Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Hamdan, M. A.; Refaat, A. A.; Abdel Wahed, M.

    2016-03-01

    This work explores the morphologic characteristics of aeolian dune sand in the southeastern part of Western Desert of Egypt. It aims to assess the movement of barchan dunes and evaluate their environmental influence on the Toshka Project. Morphometric investigation of barchan dunes in the Toshka area revealed that most barchans have high length/width (a/c) ratios (fat to pudgy), while one-fifth of the studied barchans have lower a/c ratios and so appear normal in their morphologic forms. Statistical analysis of the main parameters of barchan dunes in Toshka and other desert regions in the Kharga (Egypt), Kuwait, Southern Morocco, California and Southern Peru demonstrates that barchans of the Toshka area are distinctive in their appearance. They are characterized by distinct aspect with higher values of length and width and greater growth in height. The high-energy wind environment in addition to the large amount of drifting sand are principal factors responsible for the unique shape of Toshka barchans. The migration rate of barchan dunes in four chosen test locations, within the central and western Toshka area, ranges from about 3 to 10.82 m/year. The calculated average migration rate of these dunes is about 6 m/year in a SSW direction. Sand encroachment is more extensive in the central and western parts of the investigated Toshka area. Risk evaluation of sand dune movements in the southeastern part of the Western Desert points to medium to high sand encroachment risk values. These may represent serious hazards to the newly-established Toshka Project, threatening roads, as well as cultivated lands in the area.

  7. Mesozoic rift basins in western desert of Egypt, their southern extension and impact on future exploration

    SciTech Connect

    Taha, M.A. )

    1988-08-01

    Rift basins are a primary target of exploration in east, central, and west Africa. These intracratonic rift basins range in age from the Triassic to the Neogene and are filled with lagoonal-lacustrine sand-shale sequences. Several rift basins may be present in the Western Desert of Egypt. In the northeastern African platform, the Mesozoic Tethyan strand lines were previously interpreted to have limited southern extension onto the continent. This concept, based upon a relatively limited amount of subsurface data, has directed and focused the exploration for oil and gas to the northernmost 120 km of the Western Desert of Egypt. Recent well and geophysical data indicate a southerly extension of mesozoic rift basins several hundred kilometers inland from the Mediterranean Sea. Shushan/Faghur and Abu Gharadig/Bahrein basins may represent subparallel Mesozoic basins, trending northeast-southwest. Marine Oxfordian-Kimmeridgian sediments were recently reported from wells drilled approximately 500 km south of the present-day Mediterranean shoreline. The link of these basins with the Sirte basin to the southwest in Libya is not well understood. Exploration is needed to evaluate the hydrocarbon potential of such basins.

  8. Groundwater potential for irrigation in the East Oweinat area, Western Desert Egypt

    NASA Astrophysics Data System (ADS)

    Nour, S.

    1996-04-01

    The Nubia Sandstone aquifer system is one of the most extensive groundwater systems in North Africa, covering an area of about 2,000,000 km2, including parts of Egypt, Libya, Sudan, and Chad. In the Western Desert of Egypt, the Nubian formation has a thermal gradient of 1.1 5°C 100 m-1 with the exception of the East Oweinat area, located in the southern part of the Western Desert. This is the only part of this huge system where ground-water occurs under unconfmed conditions in an area where the Nubian sandstone crops out and is underlain by shallow basement rocks; in this area groundwater has no thermal characteristics. The aquifer system in the East Oweinat area attains a relatively high hydraulic conductivity. The direction of groundwater flow is generally northeastwards but is distorted at faults and fracture zones. Chemical analyses of groundwater in the area indicate a low salt content and suitability for irrigation purposes. As the estimated recharge to the area is low compared with the foreseen irrigation water requirement, the development of groundwater in the East Oweinat should be based on groundwater mining. Although the evaluation of the groundwater resources in East Oweinat has indicated that groundwater can be extracted at a rate of 4.7×106 m3 d-1, the long-term economics of extraction that can sustain large-scale development projects has to be assessed.

  9. Pitted and fluted rocks in the Western Desert of Egypt - Viking comparisons

    NASA Technical Reports Server (NTRS)

    Mccauley, J. F.; Breed, C. S.; Grolier, M. J.; El-Baz, F.; Whitney, M. I.; Ward, A. W.

    1979-01-01

    The Western Desert of Egypt is one of the most arid regions on earth and is probably the closest terrestrial analog to the surface of Mars. An expedition to the area in 1978 revealed an abundance of quartzite and basalt rocks that have been pitted and fluted by wind erosion and deflation of the desert surface. These pitted rocks are internally homogeneous, show no internal holes or vesicles, and are considered an important but neglected type of ventifact. They bear a striking resemblance to the pitted and fluted rocks seen by the Viking Landers, rocks that have generally been interpreted as vesicular basalts only slightly modified by wind erosion. Wind tunnel studies of the air flow over and around nonstreamlined hand specimens from the Western Desert show that windward abrasion coupled with negative flow, secondary flow, and vorticity in a unidirectional wind can explain the complex arrays of pits and flutes. These field and laboratory observations suggest that the pitted rocks at the Viking Lander sites are also ventifacts, and thus the Martian surface may be far more wind eroded than previously thought.

  10. Inverted topography in the southeastern part of the Western Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Zaki, Abdallah S.; Giegengack, Robert

    2016-09-01

    We present here a series of surficial geologic maps of 22,000 km2 of the southeastern part of the Western Desert of Egypt showing 3084 bodies of wadi-floor sediment that have been inverted by erosion to form sinuous ridges capped by alluvial gravel, here described as "inverted wadis". These features represent fragments of one or more ancient drainage systems that developed at times when rainfall, and hence overland flow, was greater than it is today in this hyperarid region. While some of the inverted wadis were tributaries to a through-flowing river that followed the course of the modern Nile, others converge on what appear to have been internal closed basins west of the Nile. Several components of this ancient drainage system have yielded artifacts assigned to an Acheulian lithic tradition, but there is not yet enough stratigraphic information available to enable us to relate this ancient drainage system to any of the proposed scenarios of Nile evolution.

  11. Extant cheilostomatous bryozoans of the Middle Miocene from the north Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Ziko, Abdelmohsen; Eweda, Shehta; El-Khawaga, Samar

    2016-12-01

    Twenty-nine extant Bryozoan species, belonging to the order Cheilostomata are described. They are from the Middle Miocene Marmarica Formation of the northern Western Desert in Egypt. The described bryozoans are collected from Matruh and Siwa areas. Fourteen species belong to the suborder Anasca, and the other fifteen species belong to the suborder Ascophora. The identified bryozoan species exhibit many zoarial growth forms. The encrusting forms are membraniporiform and celleporiform, while the erect forms are adeoniforms, eschariforms, vinculariiforms, reteporiform, and cellariiforms. They extend in the geologic record from the Eocene to the Recent, distributed mainly in the Tethyan realm, and recorded also from North America. The extant species are mainly of Mediterranean affinity, some are of wider distribution in the Atlantic and Pacific oceans, and are rarely cosmopolitan.

  12. A socio-ecological investigation of options to manage groundwater degradation in the Western Desert, Egypt.

    PubMed

    King, Caroline; Salem, Boshra

    2012-07-01

    Under increasing water scarcity, collective groundwater management is a global concern. This article presents an interdisciplinary analysis of this challenge drawing on a survey including 50 large and small farms and gardens in a village in an agricultural land reclamation area on the edge of the Western Desert of Egypt. Findings revealed that smallholders rely on a practice of shallow groundwater use, through which drainage water from adjacent irrigation areas is effectively recycled within the surface aquifer. Expanding agroindustrial activities in the surrounding area are socio-economically important, but by mining non-renewable water in the surrounding area, they set in motion a degradation process with social and ecological consequences for all users in the multi-layered aquifer system. Based on the findings of our investigation, we identify opportunities for local authorities to more systematically connect available environmental information sources and common pool resource management precedents, to counterbalance the degradation threat.

  13. Age and isotopic constraints on pleistocene pluvial episodes in the Western Desert, Egypt.

    SciTech Connect

    Crombie, M. K.; Arvidson, R. E.; Sturchio, N. C.; El Alfy, Z.; Abu Zeid, K.; Environmental Research; Washington Univ.; Egyptian Geological Survey and Mining Authority

    1997-01-01

    North Africa has undergone drastic climatic changes over the past several hundred thousand years. The timing of humid intervals called pluvials was investigated by uranium-series disequilibrium dating of travertines from the Kurkur Oasis, Western Desert, Egypt. The youngest and best dated travertines (70-160 ka) are found in Wadi Kurkur and include spring and lacustrine units exposed as 2 to 3 m high terraces. Travertines having an age of approximately 191-220 ka are exposed by differential erosion as linear mounds produced by spring systems over fracture zones in ancient wadis. The oldest travertines, having ages >260 ka, are extensive, cap limestone units above the oasis, and were deposited in paludal and lacustrine environments. Oxygen isotope ratios were measured for the wadi travertines ({delta}{sup 18}O values ranging from 16.7 to 19.1{per_thousand} SMOW) and for spring mound travertines (18.5-20.5{per_thousand}). Equilibrium oxygen isotope fractionation calculations indicate that the Kurkur travertines were deposited from waters having {delta}{sup 18}O values similar to ancient Western Desert groundwaters ({approx} -11{per_thousand}). The ages of the travertines correspond to times of monsoonal maxima, eustatic sea level high stands and interglacial maxima. Rainfall producing these groundwaters (and travertines) was significantly fractionated during atmospheric transport, in contrast to modern meteoric waters (-2.09{per_thousand}), implying a distant source for the pluvial waters. Increased precipitation, recharge of Western Desert groundwaters, and resultant travertine deposition are interpreted to be consequences of Milankovitch insolation cycle forcing, through enhanced Atlantic and Indian Ocean monsoons during interglacial time periods.

  14. Structural evolution of the Abu Gharadig field area, Northern Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    El Gazzar, A. M.; Moustafa, A. R.; Bentham, P.

    2016-12-01

    Discovered in 1969, the Abu Gharadig (AG) Field was the first large hydrocarbon discovery in the Abu Gharadig Basin of the Western Desert of Egypt. Oil production began in 1973, with gas brought into production in 1975. The field produces mainly from upper Cretaceous clastic reservoirs. The AG Basin is an E-W trending intracratonic rift basin, about 330 km long and 50-75 km wide. It was initially formed as a large half graben basin during the Jurassic time in response to Tethyan rifting and continued to subside throughout the Cretaceous time. The half graben was subsequently inverted during the Late Cretaceous as part of the Syrian Arc deformation which affected northern Egypt. The Mid-Basin Arch, the AG Anticline, and the Mubarak High are three NE-SW oriented main inversion anticlines located within the AG Basin and are controlled by inversion of pre-existing Jurassic rift faults. The AG Anticline has an overall NE-SW orientation with a gentle plunge towards the NE and SW. It is locally bounded by two NE-SW-trending inverted faults on the southwest and northeast, accounting for the asymmetry of the anticline. Reverse offset of Cretaceous horizons is obvious at these inverted faults. Fault propagation folding is developed above the tips of the inverted faults at the Late Cretaceous Abu Roash and Khoman Formations. Based on thickness changes and stratigraphic relationships, inversion started during the Santonian time and continued into the Campanian-Maastrichtian. Inversion continued during deposition of the Paleocene-Middle Eocene Apollonia Formation and the Late Eocene-Oligocene Dabaa Formation.

  15. The economic potential of El-Gedida glauconite deposits, El-Bahariya Oasis, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    El-Habaak, Galal; Askalany, Mohamed; Faraghaly, Mohamed; Abdel-Hakeem, Mahmoud

    2016-08-01

    The mining work at El-Gedida iron mine, El-Bahariya Oasis, in the Western Desert of Egypt extracts commercial iron ore deposits without attention paid to the large glauconite deposits overlying these iron ore deposits. For this reason, the present paper aims at evaluating and attracting the attention to these glauconite deposits as alternative potassium fertilizers. The study was achieved by investigating mineralogical, physical and chemical properties of the green deposits. Mineralogical and physical properties involved the determination of glauconite pellets content in different grain size fractions relative to impurities and the analysis of the percentage of clay matrix and grain size distribution. Different pre-treatment strategies and methods including comminution, sieving, magnetic separation, and X-ray diffraction were used for investigating those mineralogical and physical properties. On the other hand, chemical analyses included potassium content, heavy metal concentrations, and pH and salinity measurements. The major elements and trace elements were measured using ICP-OES and the pH was measured using a pH conductometer. Moreover, this study investigated the nature of grain boundaries and the effect of sieving on glauconite beneficiation. Results of this study suggest that El-Gedida glauconite deposits are mineralogically, physically and chemically suitable for exploitation and can be beneficiated for use as an alternative potassium fertilizer.

  16. 1st paleomagnetic investigation of Nubia Sandstone at Kalabsha, south Western Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Mostafa, R.; Khashaba, A.; El-Hemaly, I. A.; Takla, E. M.; Abdel Aal, E.; Odah, H.

    2016-06-01

    Two profiles have been sampled from the Nubia Sandstone at Aswan, south Western Desert: the 1st profile has been taken from Abu Aggag Formation and the 2nd one was from Sabaya Formation (23.25 °N, 32.75 °E). 136 oriented cores (from 9 sites) have been sampled. Abu Aggag Formation is of Late Cretaceous (Turonian) and Sabaya Formation is of early Cretaceous (Albian-Cenomanian). The studied rocks are subjected to rock magnetic measurements as well as demagnetization treatment. It has been found that hematite is the main magnetic mineral in both formations. Four profile sections from Abu Aggag Formation, yielded a magnetic component with D = 352.7°, I = 36.6° with α95 = 5.2° and the corresponding pole lies at Lat. = 82.8 °N and Long. = 283.1 °E. Five profile sections from Sabaya Formation, yielded a magnetic component with D = 348.6°, I = 33.3° with α95 = 5.8° and the corresponding pole lies at Lat. = 78.3 °N and Long. = 280.4 °E. The obtained paleopole for the two formations lies at Lat. = 80.5 °N and Long. = 281.7 °E. The obtaind magnetic components are considered primary and the corresponding paleopole reflects the age of Nubia Sandstone when compared with the previously obtained Cretaceous poles for Egypt.

  17. Remote Sensing and Shallow Geophysical Investigations on Moghra Lake in Northeastern Qattarra Depression, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Khan, S. D.; Fathy, M. S.; Azeem, M. A.

    2012-12-01

    The Western Desert of Egypt encompasses two thirds of the land area of Egypt and constitutes one of the driest regions of the Sahara. This desert has seven depressions; Siwa, Qattara, Fayium, Bahariya, Farafra, Dakhla and Kharga. These depressions may be the manifestation of old drainage basins with extensive erosion and possibly some tectonic activity. Several oases with freshwater can be found in these depressions. Geological and geophysical investigations in Qattara Depression indicate several buried fluvial channels with flow direction from highlands in southeast to northwest. Moghra Lake at the northeastern tip of Qatarra basin may be a small remnant of a larger paleo-lake including the mouth of a paleo-river. This study probed this area for presence of buried channels that may have fed the larger Moghra paleo-lake. We have used ALOS - PALSAR radar remote sensing data to identify the surface features in this region, such as channels, channel fills, and fractures. In addition, dual polarization PALSAR data (HV, HH) allowed analysis of the near surface geology and assisted in delineating areas of interest for GPR surveys. GPR data along 2D profiles were acquired using the GSSI SIR-3000 system with a 400 MHz antenna that provided images to approximately three meters in depth. All the GPS data were processed using RADAN 6.6 software. A conventional processing flow was used for data processing: The positional correction tool removed the air wave. A range-gain balanced the amplitudes and a final band-pass (50 kHz to 500 kHz) filter was applied to the data. Deconvolution was also applied for highlighting the finer details. In addition, spatial filters were used to attenuate continuous vertical noise. The migrated sections of GPR identified a major paleochannel distributary with two minor channels at the margins. The bedrock of the studied area consists of the Lower Miocene Moghra Formation (sandstone and shale intercalations). The area around the present lake is

  18. The geochemistry of uranium and thorium isotopes in the Western Desert of Egypt

    SciTech Connect

    Dabous, A.A.

    1994-11-01

    The concentrations of {sup 238}U, {sup 234}U, {sup 232}Th, and {sup 228}Th have been measured in the groundwaters of the Bahariya and Farafra oases of the Western Desert of Egypt. These waters are characterized by normal amounts of U, but unusually high concentrations of Th. The pattern of variation of the parent isotopes, {sup 238}U and {sup 232}Th, as well as the daughter isotopes, {sup 234}U, {sup 230}Th, and {sup 228}Th, is systematic within and between the two oases. From the unusually consistent distribution of the {sup 234}U/{sup 238}U activity ratios one can conclude that the samples from both oases are representative of a two-component mixing system. One component, characterized by low U content and a high {sup 234}U/{sup 238}U activity ratio, is typical of deep artesian systems and probably represents flowthrough water derived from the Nubian highlands to the south. The second component is characterized by a greater U concentration and a low activity ratio. This signature is hypothesized as being derived by leaching of downward infiltrating water during pluvial times. The source of the U may be the uraniferous phosphate strata that overly the sandstone aquifer in both oasis areas. Higher Th values are associated with the artesian flow component of the mixing system and suggests that Th-bearing minerals may be abundant in the Nubian sandstone aquifer. The distribution of {sup 230}Th and {sup 228}Th in the water samples supports this interpretation.

  19. Paleocene-Eocene transition at Naqb Assiut, Kharga Oasis, Western Desert, Egypt: Stratigraphical and paleoenvironmental inferences

    NASA Astrophysics Data System (ADS)

    El-Dawy, Moustafa, Hassan; Obaidalla, Nageh Abdelrahman; Mahfouz, Kamel Hussien; Abdel Wahed, Samar Adel

    2016-05-01

    This work depends on the study of the lower part of the Esna Formation which encompasses the Paleocene-Eocene (P-E) transition in Egypt as well as at Naqb Assiut section, Kharga Oasis, Western Desert. The Paleocene/Eocene (P/E) boundary is represented by El Dababiya Quarry Member which consists of five distinctive beds (nos. 1-5) at the GSSP. On the other hand, at Naqb Assiut section this boundary is only represented by the upper two beds (nos. 4&5), whereas, the lower three beds (nos. 1-3) are missing due to a hiatus. This hiatus is marked by the occurrence of an irregular surface contains pebbles and phosphatic materials. This hiatus may be related to the echo of Sryian Arc Orogeny at the P/E time. Biostratigraphically; four planktonic foraminiferal zones are defined from base to top as: Acarinina soldadoensis/Globanomalina pseudomenardii and Morozovella velascoensis (late Paleocene), Acarinina sibaiyaensis and Pseudohastigerina wilcoxensis/Morozovella velascoensis (early Eocene). The Acarinina sibaiyaensis Zone which represents the P//E/boundary is characterized by the occurrence of intrazonal hiatus at it's lower part. The benthonic foraminiferal taxa contain abundant representatives of Midway-type fauna (∼91% of the whole assemblages), beside few Velasco-type faunal ones (∼9%), indicating an outer neritic (150-200 m) water depth of deposition during the P-E transition. Quantitative analysis and composition of benthonic foraminiferal assemblages are indicative for various environmental changes around the P/E boundary. They reflected a high diversity, increase of epifaunal taxa, and low-intermediate productivity conditions, which indicates a well-ventilated bottom water and oligo - to mesotrophic conditions during the late Paleocene age. Rapid extinction of about 18% of the entire benthonic foraminiferal species started at the P/E boundary, where the last occurrence of Angulogavelinella avnimelechi is pronounced at the base of this boundary. There is a

  20. Upper Paleocene-Lower Eocene biostratigraphy of Darb Gaga, Southeastern Kharga Oasis Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Ouda, Khaled; Berggren, William A.; Abdel Sabour, Ayman

    2016-06-01

    Paleontological studies on the Upper Paleocene-Lower Eocene succession at Darb Gaga, southeastern Kharga Oasis, Western Desert, Egypt document the changes associated with the Paleocene-Eocene Thermal Maximum (PETM), such as 1) a radical alteration of the relative and absolute abundance of planktonic foraminifera; 2) a massive occurrence of the excursion planktonic foraminiferal taxa; 3) a widespread deposition of calcarenite yielding atypical (extremely high) faunal abundance associated with the younger phase of warming; and 4) a concentration of coprolites associated with the middle phase of warming. We also document the Lowest Occurrence (LO) of dimorphic larger benthic and excursion foraminifera during the earlier phase of warming at Darb Gaga, as recorded in Bed 1 of the Dababiya Quarry Member. The absence of these faunas in Bed 1 at Dababiya (the GSSP for the P/E Boundary) is likely to be due to both intense deficiency in dissolved oxygen and massive carbonate dissolution. Only remains (fish remains) of faunas that can tolerate the toxicity produced by low oxygen conditions are found in the stratigraphic record of this (oldest) phase at Dababiya. The Dababiya Quarry Member (DQM) at Darb Gaga reflects the unfolding of the sedimentary and biotic changes associated with the PETM global warming at, and following, the Paleocene/Eocene boundary on the southern Tethys platform. The changes began with a rapid increase in bottom and "intermediate" water temperature. The temperature increase was accompanied by removal of oxygen during the early and middle stages of warming. This led to the absence of both subbotinids and calcareous benthic foraminifera in the early and second coprolite-bearing phases (Beds 2 and 3 of the DQM). Dissolution seems to have no role during these stages as shown by the unusual abundance and good preservation of the warm-tolerant Ac. sibaiyaensis. This species reaches its maximum abundance in Bed 2 where it exhibits a broad range of size (63

  1. Environmental impact and natural hazards on Kharga Oasis monumental sites, Western Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Salman, A. B.; Howari, F. M.; El-Sankary, M. M.; Wali, A. M.; Saleh, M. M.

    2010-09-01

    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 m

  2. Eolian features in the Western Desert of Egypt and some applications to Mars.

    USGS Publications Warehouse

    El-Baz, F.; Breed, C.S.; Grolier, M.J.; McCauley, J.F.

    1979-01-01

    Relations of landform types to wind regimes, bedrock composition, sediment supply, and topography are shown by field studies and satellite photographs of the Western Desert. This desert provides analogs of Martian wind-formed features and sand dunes, alternating light and dark streaks, knob 'shadows' and yardangs. Surface particles have been segregated by wind into dunes, sand sheets, and light streaks, that can be differentiated by their grain size distributions, surface shapes, and colors. Throughgoing sand of mostly fine to medium grain size is migrating S in longitudinal dune belts and barchan chains whose long axes lie parallel to the prevailing W winds, but topographic variations such as scarps and depressions strongly influence the zones of deposition and dune morphology. -from Authors

  3. The history and fate of the Nubian Sandstone Aquifer springs in the oasis depressions of the Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Powell, Owen; Fensham, Rod

    2016-03-01

    Extraction of groundwater for agriculture has resulted in the loss of springs across arid regions of the globe. The history and fate are recorded of the artesian springs of Egypt's Western Desert, from ancient times to the present, spanning the rise and fall of the great civilisations from the Pharoanic dynasties to Persian, Greek and Roman conquests. The study area includes oases Kharga, Dakhla, Bahriya, Farafra and Siwa, and several outer and small oases around Siwa and the edge of the Qattara Depression. The region is hyper-arid, receiving 10 mm or less average annual precipitation and evaporation rates are in the vicinity of 3,000 mm/a. Groundwater in the oases is largely derived from bores discharging from the Nubian Sandstone Aquifer. Based on an extensive survey, conducted for the first time, attention is drawn to the rapid demise of springs as a result of modern irrigation schemes which continue to deplete groundwater supplies.

  4. Geoenvironmental assessment of the SIWIA area Oasis, Western Desert, Egypt, using geographical and hydrological information systems

    NASA Astrophysics Data System (ADS)

    Faid, A.; Ismail, E.; Birk, S.

    2012-04-01

    Overpopulation of Egypt has put pressure on the government for horizontal expansion for food security. Therefore, horizontal expansion in the desert for agricultural purposes is one of the solutions. Groundwater represents the main source of water supply in Siwa Oasis. The sedimentary succession comprises different water bearing formations. These aquifers bear groundwater ranging in its salinity from fresh water to brine one. These aquifers are the Quaternary deposits, the Miocene carbonate, the Eocene carbonate, the Upper Cretaceous, the Cretaceous Nubian sandstone beside Carboniferous, Devonian, Silurian and Cambrian-Ordovicean sandstone aquifers. The Paleozoic sandstone has brine water but the Mesozoic one (Cretaceous Nubian sandstone) has fresh one. The Cretaceous Nubian sandstone represents the source of exploited water in the area, where it recharges the overlying carbonate aquifers. Fifty seven wells are included in the present study to reveal the hydrogeologic conditions of the oasis. The fractured carbonate aquifers represent the main exploitable aquifers due to their availability for the farmers in spite the low water quality. The water of this aquifer has a wide range of salinity ranging from 2377 ppm to > 17000 ppm depending on the depth of aquifer and the nature of facies and fracturing of the rock. The Nubian sandstone aquifers represent the main source of water in the area where it bears fresh water (< 1000 ppm). The flow within the Nubian sandstone is directed to the area of high discharge, i.e. to the west. The groundwater of the Quaternary and the fractured carbonates reflects leaching processes (secondary salinity) and that of the Nubian sandstone reflects meteoric origin and recharge during the pluvial period. The groundwater resources are evaluated with respect to their suitability for different purposes. Depending on the present geomorphological and hydrogeological studies and the previous pedological studies a landuse map was constructed.

  5. Subsurface geology of Tertiary rocks of northeastern district of Western Desert, Egypt

    SciTech Connect

    Elzarka, M.H.; Radwan, I.A.

    1983-03-01

    The lithofacies analysis of the Tertiary rocks reveals two ancient subbasins at the north and southeast of the northeastern district, Western Desert. The lithofacies of the Paleocene and early and middle Eocene sections are mainly calcareous. Shale predominates in the late Eocene rocks. The Paleocene rocks seem to have accumulated in a lagoonal environment of epineritic depths. The Paleocene rocks of the northern subbasin indicate accumulation on an unstable shelf. The Paleocene environmental conditions seem to have prevailed during the early and middle Eocene. During the late Eocene, rocks of shallow-water and current-agitated environments accumulated. The lower clastic layers of the Oligocene, having a sand/shale ratio less than one, indicate a clastic shoreline environment-lagoonal subenvironment. The Oligocene clastics are overlain by a basaltic sheet at the eastern part of the district. The middle Miocene lithofacies indicate rock accumulation in a contemporaneously subsiding basin under lagoonal or delta-front conditions at the southern part of the district. Marine stagnant-bottom-water conditions prevailed during the accumulation of the middle Miocene rocks at the norther parts. The Pliocene rocks seem to have accumulated in lagoons, where the inflow exceeded evaporation and alternating periods of exposure and flooding by either fresh or saline water of poor circulation prevailed. The tectonic instability of the district was initiated by volcancity during the late Oligocene.

  6. Vertebrate paleontological exploration of the Upper Cretaceous succession in the Dakhla and Kharga Oases, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Sallam, Hesham M.; O'Connor, Patrick M.; Kora, Mahmoud; Sertich, Joseph J. W.; Seiffert, Erik R.; Faris, Mahmoud; Ouda, Khaled; El-Dawoudi, Iman; Saber, Sara; El-Sayed, Sanaa

    2016-05-01

    The Campanian and Maastrichtian stages are very poorly documented time intervals in Africa's record of terrestrial vertebrate evolution. Upper Cretaceous deposits exposed in southern Egypt, near the Dakhla and Kharga Oases in the Western Desert, preserve abundant vertebrate fossils in nearshore marine environments, but have not yet been the focus of intensive collection and description. Our recent paleontological work in these areas has resulted in the discovery of numerous new vertebrate fossil-bearing localities within the middle Campanian Qusier Formation and the upper Campanian-lower Maastrichtian Duwi Formation. Fossil remains recovered from the Campanian-aged Quseir Formation include sharks, rays, actinopterygian and sarcopterygian fishes, turtles, and rare terrestrial archosaurians, including some of the only dinosaurs known from this interval on continental Africa. The upper Campanian/lower Maastrichtian Duwi Formation preserves sharks, sawfish, actinopterygians, and marine reptiles (mosasaurs and plesiosaurs). Notably absent from these collections are representatives of Mammalia and Avialae, both of which remain effectively undocumented in the Upper Cretaceous rocks of Africa and Arabia. New age constraints on the examined rock units is provided by 23 nannofossil taxa, some of which are reported from the Duwi Formation for the first time. Fossil discoveries from rock units of this age are essential for characterizing the degree of endemism that may have developed as the continent became increasingly tectonically isolated from the rest of Gondwana, not to mention for fully evaluating origin and diversification hypotheses of major modern groups of vertebrates (e.g., crown birds, placental mammals).

  7. Electrical and geochemical properties of tufa deposits as related to mineral composition in the South Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Gomaa, Mohamed M.; Abou El-Anwar, Esmat A.

    2015-06-01

    The geochemical, petrographical, and electrical properties of rocks are essential to the investigation of the properties of minerals. In this paper we will try to present a study of the A. C. electrical properties of carbonate rock samples and their relation to petrographical and geochemical properties. Samples were collected from four formations from the Bir Dungul area, in the South Western Desert, Egypt. The electrical properties of the samples were measured using a non-polarizing electrode, at room temperature (~28 °C), and at a relative atmospheric humidity of (~45%), in the frequency range from 42 Hz to 5 MHz. The changes in the electrical properties were argued to the change in mineral composition. Generally, the electrical properties of rocks are changed due to many factors e.g., grain size, mineral composition, grain shape and inter-granular relations between grains. The dielectric constant of samples decreases with frequency, and increases with conductor concentration. Also, the conductivity increases with an increase of continuous conductor paths between electrodes. The petrographical and geochemical studies reveal that the deposition of the tufa deposits occurred in shallow lakes accompanied by a high water table, an alkaline spring recharge and significant vegetation cover. Diagenetically, tufa deposits were subjected to early and late diagenesis. Petrography and geochemistry studies indicated that the area of tufa deposits was deposited under the control of bacterial activity. Geochemically, the Sr content indicates that the tufa deposits formed from dissolved bicarbonate under the control of microbes and bacterial activity.

  8. Precipitation source inferred from stable isotopic composition of Pleistocene groundwater and carbonate deposits in the western desert of Egypt.

    SciTech Connect

    Sultan, M.; Sturchio, N.; Hassan, F. A.; Abdel, M.; Hamdan, R.; Mahmood, A. M.; Alfy, Z. E.; Stein, T.; Environmental Research; Univ. Coll. London; Cairo Univ.; Ain Shams Univ.; Egyptian Geological survey and Mining Authority; Washington Univ.

    1997-01-01

    An Atlantic source of precipitation can be inferred from stable isotopic data (H and O) for fossil groundwaters and uranium-series-dated carbonate spring deposits from oases in the Western Desert of Egypt. In the context of available stable isotopic data for fossil groundwaters throughout North Africa, the observed isotopic depletions ({delta}D -72 to -81{per_thousand}; {delta}{sup 18}O -10.6 to -11.5{per_thousand}) of fossil ({ge}32,000 yr B.P.) groundwaters from the Nubian aquifer are best explained by progressive condensation of water vapor from paleowesterly wet oceanic air masses that traveled across North Africa and operated at least as far back as 450,000 yr before the present. The values of {delta}{sup 18}O (17.1 to 25.9{per_thousand}) for 45,000- to >450,000-yr-old tufas and vein-filling calcite deposits from the Kharga and Farafra Oases are consistent with deposition from groundwaters having oxygen isotopic compositions similar to those of fossil groundwaters sampled recently at these locations.

  9. Origin of ferricretes in fluvial-marine deposits of the Lower Cenomanian Bahariya Formation, Bahariya Oasis, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Tanner, Lawrence H.; Khalifa, Mohamed A.

    2010-03-01

    The type section of the Lower Cenomanian Bahariya Formation at Gebel El-Dist (Bahariya Oasis, Western Desert), Egypt, comprises claystones, mudstones, siltstones and sandstones deposited in fluvial-deltaic coastal plain, lagoonal, estuarine and shallow marine environments. The formation is characterized by an abundance of ferruginous sandstones that locally weather to form prominent iron crusts. These centimeter to decimeter-scale ferruginous horizons display a continuum of features ranging from unaltered sandstone with a pervasive ferruginous matrix to distinct ironstone beds with massive, nodular, vesicular and pisolitic textures. Ferruginous sandstone typically occurs at the tops of sandstone beds, or bracketing the base and top of beds, in the fining-upward cycles of deltaic plain deposits in the lower part of the formation and on a low-energy fluvial floodplain in the middle of the formation. Indurated ironstone beds occur mainly as the caps of coarsening-upward cycles of prograding shoreface sediments through much of the formation. We interpret the ironstone crusts as ferricretes, formed by iron accumulation that resulted from the oxidation and precipitation of soluble iron or colloids transported in the sediment load or by groundwater. This accumulation possibly took place at the water table or possibly below the water table at the fresh water/saline water interface. However, base-level fall and subsequent subaerial exposure of the sediments resulted in reworking and pedogenic modification of some of the iron-impregnated horizons.

  10. Petrophysical evaluation of the hydrocarbon potential of the Lower Cretaceous Kharita clastics, North Qarun oil field, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Teama, Mostafa A.; Nabawy, Bassem S.

    2016-09-01

    Based on the available well log data of six wells chosen in the North Qarun oil field in the Western Desert of Egypt, the petrophysical evaluation for the Lower Cretaceous Kharita Formation was accomplished. The lithology of Kharita Formation was analyzed using the neutron porosity-density and the neutron porosity-gamma ray crossplots as well as the litho-saturation plot. The petrophysical parameters, include shale volume, effective porosity, water saturation and hydrocarbon pore volume, were determined and traced laterally in the studied field through the iso-parametric maps. The lithology crossplots of the studied wells show that the sandstone is the main lithology of the Kharita Formation intercalated with some calcareous shale. The cutoff values of shale volume, porosity and water saturation for the productive hydrocarbon pay zones are defined to be 40%, 10% and 50%, respectively, which were determined, based on the applied crossplots approach and their limits. The iso-parametric contour maps for the average reservoir parameters; such as net-pay thickness, average porosity, shale volume, water saturation and the hydrocarbon pore volume were illustrated. From the present study, it is found that the Kharita Formation in the North Qarun oil field has promising reservoir characteristics, particularly in the northwestern part of the study area, which is considered as a prospective area for oil accumulation.

  11. Palynostratigraphy and paleoenvironmental significance of the Cretaceous succession in the Gebel Rissu-1 well, north Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    El Beialy, Salah; El-Soughier, Maher; Mohsen, Sayed Abdel; El Atfy, Haytham

    2011-02-01

    Palynological investigation of the Cretaceous Abu Roash, Bahariya, Kharita, Alamein, Alam El Bueib and Betty formations, encountered in the Gebel Rissu-1 well, north Western Desert, Egypt yielded 27 species of pteridophytic spores, 24 of gymnosperm pollen, 25 of angiosperm pollen and 11 of dinoflagellate cysts in addition to some acritarchs, foraminiferal test linings and freshwater algae. This enabled us to recognize five miospore biozones arranged from youngest to oldest as: Classopollis brasiliensis- Afropollis cf. kahramanensis- Dichastopollenites ghazalataensis Assemblage Zone (Late Cenomanian); Elaterosporites klaszii- Sofrepites legouxae- Afropollis jardinus Assemblage Zone (Middle/Late Albian-Early Cenomanian); Pennipollis peroreticulatus- Duplexisporites generalis-Tricolpates Assemblage Zone (Early Aptian-Early Albian); Tucanopollis crisopolensis- Afropollis sp. Assemblage Zone (Barremian) and Appendicisporites cf. tricornitatus- Ephedripites spp. Assemblage Zone (Late Neocomian). The Early Cretaceous Kharita, Alam El Bueib and the Betty formations encountered in the Gebel Rissu-1 well are interpreted to indicate oxic proximal and distal shelf deposits, characterized by type III/IV, V kerogen, which is gas prone but having little potential to produce hydrocarbons. The Upper Cretaceous Abu Roash and Bahariya formations are characterized by a distal suboxic-anoxic and marginal dysoxic-anoxic environment, and their kerogen type III/II indicates gas/oil prone nature. The Bahariya and Kharita Albian-Cenomanian sediments in the present study witnessed the onset of a semi-arid to arid climate, with local or seasonal humid conditions, based on the continuous high abundance of the elaterates pollen and Afropollis-producing plants that inhabited the paleotropical humid coastal plains.

  12. Sedimentology of the fluvial and fluvio-marine facies of the Bahariya Formation (Early Cenomanian), Bahariya Oasis, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Khalifa, M. A.; Catuneanu, O.

    2008-05-01

    The Lower Cenomanian Bahariya Formation in the Bahariya Oasis, Western Desert, Egypt, was deposited under two coeval environmental conditions. A fully fluvial system occurs in the southern portion of the Bahariya Oasis, including depositional products of meandering and braided streams, and a coeval fluvio-marine setting is dominant to the north. These deposits are organized into four unconformity-bounded depositional sequences, whose architecture is shaped by a complex system of incised valleys. The fluvial portion of the lower two depositional sequences is dominated by low-energy, meandering systems with a tabular geometry, dominated by overbank facies. The fluvial deposits of the upper two sequences represent the product of sedimentation within braided streams, and consist mainly of amalgamated channel-fills. The braided fluvial systems form the fill of incised valleys whose orientation follows a southeast-northwest trending direction, and which truncate the underlying sequences. Four sedimentary facies have been identified within the braided-channel systems, namely thin-laminated sandstones (Sh), cross-bedded sandstones (Sp, St), massive ferruginous sandstones (Sm) and variegated mudstones (Fm). The exposed off-channel overbank facies of the meandering systems include floodplain (Fm) and crevasse splay (Sl) facies. The fluvio-marine depositional systems consist of interbedded floodplain, coastal and shallow-marine deposits. The floodplain facies include fine-grained sandstones (Sf), laminated siltstones (Stf) and mudstones (Mf) that show fining-upward cycles. The coastal to shallow-marine facies consist primarily of mudstones (Mc) and glauconitic sandstones (Gc) organized vertically in coarsening-upward prograding cyclothems topped by thin crusts of ferricrete (Fc). The four depositional sequences are present across the Bahariya Oasis, albeit with varying degrees of preservation related to post-depositional erosion associated with the formation of sequence

  13. Sedimentology, sequential analysis and clay mineralogy of the lower Eocene sequence at Farafra Oasis area, Western Desert of Egypt

    NASA Astrophysics Data System (ADS)

    El Ayyat, Abdalla M.

    2013-02-01

    Integrated sedimentological studies, sequential analysis and clay mineralogy on the lower Eocene rocks in the Western Desert provided important information on the reconstruction of the depositional basin, cyclicity, and paleoclimatic conditions. Two formations are recognized; the Esna and Farafra formations, with a gradational contact in-between. The studied sequence exhibits lateral facies changes as revealed from field and microfacies investigations. Eight facies were recognized and summarized in a carbonate ramp model. It represents also a general regressive trend, which records a transition from an outer ramp into a peritidal zone. The facies stacking patterns constitute several kinds of meter-scale, shallowing-upward cycles. Two different types of depositional cycles are here defined. The stratigraphic sections show a hierarchical organization of many cycles defined by five depositional sequences. It is suggested that composite eustatic sea level oscillations caused by cyclic perturbations of the Earth's orbit played a fundamental role in determining the formation of the observed hierarchical cyclic organization. Summing up, it is believed that the paleotopography had resulted from the impact of the Syrian Arc Folding System. A confusing additional complication is introduced by syndepositional sedimentary structures, especially during the late Cretaceous/Eocene times, coupled by several tensional forces. Clay mineralogy has revealed the presence of smectite, kaolinite and illite. Their origin may be attributed to the gradual increase in the amount of erosion of the newly elevated crystalline source rocks to the south of Egypt, in areas of moderate rainfall and rapid weathering and/or to reworking processes of soils which presumably developed on basement rocks. Changes in source rocks or climatic influence during the early Eocene may account for the observed differences in clay mineral abundances.

  14. Assessment of waterlogging in agricultural megaprojects in the closed drainage basins of the Western Desert of Egypt

    NASA Astrophysics Data System (ADS)

    El Bastawesy, M.; Ramadan Ali, R.; Faid, A.; El Osta, M.

    2013-04-01

    This paper investigates the development of waterlogging in the cultivated and arable areas within typical dryland closed drainage basins (e.g. the Farafra and Baharia Oases), which are located in the Western Desert of Egypt. Multi-temporal remote sensing data of the Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM+) were collected and processed to detect the land cover changes; cultivations, and the extent of water ponds and seepage channels. The Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) has been processed to delineate the catchment morphometrical parameters (i.e. drainage networks, catchment divides and surface areas of different basins) and to examine the spatial distribution of cultivated fields and their relation to the extracted drainage networks. The soil of these closed drainage basins is mainly shallow and lithic with high calcium carbonate content; therefore, the downward percolation of excess irrigation water is limited by the development of subsurface hardpan, which also saturates the upper layer of soil with water. The subsurface seepage from the newly cultivated areas in the Farafra Oasis has revealed the pattern of buried alluvial channels, which are waterlogged and outlined by the growth of diagnostic saline shrubs. Furthermore, the courses of these waterlogged channels are coinciding with their counterparts of the SRTM DEM, and the recent satellite images show that the surface playas in the downstream of these channels are partially occupied by water ponds. On the other hand, a large water pond has occupied the main playa and submerged the surrounding fields, as a large area has been cultivated within a relatively small closed drainage basin in the Baharia Oasis. The geomorphology of closed drainage basins has to be considered when planning for a new cultivation in dryland catchments to better control waterlogging hazards. The "dry-drainage" concept can be implemented as the drainage and seepage water can be

  15. Correlation of Aerogravity and BHT Data to Develop a Geothermal Gradient Map of the Northern Western Desert of Egypt using an Artificial Neural Network

    NASA Astrophysics Data System (ADS)

    Mohamed, Haby S.; Abdel Zaher, Mohamed; Senosy, Mahmoud M.; Saibi, Hakim; El Nouby, Mohamed; Fairhead, J. Derek

    2015-06-01

    The northern part of the Western Desert of Egypt represents the second most promising area of hydrocarbon potential after the Gulf of Suez province. An artificial neural network (ANN) approach was used to develop a new predictive model for calculation of the geothermal gradients in this region based on gravity and corrected bottom-hole temperature (BHT) data. The best training data set was obtained with an ANN architecture composed of seven neurons in the hidden layer, which made it possible to predict the geothermal gradient with satisfactory efficiency. The BHT records of 116 deep oil wells (2,000-4,500 m) were used to evaluate the geothermal resources in the northern Western Desert. Corrections were applied to the BHT data to obtain the true formation equilibrium temperatures, which can provide useful constraints on the subsurface thermal regime. On the basis of these corrected data, the thermal gradient was computed for the linear sections of the temperature-versus-depth data at each well. The calculated geothermal gradient using temperature log data was generally 30 °C/km, with a few local high geothermal gradients in the northwestern parts of the study area explained by potential local geothermal fields. The Bouguer gravity values from the study area ranged from -60 mGal in the southern parts to 120 mGal in the northern areas, and exhibited NE-SW and E-W trends associated with geological structures. Although the northern Western Desert of Egypt has low regional temperature gradients (30 °C/km), several potential local geothermal fields were found (>40 °C/km). The heat flow at each well was also computed by combining sets of temperature gradients and thermal conductivity data. Aerogravity data were used to delineate the subsurface structures and tectonic framework of the region. The result of this study is a new geothermal gradient map of the northern Western Desert developed from gravity and BHT log data.

  16. Larger benthic foraminiferal turnover across the Eocene-Oligocene transition at Siwa Oasis, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Orabi, H.; El Beshtawy, M.; Osman, R.; Gadallah, M.

    2015-05-01

    In the Eocene part of the Siwa Oasis, the larger foraminifera are represented by the genera Nummulites, Arxina, Operculina, Sphaerogypsina, Asterocyclina, Grzybowskia, Silvestriella, Gaziryina and Discocyclina in order of abundance. Operculina continues up to the early Oligocene as modern representatives in tropical regions, while the other genera became extinct. Nevertheless, the most common larger foraminiferal genus Lepidocyclina (Nephrolepidina) appears only in the lowermost Oligocene. In spite of the Eocene-Oligocene (E/O) transition is thought to have been attended by major continental cooling at northern middle and high latitudes, we discover that at the Siwa Oasis, there is a clear warming trend from the late Eocene (extinction level of Nummulites, Sphaerogypsina, Asterocyclina, Grzybowskia, Silvestriella and Discocyclina) to the early Oligocene is observed due to the high abundance of Operculina and occurrence of kaolinite and gypsiferous shale deposits in both Qatrani and El Qara formations (Oligocene) at this transition. The El Qara Formation is a new rock unit proposed herein for the Oligocene (Rupelian age) in the first time. Several episodes of volcanic activity occurred in Egypt during the Cenozoic. Mid Tertiary volcanicity was widespread and a number of successive volcanic pulses are starting in the late Eocene. The release of mantle CO2 from this very active volcanic episode may have in fact directly caused the warm Eocene-Oligocene greenhouse climate effect.

  17. Palaeoenvironment and Holocene land use of Djara, Western Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Kindermann, Karin; Bubenzer, Olaf; Nussbaum, Stefanie; Riemer, Heiko; Darius, Frank; Pöllath, Nadja; Smettan, Ursula

    2006-07-01

    The results of the interdisciplinary project ACACIA support the assumption of a more humid climate at Djara, on the Egyptian Limestone Plateau, which is a hyper-arid desert today, during the early and mid-Holocene. The ancient plant and animal inventories give new impetus for the suggestion of an interfingering of two climatic regimes, the winter rains from the north and west and the summer monsoonal rains from the south, on the latitude of Djara. A playa sediment sequence, the composition of plant and animal taxa as well as the reconstructed settlement patterns indicate a semi-arid climate with alternating more humid and drier conditions. The concentration of prehistoric sites in the Djara depression points to locally favourable conditions in contrast to the surrounding plateau surface. The widespread catchment and a distinct system of palaeochannels offered fresh water over a period of time due to the run-off from the plateau surface after rain events. Although the ecological conditions were better during the Holocene humid phase than they are today, a sedentary way of life was improbable. The hydrological constraints require altogether highly mobile subsistence strategies. Shells of the Nile bivalve Aspatharia sp. ( Spathopsis sp.) give evidence for contacts between Djara and the Nile Valley, which remains beside the Egyptian oases an important retreat area with perennially available water. The decrease of radiocarbon dates and related archaeological sites around 6300 BP (c. 5300 cal BC) indicate the depopulation of the Djara region as a consequence of the drying trend. While the drop off of the 14C-dates can also be observed in other desert research areas of the ACACIA-project, we date the end of the Holocene humid phase about 300 years earlier than previously suggested.

  18. Preservation of primary structures and organic matter in Pleistocene spring carbonates, Western Desert, Egypt: Relationship to macroscopic texture and age.

    NASA Astrophysics Data System (ADS)

    Pohlman, E.; Smith, J. R.

    2005-12-01

    Spring-deposited carbonates (tufas) along the flanks of the Libyan Escarpment in Dakhleh and Kharga Oasis record relatively humid conditions which prevailed in the Egyptian Sahara periodically throughout the Pleistocene. Previous work, particularly Nicoll et al.(1999), has suggested the Western Desert tufas, though certainly displaying evidence of secondary cementation by sparry calcite, aggrading neomorphism, etc. do in many instances preserve primary features, particularly organosedimentary lamination, and a clotted microbial texture. In order to facilitate field-based selection of suitable, unaltered samples for geochemical analysis, we undertook a petrographic examination of tufa samples in order to determine whether certain macroscopic features (e.g., color, porosity, presence of detrital iron oxides, preservation of visible plant casts) could be quantitatively correlated to the degree of diagenesis present in thin sections as indicated by percent calcite spar. We also determined total organic content through peroxide digestion, as younger samples (determined by U-series dating and by geomorphic context) qualitatively appeared to contain both more casts of botanical remains, and better defined microbial textures. Older and more altered tufas also generally had heavier (less organically-influenced) carbon isotopic signatures, further suggesting a relationship between diagenesis, organic content, and age. Petrographic analysis included descriptions of sample texture, spatial relationship of textural elements (e.g., pores, plant casts, detrital material), and frequency of biological inclusions or casts. Point counts were performed to estimate sample mineralogy and porosity. Tufas are predominantly micritic calcite, with little (generally <2%) sparry calcite. Porosity may be as great as 46%. Most samples examined displayed some evidence of primary (generally microbial) textures. The expected relationship between porosity and diagenetic alteration, however, was not

  19. A Study of Hydrogeological Conditions of the Nubian Sandstone Aguifer in the Area between Abu Simbel and Toschka, Western Desert, Egypt.

    NASA Astrophysics Data System (ADS)

    Dahab, K. A.; Ebraheem, A. M.; El Sayed, E. A.

    2001-05-01

    A Study of Hydrogeological Conditions of the Nubian Sandstone Aquifer in the Area between Abu Simbel and Toschka, Western Desert, Egypt. By K. A. Dahab*, A. M. Ebraheem**, and E. El Sayed*** *Geology Department, Faculty of Science, Menofia University, Shibin El Kom, Egypt. ** Geology Department, Faculty of Science, Assiut University, Assiut, Egypt. *** Geology Department, Faculty of Science, Minia University, Minia, Egypt. The Nubian Sandstone Aquifer in the area between Toschka and Abu Simbil is small portion of the very well known Nubian Sandstone Aquifer System in the Eastern Sahara, which covers the entire area of southwest Egypt, southeast Libya, northeast Chad, and northern Sudan. Toscha area is currently the site of intensive drilling and development for a huge land reclamation project. The drilling information was used to study the hydrogeological setting of the Nubian Sandstone aquifer in the area. The obtained results indicate that the lithological characteristics and tectonic setting is strongly affecting the groundwater flow pattern as well as the aquifer potentiality of the nubian sandstone aquifer in the area. The aquifer potentiality in this area is low if compared to that of east Oweinat or Dakhla areas. The aquifer is mainly composed of hard ferruginous sandstone with great shale and clay intercalation with a thickness ranging from 140 to 230 meters. Groundwater in this aquifer belongs to fresh to slightly brackish type (salinity is ranging from 240 to 1300 ppm). Ion dominance ordering reveals that sodium cation is mostly predominating over calcium and magnesium whereas chloride is predominant over sulfate and bicarbonate. The groundwater is related to meteoric origin. The high concentration of sodium, chloride, and sulfates reflect leaching and dissolution processes of gypsiferous shales and clay as well as long residence time of water.

  20. The Climate and its Impacts on deterioration and weathering rate of EI-Nadura Temple in El- Kharga Oasis, Western Desert of Egypt.

    NASA Astrophysics Data System (ADS)

    Ismael, Hossam

    2015-04-01

    Undoubtedly, El-Kharga Oasis monumental sites are considered an important part of our world's cultural heritage in the South Western Desert of Egypt. These sites are scattered on the floor of the oasis representing ancient civilizations. The Roman stone monuments in Kharga represent cultural heritage of an outstanding universal value. Such those monuments have suffered weathering deterioration. There are various elements which affect the weathering process of stone monuments: climate conditions, shapes of cultural heritages, exposed time periods, terrains, and vegetation around them, etc. Among these, climate conditions are the most significant factor affecting the deterioration of Archeological sites in Egypt. El- Kharga Oasis belongs administratively to the New Valley Governorate. It is located in the southern part of the western desert of Egypt, lies between latitudes 22°30'14" and 26°00'00" N, and between 30°27'00" and 30°47'00" E. The area of El Kharga Oasis covers about 7500 square kilometers. Pilot studies were carried out on the EI-Nadura Temple, composed of sandstones originating from the great sand sea. The major objective of this study is to monitor and measure the weathering features and the weathering rate affecting the building stones forming El-Nadora Roman building rocks in cubic cm. To achieve these aims, the present study used analysis of climatic data such as annual and seasonal solar radiation, Monthly average number of hours of sunshine, maximum and minimum air temperatures, wind speed, which have obtained from actual field measurements and data Meteorological Authority of El-Kharga station for the period 1977 to 2010 (33 years), and from the period 1941-2050 (110 years) as a long term of temperature data. Several samples were collected and examined by polarizing microscopy (PLM), X-ray diffraction analysis (XRD) and scanning electron microscopy equipped with an energy dispersive X-ray analysis system (SEM-EDX). The results were in

  1. Inferring the subsurface basement depth and the structural trends as deduced from aeromagnetic data at West Beni Suef area, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Khalil, Ahmed; Abdel Hafeez, Tharwat H.; Saleh, Hassan S.; Mohamed, Waheed H.

    2016-12-01

    The present work aimed to delineate the subsurface structures and to estimate the magnetic source depth at the selected area lying in West Beni Suef area, Western Desert, Egypt, following different geomagnetic techniques. The analysis of aeromagnetic data demonstrates five significant tectonic faults trending to NW-SE, ENE-WSW, NE-SW, E-W and NNW-SSE directions constructed using Euler deconvolution techniques. The execution of this study is initiated by transformation of the total intensity aeromagnetic data to the reduced to pole (RTP) magnetic intensity. This is followed by applying several transformation techniques and various filtering processes through qualitative and quantitative analyses on magnetic data. The reduced to the northern magnetic pole (RTP) data are separated spectrally into regional and residual magnetic components using the computed power spectrum of the magnetic data. The estimated mean depths of both regional and residual sources are found to be 5.27 km and 2.78 km respectively. Also, depth estimations have been conducted by application of the Euler deconvolution and 2-D modeling techniques. The results indicate that the eastern and northern parts of the study area discriminate deeper basement relief and the depth of basement surface reaches to 5095 m. While the southern and western parts of the study area discriminate shallower basement relief and the depth of basement surface reaches to 227 m. This study has given a clear picture of the geologic structures beneath the study area.

  2. Interactive interpretation of airborne gravity, magnetic, and drill-hole data within the crustal framework of the northern Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Mohamed, Haby S.; Senosy, Mahmoud. M.; Abdel Zaher, Mohamed

    2016-11-01

    The northern part of Western Desert represents the second most important oil-producing and gas provinces in Egypt. The aim of the present study is to highlight the subsurface structures, tectonic framework, and variation of the crust and upper mantle of the northern Western Desert. Geophysical data in the form of airborne gravity and magnetic maps as well as drill-hole data were used to achieve the objectives of the study. 2D interactive sequential modeling of aerogravity and aeromagnetic data was done along some selected profiles with constraints of the existing deep drill-holes at the study area. From these models, three maps for the depths to Precambrian basement, Conrad, and Moho surfaces were constructed. The results of this study indicate that the depth to the basement surface (thickness of the sedimentary section) ranges between 900 m at the southern parts and more than 5500 m at the northern parts. Meanwhile, the depth of Conrad discontinuity which reflect thickness of the upper crust; varies approximately between 10,000 m at the central and northern parts and 17,000 m at the southern parts of the area. While the Moho depth which represents the crustal thickness ranges from 27,000 m at the northern parts to 39,000 m southward. Integrating the results shows that the main compressive stress which influenced the studied area is in N55°W direction that supposed to cause primary shear in N25°W and N85°W directions with right and left lateral movements, respectively.

  3. Curie point depth and heat flow from spectral analysis of aeromagnetic data over the northern part of Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Saada, Saada Ahmed

    2016-11-01

    The present work aims to estimate the Curie point depth and the surface heat flow for the northern part of the Western Desert using aeromagnetic data. Applying spectral analysis to aeromagnetic anomalies has provided equitable promising geological results, useful for further geothermal or petroleum exploration. The total intensity aeromagnetic map was first reduced to the north magnetic pole to correct the shape and position of different magnetic anomalies over their causative bodies. Secondly, the short wavelengths were removed to enhance the deeper long wavelengths related to the deep sources. Spectral analysis indicates that the area is underlined by an average Curie point depth of about 27 km. This implies an average thermal heat flow (53 mW/m2) lower than the average global heat flow. The investigated area was divided into eighteen blocks, where the average depths to centroid and top of the magnetic source were estimated for each block. The results of this work show a general depth increase of the magnetic boundaries from 24.5 km in the southern area to 33 km at the northern part. The calculated surface heat flow decreases from about 56 to 42 mW/m2 in the same direction. Consequently, this area is characterized by its low geothermal gradient and surface heat flow. This low geothermal gradient indicates that the upper mantle contributes to the magnetic features at the northern offshore parts. This work also recommends by deep drilling for petroleum exploration and production within the Egyptian Mediterranean Sea exploration strip.

  4. The bivalve Placuna (Indoplacuna) miocenica from the Middle Miocene of Siwa Oasis, Western Desert of Egypt: Systematic paleontology, paleoecology, and taphonomic implications

    NASA Astrophysics Data System (ADS)

    El-Sabbagh, Ahmed M.; El Hedeny, Magdy M.; Rashwan, Mohammed A.; Abdel Aal, Abdel Aal A.

    2016-04-01

    The present study investigated the epifaunal, free lying bivalve Placuna (Indoplacuna) miocenica (Fuchs, 1883) encountered in the Middle Miocene Marmarica Formation of Siwa Oasis, Western Desert, Egypt, in terms of systematic paleontology, paleoecology and taphonomy. Well to moderately preserved shells of this species were collected from three sections. They have been found embedded in sandy, marly and chalky limestones. Although they are extremely thin and fragile, they occurred as complete disarticulated and articulated valves. Specimens of P. (I.) miocenica are highly accumulated in the north Siwa section forming a coquinoid band (30 cm thick). In addition, they are generally distributed sporadically in different stratigraphic levels within the three studied sequences. Taphonomic observations indicated that these shells were affected by encrustation, bioerosion, disarticulation, fragmentation and abrasion. Moreover, valves of this species suffered minor chipping along their fragile margins. The occurrence of the studied species associated with oysters and other benthic faunal assemblages within carbonate sediments revealed shallow, low energy, warm and intertidal environments with periods of relatively agitated conditions.

  5. Characterization of magnetic spherical fractions in sand deposits for interpretation of environmental change around the El- Zayyan temple, Kharga Oasis, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Watanabe, Makiko; Koizumi, Natsuko; Kato, Sayuri; Kikuchi, Ryohei; Kamei, Hiroyuki

    2014-05-01

    Desertification in North Africa has rapidly advanced over the last 6,000 years. Such environmental changes began in the Early Dynastic Period of Egypt (4200 - 3150 BC), and the occupation of Achaemenid Persian and Roman cultures in Egypt occurred under even drier climates. Kharga is the largest oasis of the five oases, located in the western desert of Egypt that contains a treasure trove of archaeological resources. This oasis has been highlighted to promote resource exploration and development of archaeological tourism since the 1980's. The El-Zayyan temple is located 27 km south of the central Kharga oasis. Zayyan was once called 'Tchonemyris', which has connection with the means of 'huge well' in Greek. Although major portions of the temple were rebuilt in 140 AD during the rule of the Roman Emperor Antoninus Pius, this temple is considered to be originally built in the Ptolemaic period (4c-1c BC). It is likely that the area had a sufficient water supply in the past as the El-Zayyan temple stands at the lowest point (-18 m a.s.l.) in the Kharga oasis. Furthermore, the El-Ghueita temple that stands on a hill top at 68.5 m a.s.l., 4 km northward from the El-Zayyan temple, has given name that means 'beautiful garden' in Greek. From these facts, we can imagine that the past landscape of this area contained green surroundings. The El-Ghueita temple was well known as a production centre of high quality wine since the mid-Dynastic age (2050 -1786 BC). As this area is currently arid, it is expected that there were irrigation facilities to maintain the vast farm land during the ancient period. To deepen our knowledge of how people developed their technologies and conducted their life within the natural environment of a drastic drying period, understanding the process of environmental change on a region scale is necessary. The aim of this study was to extract proxies from sand deposits in the western desert area to estimate the change in the environment. We examined the

  6. Hydrogeological aspects and environmental concerns of the New Valley Project, Western Desert, Egypt, with special emphasis on the southern area

    NASA Astrophysics Data System (ADS)

    Assaad, Fakhry A.

    1988-12-01

    The New Valley Project has been given much attention in the past 20 years especially from the hydrogeological point of view concerning groundwater utilization for the reclamation of a large area of the Western Desert. Lithological, petrophysical, and petrographical studies were conducted on four wells south of Beris Oasis, namely Beris 20, Beris 15, Beris 14, and Beris 13, and are defined by latitudes 24°25'E and 24°35'E and longitudes 30°30'N and 30°46'N. The Nubian sedimentation is of Posttectonic deposition that took place over the uplifted Precambrian granitic basement and is Lower Cretaceous, whereas the upper most variegated shales of the cap rock are Upper Cretaceous. The Nubian sandstones in the area south of Beris Oasis contain hematitic stains and/or fine granular authigenic hematite, thin laminae of brown ferruginous quartzite is also recorded denoting oxidizing conditions in the basin of deposition. Thin streaks of carbonaceous shales are met with in different depths to the south of Beris area, may be taken to denote oscillations in the sea level and accordingly its depths, and are responsible for the change in the oxidation-reduction potential during the deposition of the corresponding beds. Lithologic logs were interpreted together with the electric and micro-logs for adjustment of the shale breaks and showed that there are five water-bearing zones, named from bottom to top: A, B, C, D, and E, and are mainly unfossiliferous orthoquartzites, separated from each other by impervious beds of siltstones, shales, and clays of varying thicknesses. This zoning had been found valid in other parts of the Kharga Oases and could be applied locally in the Kharga Oases area. Mechanical analysis was performed mainly on 39 samples, of which 18 were core samples and 21 were cuttings, that were raised from four wells dug in the area south of Beris Oasis, Kharga Oases. Porosity and permeability tests were carried out on the 18 core samples only. The implication of

  7. Geophysical contribution to evaluate the subsurface structural setting using magnetic and geothermal data in El-Bahariya Oasis, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    El All, Esmat Abd; Khalil, Ahmed; Rabeh, Taha; Osman, Salah

    2015-12-01

    The future development of agriculture, industry, and civil activity is planned to be in the Western Desert, Egypt. El-Bahariya Oasis is located in the heart of the Western Desert at a distance of about 370 km to the southwest of Cairo. The area under investigation is located between latitudes 28°06‧N & 28°16‧N and longitudes 28°54‧E & 29°04. The Bahariya depression comprises a total area of approximately 2250 km2. The main target of the present study is to delineate the shallow and deep subsurface structures of the study area. To achieve this, two geophysical methods (magnetic and geothermal) have been used. A detailed land magnetic survey has been acquired. Fifty three land magnetic stations have been measured in a mesh like area with 500 m spacing interval. The necessary corrections concerning daily variation, the regional gradient and time variations have been applied. Then, the total magnetic intensity anomaly map (TMI) has been constructed and reduced to the pole magnetic map (RTP). The Euler deconvolution has been applied to the TMI anomaly data as well as the analytical signal technique. Also, the magnetic interpretation has been carried out using the high-pass filtering technique and spectral frequency analysis. The analysis of the magnetic data shows that the dominant tectonic trends are NW-SE and E-W. The results show that, the average calculated depth ranges between 0.1 km and 0.32 km, while the depth to the basement intrusion is 0.4 km, below the measuring level. The geothermal studies in EL Bahariya-Oasis comprise subsurface temperature contour map which illustrates that the study area has geothermal groundwater reservoirs. The measurements of the geothermal properties for measured rock samples show that the rocks of the study area have moderate values of geothermal properties. This may be due to the seasonal variation in soil temperatures. These soil thermal properties depend on soil porosity and moisture content.

  8. The uppermost deposits of the stratigraphic succession of the Farafra Depression (Western Desert, Egypt): Evolution to a Post-Eocene continental event

    NASA Astrophysics Data System (ADS)

    Sanz-Montero, M. E.; Wanas, H.; Muñoz-García, M. B.; González-Acebrón, L.; López, M. V.

    2013-11-01

    This paper gives insight into continental sedimentary deposits that occur at the uppermost part of the stratigraphic succession present in the north-eastern sector of the Farafra Depression (Western Desert, Egypt). Using space imagery to complete the field work, the geology of the area has been mapped and the presence of a N-S oriented fault system is documented. The analysis of the morphotectonic features related to this fault system allows reconstructing the structural and sedimentological evolution of the area. The study indicates that the continental deposits were accumulated in alluvial systems that unconformably overlie shale and evaporitic rocks attributable to the Paleocene-Eocene Esna Formation. The deposits of the Esna Formation show soft-sediment deformation features, which include slump associated to dish and pillar sedimentary structures and provide evidence of syndepositional tectonic activity during the sedimentation of this unit. The outcrops are preserved in two areas on separated fault-bounded blocks. Proximal alluvial fan facies crop out in a dowthrown block close to the depression boundary. The proximal facies are made up mostly by polymictic conglomerates which occasionally contain boulders. The conglomerate clasts are mainly quartz, carbonate, anhydrite satin spar vein, mudrock, ironstone and nummulite fossils. The mid-fan facies consist of trough cross-bedded, rippled and cross-laminated quartzarenites with reworked glauconite grains and carbonate rock fragments, interpreted as deposited by distributary streams. The distal alluvial fan deposits consist of sandy marls that evolve toward the top of the sections into root-bioturbated lacustrine limestone beds that are locally silicified. The limestones are biomicrites containing characea, ostracods and gastropods with fenestral porosity. A number of features, including clast provenance (mainly from marine Paleocene and Eocene rocks), the observed fractural pattern (N-S direction related to the

  9. A shell concentration of the Middle Miocene Crassostrea gryphoides (Schlotheim, 1813) from Siwa Oasis, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    El-Sabbagh, Ahmed M.; El Hedeny, Magdy M.

    2016-08-01

    A concentration of heavy, thick-shelled, large-sized, and elongated population of the oyster Crassostrea gryphoides (Schlotheim, 1813) was recorded in shallow-marine deposits of the basal Oasis Member of the Middle Miocene Marmarica Formation exposed at Siwa Oasis, Egypt. The oyster assemblage is resedimented as a lens-shaped bank up to 80-100 cm thick and about 220 m long. Crassostrea gryphoides specimens are embedded in a yellowish green, soft marl matrix. This is the first documented occurrence of this lens at Siwa Oasis. The lensoid structure is bounded by a lower marl and an upper shale beds of about 2 m and 1.5 m thick, respectively. Assemblage within this lens is characterized by extreme variations of Crassostrea gryphoides, forming an almost monotypic assemblage. The shell packing was dense (shell percentages higher than 75%) at the base and the center of the lens, whereas it exhibits loose packing at the top and right and left sides of the lens (shell percentage less than 15%). Valves are poorly sorted and randomly orientated (both in surface and cross section views). Encrustation and bioerosion have observed on both sides of the left and right valves. The relatively limited varieties of encrusters together with moderate frequency of borings indicate moderate to high sedimentation rate. On the other hand, the low abundance of fragmented and abraded shells indicates good preservation and minimal transport. The studied lens concentration is interpreted as proximal tempestites assemblage.

  10. Tectonic and provenance history of the Neotethyan margin in NE Africa recorded by detrital zircon (U-Th)/He thermochronometry from a borehole in the Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Stockli, D.; Glauser, T.; Bosworth, W.; Maher, T.; Clare, A.

    2009-04-01

    The subsurface of the Western Desert of Egypt contains multiple stacked sedimentary basin deposits separated by major unconformities reflecting the long-lived tectonic evolution of the Neotethyan continental margin in eastern North Africa. In this study, zircon (U/Th)/He (ZHe) data were collected from cuttings from a ~15000 ft borehole that penetrated Tertiary and Cretaceous strata and a major erosional unconformity at 13000 ft that juxtaposes Cretaceous and Cambro-Ordovician strata. A total of 56 samples spanning the borehole from 750-15400 ft yielded >200 single-grain ZHe ages in order to elucidate the thermal evolution of the borehole and constrain the thermal history of detrital provenance. ZHe ages above the unconformity are significantly older than the depositional age, suggesting detrital ZHe ages that were not reset subsequent to deposition. ZHe ages from Cambro-Ordovician strata below the unconformity are substantially younger than the minimum depositional age suggesting major cooling and resetting of zircon (>200C) during the Hercynian orogeny. In detail, ZHe ages form Cretaceous strata above the unconformity show the following trends. (1) ZHe ages from 6000-9000 ft (Aptian-Early Cenomanian) are characterized by a ZHe age peak at ~450 Ma and a minor Albian peak, (2) samples from 9000-12000 ft (Late Hauterivian-Barremian) show two major detrital ZHe age peaks at ~450 and 350 Ma, while (3) samples from 12000-13000 ft (Early Hauterivian) exhibit three dominant ZHe age components at ~450 Ma, 350 Ma, and 170-200 Ma. Additional cuttings from an offset containing complete stratigraphy yielded ZHe ages that mainly represent a strong Hercynian input as well as Late Triassic and Early Jurassic components of Tethyan related input. These ZHe age peaks display provenance characteristics typical for cooling signatures of rocks from the eroding Arabian-Nubian Shield, a North-African Hercynian source, and eroded material from exhumed fault blocks along the Triassic

  11. Pseudospherulitic fibrous calcite from the Quaternary shallow lacustrine carbonates of the Farafra Oasis, Western Desert, Egypt: A primary precipitate with possible bacterial influence

    NASA Astrophysics Data System (ADS)

    Wanas, H. A.

    2012-04-01

    Pseudospherulitic fibrous calcite (PFC) has been found as a major constituent (85-90%) within thin massive limestone beds of the Quaternary mudflat-shallow lacustrine facies association (1.5-2 m thick) that forms part of combined facies associations of the Quaternary clastic-carbonate unit (25-30 m thick) at Bir-Karawein area in the Farafra Oasis, Western Desert, Egypt. The thin massive limestone beds (2-5 cm thick) are devoid of pedogenic features and marine fossils. They form a rhythmic cyclic succession with thin massive mudrocks (5-10 cm thick). The mudflat-shallow lacustrine facies association herein occurs within a depositional sequence of distal alluvial-floodplain (6-12 m thick) and palustrine (1.5-4.5 m thick) facies associations. The PFC is a composed of loosely packed rounded to sub-rounded single low-Mg-calcite crystals (150-250 μm-sized) with intracrystalline fibrous microfabric marked by fibers (150-250 μm long and 10-20 μm wide) radiating from the center of the individual crystals and displaying irregular internal growth with lobate pattern. The PFC crystals show non-planar to highly irregular intercrystalline boundaries. Under SEM, the individual crystal fibers group of PFC form ellipsoid to sub-globular bodies. Each PFC crystal exhibits successive zones of thick non-luminescence and thin brightly orange to dull luminescence. The matrix (10-15%) between the PFC crystals is mainly a honeycomb-like smectite. The PFC is postulated to be a primary precipitate. This concept is reached because the PFC: (i) does not display the criteria of typical Microcodium structures, root-calcification, speleothem structures, calcite spherulites of laminar calcretes, and calcitization of precursor dolomite or aragonite, (ii) possesses homogenous compositional and textural characteristics, and (iii) occurs within limestone beds that lie in between impermeable massive mudrock beds that dampen diagenesis. A role for possible bacterial contribution in crystallization of

  12. Basin deconstruction-construction: Seeking thermal-tectonic consistency through the integration of geochemical thermal indicators and seismic fault mechanical stratigraphy ​- Example from Faras Field, North Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Pigott, John D.; Abouelresh, Mohamed O.

    2016-02-01

    To construct a model of a sedimentary basin's thermal tectonic history is first to deconstruct it: taking apart its geological elements, searching for its initial conditions, and then to reassemble the elements in the temporal order that the basin is assumed to have evolved. Two inherent difficulties implicit to the analysis are that most organic thermal indicators are cumulative, irreversible and a function of both temperature and time and the non-uniqueness of crustal strain histories which complicates tectonic interpretations. If the initial conditions (e.g. starting maturity of the reactants and initial crustal temperature) can be specified and the boundary conditions incrementally designated from changes in the lithospheric heat engine owing to stratigraphic structural constraints, then the number of pathways for the temporal evolution of a basin is greatly reduced. For this investigation, model input uncertainties are reduced through seeking a solution that iteratively integrates the geologically constrained tectonic subsidence, geochemically constrained thermal indicators, and geophysically constrained fault mechanical stratigraphy. The Faras oilfield in the Abu Gharadig Basin, North Western Desert, Egypt, provides an investigative example of such a basin's deconstructive procedure. Multiple episodes of crustal extension and shortening are apparent in the tectonic subsidence analyses which are constrained from the fault mechanical stratigraphy interpreted from reflection seismic profiles. The model was iterated with different thermal boundary conditions until outputs best fit the geochemical observations. In so doing, the thermal iterations demonstrate that general relationship that basin heat flow increases decrease vertical model maturity gradients, increases in surface temperatures shift vertical maturity gradients linearly to higher values, increases in sediment conductivities lower vertical maturities with depth, and the addition of "ghost" layers

  13. Carrion insects of the Egyptian western desert.

    PubMed

    Hegazi, E M; Shaaban, M A; Sabry, E

    1991-09-01

    A general survey was made on the zoosaprophagous insects and their associates in a natural ecosystem in the Egyptian western desert (80 km west of Alexandria, 12 km from the Mediterranean Sea shore). Two types of traps were used, one for flying insects and the other for soil-burrowing insects. Two types of decaying media were used as baits: the common freshwater fish (Tilapia zilii Gerv.) and the desert snail (Eremina desertorum). More than 30 insect species were trapped. The following orders and families were represented: Diptera (Calliphoridae, Sarcophagidae, Muscidae); Coleoptera (Histeridae, Scarabaeidae, Dermestidae, Tenebrionidae); Hymenoptera (Chalcididae, Pteromalidae, Eulophidae, Formicidae). Monthly totals of numbers trapped in each of these groups are presented.

  14. Remote sensing observations of sand movement in the Bahariya Depression, Western Egypt

    NASA Technical Reports Server (NTRS)

    Maxwell, Ted A.; Jacobberger, Patricia A.

    1987-01-01

    Aerial photographs taken in the 1940's have been used in combination with recent Landsat MSS and TM data to study dune movement in the Western Desert of Egypt. The El-Ghorabi dunes track northwest to southeast along the eastern edge of the Bahariya Depression. These dunes are of complex longitudinal form with well-defined, lag-covered interdune corridors. Studies using both aerial coverage and multitemporal MSS and TM image data reveal little or no net southward extension or movement of the seifs, although field measurements and remote sensing data indicate small-scale lateral migration of dune crests and interdune corridors through time. The primary process of sand transport for these dunes seems to be in response to seasonal shifts in dominant wind direction, as reflected in the development and rapid response of sand shadows leeward of the main dune masses.

  15. Soil seed bank in different habitats of the Eastern Desert of Egypt.

    PubMed

    Gomaa, Nasr H

    2012-04-01

    The floristic composition and species diversity of the germinable soil seed bank were studied in three different habitats (desert salinized land, desert wadi, and reclaimed land) in the Eastern Desert of Egypt. Moreover, the degree of similarity between the seed bank and the above-ground vegetation was determined. The seed bank was studied in 40 stands representing the three habitats. Ten soil samples (each 25 × 20 cm and 5 cm depth) were randomly taken per stand. The seed bank was investigated by the seedling emergence method. Some 61 species belonging to 21 families and 54 genera were identified in the germinable seed bank. The recorded species include 43 annuals and 18 perennials. Ordination of stands by Detrended Correspondence Analysis (DCA) indicates that the stands of the three habitats are markedly distinguishable and show a clear pattern of segregation on the ordination planes. This indicates variations in the species composition among habitats. The results also demonstrate significant associations between the floristic composition of the seed bank and edaphic factors such as CaCO3, electrical conductivity, organic carbon and soil texture. The reclaimed land has the highest values of species richness, Shannon-index of diversity and the density of the germinable seed bank followed by the habitats of desert wadi and desert salinized land. Motyka's similarity index between the seed bank and the above-ground vegetation is significantly higher in reclaimed land (75.1%) compared to desert wadi (38.4%) and desert salinized land (36.5%).

  16. Genetic Aspects of Gold Mineralization at Some Occurrences in the Eastern Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Abd El Monsef, M.; Slobodník, M.; Salem, I. A.

    2012-04-01

    The Eastern Desert of Egypt is well known as a gold-mining area since ancient times, there're more than 95 gold deposits and occurrences spread the whole area covered by the basement rocks of Precambrian age. The basement rocks of the Eastern Desert of Egypt constitute the Nubian Shield that has formed a continuous part of the Arabian-Nubian Shield before the opening of Red Sea (Oligocene-Early Miocene). Commonly, the system of gold-bearing quartz veins in the Eastern Desert is clearly structural controlled related to brittle-ductile shear zones that mostly developed during late deformational stages of the evolution history for basement rocks in the Eastern Desert. This running study principally aims to contribute the mineral resource potential of the gold deposits in Egypt, so particularly Fatira, Gidami and Atalla occurrences have been involved into a comprehensive study based on field, structural, mineralogical, geochemical and genetic investigations. It is intended to better understanding for the characteristics, distribution controls, conditions and age of mineralization in relation to the age of the hosting rocks intrusion to find if there're genetic links between the gold mineralization and the evolution of the host intrusive complex. Several authors suggested that the gold mineralization was related to the intrusion of the (postorogenic) Younger granites. Other authors interpret these deposits as products of hydrothermal activity induced either by metamorphism or cooling effects of early Paleozoic magmatism or as combined metamorphic/magmatic episodes. The prime focus will be directed to the ore itself and the associated hydrothermal alteration zones based on detailed maps and well-distributed samples network and geochemical anomalies distribution. The laboratory studies included microscopic examination (reflecting and transmitting microscopy) to allow for determination of the hosting rocks types and mineralogical changes related to the gold mineralization

  17. Microfacies analysis of foraminifera rich sedimentary rocks from the Desert Plateau, central Egypt.

    NASA Astrophysics Data System (ADS)

    Karnitschar, C.; Briguglio, A.; Hohenegger, J.

    2012-04-01

    Microfacies analysis on some samples from the Thebes Group have been carried on by means of thin sections. The study area is included in the Libyan Desert Plateau (central Egypt) at following coordinates N27° 36'30.58" E29° 44'58.34", near the biggest dune of Egypt, the Ghard Abu Muharik. Because of the round shape of the rocks and the desert patina on the surface they could easily be classified as the so called "Melonstones", which are located more southwards and mainly composed by stromatolites. On the contrary, the investigated samples show a completely different fauna and therefore have been separated from the "Melonstones". Even if shape and size are very similar and the desert patina covers all surfaces the same way the differences are impressive. To investigate the samples, two thin-sections have been prepared and analyzed at the microscope. The observed fauna is composed by: agglutinated benthic foraminifera (e.g., Dictyoconus egypticus), complex larger miliolids (e.g., Pseudolacazina cf. danatae, Fabularia sp.), alveolinids (Alveolina vredenburgi), green algae (Dasycladaceae), echinoids and corals. Because of the presence of symbionts bearing larger benthic foraminifera, which need light to feed photosymbionts, the rock was formed in a shallow water environment. With the abundant rock-building benthic foraminifera and calcareous algae the limestone shows a tendency to the packstone/wackestone facies. Based on the presence of Alveolina vredenburgi, the age of the samples can be estimate as lowermost Eocene belonging to the shallow benthic zone 5 (sensu Serra-Kiel et al., 1998). According the obtained data on stratigraphy and palaeoecology, a partial palaeoenvironmental reconstruction is possible for the Libyan Desert Plateau where outcrops are largely missing. Because of the round shape of the samples and the patina which covers them all around it can be assumed that they have been transported from longer distance. According to the geological map of the

  18. Natural radioactivity and rare earth elements in feldspar samples, Central Eastern desert, Egypt.

    PubMed

    Walley El-Dine, Nadia; El-Shershaby, Amal; Afifi, Sofia; Sroor, Amany; Samir, Eman

    2011-05-01

    The pegmatite bodies of the Eastern Desert of Egypt are widely distributed especially along the Marsa-Alam-Idfu road. The Abu Dob area covers about 150km(2) of the Arabian Nubian shield at the central part of the Eastern Desert of Egypt. Most of the pegmatite is zoned; the zonation starts with milky quartz at the core followed by alkali feldspar at the margins. The feldspars vary in color from rose to milky and in composition from K-feldspar to Na-feldspar, sometimes interactions of both types are encountered. Thirteen feldspar samples were collected from different locations in the Abu Dob area for measuring the natural radioactivity of (238)U, (232)Th and (40)K using an HPGe detector. The variation in concentration of radionuclides for the area under investigation can be classified into regions of high, medium and low natural radioactivity. The average concentration in BqKg(-1) has been observed to be from 9.5 to 183675.7BqKg(-1) for (238)U, between 6.1 and 94,314.2BqKg(-1) for (232)Th and from 0 to 7894.6BqKg(-1) for (40)K. Radium equivalent activities (Ra(eq)), dose rate (D(R)) and external hazard (H(ex)) have also been determined. In the present work, the concentration of rare earth elements are measured for two feldspar samples using two techniques, Environmental Scanning Electron microscope XIL 30 ESEM, Philips, and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The existence of rare earth elements in this area are very high and can be used in different important industries.

  19. 77 FR 26950 - Designation of Areas for Air Quality Planning Purposes; California; Western Mojave Desert Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-08

    ... Desert Ozone Nonattainment Area; Reclassification to Severe AGENCY: Environmental Protection Agency (EPA... State of California to reclassify the Western Mojave Desert ozone nonattainment area from ``Moderate... Indians of California located within the boundaries of the Western Mojave Desert area in the same...

  20. Holocene environmental changes in the Gebel Umm Hammad, Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Moeyersons, Jan; Vermeersch, Pierre M.; Beeckman, Hans; Van Peer, Philip

    1999-01-01

    Gebel Umm Hammad in the Red Sea Mountains east of Quseir, Egypt, today enjoys small but irregular amounts of winter rain, enabling the widening of joint controlled openings in the Thebes Limestone. Cavities are especially affected by flaking, while rock fragmentation is more active on the outside. The sedimentological and botanical study of fan deposits at the outlet of a karstic shaft in the Tree Shelter showed the local Holocene environmental evolution. Three periods of different degree of aridity can be considered: (i) Before 8120±45 BP (UtC-5389), bedload aggradation points to rare but occasionally heavy rains, lasting for several hours, attaining intensities of more than 76 mm/h and covering some 20 km 2. Wadi flash floods occasionally attained bankfull stage. (ii) Since 8120±45 BP (UtC-5389), such heavy rains have not occurred in the Egyptian Red Sea Mountains. Instead, a more moderate but maybe wetter precipitation regime was established. The karstic shafts were active, and there was water and life in the desert. Two humid pulses can be distinguished within this period. The first occurs at ±8000 BP, the second between 6630±45 (GrN-22560) and 6770±60 BP (GrN-22562). (iii) After the last wet culmination, there was a gradual shift to drier conditions. Shortly after ±5000 BP, modern climatic conditions are believed to have been attained. Today, the occasional rain storms are less heavy than before ±8000 BP. Bankfull stage river floods do not occur. Instead, secondary channels are eroded in the wadi beds. The general arid character during the whole period and the inherent local and temporal variations in precipitation patterns might explain apparent aberrations between the palaeoenvironmental evolution of the Tree Shelter site and other remote study areas in Egypt and Sudan.

  1. Technologies Applied in the Toshka Project of Egypt

    ERIC Educational Resources Information Center

    Wahby, Wafeek S.

    2004-01-01

    The Toshka Project, located in Egypt, involves excavating a canal to carry about 380 billion ft[supercript 3] of water every year from Lake Nasser to the Toshka Depression, southwest of Aswan. This will eventually create a new valley to the River Nile in the western desert of Egypt in addition to the currently existing prehistoric river course.…

  2. Extensional collapse along the Sevier Desert reflection, northern Sevier Desert basin, western United States

    NASA Astrophysics Data System (ADS)

    Coogan, James C.; Decelles, Peter G.

    1996-10-01

    Newly released and previously published seismic reflection data from the northern Sevier Desert basin provide a complete seismic transect between the tilted western margin of the basin and the eastern breakaway zone. When tied to well and surface age data, the transect delineates a continuum of extensional fault and basin fill geometries that developed between late Oligocene and Pleistocene time across the basin. A minimum of 18 km of top-to-the-west normal displacement is estimated across the Sevier Desert from only the most conspicuous growth geometries and offsets across listric normal faults that sole downward into the Sevier Desert reflection (SDR). The SDR clearly marks a normal fault zone beneath the entire basin, where stratal truncations are imaged for 50% of the 39 km length of the reflection east of the Cricket Mountains block. Restoration of extensional displacement along this entire 39 km fault length is necessary to reconstruct the pre-Oligocene configuration and erosion level of Sevier thrust sheets across the Sevier Desert area. The SDR normal fault zone underlies the former topographic crest of the Sevier orogenic belt, where it accommodated extensional collapse after cessation of regional contractile tectonism.

  3. Specific activity and hazards of granite samples collected from the Eastern Desert of Egypt.

    PubMed

    Arafa, Wafaa

    2004-01-01

    Fifty granitic rock samples were collected from different plutons in the central part of the Eastern Desert of Egypt and were analyzed for specific concentrations of (238)U, (232)Th and (40)K radionuclei. The measurements were carried out using a high performance and stability Nomad Plus spectroscopy system attached to a 1.7 keV (FWHM) HPGe detector. The spectra were analyzed using the direct gamma counting comparison method as well as the traditional absolute efficiency curve method. The highest average value of (238)U concentration (1184 Bq kg(-1)) was observed at EI Misikat region whereas the highest average values of (40)K and (232)Th concentration (2301.8 and 162.5 Bq kg(-1) respectively), were detected at Gabal Homret Waggat area. The radium equivalent activity (Ra(eq)), the absorbed dose rate (D), the external hazard index (H(ex)) and the annual gonadal dose equivalent were also calculated and compared to the international recommended values. Radon exhalation rate from the rock samples were measured using the activated charcoal canister method. The average value of radon exhalation varies from 0.052 to 0.69 Bq m(-2) h(-1) and depends on the specific concentration of uranium.

  4. Petrogenesis of selected A-type granitic intrusions from Central Eastern Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Hassan, Tharwat; Asran, Asran; Amron, Taha; Hauzenberger, Christoph

    2014-05-01

    The Pan-African orogeny in the Arabian-Nubian Shield was terminated by intrusion of A-type granites (~ 595 Ma; Greenberg, 1981) and its volcanic equivalents. Subsequent to the intrusions of these granitic bodies the shield was exhumed. Eroded A-type granite pebbles were found in the molasse sediments that were deposited in intermountain basins. Therefore the A-type granites provide information about the last stage of the Pan-African geochemical system. Preliminary whole-rock geochemical data of three granitic intrusions (Kadabora, Um Naggat and El shiekh Salem) from the Central Eastern Desert of Egypt; indicate that all of them are peraluminous and with A-type characteristics. These intrusions show low CaO content (average 0.43 %wt), high FeOT/MgO ratio (10.46-121.88), high Na2O+K2O (average 8.04 %wt), marked enrichment of high field strength elements (Y, Nb and Ga except Zr), depletion in MgO (0.01-0.11 %wt) and with low concentration of Sr and Ba. The studied granitoids were emplaced in within plate tectonic regime. References: Greenberg, J.K. (1981): Characteristic and origin of Egyptian younger granites. Bull. Geol. Soc. Am. Part 1, v.92: 224-232.

  5. Sequence stratigraphy of the Cenomanian Galala Formation, north Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Khalifa, M. A.; Abu El-Ghar, Mohamed S.; Helal, S. A.; Hussein, A. W.

    2014-01-01

    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 coarsening- and fining-upward parasequences. The TSTs form a series of aggradational-retrogradational, shallowing-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.

  6. The use of remote sensing and GIS for the estimation of water loss from Tushka lakes, southwestern desert, Egypt

    NASA Astrophysics Data System (ADS)

    Bastawesy, Mohamed A.; Khalaf, Fikry I.; Arafat, Sayed M.

    2008-10-01

    As a result of the spill-over of the excess water from lake Nasser, the great reservoir formed by the Aswan High Dam on the Nile, the Tushka lakes came into being within natural geological depressions in the southeastern part of the western desert of Egypt. By the end of 1998, the water of river Nile had entered Tushka depressions for the first time, once lake Nasser's water level had exceeded 178 m above the mean sea level. Intermittently, water continued to discharge into the depressions until the end of 2001 forming four lakes; however, the lakes began to shrink because of the inconsistency of flooding levels. The behavior of hydrological regime of these lakes during the period 2002-2006 was assessed using an integration of remote sensing and GIS techniques, which found that the total surface area of the lakes had diminished from 1591 km 2 to 937 km 2, and their water volumes reduced from 25.26 billion m 3 to 12.67 billion m 3. The study further revealed that the levels of the lakes surfaces had lowered by approximately 10 m over the course of those four years. This significant rate and volume of water loss can be attributed to both evaporation and infiltration. A comparison between the average annual evaporation rate at Tushka lakes and the calculated water loss revealed that most of Tushka lakes' water is lost through evaporation with a very limited amount being percolated to the ground water. Assuming that no further over flooding of the Nile will occur, these lakes will start to vanish in 2012 and disappear completely by 2020, which will result in significant environmental impacts.

  7. Egypt.

    PubMed

    1987-12-01

    Attention in this discussion of Egypt is directed to the following: geography; the people; history; government and political conditions; the economy; defense; foreign relations; and relations between Egypt and the US. The population totaled 50.5 million in 1986 with an annual growth rate of 2.8%. The infant mortality rate is 102/1000 (1986), and life expectancy is 58.3 years. Located in the northeastern corner of Africa, Egypt has a land area of about 1 million square kilometers and is bounded by the Mediterranean Sea, Libya, Sudan, the Red Sea, the Gulf of Aqaba, and Israel. Egypt is the most populous country in the Arab world. Egyptians are a fairly homogenous people of Hamitic origin. Mediterranean and Arab influences appear in the north, and there is some mixing in the south with the Nubians of northern Sudan. Egypt has been a unified state for over 5000 years, and archeological evidence indicates that a developed Egyptian society has existed for considerably longer. The constitution of Egypt provides for a strong executive with authority vested in an elected president who can appoint 1 or more vice presidents, a prime minister, and a cabinet. Egypt's legislative body has 458 members -- 448 popularly elected and 10 appointed by the president. Power is concentrated in the hands of the president and the National Democratic Party's majority in the People's Assembly, but opposition parties organize, publish their views, and represent their followers at various levels in the political system. The process of gradual political liberalization begun by Sadat has continued under Mubarak. In fiscal year 1987 the gross domestic product (GDP) reached about US$30 billion. Agriculture and services each contribute about 1/3 of GDP; the remainder comes from industry, petroleum, mining, electricity, and construction. At this time, the Egyptian economy faces several challenges. In 1986 the government of Egypt initiated a major review of economic policy and initiated an economic

  8. Chemical and isotopic constraints on the origin of Wadi El-Tarfa ground waters, Eastern Desert, Egypt.

    SciTech Connect

    Sultan, M.; Sturchio, N. C.; Abdel Hady, Y.; El Anbeawy, M.; Environmental Research; Cairo Univ.

    2000-10-01

    We evaluated the use of the renewable ground water resources of the Eastern Desert to develop sustainable agriculture in Upper Egypt, an alternative that could alleviate some of Egypt's dependence on water from the Nile River. Ground water from shallow aquifers in the Eastern Desert of Egypt, near the intersection of Wadi El-Tarfa and the Nile River, was analyzed for chemical compositions, stable isotope ratios, and tritium activities. The ground water has a range in total dissolved solids of 300 to 5000 mg/L. Values of {delta}D and {delta}{sup 18}O range from -10 to +34 %o and -2 to +5.2 %o, respectively, and defines a line having a slope of 5.7 that intersects the meteoric water line at about {delta}D = -15% on a plot of 8D versus {delta}{sup 18}O. These findings indicate that the water might have been derived by a combination of evaporation of and salt addition to regional precipitation. Only one sample could have been derived directly by evaporation and transpiration of modern Nile River water. Salinization of the ground water could have occurred through dissolution of marine aerosol dry fallout, carbonate minerals, gypsum, and other trace evaporitic minerals at and near the ground surface. Tritium activities ranged from 0.04 to 12.9 TU (tritium unite), indicating that all but one of the samples were derived at least partly from precipitation that occurred within the last 45 years. These data indicate that Nubian Aquifer paleowater is not a significant component of the shallow aquifers of this portion of the Eastern Desert. The most likely source of this ground water is sporadic flash flood events yielding locally voluminous recharge that accumulates in coarse sediments and fractured rock beneath alluvial channels. The magnitude of this renewable ground water resource and its potential for supporting sustainable agriculture require further investigation.

  9. Structures controlling U and Th mineralisation in the Gebel Felat area of the south Eastern Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Kamel, Ahmed Farouk

    1997-05-01

    In the Eastern Desert of Egypt, younger granites host U and Th mineralisations which are concentrated along faults and joints. In particular, the Gebel Felat Pluton is characterised by a high level of radioactivity as shown by an aeroradiometric survey. The U content is 82 ppm and the Th content is 15 ppm in areas of high radioactivity. The rocks are cross-cut by two main sets of fractures trending east-west and northwest-southeast. The contour maps of these two trends can be correlated with the aeroradiometric map of the same area.

  10. Paleoenvironmental signals and paleoclimatic condition of the Early Maastrichtian oil shales from Central Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Fathy, Douaa; Wagreich, Michael; Zaki, Rafat; Mohamed, Ramadan S. A.

    2016-04-01

    Early Maastrichtian oil shales are hosted in the Duwi Formation of the Central Eastern Desert, Egypt. The examined member represents up to 20% of the total Duwi Formation. This interval is mainly composed of siliciclastic facies, phosphorites facies and carbonate facies. Oil shales microfacies is mainly composed of smectite, kaolinite, calcite, fluorapatite, quartz and pyrite. They are enriched in a number of major elements and trace metals in particular Ca, P, V, Ni, Cr, Sr, Zn, Mo, Nb, U and Y compared to the post-Archaean Australian shale (PAAS). Chondrite-normalized REEs patterns of oil shales for the studied area display light rare earth elements enrichment relatively to heavy rare earth elements with negative Ce/Ce* and Eu/Eu* anomalies. The most remarkable indicators for redox conditions are enrichments of V, Mo, Ni, Cr, U content and depletion of Mn content. Besides, V/V+Ni, V/Ni, U/Th, Ni/Co, authigentic uranium ratios with presence of framboidal shape of pyrite and its size are reflecting the deposition of these shales under marine anoxic to euxinic environmental conditions. Additionally, the ratio of Strontium (Sr) to Barium (Ba) Sr/Ba reflected highly saline water during deposition. Elemental ratios critical to paleoclimate and paleoweathering (Rb /Sr, Al2O3/TiO2), CIA values, binary diagram between (Al2O3+K2O+Na2O) and SiO2 and types of clay minerals dominated reflect warm to humid climate conditions prevailing during the accumulation of these organic-rich petroleum source rocks.

  11. Red Sea rift-related Quseir basalts, central Eastern Desert, Egypt: Petrogenesis and tectonic processes

    NASA Astrophysics Data System (ADS)

    Farahat, Esam S.; Ali, Shehata; Hauzenberger, Christoph

    2017-01-01

    Mineral and whole-rock chemistry of Red Sea rift-related Tertiary basalts from south Quseir city, central Eastern Desert of Egypt is presented to investigate their petrogenesis and relationship to tectonic processes. The south Quseir basalts (SQB) are classified as high-Ti (TiO2 >2 wt.%) subalkaline transitional lava emplaced in an anorogenic tectonic setting. Their Mg# varies from 48 to 53 indicating the evolved nature of the SQB. Pearce element ratios suggest that the SQB magmas evolved via fractional crystallization of olivine + clinopyroxene ± plagioclase, but the absence of Eu anomalies argues against significant plagioclase fractionation. Clinopyroxene compositions provide evidence for polybaric fractionation of the parental mafic magmas. Estimated temperatures of crystallization are 1015 to 1207 °C for clinopyroxene and 1076 to 1155 °C for plagioclase. These values are interpreted to result from early stage crystallization of clinopyroxene followed by concurrent crystallization of clinopyroxene and plagioclase. The incompatible trace element signatures of the SQB (La/Ba = 0.08-0.10 and La/Nb = 0.89-1.04) are comparable to those of ocean island basalts (OIB) generated from an asthenospheric mantle source unaffected by subduction components. Modeling calculations indicate that the SQB primary magmas were derived from 4-5% partial melting of a garnet-bearing lherzolite mantle source. The NE Egyptian basaltic volcanism is spatially and temporally related to Red Sea rifting and to the local E-W striking faults, confirming a relationship to tectonic activity. Our results suggest that the extensional regime associated with Red Sea rifting controlled the generation of the Egyptian basalts, likely as a result of passive upwelling of asthenospheric mantle.

  12. Holocene Paleoecology of the Western Tenere Desert, Niger, Africa

    NASA Astrophysics Data System (ADS)

    Sereno, P. C.; Caran, S. C.; Housh, T. B.

    2007-12-01

    Multiple paleontological, sedimentological, and isotopic/ionic geochemical indicators permit reconstruction of the Holocene ecology of the western Tenere Desert (southern Sahara hyper-desert). Modern precipitation is highly erratic, averaging 25 mm yearly, and vegetative cover is negligible. From the early to middle Holocene, however, grassland-shrublands and seasonal to permanent lakes and wetlands predominated, supporting diverse limnic, riparian, and upland communities. Annual precipitation probably was comparable to that of the modern southern Sahel, exceeding 350 mm. Coarse-grained sediment washed into the large lacustrine basin from exposures of metamorphic, plutonic, and volcanic rocks in the nearby Air Massif highland. Lake margins fluctuated in response to runoff and limited ground-water discharge. The water was non-saline and there is no evidence of evaporite deposition. Aquatic and riparian macrophytes thrived, as did an extensive lacustrine-palustrine macrofauna. A Sahelian flora of mixed grasses, thorn shrubs, and perhaps some larger woodland species occupied the contiguous uplands, supporting resident and migratory mammalian and avian faunas. Lake levels were high until 6300 to 5200 BP, possibly as late as 4800 BP locally. Deflation of lacustrine deposits during a subsequent dry period provided finer-grained eolian sediment accreting as proximal dunes. The composition of mineral sediment within the middle to late Holocene dunes is different from, but clearly a subset of the lacustrine deposits. Organic matter reworked from the lake sediment was deposited in the dunes and oxidized in situ, generating CO2 that dissolved in soil moisture, producing bicarbonate. The bicarbonate reacted with calcium from weathered minerals, producing calcic cementation about 5100 BP. The resulting petrocalcic horizon was later exposed, weathered, and colonized by sparse terrestrial vegetation for one or more brief periods. A late phase of pedogenesis concurrent with or

  13. The Neoproterozoic Abu Dahr ophiolite, South Eastern Desert, Egypt: petrological characteristics and tectonomagmatic evolution

    NASA Astrophysics Data System (ADS)

    Gahlan, Hisham A.; Azer, Mokhles K.; Khalil, Ahmed E. S.

    2015-10-01

    The Neoproterozoic Abu Dahr ophiolite, South Eastern Desert, Egypt, is one of the best preserved and least dismembered ophiolite successions in the Arabian-Nubian Shield. It contains a Penrose-type ophiolite sequence from mantle section below mafic crust upward to oceanic sedimentary cover overlying mafic volcanics, although the original magmatic (stratigraphic) contact between the mantle and crustal sections is disrupted by tectonism. The Abu Dahr ophiolite is metamorphosed under greenschist facies conditions, and low-temperature alteration is widespread. Petrography reveals that: (i) the mantle is homogenous, serpentinized, and dominated by harzburgite and less abundant dunite; (ii) the cumulate ultramafics are represented by wehrlite and pyroxenite; and (iii) the crustal section is represented by metagabbros, meta-anorthosites and metabasalts. The Abu Dahr serpentinized peridotites show high Mg# (0.92-0.93), with enrichment of Ni, Cr and Co, and depletion of Al2O3 and CaO, and nearly flat and unfractionated REE chondrite-normalized pattern. Major and trace element characteristics of the Abu Dahr metagabbro and metabasalt (crustal section) indicate a tholeiitic to calc-alkaline affinity. Units of the crustal section have low-Nb and Zr concentrations, low Dy/Yb and relatively elevated La/Yb ratios, high U/Yb and Th/Yb ratios, and LREE enriched chondrite-normalized pattern. All of the Abu Dahr ophiolite units have trace-element signatures characterized by enrichment of LILE over HFSE. Rare and trace element patterns indicate a genetic link between the Abu Dahr mantle, cumulate ultramafics, and crust. Chromian spinel has survived metamorphism and is used as a petrogenetic indicator in the Abu Dahr serpentinized peridotites. The spinel is homogeneous with a limited composition, and shows high-Cr# (>0.6) combined with low-TiO2 character (mostly <0.1 wt.%). The Abu Dahr ophiolite is interpreted as a fragment of depleted oceanic lithosphere that experienced high degrees

  14. Peculiar Feldspar And Quartz Inclusions Within Zircons From Anorthosites, North Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Eliwa, H. A.; Dawoud, M. I.; Khalaf, I. M.; Negendank, J. F.; Itaya, T.

    2004-12-01

    Zircons from three anorthosite outcrops along Wadi Dib area, north Eastern Desert of Egypt contain abundant and conspicuous inclusions of quartz, feldspar, amphibole and apatite. These anorthosites, as (50-100m thick) layers, represent the top of mafic-ultramafic intrusions exhibiting rhythmic layering visible by reputation of melanocratic and leucocratic layers. Field and microscopic studies exhibit that these anorthosites were affected by the action of residual magmatic solutions associated with the late stage crystallization of the younger granites, which modified their mineralogical composition. They are composed totally of plagioclase with subordinate amount of clinoenstatite, augite, amphibole, biotite, K-feldspar, and quartz. Accessories are magnetite, ilmenite, apatite and zircon. The abundance and the mode of occurrence of K-feldspar, quartz, and biotite with apatite and zircon among the megacrysts suggest their formation is ascribed to the interaction with the residual solutions. The microprobe data exhibit difference between feldspar and amphiboles contained herein zircons and those as anorthosite mineral constituents. The genetic relationship between zircons and their inclusions suggests later growth of zircons than inclusions and most probably at the final stage of rock modification. Zircons are magmatic and found in the interstitial feldspar and quartz among plagioclase megacrysts in aggregates or as individual grains. The microscopic and SEM images investigation exhibit that most zircons are subhedral to euhedral equant and prismatic crystals. Most zircons have same range of crystal morphologies and internal growth structures with predominance of prism /{100/} and pyramid /{101/} and occasionally prism /{110/} and pyramid /{111/}. No evidences for poly-faceted grains, inherited cores or later overgrowths were detected. CL images distinguished zircons with visible core-rim structures and others with regular and continuous growth zones contained herein

  15. Medium-to high-pressure garnet-amphibolites from Gebel Zabara and Wadi Sikait, south Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Surour, Adel A.

    1995-10-01

    Garnet-amphibolites from Gebel Zabara and Wadi Sikait in the southern Eastern Desert of Egypt occur as highly flattened metamorphosed basic volcanic bands enclosed within garnetiferous metasediments. Samples from both localities have almost the same metamorphic assemblage of garnet-amphibole-plagioclase-ilmeniterutile. An electron microprobe study indicates that garnet, amphibole and plagioclase are cryptically zoned only in samples from Wadi Sikait. The composition of amphiboles (tschermakitic hornblende to tschermakite) reflects a temperature range equivalent to that of the staurolite-kyanite zone of the metapelitic sequences. Geothermometric calculations of the pairs garnet-amphibole and amphibole-plagioclase indicate average temperatures of 550°C for samples from Wadi Sikait and Gebel Zabara, respectively. Pressures of about 6.8 kbar and 7.7 kbar are obtained using some mineral equilibria of both silicates and opaque phases. The garnet-amphibolites are considered as a part of the infrastructural suite in the Eastern Desert. A comparison with the Pan-African amphibolites from the Eastern Desert and Sinai is presented.

  16. Western Mojave Desert, Rate of Progress Demonstration; Proposed Approval of California Air Plan Revision

    EPA Pesticide Factsheets

    EPA is proposing to approve a state implementation plan revision submitted by the State of California to meet Clean Air Act requirements applicable to the Western Mojave Desert (WMD) ozone nonattainment area.

  17. Genesis of secondary uranium minerals associated with jasperoid veins, El Erediya area, Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Abd El-Naby, Hamdy H.

    2008-11-01

    Uranium mineralization in the El Erediya area, Egyptian Eastern Desert, has been affected by both high temperature and low temperature fluids. Mineralization is structurally controlled and is associated with jasperoid veins that are hosted by a granitic pluton. This granite exhibits extensive alteration, including silicification, argillization, sericitization, chloritization, carbonatization, and hematization. The primary uranium mineral is pitchblende, whereas uranpyrochlore, uranophane, kasolite, and an unidentified hydrated uranium niobate mineral are the most abundant secondary uranium minerals. Uranpyrochlore and the unidentified hydrated uranium niobate mineral are interpreted as alteration products of petscheckite. The chemical formula of the uranpyrochlore based upon the Electron Probe Micro Analyzer (EPMA) is A {left( {{text{U}}_{{1.07}} {text{Ca}}_{{0.28}} {text{Pb}}_{{0.03}} {text{Na}}_{{0.21}} {text{Mg}}_{{0.02}} } right)}_{{Σ 1.6}} B {left( {{text{Nb}}_{{0.57}} {text{Si}}_{{0.62}} {text{Zr}}_{{0.35}} {text{P}}_{{0.20}} {text{Fe}}_{{0.17}} {text{Al}}_{{0.06}} {text{Ti}}_{{0.03}} } right)}_{{Σ 2}} . It is characterized by a relatively high Zr content (average ZrO2 = 6.6 wt%). The average composition of the unidentified hydrated uranium niobate mineral is ^{{text{U}}} {left( {{text{U}}_{{1.89}} {text{Ca}}_{{0.49}} {text{Pb}}_{{0.13}} {text{Na}}_{{0.06}} {text{Mg}}_{{0.02}} } right)}_{{Σ 2.59}} ^{{{text{Nb}}}} {left( {{text{Nb}}_{{1.31}} {text{Fe}}_{{0.34}} {text{Si}}_{{0.14}} {text{P}}_{{0.10}} {text{Ti}}_{{0.05}} {text{Zr}}_{{0.03}} {text{Al}}_{{0.03}} } right)}_{{Σ 2.0}} , where U and Nb represent the dominant cations in the U and Nb site, respectively. Uranophane is the dominant U6+ silicate phase in oxidized zones of the jasperoid veins. Kasolite is less abundant than uranophane and contains major U, Pb, and Si but only minor Ca, Fe, P, and Zr. A two-stage metallogenetic model is proposed for the alteration processes and uranium mineralization at

  18. Diagenesis of the lower Eocene Thebes Formation, Gebel Rewagen area, Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Shaaban, Mohamad N.

    2004-03-01

    The diagenesis of lower Eocene shallow water carbonates with flint was studied in the Gebel Rewagen area, Eastern Desert, Egypt. The carbonates are mainly wackestones to packstones with benthic bioclasts embedded in a dark red luminescent micrite matrix. The studied succession displays a complex diagenetic history that involves syngenetic and late diagenetic processes. Silica, which exists either as persistent bands, nodules and/or silicified benthic bioclasts shows a distinctive pattern regarding its distribution, source, depositional environments and timing. Three lines of evidence support a syngenetic origin of the chert bands: (1) they alternate in a cyclic manner within the host carbonates and (2) they exhibit noticeable lateral persistence throughout the investigated area following the strata boundaries and (3) there is a lack of any carbonate dissolution in limestone adjacent to chert bands. The deposition of silica bands in association with shallow water carbonates is possibly related to eustatic sea-level changes, which were accompanied by episodic variations in silica and carbonate productivities. With a relative sea-level fall and the establishment of a lowstand period at the end of the early Eocene, a basinward shift of the groundwater zones is expected within the carbonate platform. During this period some late diagenetic processes took place, which involve: (1) the formation of siliceous and carbonate concretionary growths, (2) partial silicification of bioclasts, (3) neomorphic stabilization of the CaCO 3 bioclasts and (4) the formation of equant calcite cement. Siliceous and carbonate concretions are believed to have taken place within microenvironments created and controlled by sulphate-reducing bacteria and physico-chemical and kinetic factors near a marine-meteoric water mixing zone. This is inferred from the distribution of iron sulphides, the non-ferroan nature of all concretions and the depleted δ13C (-5.4‰ to -6.0‰ PDB) and δ18O (-5.8

  19. Estimating and interpretation of radioactive heat production using airborne gamma-ray survey data of Gabal Arrubushi area, Central Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Youssef, Mohamed A. S.

    2016-02-01

    The present work deals with mapping of radioactive heat production from rocks in the Gabal Arrubushi area in the Central Eastern Desert of Egypt based on airborne spectral gamma-ray survey data. The results show that the radioactive heat production in the areas ranges from 0.01 μWm-3 to 5.2 μWm-3. Granites, muscovite and sericite schists in the western part of Gabal Arrubushi area have abnormally high radioactive heat production values from 2.57 μWm-3 to 4.44 μWm-3. Meanwhile, the higher averages of radioactive heat production of these rock units change from 1.21 μWm-3 to 1.5 μWm-3. The intermediate averages of heat production of felsitic mylonite schist, chlorite schist, felsites, amphibolites and Hammamat sediments are below the crustal average value range, i.e., from 0.8 μWm-3 to 1.2 μWm-3. The lowest averages of heat production values are less than 0.8 μWm-3 and found in the following rock units: Wadi sediments, rhyolites, andesites, gabbro and serpentinites.

  20. Petrogenetic and geotectonic significance of Neoproterozoic suprasubduction mantle as revealed by the Wizer ophiolite complex, Central Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Farahat, E. S.; Hoinkes, G.; Mogessie, A.

    2011-10-01

    Ophiolite complexes, formed in a suprasubduction zone environment during Neoproterozoic time, are widely distributed in the Eastern Desert of Egypt. Their mantle sections provide important information on the origin and tectonic history of ocean basins these complexes represent. The geochemistry and mineralogy of the mantle section of the Wizer ophiolite complex, represented by serpentinites after harzburgite containing minor dunite bodies, are presented. Presence of antigorite together with the incipient alteration of chromite and absence of chlorite suggests that serpentinization occurred in the mantle wedge above a Neoproterozoic subduction zone. Wizer peridotites have a wide range of spinel compositions. Spinel Cr# [100Cr/(Cr + Al)] decrease gradually from dunite bodies (Cr# = 81-87) and their host highly depleted harzburgites (Cr# = 67-79) to the less depleted harzburgites (Cr# = 57-63). Such decreases in mantle refractory character are accompanied by higher Al and Ti contents in bulk compositions. Estimated parental melt compositions point to an equilibration with melts of boninitic composition for the dunite bodies (TiO2 = ~<0.07-0.22 wt%; Al2O3 = 9.4-10.6 wt%), boninitic-arc tholeiite for the highly depleted harzburgites (TiO2 = <0.09-0.28 wt%; Al2O3 = 11.2-14.1 wt%) and more MORB-like affinities for the less depleted harzburgites (TiO2 = ~<0.38-0.51 wt%; Al2O3 = 14.5-15.3 wt%). Estimated equilibrium melts are found in the overlying volcanic sequence, which shows a transitional MORB-island arc geochemical signature with a few boninitic samples. Enrichment of some chromites in TiO2 and identification of sulfides in highly depleted peridotites imply interaction with an impregnating melt. A two-stage partial melting/melt-rock reaction model is advocated, whereby, melting of a depleted mantle source by reaction with MORB-like melts is followed by a second stage melting by interaction with melts of IAT-boninitic affinities in a suprasubduction zone environment to

  1. Desert landforms of southwest Egypt: A basis for comparison with Mars

    NASA Technical Reports Server (NTRS)

    El-Baz, F. (Editor); Maxwell, T. A. (Editor)

    1982-01-01

    Geologic interpretations of The Gilf Kebir-Uweinat of Apollo-Soyuz photographs were verified. The photographs and LANDSAT images showed features reminiscent of those depicted by Mariner and Viking missions to Mars. These features were to better understand their morphologic analogs on Mars. It is indicated that climate change played a significant role in the formation of the eastern Sahara. It is also revealed that correlations between the eolian features in southwestern Egypt and the wind blown patterns on the surface of Mars result in a better understanding of eolian activity on both planets.

  2. Natural radionuclide concentrations in granite rocks in Aswan and Central-Southern Eastern Desert, Egypt and their radiological implications.

    PubMed

    Issa, Shams A M; Uosif, M A M; Abd el-Salam, L M

    2012-07-01

    Different types of granites, used extensively in local construction, were collected from five localities in Egypt, namely: Abu Ziran (Central Eastern Desert), Gabal El Maesala (Aswan) and three areas from Wadi Allaqi, (Gabal Abu Marw, Gabal Haumor and Gabal um Shalman), in the South Eastern Desert. Granite samples were studied radiologically, petrographically and geochemically. The contents of natural radionuclides ((226)Ra, (232)Th and (40)K) were measured in investigated samples by using gamma spectrometry [NaI (Tl) 3'×3']. The activity concentrations of (226)Ra, (232)Th and (40)K in the selected granite samples ranged from 9±0.5 to 111±7, 8±1 to 75±4 and 100±6 to 790±40 Bq kg(-1), respectively. The external hazard index (H(ex)), absorbed dose and annual effective dose rate were evaluated to assess the radiation hazard for people living in dwellings made of the materials studied. The calculated radium equivalents were lower than the values recommended for construction materials (370 Bq kg(-1)). The excess lifetime cancer risks were also calculated. Petrographically, the granites studied are varied in the form of potash-feldspar, quartz, plagioclase, mica and hornblende. The accessory minerals are zircon, apatite and allanite. Geochemically, the chemical composition of the granite is studied especially for major oxides. They are characterized to have SiO(2), K(2)O, Na(2)O and Al(2)O(3) with depletion in CaO, MgO, TiO(2) and P(2)O(5).

  3. Some biomedical applications of Balanites aegyptiaca grown naturally in radioactive area, Southeastern Desert, Egypt.

    PubMed

    Morsy, A M A; Ahmad, I A; Kamel, A M

    2010-06-15

    Balanites aegyptiaca is a naturally grown desert plant at some radioactive places in Wadi El-Gemal area, Southeastern Desert. The aim of the present study was to highlight on the B. aegyptiaca species grown naturally at radioactive places in Wadi El-Gemal area (fruit part) on the ability of using the fruit in some biomedical application (glucose, cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol and diabetes). The investigated plant was collected from different location at Wadi El-Gemal area. The uranium content was determined previously and different concentrations from the fruit with highest uranium content were used to examine the effect of B. aegyptiaca (fruit part) on the glucose, triglycerides, total cholesterol (HDL and LDL-cholesterol) levels using experimental rats. Different analysis techniques were used in order to determine different parameters. The obtained data suggest the beneficial role of B. aegyptiaca fruit as an anti-diabetic and hypo-lipidimic agent.

  4. A fore-arc setting of the Gerf ophiolite, Eastern Desert, Egypt: Evidence from mineral chemistry and geochemistry of ultramafites

    NASA Astrophysics Data System (ADS)

    Abdel-Karim, Abdel-Aal M.; Ali, Shehata; Helmy, Hassan M.; El-Shafei, Shymaa A.

    2016-10-01

    The Gerf ophiolite is the largest mantle-derived complex in the Arabian-Nubian Shield (ANS). This ophiolitic complex extends for tens of kilometers in the south Eastern Desert (SED) of Egypt as part of the Allaqi-Heiani and Oneib-Sol Hamed suture zones. The ultramafic section of the Gerf ophiolite comprises serpentinites, serpentinized peridotites and minor pyroxenites. All rocks contain relics of original magmatic phases. The elevated Cr# (> 0.84) of Cr-spinels indicates that these rocks represent highly-depleted mantle residues after high degrees of melt extraction. Mineral and bulk-rock chemistry show that the Gerf ophiolite suite represents fragments of oceanic lithosphere that developed in fore-arc setting in a supra-subduction zone (SSZ) environment. The pyroxenites have a LREE-enriched pattern relative to the serpentinites while the serpentinized peridotites display depleted patterns [average (La/Yb)n = 0.56)]. Modeling of LREE suggests that the LREE-enriched pyroxenites and serpentinites could have been produced via contamination of their mantle source by crustal material and/or subduction-related slab fluids during the mantle evolution in a SSZ setting or soon after ophiolite assemblage obduction onto the continental crust. In contrast, the LREE-depleted serpentinized peridotites could have been generated through MORB melt/mantle rock reaction.

  5. Mapping of Gold Mineralization Alteration Zones in Central Eastern Desert Egypt using Spectral Angular Mapper and Aeromagnetic Data

    NASA Astrophysics Data System (ADS)

    Hasan, E.; Fagin, T.; El Alfy, Z.

    2014-12-01

    Central Eastern Desert (CED), Egypt has long history of gold exploration and exploitation. In this study, we integrated Spectral Angular Mapper (SAM) technique and aeromagnetic data to map the gold mineralization associated within alteration zones in CED. The spectral reflectance curves of five main alteration minerals (Hematite, Illite, Kaolinite, Chlorite, and Quartz) were utilized as end members in the SAM supervised classification of ETM+ data. Each alteration mineral type was represented as a binary image that overlaid together to obtain single primary alteration map in CED. The possible pathways for the alteration migration was defined based on the subsurface and surface lineation features. For the subsurface lineation, Euler deconvolution filter was applied on the aeromagnetic data to locate the deep-seated faults. The surface lineation and shear zones were extracted from ETM+ data and used together with the subsurface lineation map to obtain a structural map. Layer intersection and fuzzy membership operation were applied for the entire datasets to identify the possible sites of alteration zones. Several GPS readings were taken from the field areas around the gold mine sites, and used as validation points for our primary results.

  6. Rare earth elements content in geological samples from eastern desert, Egypt, determined by instrumental neutron activation analysis.

    PubMed

    El-Taher, A

    2010-09-01

    Twenty representative geological samples (tonalite, granodiorite, adamellite, syenogranite, rapakivi syenogranite, alkali feldspar granite and monzogranite) were collected from G. Kattar area in Eastern Desert, Egypt, for analysis by instrumental neutron activation as a sensitive nondestructive analytical tool for the determination of 14 rare earth elements (REEs) and to find out the following: (1) what information could be obtained about the REEs and distribution patterns of REEs in geological samples under investigation, (2) to estimate the accuracy, reproducibility and detection limit of the INAA method in case of the given samples. The samples were properly prepared together with standard reference material and simultaneously irradiated in a neutron flux of 7x10(11)n/cm(2)s in the TRIGA Mainz research reactor facilities. The gamma spectra were collected by an HPGe detector and the analysis was done by means of a computerized multichannel analyzer. The choice of the nuclear reaction, irradiation and decay times, and of the proper gamma radiation in counting are presented and discussed. The results are found to be in good agreement with certified values.

  7. Magmatic and solid state structures of the Abu Ziran pluton: Deciphering transition from thrusting to extension in the Eastern Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Fritz, Harald; Loizenbauer, Jürgen; Wallbrecher, Eckart

    2014-11-01

    The 606 Ma old Abu Ziran granite of the Eastern Desert of Egypt intruded the southern margin of the Meatiq dome in a sinistral shear extensional setting. Its emplacement was enabled by a system of NW-trending sinistral shears, related Riedel shears and N-S extensional shear zones and faults. Magmatic flow was east-directed and controlled by Riedel shears that progressively rotated to an orientation favourable for extension. Strain markers that document magmatic flow show eastward decreasing strain together with strain increase from pluton centre to margins. This is explained by Newtonian flow between non-parallel plates and differences in flow velocities across the pluton. Solid state fabrics including shear fabrics, orientation of late magmatic dykes and quartz tension gashes, together with quartz C-axes distributions, document southward extensional shear within the solidified pluton and adjacent host rocks. Extensional shear is correlated with exhumation of the Meatiq dome coeval and soon after pluton solidification (585 Ma). Pressure temperature evolutionary paths, derived from fluid inclusions, show a clockwise path with exhumation by isothermal decompression in the Meatiq dome. By contrast, the overlying volcanosedimentary nappes experienced an anti-clockwise path released by temperature rise due to pluton emplacement followed by isobaric cooling. Quartz fabrics indicate high-temperature coaxial N-S flow in the northern Meatiq dome and lower-temperature, non-coaxial southward flow within the overlaying superficial nappe. This is explained by the exhumation process itself that progressively localised into simple shear domains when rocks approached higher crustal levels. Late extension at ca. 580 Ma was pure shear dominated and resulted in reversal of shear, now dextral, in the western Meatiq shear zone.

  8. North-South Partnership in Space Research and Application: Space Research Center at Minufiyia University, Egypt, as Case Study

    NASA Astrophysics Data System (ADS)

    Shaltout, M.

    With the starting the year 2002 the Minufiyia University Council taked an Issue by construction Space Research Center, as a first Center for Space Research in the Egyptian Universities (20 Universities), as a part from the Desert Environment Research Institute for temporal time, then after the growth, it will be independent center. The green area of Egypt (Nile Valley and Delta) are 4% only from the total area of Egypt, the remain 96% is desert area. The most useful thing is to study the desert from space. For that the suggested projects to be performed in this new center are: 1.Monitoring the storage tanks of the underground water in the Egyptian Desert (Sahara) by artificial satellites as GRACE of NASA and DLR. 2.Building 32 meter Radio telescope at Abu-Simbel in the South of Egypt as part of the European VLBI network (EVN) to cover the gab between the radio telescope in the western Europe and the radio telescope at Hartebessthock in South Africa. The cooperation of International interested institutions is being explored for this important project of Egypt. 3.Solar activity and the climatic changes through the 21st century as clarified by global solar radiation data at Khargha Oases at the western desert of Egypt. 4.Testing of the Martian exploration instruments for 2003 and 2005 space trips to Mars in the western desert of Egypt, as it is the driest area in the worl d, where are similarity between the dry atmosphere of Sahara and the atmosphere of Mars, also in the soil, and dry valleys. In collaboration with NASA and ESA. 5.Studding the eastern structure, due to meteoric impact in the western desert of Egypt since 28 Million years. Also, studding the meteors chemistry, for meteors found in the Egyptian desert, and the origin of life as meteor (Nachlet) in collaboration with NASA and ESA. Solar energy and humidity distribution over Sahara from artificial Satellite Meteostat observations.

  9. The way forward in capacity building in developing countries: space research center at Minoufiyia University, Egypt, as case study

    NASA Astrophysics Data System (ADS)

    Mosalam Shaltout, M. A.

    With the starting the year 2002 the Menoufiyia University Council taked an Issue by construction Space Research Center, as a first Center for Space Research in the Egyptian Universities (20 Universities), as a part from the Desert Environment Research Institute for temporal time, then after the growth, it will be independent center. The green area of Egypt (Nile Valley and Delta) are 4% only from the total area of Egypt, the remain 96% is desert area. The most useful thing is to study the desert from space. For that the suggested projects to be performed in this new center are: 1. Monitoring the storage tanks of the underground water in the Egyptian Desert (Sahara) by artificial satellites as GRACE of NASA and DLR. 2. Building 32 meter Radio telescope at Abu-Simbel in the South of Egypt as part of the European VLBI network (EVN) to cover the gab between the radio telescope in the western Europe and the radio telescope at Hartebessthock in South Africa. The cooperation of International interested institutions is being explored for this important project of Egypt. 3. Solar activity and the climatic changes through the 21st century as clarified by global solar radiation data at Khargha Oases at the western desert of Egypt. 4. Testing of the Martian exploration instruments for 2005 space trips to Mars in the western desert of Egypt, as it is the driest area in the world, where are similarity between the dry atmosphere of Sahara and the atmosphere of Mars, also in the soil, and dry valleys. In collaboration with NASA and ESA. 5. Studding the eastern structure, due to meteoric impact in the western desert of Egypt since 28 Million years. Also, studding the meteors chemistry, for meteors found in the Egyptian desert, and the origin of life as meteor (Nachlet) in collaboration with NASA and ESA. 6. Solar energy and humidity distribution over Sahara from artificial Satellite Meteostat observations.

  10. Ground-water quality and geochemistry, Carson Desert, western Nevada

    USGS Publications Warehouse

    Lico, Michael S.; Seiler, R.L.

    1994-01-01

    Aquifers in the Carson Desert are the primary source of drinking water, which is highly variable in chemical composition. In the shallow basin-fill aquifers, water chemistyr varies from a dilute calcium bicarbonate-dominated water beneath the irrigated areas to a saline sodium chloride- dominated water beneath unirrigated areas. Water samples from the shallow aquifers commonly have dissolved solids, chloride, magnesium, sulfate, arsenic, and manganese concentrations that exceed State of Nevada drinking-water standards. Water in the intermediante basin-fill aquifers is a dilute sodium bicarbonate type in the Fallon area and a distinctly more saline sodium chloride type in the Soda Lake-Upsal Hogback area. Dissolved solids, chloride, arsenic, fluoride, and manganese concen- trations commonly exceed drinking-water standards. The basalt aquifer contains a dilute sodium bicarbonate chloride water. Arsenic concentrations exceed standards in all sampled wells. The concen- trations of major constituents in ground water beneath the southern Carson Desert are the result of evapotranspiration and natural geochemical reactions with minerals derived mostly from igneous rocks. Water with higher concentrations of iron and manganese is near thermodynamic equilibrium with siderite and rhodochrosite and indicates that these elements may be limited by the solubility of their respective carbonate minerals. Naturally occurring radionuclides (uranium and radon-222) are present in ground water from the Carson Desert in concen- tratons higher than proposed drinking-water standards. High uranium concentrations in the shallow aquifers may be caused by evaporative concentration and the release of uranium during dissolution of iron and manganese oxides or the oxidation of sedimentary organic matter that typically has elevated uranium concentrations. Ground water in the Carson Desert does not appear to have be contaminated by synthetic organic chemicals.

  11. Structural lineaments in the basement rocks of the central Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Kamel, A. F.

    The Egyptian basement rocks outcrop in Eastern Desert, southern Sinai and southwestern Desert. The rocks belong to Precambrian and consist of igneous and metamorphic rocks which are characterized by crystalline character. Not much work has been done on the tectonics and structure of the basement rocks in Eastern Desert. The present work is a photogeological interpretation of the structural lineaments representing dykes, faults and joints in central Eastern Desert to differentiate between igneous and metamorphic rocks. The photogeological interpretation was carried out using normal aerial photographs scale 1:40 000 and photomosaics scale 50 000. The main trends of lineaments in the studied area are: E-W, ENE-WSW and WNW-ESE, constituting 58.4% of the total length and 54.5% of the total number. Correlating the structural lineaments in igneous rocks of Gebel El Bakriya locality with those in the metamorphic rocks of Gebel Abu Mireiwa shows that there is a marked difference between the two types. Lineaments in igneous rocks are elongated and widely spaced while those in metamorphic rocks are short and closely spaced. The different trends of joints in igneous rocks can be arranged as follows: WNW>E-W>NW>NNW>ENE>NE>N-S>NNE while the different trends of lineaments in metamorphic rocks can be arranged as follows: E-W>ENE>WNW>NW>NNW>NE>N-S>NNE. Comparison between the structural contour maps constructed for the total length of all lineaments and those representing joints in igneous and metamorphic rocks indicates that igneous rocks have lower density of lineaments than metamorphic rocks. The total length of all lineaments in Gebel El Bakriya amounts to 375 km, while lineaments representing joints have a total length of 150 km. In the metamorphic rocks of Gebel Abu Mireiwa, the total length of all lineaments is 425 km and those representing joints have a total length of 175 km. It was found that there is a relationship between the structural lineaments and radioactivity of

  12. Investigation of geotechnical parameters from CSEM mapping and monitoring data at the oases Kharga and Baris of Sahara desert, Egypt

    NASA Astrophysics Data System (ADS)

    Hachay, Olga; Khachay, Oleg; Attia, Magdy; Khalil, Ahmed; Mekkawi, Mahmoud; Soliman, Mamdouh

    2016-04-01

    The site of investigation, oasis Kharga, is located at about 600 km south of Cairo, Egypt; Baris is about 90 km from Kharga also to south and towards more inside the desert. The work was aimed to investigate the rock mass stability at Baris and to estimate the water intake in the Oasis Kharga. A controlled source electromagnetic (CSEM) approach developed earlier by IGF UB RAS (Geophysical Federal Institute, Ural Branch of Russian Academy of Science) is applied to image the ranked deformation levels in the massive structure of the Baris. The wide profile system of observation has been used to monitor the three components of the alternating magnetic field along predefined measuring lines in the study area. Here we can show the first results that we shall continue during some cycles of monitoring. The second part of our work was linked with mapping the massif structure inside the oasis City, where only using our device we could construct the geoelectrical sections for 5 profiles and show the real structure of the water volume and its complicated structure up to 200 meters depth recording the values of real not apparent resistivity. The analytical treatments provided good information about the structure of the rock massive and its rank of degradation, the lateral distribution of the geotechnical heterogeneity, and finally a conclusive outcome about foundation stability. We can conclude that the general dynamic state close to the destruction level within the investigation areas is getting worse over the time; this is reflected in the crack's densities and positions, also on the changes in the lateral distribution of geoelectrical heterogeneity as an indicator of the saturation of the surface rock in the study area with water [1,2]. References 1. Magdy A. Atya, Olga A. Hachay, Mamdouh M. Soliman, Oleg Y. Khachay, Ahmed B. Khalill, Mahmoud Gaballah, Fathy F.Shaaban and Ibrahim A.El. Hemali. CSEM imaging of the near surface dynamics and its impact for foundation stability

  13. Shelf architectures of an isolated Late Cretaceous carbonate platform margin, Galala Mountains (Eastern Desert, Egypt)

    NASA Astrophysics Data System (ADS)

    Scheibner, C.; Marzouk, A. M.; Kuss, J.

    2001-12-01

    An asymmetrical carbonate platform margin to basin transect has been investigated in the Upper Campanian-Maastrichtian succession of the Galala Mountains, northern Egypt. Identification of systems tracts and their lateral correlation was possible in slope sections only, whereas the monotonous chalk-marl alternations of the basinal sections could not be subdivided with respect to sequence stratigraphic terminology. The platform asymmetry is expressed by varying large-scale depositional architectures exhibiting a rimmed platform with a sigmoidal slope curvature in south-easterly dip-sections and a ramp with a linear slope curvature in south-westerly dip-sections. The rimmed platform is subdivided into a gentle upper slope and a steep lower slope. The platform formed as a result of the initial topography that was controlled by the tectonic uplift of the Northern Galala/Wadi Araba Syrian Arc structure. The calculated angles of the steep lower slope of the rimmed part range from 5 to 8°, whereas the ramp part has an angle of less than 0.1°.

  14. Heat production rate from radioactive elements in igneous and metamorphic rocks in Eastern Desert, Egypt.

    PubMed

    Abbady, Adel G E; El-Arabi, A M; Abbady, A

    2006-01-01

    Radioactive heat-production data of Igneous and Metamorphic outcrops in the Eastern Desert are presented. Samples were analysed using a low level gamma-ray spectrometer (HPGe) in the laboratory. A total of 205 rock samples were investigated, covering all major rock types of the area. The heat-production rate of igneous rocks ranges from 0.11 (basalt) to 9.53 microWm(-3) (granite). In metamorphic rocks it varies from 0.28 (serpentinite ) to 0.91 microWm(-3) (metagabbro). The contribution due to U is about 51%, as that from Th is 31% and 18% from K. The corresponding values in igneous rocks are 76%, 19% and 5%, respectively. The calculated values showed good agreement with global values except in some areas containing granites.

  15. Pressure, temperature and oxygen fugacity conditions of calc-alkaline granitoids, Eastern Desert of Egypt, and tectonic implications

    NASA Astrophysics Data System (ADS)

    Helmy, H. M.; Ahmed, A. F.; El Mahallawi, M. M.; Ali, S. M.

    2004-02-01

    Five calc-alkaline plutons; Um Tagher, Abu Zawil, Um Gidri, Um Anab and El Ghuzah, in the northern Eastern Desert of Egypt were subjected to petrographic and mineralogical investigations. They are composed of varying proportions of quartz + plagioclase + potash feldspar + biotite + hornblende ± epidote ± calcite + titanite + magnetite + apatite and zircon. Electron microprobe analyses of coexisting hornblende and plagioclase (hornblende-plagioclase thermometry), Al content in hornblende (aluminum-in-hornblende barometry) and the assemblage titanite-magnetite-quartz were used to constrain the P, T and fO 2 during the crystallization of the parent magmas in the different plutons. The plutons crystallized under varying pressures (5.4-2.1 kbar) and wide range of temperature (785-588 °C) from highly oxidized magmas (log fO 2 -21 to -13). The pressure data discriminate three categories of granitoid emplaced at different crustal levels: (a) upper crust granitoids (e.g., El Ghuzah, and Abu Zawil) emplaced at depths <9 km; (b) intermediate crust granitoids (e.g., Um Gidri and Um Anab) emplaced at depths <13 km; and (c) lower crust granitoids (e.g., Um Tagher) emplaced at depths <21 km. The depths of emplacement seem to increase from northwest to southeast. It is likely that the magmas forming these plutons were generated at different depths; they were similar in composition but varied substantially in their water and volatile contents. High water and volatile contents allowed the magma of some plutons to reach shallower crustal levels without complete solidification. Although these complexes were crystallized at different depths, they were later uplifted to the same level by upward faulting.

  16. The Neoproterozoic Kolet Um Kharit bimodal metavolcanic rocks, south Eastern Desert, Egypt: a case of enrichment from plume interaction?

    NASA Astrophysics Data System (ADS)

    Farahat, E. S.

    2006-04-01

    Neoproterozoic metavolcanic rocks of Kolet Um Kharit (KUKh) in the southern Eastern Desert of Egypt have been traditionally regarded as a bimodal island-arc sequence. However, geological and geochemical arguments presented here make this interpretation doubtful. Geochemically, these rocks are classified into mafic (tholeiitic basalts) and felsic (high-K rhyodacites to rhyolites) groups. Both the KUKh mafic and felsic metavolcanic rocks show similar geochemical characteristics, implying a genetic link. They have comparable trace element ratios, such as Zr/Nb (27 30 vs. 20 36), Y/Nb (5.44 6.25 vs. 5.05 5.9), K/Rb (577 1164 vs. 573 937), Ba/La (4.29 25 9 vs. 11.4 16.2), Nb/Yb (1.82 2.03 vs. 1.76 1.99). Similarly both groups have parallel LREE-enriched patterns (La/YbCN=2.37 2.81 vs. 2.55 3.17); and negative Nb and Ta anomalies (Nb/Lapm=0.51 0.58 vs. 0.45 0.52 and Ta/Lapm=0.51 0.62 vs. 0.49 0.55). The observed negative Nb and Ta anomalies in the KUKh metavolcanic rocks cannot be attributed to crustal contamination or fractional crystallization. These rocks could represent either a remnant of break-up LIP or were derived from an enriched mantle source containing subduction components beneath an intraoceanic back-arc basin. The recognition of the KUKh rocks as derived from an enriched mantle source revives interest in models that involve enrichment from “plume” interaction during the evolution of the Arabian-Nubian Shield.

  17. Integration of geophysical and geological data for delimitation of mineralized zones in Um Naggat area, Central Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Gaafar, Ibrahim

    2015-06-01

    An integrated approach for geophysical, geological and mineralogical data was followed for Um Naggat area, Central Eastern Desert, Egypt, in order to delineate its mineralized zones. The albitized granites are well-defined on the Th- and U-channel images, by their anomalous shapes, reaching 150 ppm and 90 ppm respectively, beside low K content. Interpretations of the aeromagnetic maps delineated four regional structural trends oriented due NNW, NW, ENE and E-W directions. They are identified as strike-slip faults, which coincide well with field observations, where NW-trending faults cut and displace right laterally ENE-trending older ones. The interaction between these two strike-slip fault systems confining the albite granite is easily identified on the regional data presenting longer wavelength anomalies, implying deep-seated structures. They could represent potential pathways for migration of enriched mineralized fluids. Geochemically, albite granites of peraluminous characteristics that had suffered extensive post-magmatic metasomatic reworking, resulted into development of (Zr, Hf, Nb, Ta, U, Th, Sn) and albite-enriched and greisenized granite body of about 600 m thick, and more than 3 km in strike length. The albite granite is characterized by sharp increase in average rare metal content: Zr (830 ppm), Hf (51 ppm), Nb (340 ppm), Ta (44 ppm), and U (90 ppm). Thorite, uranothorite, uraninite and zircon are the main uranium-bearing minerals of magmatic origin within the enclosing granite. However, with respect to Zr, Nb, and Ta, the albitized granite can be categorized as rare metal granite. The integration of airborne geophysical (magnetic and γ-ray spectrometric), geological, geochemical and mineralogical data succeeded in assigning the albite granite of Um Naggat pluton as a mineralized zone. This zone is characterized by its high thorium and uranium of hydrothermal origin as indicated by its low Th/U ratio, with rare metals mineralization controlled by two

  18. Remote sensing detection of gold related alteration zones in Um Rus area, Central Eastern Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Amer, Reda; Kusky, Timothy; El Mezayen, Ahmed

    2012-01-01

    Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Phased Array L-band Synthetic Aperture Radar (PALSAR) images covering the Um Rus area in the Central Eastern Desert of Egypt were evaluated for mapping geologic structure, lithology, and gold-related alteration zones. The study area is covered by Pan-African basement rocks including gabbro and granodiorite intruded into a variable mixture of metavolcanics and metasediments. The first three principal component analyses (PCA1, PCA2, PCA3) in a Red-Green-Blue (RGB) of the visible through shortwave-infrared (VNIR + SWIR) ASTER bands enabled the discrimination between lithological units. The results show that ASTER band ratios ((2 + 4)/3, (5 + 7)/6, (7 + 9)/8) in RGB identifies the lithological units and discriminates the granodiorite very well from the adjacent rock units.The granodiorites are dissected by gold-bearing quartz veins surrounded by alteration zones. The microscopic examination of samples collected from the alteration zones shows sericitic and argillic alteration zones. The Spectral Angle Mapper (SAM) and Spectral Information Divergence (SID) supervised classification methods were applied using the reference spectra of the USGS spectral library. The results show that these classification methods are capable of mapping the alteration zones as indicated by field verification work. The PALSAR image was enhanced for fracture mapping using the second moment co-occurrence filter. Overlying extracted faults and alteration zone classification images show that the N30E and N-S fractures represent potential zones for gold exploration. It is concluded that the proposed methods can be used as a powerful tool for ore deposit exploration.

  19. Ophicarbonates: calichified serpentinites from Gebel Mohagara, Wadi Ghadir area, Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Surour, Adel A.; Arafa, Ebtisam H.

    1997-04-01

    An ophicalcite occurrence is recorded in the uppermost part of the Precambrian ophiolitic serpentinites at Gebel Mohagara (Wadi Ghadir area) in the Egyptian Eastern Desert. In this locality, the serpentinites and their ophicalcites are sometimes directly overlain by pelagic shales and calcareous sediments along thrust planes. Field relations suggest that these ophicalcites are present as serpentine-carbonate breccias that develop along conjugate shear planes and brecciation zones. Typical sedimentary features are common, such as the presence of micritic carbonate, colloform texture, geopetal-like structures and the presence of vugs. The latter are often filled by coarse calcite spars due to diagenesis and neomorphism. Another older type of less brecciated ophicarbonates (ophimagnesites) is also present and shows extensive replacement of serpentine minerals by magnesite. The ophicalcites are considered as sedimentary breccias formed in a weathered serpentinite lithology with fabrics of typical calichified rocks. It is believed that the calichified serpentinites represent a reworked oceanic calcite that have been formed after the obduction of the ophiolite nappe on the continent. The dissolution of the calcareous material in the pelagic cap furnished the needed carbonate influx to fill the brecciated serpentinite below.

  20. Late Neoproterozoic Nuqara Dokhan Volcanics, Central Eastern Desert, Egypt: Geochemistery and petrogenesis

    NASA Astrophysics Data System (ADS)

    Hassan, Tharwat; Asran, Asran; Amron, Taha; Natflos, Theo

    2014-05-01

    The Nuqara volcanic is one of the northernmost outcrops of the Arabian-Nubian Shield Dokhan volcanics. The origin and tectonic setting of the late Neoproterozoic Dokhan volcanics (ca. 610-560 Ma) in the Egyptian Eastern Desert is highly debated. The debate concerns the tectonic setting where they formed during transition between convergent to extensional regime or after the East- and the West-Gondwana collision (~600Ma). In order to solve this problem, lavas from Nuqara area were studied geologically and geochemically. Nuqara Dokhan volcanics comprises two main rock suites: (a) an intermediate volcanic suite, consisting of basaltic andesite, andesite and their associated pyroclastics rocks; and (b) a felsic volcanic suite composed of dacite, rhyolite and ignimbrites. The two suites display well-defined major and trace element trends and continuum in composition with wide ranges in SiO2 (52-75.73%), CaO (9.19-0.22%), MgO (5.29-0.05%), Sr (1367-7.4 ppm), Zr (688.5-172.7 ppm), Cr (207-0.4 ppm), and Ni (94.3-0.2 ppm). The Nuqara Dokhan volcanics are characterized by strong enrichment in LILE relative to HFSE and affiliated to the calc-alkaline subducted - related magmatism. Geochemical Modeling displays that the evolution of these rocks was governed by fractional crystallization of plagioclase, amphiboles, pyroxene, magnetite and apatite in the intermediate varieties and plagioclase, amphibole, magnetite, apatite and zircon in the felsic varieties. The obtained mineral chemistry of these volcanics reveals: (a) Plagioclase range in composition from An55 to An40 in basaltic andesite and from An39 to An24 in andesite. (b) Alkali feldspars have sanidine composition. (c) Clinopyroxenes have augite composition. The low Al2O3 contents (1.94-5.588 wt %) indicate that clinopyroxene crystallized at low - pressure conditions. (d) Amphiboles have magnesio- hornblende composition.

  1. Significance of SHRIMP U-Pb dating of the Imperial Porphyry and associated Dokhan Volcanics, Gebel Dokhan, north Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Wilde, S. A.; Youssef, K.

    2000-08-01

    SHRIMP U-Pb zircon dating was undertaken on two samples of Dokhan Volcanics from the type area at Gebel Dokhan, north Eastern Desert, Egypt. A quartz andesite from the Imperial Porphyry unit has a weighted 206Pb/238U age of 593 ± 13 Ma (2σ). A sample of grey andesite, from ~450 m lower in the succession, has a weighted 206Pb/238U age of 602 ± 9 Ma (2σ). These ages are interpreted to record the time of eruption of the Dokhan Volcanics. Two concordant zircon cores in the upper sample define a weighted 206Pb/238U age of 685 ± 16 Ma (2σ), indicating inheritance from an older source. These cores have oscillatory zoning and may be derived from the 'older' granite basement or even an earlier volcanic sequence in the area. Care should, therefore, be taken in correlating all volcanic rocks in the Eastern Desert of Egypt with the Dokhan Volcanic Formation, as defined at the type locality.

  2. Petrology of a Neoproterozoic Alaskan-type complex from the Eastern Desert of Egypt: Implications for mantle heterogeneity

    NASA Astrophysics Data System (ADS)

    Khedr, Mohamed Zaki; Arai, Shoji

    2016-10-01

    This paper details petrological and geochemical studies of an ultramafic-mafic intrusion in the Southern Eastern Desert of Egypt. The Dahanib complex shows a concentric zonation, from dunites at the core, through chromitites, clinopyroxene-rich dunites, wehrlites, harzburgites, gabbronorites and layered gabbros, to hornblende gabbros/diorites at the rim, similar to other Alaskan-type complexes. These lithologies typically feature cumulate textures and layering. Their pyroxenes (Mg#s, 0.54-0.94) evidence Fe, Mn and Na enrichment, but Al, Cr, Mg and Ti are depleted with differentiation. Their chromian spinels have a wide range of Cr# (0.31-0.61), along with high Ti and Fe, as a result of their origin through crystal accumulation and reaction with interstitial liquids. The clinopyroxenes (Cpxs) in peridotites and gabbroic rocks, which are high in REE concentration (2-100 times chondrite), are depleted in LREE relative to HREE and are similar to Cpx crystallized from asthenospheric melts. The mineral inclusions in spinel, the chemistry of Cpx in peridotites (rich in Al, Cr, Na, Ti and ΣREE = 13.7), and the melts in equilibrium with Cpx suggest that the Neoproterozoic lithosphere were partially refertilized by trace asthenospheric melts. The early magmas were possibly enriched by Mg, Cr, Ni, Ti, V and Sr, while the evolved types were rich in Fe, Mn, Na, Li, Zr, Co and REE via crystal accumulation and the interaction with interstitial liquids. The Neoproterozoic sub-arc mantle in Egypt is chemically heterogeneous and generally low in Nb, Ta, Zr and K, due to the low solubility of HFSE in slab-derived fluids and no other external addition of these elements. The large variations in lithology and chemistry, as well as the occurrence of scattered chromitite clots in the Dahanib peridotites, are related to a continuous supply of primitive magmas and/or the reaction between interstitial liquids and early cumulus crystals during multistage fractional crystallization. The

  3. Ground geophysical study for development and exploration of El Missikat radioactive minerals prospect, Central Eastern Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Elkattan, E. M.; Sadek, H. S.; Rabie, S. I.; Hassanein, H. I.

    1995-08-01

    The El Missikat area lies in the Eastern Desert of Egypt, 85 km west of Qena town. The area being studied is covered mainly by pink granite, quartz-diorite rocks and wadi deposits. The importance of the area originates from previous studies, including airborne geophysics, surface geology and mining geology which indicate that the area has features of radioactive mineralization at the northeastern periphary of G. El Missikat. The present study deals with the use of ground geophysical methods (totalcount radiometric and magnetic) in the exploration of radioactive mineralization and their relation to the geology and structural pattern of the area. The ground total-count radiometric method is used to describe the radioactivity of different rock units and the construction of the standard deviation (or anomaly) contour map to define the anomalous radioactive zones. Eight prominent radioactive anomalies were outlined from this study and they represented targets of high priority for ground follow-up. Accordingly, to emphasize the extension of the anomalous zones at the subsurface, γ-ray logging was carried out on a total-count basis in one inclined drill hole (120 m depth) with dip angle 29 and azimuth N20°W at a selected location. In addition five subsurface radiometric anomalies were identified by γ-ray logging interpretation. The interpreted radioactive anomaly No. IV is considered a good indication of the subsurface continuity of a surface mineralized zone associated with the silica vein which was geologically mapped at the north of El Missikat well number II. Meanwhile, the total magnetic intensity survey was used to delineate the major structural features. The results of this study revealed the presence of six major, deep-seated faults, five basement tectonic blocks, basic or/and acidic zones, near-surface faults, contact between granite and quartz-diorite and several shear zones as well as dykes and veins. The integration between results of these two methods

  4. Petrogenesis of cogenetic silica-oversaturated and -undersaturated syenites of Abu Khruq ring complex, South Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Mogahed, Moustafa M.

    2016-12-01

    The upper Cretaceous Abu Khruq ring complex (ARC) is located in the South Eastern Desert of Egypt displays concentric zonation of syenitic rocks from quartz-rich syenite at the margin, through alkali feldspar syenite to nepheline syenite in the centre. The syenitic rocks occur with nepheline monzogabbro, volcanic rocks (phonolite and trachyte) and the quartz- and nepheline-bearing pegmatites. Rocks of contrasting composition (mafic and salic) exhibit sophisticate geometric relationships. The nepheline monzogabbroic rocks have pillowy xenoliths forms within the salic (nepheline syenite and quartz alkali feldspar syenite) rocks, suggesting synchronous emplacement of the mafic and salic magmas. Clinopyroxene analysis of mafic and salic plutonic rocks of the ARC revealed that the overall pyroxene trend suggesting that fractionation involved a late, progressive increase in Na, in a reaction of the type Ca Mg Fe2+↔Na Fe3+. The chemistry of the analysed amphiboles are compositionally similar to those from typical differentiated peralkaline suites. Geochemically, the complex is enriched in the LILE, HFSE and REE. The concentrations of the compatible elements (V, Sr and Ba) generally decrease with increasing silica, consistent with fractional crystallization. A generalised increase in the Nb/Ta from the nepheline monzogabbro to nepheline syenite compositions is attributed to titanite fractionation. All the rock samples show relative increment of the LREE content than the HREE indicating weak to steep fractionated REE patterns (La/Yb) from 9.43 to 10.86, and thus retaining the geochemical characteristics of anorogenic suites. The magma sources of ARC are not derived from normal primitive mantle. The early stages of differentiation involved extensive olivine and pyroxene fractionation, the fractionation of amphibole, titanite, magnetite, apatite and feldspar may have been involved in the genesis of the salic differentiated compositions. The deviation towards silica

  5. Natural radioactivity and radiation hazard assessment of phosphate mining, Quseir-Safaga area, Central Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Gaafar, Ibrahim; El-Shershaby, Amal; Zeidan, Ibrahim; El-Ahll, Lina Sayed

    2016-06-01

    Quseir-Safaga area, Central Eastern Desert, Egypt, includes Duwi Formation, which contains uranium-bearing phosphate beds. The present work used the integrated carborne γ-ray spectrometric data, X-ray analysis and HPGe γ-ray spectrometer data to investigate the radioactive zones at this area. Carborne γ-ray spectrometric survey revealed an increase of equivalent uranium, up to 182 ppm. Maps were drawn to show the results of the three radioelements K, eU, eTh and the eU/eTh ratio. The eU and (eU/eTh) maps reveal that there are twelve important anomalies, associated mainly with phosphate mines. The Hamrawein mines at the northwestern part in the study area seem to represent the highest U-anomalies. Twelve phosphate samples were collected from the determined twelve anomalies. They were analyzed with HPGe detector gamma-ray spectrometer. It was found that the results of radioelement concentrations by carborne survey agree well with that obtained by HPGe. Both of them show that phosphate mines effectively contribute to eU anomalies, occurring in the study area. Meanwhile, 40K, 238U and 232Th concentrations in phosphate samples range from 91 to 169, 864 to 3104 and 28.4 to 106 Bq/kg respectively. The highest concentration of 238U (3104 Bq/kg) occurs in the north of the studied area, close to Hamrawein city. The average concentration of 238U in the analyzed samples is 1766 Bq/kg, which is 53 times higher than the worldwide average value reaching 33 Bq/kg. The highest 232Th concentration value reaching 106 Bq/kg is 2.4 times higher than the worldwide value attaining 45 Bq/kg. The absorbed dose rate for the phosphate samples shows the highest value reaching 1468 nGy/h. This is more than 25 times the worldwide average value 58 nGy/h. The annual effective absorbed dose is also high and reached 1.8 mSv/y, which is about twice higher than the permitted value for public exposure of 1.0 mSv/y. The maximum external hazardous index value of 9.2 is more than nine times the unity

  6. Stratigraphy, facies architecture, and palaeoenvironment of Neoproterozoic volcanics and volcaniclastic deposits in Fatira area, Central Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Khalaf, Ezz El Din Abdel Hakim

    Fatira area in the Central Eastern Desert, Egypt, is a composite terrane consisting of Neoproterozoic volcanics and sediments laid down in submarine to subaerial environment, intruded by voluminous old to young granitic rocks. The various lithofacies of the study area can be grouped in three distinct lithostratigraphic sequences, which are described here in stratigraphic order, from base to top as the Fatira El Beida, Fatira El Zarqa and Gabal Fatira sequences. Each depositional sequence, is intimately related to volcanic activity separated by time intervals of volcanic inactivity, such as marked hiatuses, reworked volcaniclasts, and or turbidite sedimentation. Four submarine facies groups have been recognized within the oldest, folded eruption sequence of Fatira El Beida. The southern part of the study area is occupied by sheet lava (SL), pillow lavas (PL), pillow breccias (PB), and overlying Bouma turbiditic volcaniclastites (VC). The four facies groups of Fatira El Beida sequence occur in a predictable upward-deepening succession, essentially from base to top, an SL-PL-PB-VC stacking pattern. The coeval tholeiitic mafic and felsic volcaniclastic rocks of this sequence indicate an extensional back-arc tectonic setting. The El Beida depositional sequence appears to fit a submarine-fan and slope-apron environment in an intra-arc site. The Fatira El Zarqa sequence involves a large volume of subaerial calc-alkaline intermediate to felsic volcanics and an unconformably overlying siliciclastic succession comprising clast-supported conglomerates (Gm), massive sandstone sheet floods (Sm) and mudstones (FI), together with a lateritic argillite paleosol (P) top formed in an alluvial-fan system. The youngest rock of Gabal Fatira sequence comprises anorogenic trachydacites and rhyolites with locally emergent domes associated with autobrecciation and sill-dyke rock swarms that could be interpreted as feeders and subvolcanic intrusions. Unconformity and lithofacies assemblages

  7. Stratigraphy, sedimentology and tectonic evolution of the Upper Cretaceous/Paleogene succession in north Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    El Ayyat, Abdalla M.; Obaidalla, Nageh A.

    2013-05-01

    The stratigraphy, sedimentology and syn-depositional tectonic events (SdTEs) of the Upper Cretaceous/Paleogene (K-P) succession at four localities in north Eastern Desert (NED) of Egypt have been studied. These localities are distributed from south-southwest to north-northeast at Gebel Millaha, at North Wadi Qena, at Wadi El Dakhal, and at Saint Paul Monastery. Lithostratigraphically, four rock units have been recorded: Sudr Formation (Campanian-Maastrichtian); Dakhla Formation (Danian-Selandian); Tarawan Formation (Selandian-Thanetian) and Esna Formation (Thanetian-Ypresian). These rock units are not completely represented all over the study area because some of them are absent at certain sites and others have variable thicknesses. Biostratigrapgically, 18 planktonic foraminiferal zones have been recorded. These are in stratigraphic order: Globotruncana ventricosa Zone (Campanian); Gansserina gansseri, Contusotruncana contusa, Recimguembelina fructicosa, Pseudohastigerina hariaensis, Pseudohastigerina palpebra and Plummerita hantkenenoides zones (Maastrichtian); Praemurica incostans, Praemurica uncinata, Morozovella angulata and Praemurica carinata/Igorina albeari zones (Danian); Igorina albeari, Globanomanlina pseudomenradii/Parasubbotina variospira, Acarinina subsphaerica, Acarinina soldadoensis/Globanomanlina pseudomenardii and Morozovella velascoensis zones (Selandian/Thantian); and Acarinina sibaiyaensis, Pseudohastigerina wilcoxensis/Morozovella velascoensis zones (earliest Ypresian). Sedimentologically, four sedimentary facies belts forming southwest gently-dipping slope to basin transect have been detected. They include tidal flats, outer shelf, slumped continental slope and open marine hemipelagic facies. This transect can be subdivided into a stable basin plain plus outer shelf in the extreme southwestern parts; and an unstable slope shelf platform in the northeastern parts. The unstable slope shelf platform is characterized by open marine hemipelagic

  8. Integrating geologic and satellite imagery data for high-resolution mapping and gold exploration targets in the South Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Zoheir, Basem; Emam, Ashraf

    2012-05-01

    The granitoid-greenstone belts of the Arabian-Nubian Shield are well-endowed with lode gold and massive sulfide ores. Although generally characterized by excellent outcrops and arid desert realm, poor accessibility and lack of finance have been always retardant to detailed geologic mapping of vast areas of the shield. Lack of comprehensive geological information and maps at appropriate scales would definitely hinder serious exploration programs. In this study, band ratioing, principal component analysis (PCA), false-color composition (FCC), and frequency filtering (FFT-RWT) of ASTER and ETM+ data have substantially improved visual interpretation for detailed mapping of the Gebel Egat area in South Eastern Desert of Egypt. By compiling field, petrographic and spectral data, controls on gold mineralization have been assessed in terms of association of gold lodes with particular lithological units and structures. Contacts between foliated island arc metavolcanics and ophiolites or diorite are likely to be favorable loci for auriferous quartz veins, especially where the NW-SE foliation is deflected into steeply dipping NNW-trending shear planes. High-resolution mapping of the greenstone belt, structures and alteration zones associated with gold lodes in the study area suggests that dilatation by foliation deflection was related to emplacement of the Egat granitic intrusion, attendant with a sinistral transpression regime (i.e., ˜640-550 Ma?). Gold mineralization associated with granitoid intrusions in transpression-induced pull-apart structures elsewhere in the Eastern Desert (e.g., Fawakhir, Sukari and Hangaliya mines) emphasize the reliability of this setting as a model for gold exploration targets in greenstone terrains of Egypt, and may be elsewhere in the Arabian-Nubian Shield.

  9. Northeast Egypt as seen from STS-58

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This oblique view, looking northeast from central Egypt, shows great expanses of the sand covered and rocky Western Desert in the foreground (bottom). The dark patches bottom right are the Dakhla Oases on the south side of an escarpment. The northern half of Egypt's Nile appears here, from about the latitude of Luxor to the delta. Green colors indicate the small area of crops which feed Egypt's population of 55 million. The Nile Delta is partly obscured by a band of clouds, but can be discerned at the coast as a flattened triangle of green. The smaller triangle close by is the Falyum Basin, a depression irrigated by water from the Nile. The coast of the Mediterranean Sea appears left.

  10. Morphodynamic implications for shoreline management of the western-Mediterranean sector of Egypt

    NASA Astrophysics Data System (ADS)

    Frihy, Omran E.

    2009-09-01

    Although the western-Mediterranean coast of Egypt between Sallum and Alexandria, ~550 km long, has maintained a considerable equilibrium throughout history, developers have built traditional protective structures in an effort to form sheltered recreational beaches without taking into consideration its geomorphologic characteristics, coastal processes and their harmful impact on the coastal environment and human safety. The improper practices in this environmentally valuable region have induced us to undertake an initiative to carry out a morphodynamic analysis to provide a framework for understanding the relationship between coastal morphology and the prevailing dynamic forces. Based on the degree of natural protection or wave sheltering, the study shoreline can be categorized into four distinct morphotypical stretches: (1) high-energy wave-exposed shores and the outer margins of the rocky headlands, (2) moderate to high wave-energy beaches along semi-exposed embayments and bays mostly downdrift of the rocky headlands, (3) low-wave energy at semi-exposed headland lee-sided and pocket beaches, and (4) calm wave-sheltered enclosing water basins for safe anchorages, moorings and recreation beaches. The results deducted will have practical applications for shoreline management initiatives regarding sustained sites suitable for future beachfront development such as safe swimming conditions, sport facilities, water intakes and sheltered areas for vessels. In addition, benefits realized by the understanding of the morphodynamic processes would enhance our awareness of the significance of the role of western coast morphodynamics in supporting sustainable development via shoreline management. As far as sustainability is concerned, the selection of appropriate sites would help avoiding or minimizing the formation of the hard structures needed for creating safe recreation beaches. On a national scale, results reached could provide reliable database for information that can be

  11. Magnetic fabrics and Pan-African structural evolution in the Najd Fault corridor in the Eastern Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Abdeen, Mamdouh M.; Greiling, Reinhard O.; Sadek, Mohamed F.; Hamad, Sayed S.

    2014-11-01

    dykes dissecting it, the highest susceptibilities exceed 7 × 10-2 SI units in magnetite-bearing serpentinite. Early orogenic rocks are characterized by relatively high anisotropies (P‧ up to 1.7) and are deformed in numerous shear zones. Most of these shear zones can be related to the Najd Fault System. In contrast, late orogenic sediments and intrusives show mostly low anisotropies. However, magnetic lineations are still distinctly oriented parallel with the Najd Fault trend. The very latest Pan-African intrusives, the broadly N-S trending dykes crosscutting the Kadabora pluton, imply c. E-W directed extension. Such an extension is consistent with the magnetic fabric in some of the dykes. Therefore, the Kadabora dykes mark the end of Najd wrenching and a late stage of extension in this part of the Eastern Desert of Egypt. The other dykes display mostly primary fabrics, related to magma flow during their intrusion and are thus post-deformational with regard to the Pan-African orogeny.

  12. Water Management Strategy in Assessing the Water Scarcity in Northern Western Region of Nile Delta, Egypt

    NASA Astrophysics Data System (ADS)

    Mabrouk, Badr; Arafa, Salah; Gemajl, Khaled

    2015-04-01

    Sustainable development in the Nile Delta of Egypt is retarded by serious environmental problems, where land-use and land-cover of the region are subjected to continuous changes; including shoreline changes either by erosion or accretion, subsidence of the delta, as well as by sea level rise due to climate change. The current research attempts to; (1) study the vulnerability of the northern western region of the Nile Delta coastal zone to climate change/sea level rise while setting basic challenges, review adaptation strategies based on adaptation policy framework, and highlight recommended programs for preparedness to climate change, (2) study the scarcity of water resources in the area of study with review of the socioeconomic impacts and the critical need of establishing desalination plants with new standards assessing the environmental situation and population clusters, and (3) monitor of the brine water extracted from the desalination plants and injected to subsurface strata. This monitoring process is divided into 3 main directions: 1) studying the chemical characteristics of water extracted from the water desalinations plants qualitatively and quantitatively. 2) mapping the subsurface of which that brine water will be injected to it and the flow directions and effects using resistivity data, and 3) using GIS and suitable numerical models in order to study the effect, volume, flow of the brine water and its long term environmental impacts on the area. The results indicate that the area is particularly vulnerable to the impact of SLR, salt water intrusion, the deterioration of coastal tourism and the impact of extreme dust storms. This in turn will directly affect the agricultural productivity and human settlements in coastal zones. The paper presents different scenarios for water management and recommends the most suitable scenarios in order to establish a core for water management strategy in the region according to existing socio-economic and environmental

  13. Sequence stratigraphy of the Lower Cenomanian Bahariya Formation, Bahariya Oasis, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Catuneanu, O.; Khalifa, M. A.; Wanas, H. A.

    2006-08-01

    The Lower Cenomanian Bahariya Formation corresponds to a second-order depositional sequence that formed within a continental shelf setting under relatively low-rate conditions of positive accommodation (< 200 m during 3-6 My). This overall trend of base-level rise was interrupted by three episodes of base-level fall that resulted in the formation of third-order sequence boundaries. These boundaries are represented by subaerial unconformities (replaced or not by younger transgressive wave ravinement surfaces), and subdivide the Bahariya Formation into four third-order depositional sequences. The construction of the sequence stratigraphic framework of the Bahariya Formation is based on the lateral and vertical changes between shelf, subtidal, coastal and fluvial facies, as well as on the nature of contacts that separate them. The internal (third-order) sequence boundaries are associated with incised valleys, which explain (1) significant lateral changes in the thickness of incised valley fill deposits, (2) the absence of third-order highstand and even transgressive systems tracts in particular areas, and (3) the abrupt facies shifts that may occur laterally over relatively short distances. Within each sequence, the concepts of lowstand, transgressive and highstand systems tracts are used to explain the observed lateral and vertical facies variability. This case study demonstrates the usefulness of sequence stratigraphic analysis in understanding the architecture and stacking patterns of the preserved rock record, and helps to identify 13 stages in the history of base-level changes that marked the evolution of the Bahariya Oasis region during the Early Cenomanian.

  14. Environmental pollutant isotope measurements and natural radioactivity assessment for north Tushki area, south western desert, Egypt.

    PubMed

    Sroor, A; Afifi, S Y; Abdel-Haleem, A S; Salman, A B; Abdel-Sammad, M

    2002-09-01

    Natural radioactive materials under certain conditions can reach hazardous radiological levels. The natural radionuclide (238U, 232Th, 40K) contents of rock samples at various locations in the North Tushki area were investigated using gamma-spectrometric analysis. Estimates of the measured radionuclide content have been made for the absorbed dose rate of gamma radiation. The equivalent radium (Req) and the external hazard index (Hex) which resulted from the natural radionuclides in soil are also calculated and tabulated. The studied samples have been collected from various rock exposures in the North Tushki area. The distribution of major oxides, U and Th were studied. It is found that the enrichment and depletion of the major oxides are mainly due to the effect of hydrothermal alteration, which caused mobility of some major oxides, which increases some elements and decreases others. It is important to mention that the study area is far from the development region of the Tushki project and is only a local hazard. Therefore, additional regional studies of the Tushki Project area should be under taken to explore any unexpected environmental hazard due to the high concentration of the radioactive elements, which have been observed at its north boundary.

  15. Application of LANDSAT satellite imagery for iron ore prospecting in the western desert of Egypt

    NASA Technical Reports Server (NTRS)

    Elshazly, E. M.; Abdel-Hady, M. A.; Elghawaby, M. A.; Khawasik, S. M. (Principal Investigator)

    1977-01-01

    The author has identified the following significant results. The delineation of the geological units and geological structures through image interpretation, corroborated by field observations and structural analysis, led to the discovery of new iron ore deposits. A new locality for iron ore deposition, namely Gebel Qalamun, was discovered, as well as new occurrences within the already known iron ore region of Bahariya Oasis.

  16. 100 Kyr Old Desert of Western India: Morhodynamics and Environmental Significance

    NASA Astrophysics Data System (ADS)

    Bhatt, N.

    2012-04-01

    The Late Quaternary oscillations in sea levels and resultant changes in the coastal environment have remained a popular aspect of study amongst the earthscientists and archaeologists. The Saurashtra peninsula of the western India that lies on the southwestern side of the Thar Desert, has archived a fascinating record of such environmental changes since last interglacial (~120kyr) in the form of a fossil desert exhibiting various aeolian land forms constituted by the sand largely derived from the coastal areas due to an oscillatory sea level change. A variety of dunes viz., coastal transverse, parabolic, longitudinal, barchans, climbing and falling dunes along with valley fills and sand sheets have been mapped. Being biogenic calcium carbonate rich, the sands have been lithified under the influence of an increase in moisture and thus the dune and bed forms are preserved in its best shape. The intense aeolian activities are also evident in the form of desert varnish on rocky outcrops. The sequence comprises smaller climate perturbations in the form of stabilization, erosion and karstification of older dunes and deposition of fluvial sediments in between. The paper deals with the mode of occurrence, response of sediments to wind dynamics and palaeo topography, internal structures, later modifications of sediments and significance of the geochronologically constrained aeolianites in understanding of environmental changes since 100kyr in the region.

  17. Benefits of protective fencing to plant and rodent communities of the western Mojave Desert, California

    NASA Astrophysics Data System (ADS)

    Brooks, Matthew L.

    1995-01-01

    Human disturbance in the western Mojave Desert takes many forms. The most pervasive are livestock grazing and off-highway vehicle use. Over the past few decades several areas within this region have been fenced to preclude human disturbance. These areas provide opportunities to study the impact of human activities in a desert ecosystem. This paper documents the response of plant and small mammal populations to fencing constructed between 1978 and 1979 at the Desert Tortoise Research Natural Area, Kern County, California. Aboveground live annual plant biomass was generally greater inside than outside the fenced plots during April 1990, 1991, and 1992. The alien grass Schismus barbatus was a notable exception, producing more biomass in the unprotected area. Forb biomass was greater than that of alien annual grasses inside the fence during all three years of the study. Outside the fence, forb biomass was significantly higher than that of alien grasses only during spring 1992. Percent cover of perennial shrubs was higher inside the fence than outside, while no significant trend was detected in density. There was als more seed biomass inside the fence; this may have contributed to the greater diversity and density of Merriam's kangaroo rats ( Dipodomys merriami), long-tailed pocket mice ( Chaetodipus formosus), and southern grasshopper mice ( Onychomys torridus) in the protected area. These results show that protection from human disturbance has many benefits, including greater overall community biomass and diversity. The significance and generality of these results can be further tested by studying other exclosures of varying age and configurations in different desert regions of the southwestern United States.

  18. Trace elements assessment in agricultural and desert soils of Aswan area, south Egypt: Geochemical characteristics and environmental impacts

    NASA Astrophysics Data System (ADS)

    Darwish, Mohamed Abdallah Gad; Pöllmann, Hebert

    2015-12-01

    Determination of chemical elements, Al, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, P, Pb, Sc, Sr, Ti, Y, and Zn have been performed in agricultural and desert soils and alfalfa (Medicago sativa) at Aswan area. Consequently, the pollution indices, univariate and multivariate statistical methods have been applied, in order to assess the geochemical characteristics of these elements and their impact on soil environmental quality and plant, and to reach for their potential input sources. The investigation revealed that the mean and range values of all element concentrations in agricultural soil are higher than those in desert soil. Furthermore, the agricultural soil displayed various degrees of enrichment and pollution of Cd, Zn, Mo, Co, P, Ti, Pb. The geochemical pattern of integrated pollution indices gave a clear image of extreme and strong pollution in the agricultural soil stations, their poor quality with high risk to human health and considered as a tocsin for an alert. In contrast, the desert soil is the good environmental quality and safe for plant, animal and human health. Alfalfa is tolerant plant and considered as a biomarker for P and Mo in polluted agricultural soil. Four geochemical associations of analyzing elements in agricultural soil and three ones in desert soil have been generated, and their enhancements were essentially caused by various anthropogenic activities and geogenic sources. The investigation also revealed that the broad extended desert soil is fruitful and promising as cultivable lands for agricultural processes in the futures.

  19. Habitat invasibility and dominance by alien annual plants in the western Mojave Desert

    USGS Publications Warehouse

    Brooks, M.L.

    1999-01-01

    Patterns of habitat invasibility and alien dominance, respectively measured as species richness and biomass of alien annual plants, were evaluated in association with four habitat factors at the Desert Tortoise Research Natural Area (DTNA) in the western Mojave Desert, USA. Habitat factors varied in levels of disturbance outside (high) and inside (low) the DTNA, and in levels of soil nutrients in washlet (high) and hummock (low) topographic positions, in Larrea-north (high), Larrea-south (medium), and interspace (low) microhabitats near creosote bushes (Larrea tridentata), and during 1995 when rainfall was 207% (high) and 1994 when rainfall was 52% (low) of the long-term average. Dominant alien plants included the annual grasses Bromus rubens, Bromus trinii, and Schismus spp., and the forb Erodium cicutarium. Species richness and dominance of alien annual plants were slightly higher where disturbance was high, and much higher where soil nutrients were high. B. rubens and B. trinii were most dominant in washlets and in the Larrea-north microhabitats during both years. These two species evolved in mesic ecosystems, and appeared to be particularly limited by soil nutrients at this site. Schismus spp. and E. cicutarium were also most dominant in washlets, but their dominance varied between interspaces in 1994 and the Larrea-south microhabitat in 1995. Monitoring to detect the invasion of new annual plants should focus on regions of high rainfall and nitrogen deposition and on washes and beneath-canopy microhabitats. The ecological range of each alien species should be evaluated separately, because their evolutionary origins may greatly affect their patterns of invasion and dominance in the Mojave Desert.

  20. Estimation of heat generation by radioactive decay of some phosphate rocks in Egypt.

    PubMed

    Din, Khaled Salahel

    2009-11-01

    Radiogenic heat production data for phosphate rocks outcropping on the three main areas Eastern Desert, Western Desert and Nile Valley are presented. They were derived from uranium, thorium and potassium concentration measurements of gamma radiation originating from the decay of (214)Bi ((238)U series), (208)Tl ((232)Th series) and the primary decay of (40)K. A low radioactive heat production rate (0.32+/-0.1 microWm(-3)) was found for Wadi Hegaza, whereas the highest value (19+/-4.1 microWm(-3)) was found for Gabel Anz, Eastern Desert of Egypt.

  1. Egypt and Red Sea

    NASA Technical Reports Server (NTRS)

    1982-01-01

    A panaramic view of eastern Egypt, The Red Sea and Saudi Arabia beyond (24.0N, 33.0E). In this desert country, where water is life, the high Aswan Dam and the impounded waters of the Nile River in the foreground assure water availability into the next century. The Red Sea beyond, part of the Suez Canal seaway, serves as a commercial link to the world and separates Egypt from Saudi Arabia.

  2. Interstratified vermiculite-mica in the gneiss-metapelite-serpentinite rocks at Hafafit area, Southern Eastern Desert, Egypt: From metasomatism to weathering

    NASA Astrophysics Data System (ADS)

    Harraz, H. Z.; Hamdy, M. M.

    2010-09-01

    The Hafafit vermiculite in the Southern Eastern Desert of Egypt at the contact of the metapelite and serpentinite rocks with the pegmatites and gneisses of the Hafafit uplift is the only known deposit in the Arabian-Nubian Shield (ANS) rocks of the Eastern Desert (ED). It is distinctively interstratified with mica. The mineralogy and mineral chemistry of this vermiculite at four sites (HV1, HV2, HV3 and HV4) were studied to better understand its origin, which might refers to a specific geologic setting retained to Hafafit area. The vermiculite at Hafafit forms with phlogopite, actinolite-tremolite, asbestos-anthophyllite-talc and talc zones that are arranged from pegmatite and gneisses to the metapelite and serpentinite rocks. These zones were probably formed by metasomatism that related to the intrusion of the granitoid rocks and the connected pegmatites in the upper Pan-African. The XRD and EMPA studies of the interstratified vermiculite-mica concluded that vermiculitization took place through a layer-by-layer transformation of original micas. This formed, in decreasing abundance, mixed-layer phases of biotite/vermiculite (hydrobiotite), phlogopite/vermiculite (hydrophlogopite) and chlorite/vermiculite (corrensite) and discrete phases of vermiculite, chlorite and smectite. A model is suggested, in which chemical weathering by the moving downward meteoric water led to replacement of the interlayer K, in biotite from gneiss and in phlogopite from metasomatic zones, by H 2O molecules, Fe 2+ was oxidized and (OH) - replaced O 2- forming hydrobiotite and hydrophlogopite. By more K remove, Fe was replaced by Mg with the introduction of more layers of H 2O molecules leading to formation of the vermiculite. Weathering formed corrensite mixed-layer and chlorite expandable minerals on the expense of chlorite. Formation of the incomplete smectite-like layers and Al-hydroxy interlayers (13.97 Ǻ) took place at the expense of vermiculite, replacing the Mg interlayer cations

  3. Prospecting cold deserts of north western Himalayas for microbial diversity and plant growth promoting attributes.

    PubMed

    Yadav, Ajar Nath; Sachan, Shashwati Ghosh; Verma, Priyanka; Saxena, Anil Kumar

    2015-06-01

    Microbial communities in different samples collected from cold deserts of north western Himalayas, India, were analyzed using 16S rRNA gene sequencing and phospholipid fatty acids (PLFA) analysis. A total of 232 bacterial isolates were characterized employing 16S rDNA-Amplified Ribosomal DNA Restriction Analysis with the three restriction endonucleases Alu I, Msp I and Hae III, which led to formation of 29-54 groups for the different sites, adding up to169 groups. 16S rRNA gene based phylogenetic analysis, revealed that 82 distinct species of 31 different genera, belonged to four phyla Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria. PLFA profiling was performed for concerned samples which gave an estimate of microbial communities without cultivating the microorganisms. PLFA analysis led to characterization of diverse group of microbes in different samples such as gram-negative, gram-positive bacteria, actinomycetes, cyanobacteria, anaerobic bacteria, sulphate reducing bacteria and fungi. The representative strains were screened for their plant growth promoting attributes, which included production of ammonia, HCN, gibberellic acid, IAA and siderophore; solubilization of phosphorus and activity of ACC deaminase. In vitro antifungal activity assay was performed against Rhizoctonia solani and Macrophomina phaseolina. Cold adapted microorganisms may serve as inoculants for crops growing under cold climatic conditions. To our knowledge, this is the first report for the presence of Arthrobacter nicotianae, Brevundimonas terrae, Paenibacillus tylopili and Pseudomonas cedrina in cold deserts and exhibit multifunctional PGP attributes at low temperatures.

  4. Nest site characteristics and nesting success of the Western Burrowing Owl in the eastern Mojave Desert

    USGS Publications Warehouse

    Longshore, Kathleen M.; Crowe, Dorothy E.

    2013-01-01

    We evaluated nest site selection at two spatial scales (microsite, territory) and reproductive success of Western Burrowing Owls (Athene cunicularia hypugaea) at three spatial scales (microsite, territory, landscape) in the eastern Mojave Desert. We used binary logistic regression within an information-theoretic approach to assess factors influencing nest site choice and nesting success. Microsite-scale variables favored by owls included burrows excavated by desert tortoise (Gopherus agassizii), burrows with a large mound of excavated soil at the entrance, and a greater number of satellite burrows within 5 m of the nest burrow. At the territory scale, owls preferred patches with greater cover of creosote bush (Larrea tridentata) within 50 m of the nest burrow. An interaction between the presence or absence of a calcic soil horizon layer over the top of the burrow (microsite) and the number of burrows within 50 m (territory) influenced nest site choice. Nesting success was influenced by a greater number of burrows within 5 m of the nest burrow. Total cool season precipitation was a predictor of nesting success at the landscape scale. Conservation strategies can rely on management of habitat for favored and productive nesting sites for this declining species.

  5. Bi-Static Deep Electromagnetic Soundings for Martian Subsurface Characterization: Experimental Validation in the Egyptian Western Desert

    NASA Astrophysics Data System (ADS)

    Ciarletti, V.; Le Gall, A.; Berthelier, J. J.; Corbel, Ch.; Dolon, F.; Ney, R.; Reineix, A.; Guiffaud, Ch.; Clifford, S.; Heggy, E.

    2007-03-01

    A bi-static version of the HF GPR TAPIR developed for martian deep soundings has been operated in the Egyptian Western Desert. The study presented focuses on the retrieval of the direction of arrival of the observed echoes on both simulated and measured d

  6. Resilience to disturbance and resistance to alien grass invasions in the cold desert of western North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alien grass invasions are resulting in ecosystem-level transformations of entire landscapes in arid and semi-arid ecosystems. The cold desert of western US is undergoing such a transformation, and is considered one of the most imperiled large ecosystems in the US. To address the rapid and complex ch...

  7. Upper Oligocene evaporites in basin fill of Sevier Desert region, western Utah ( USA).

    USGS Publications Warehouse

    Lindsey, D.A.; Glanzman, R.K.; Naeser, C.W.; Nicholas, D.J.

    1981-01-01

    The basin fill beneath the Sevier Desert of western Utah contains evaporites that were deposited in a broad closed basin. All of the basin fill penetrated by the Gulf Oil 1 Gronning contains abundant volcanic detritus and its alteration products of Cenozoic age. Fission-track dating of tuffaceous sandstone yields ages of 26-28 m.y. Fossil pollen from mudstone in the evaporite-bearing strata includes forms no older than late Oligocene, in good agreement with the fission-track ages. Thus the age of evaporites is late Oligocene and younger. Anhydrite is present throughout approximately 900m of volcaniclastic rocks in the lower part of the section cut by the Gulf hole. Fossil pollen are indicative of an arid to semiarid flora.-from Authors

  8. Desert varnish and environmental change near Broken Hill, Western New South Wales

    NASA Astrophysics Data System (ADS)

    Dragovich, D.

    1988-12-01

    Desert varnish is widespread in arid Australia, and occurs as a thin often discontinuous manganese-enriched surface coating near Broken Hill, western New South Wales. Radiocarbon dating of calcium carbonate associated with this varnish indicated that major varnishing took place before about 10,000 years B.P., with varnish-forming conditions continuing during the Holocene. Small patches of varnish on secondary carbonate, on non-varnished rock and sometimes on existing varnish suggest that current environmental conditions allow for some varnish formation. Loss of varnish has resulted from within-channel abrasion, weathering by lichens, minor breakdown of varnish substrates, and localized weathering, possibly related to a previously higher soil surface.

  9. Physical and temporal isolation of mountain headwater streams in the western Mojave Desert, Southern California

    USGS Publications Warehouse

    Izbicki, J.A.

    2007-01-01

    Streams draining mountain headwater areas of the western Mojave Desert are commonly physically isolated from downstream hydrologic systems such as springs, playa lakes, wetlands, or larger streams and rivers by stream reaches that are dry much of the time. The physical isolation of surface flow in these streams may be broken for brief periods after rainfall or snowmelt when runoff is sufficient to allow flow along the entire stream reach. Despite the physical isolation of surface flow in these streams, they are an integral part of the hydrologic cycle. Water infiltrated from headwater streams moves through the unsaturated zone to recharge the underlying ground-water system and eventually discharges to support springs, streamflow, isolated wetlands, or native vegetation. Water movement through thick unsaturated zones may require several hundred years and subsequent movement through the underlying ground-water systems may require many thousands of years - contributing to the temporal isolation of mountain headwater streams. ?? 2007 American Water Resources Association.

  10. The distribution of radioelements in El Gluf biotite granite, north Eastern Desert, Egypt: a guide to the recognition of anomalously radioactive zones

    NASA Astrophysics Data System (ADS)

    Ammar, A. A.; Elkattan, E. M.; Elsadek, M. A.

    1993-05-01

    El-Gluf area is located in the north Eastern Desert of Egypt. It is underlain mainly by Precambrian basement rocks and Phanerozoic sediments. It has been systematically surveyed using high-sensitivity airborne gamma-ray spectrometric and magnetic methods. To identify and outline significant radiometric zones of anomalously high uranium and thorium concentrations in El Gluf biotite granite. These zones could be favourable for potential economic radioactive and/or metallic mineralization. This study could serve as a model for investigating the relationship between the geological structure and radioactive mineralization. Statistical analysis of the gamma-ray spectrometric data were carried out to delineate anomalies. A two-dimensional trend analysis of faults as tracedfrom the geological map, the radiometric gradients, magnetic lineations and the courses of wadis (valleys) were carried out to delineate major and minor trends in the area. Seven spectrometric anomalies (two pure uranium, two pure thorium, and three mixed) could be related to the prevailing faulting directions: N-S, N-W and NE. The NW and NE fault trends proved to have a significant impact on the localization of radiometric anomalies, which may point to potential and structurally controlled uranium and thorium mineralizations whose structures are considered to have acted as channel ways for the mineralized solutions.

  11. Petrology of the Motaghairat mafic-ultramafic complex, Eastern Desert, Egypt: A high-Mg post-collisional extension-related layered intrusion

    NASA Astrophysics Data System (ADS)

    Abdel Halim, Ali H.; Helmy, Hassan M.; Abd El-Rahman, Yasser M.; Shibata, Tomoyuki; El Mahallawi, Mahmoud M.; Yoshikawa, Masako; Arai, Shoji

    2016-02-01

    The geodynamic settings of the Precambrian mafic-ultramafic complexes in the Eastern Desert of Egypt have important bearing on understanding the geotectonic evolution of the Arabian Nubian Shield. We present a detailed petrological study on a layered mafic-ultramafic intrusion that is located at the contact between the Precambrian continental crust and the Miocene Red Sea oceanic crust. The Motaghairat layered intrusion consists of basal lherzolite, orthopyroxenite, troctolite, olivine gabbro and anorthosite on the top. Variations in modal mineralogy and mineral chemistry along with the chemical composition of these units suggest their derivation from a common high-Mg tholeiitic parent melt through fractional crystallization processes. The parental magma was derived from a metasomatised mantle source. The primitive mantle-normalized patterns of the calculated melts exhibit enrichment in U relative to Th and Ba relative LREE which indicate that the enriched lithospheric mantle source was metasomatised by fluids derived from a subducted oceanic crust rather than by a sediment melt. Geological and petrological evidences suggest that the layered Motaghairat intrusion was emplaced during post-orogenic extension following subduction break-off and lithospheric delamination after the collision between the amalgamated island arc terranes and the Saharan Metacraton. The heat source required to melt the metasomatised lithospheric mantle was derived from the upwelling of hot asthenosphere after the subduction-break-off.

  12. Neoproterozoic diamictite in the Eastern Desert of Egypt and Northern Saudi Arabia: evidence of ~750 Ma glaciation in the Arabian-Nubian Shield?

    NASA Astrophysics Data System (ADS)

    Ali, Kamal A.; Stern, Robert J.; Manton, William I.; Johnson, Peter R.; Mukherjee, Sumit K.

    2010-06-01

    The Neoproterozoic Atud diamictite in Wadi Kareim and Wadi Mobarak in the Eastern Desert of Egypt and the Nuwaybah formation in NW Saudi Arabia consist of poorly sorted, polymictic breccia, with clasts up to 1 m of granitoid, quartz porphyry, quartzite, basalt, greywacke, marble, arkose, and microconglomerate in fine-grained matrix. Stratigraphic relations indicate that the diamictite was deposited in a marine environment. Integrated field investigation, petrographic study and U-Pb SHRIMP zircon ages demonstrate that the Atud and Nuwaybah are correlative. The distribution of zircon ages indicate that ~750 Ma ages are dominant with a significant component of older materials, characterized by minor Mesoproterozoic and more abundant Paleoproterozoic and Neoarchean ages. Some matrix and metasedimentary clast zircons yield ages that are a few 10s of Ma younger than the age of the youngest clast (754 ± 15 Ma), suggesting Atud/Nuwaybah diamictite deposition ~750 Ma or slightly later, broadly consistent with being deposited during the Sturtian glaciation (740-660 Ma). The Paleoproterozoic and Neoarchean clasts have no source within the ensimatic Arabian-Nubian Shield. The distribution of the pre-Neoproterozoic ages are similar to the distribution of the pre-Neoproterozoic ages in Yemen and Saharan Metacraton, suggesting that these clasts have been transported hundreds of kilometers, maybe by ice-rafting. The Atud diamictite may represent important evidence for Cryogenian “Snowball Earth” in the Arabian-Nubian Shield.

  13. An assessment of the external radiological impact in granites and pegmatite in central Eastern Desert in Egypt with elevated natural radioactivity.

    PubMed

    Uosif, M A M; Abdel-Salam, L M

    2011-11-01

    The contents of natural radionuclides ((226)Ra, (232)Th and (40)K) were measured in investigated samples (granite Gabal Ras Barud, Eastern Desert in Egypt) by using gamma spectrometry (NaI (Tl) 3″×3″). The activities of (226)Ra, (232)Th series and (40)K are between (3.8±0.5 and 172.8±1135.1±56.8 8.6), (2.3±0.3 and 103.8±5.2) and (53.1±2.7 and 1135.1±56.8) Bq kg(-1), respectively. With average total annual dose being only 67.2 μSv y(-1), this value is about 6.72 % of the 1.0 mSv y(-1) recommended by the International Commission on Radiological Protection (ICRP-60, 1990) as the maximum annual dose to members of the public. Geochemical studies revealed that Gabal Ras Barud is formed from a highly fractionated biotite granite, with SiO(2) >75 % and generally enriched in alkali with K/Na >8 %.

  14. Application of kinematic vorticity and gold mineralization for the wall rock alterations of shear zone at Dungash gold mining, Central Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Kassem, Osama M. K.; Abd El Rahim, Said H.; El Nashar, EL Said R.; AL Kahtany, Kaled M.

    2016-11-01

    The use of porphyroclasts rotating in a flowing matrix to estimate mean kinematic vorticity number (Wm) is important for quantifying the relative contributions of pure and simple shear in wall rocks alterations of shear zone at Dungash gold mine. Furthermore, it shows the relationship between the gold mineralization and deformation and also detects the orientation of rigid objects during progressive deformation. The Dungash gold mine area is situated in an EW-trending quartz vein along a shear zone in metavolcanic and metasedimentary host rocks in the Eastern Desert of Egypt. These rocks are associated with the major geologic structures which are attributed to various deformational stages of the Neoproterozoic basement rocks. We conclude that finite strain in the deformed rocks is of the same order of magnitude for all units of metavolcano-sedimentary rocks. The kinematic vorticity number for the metavolcanic and metasedimentary samples in the Dungash area range from 0.80 to 0.92, and together with the strain data suggest deviations from simple shear. It is concluded that nappe stacking occurred early during the underthrusting event probably by brittle imbrication and that ductile strain was superimposed on the nappe structure during thrusting. Furthermore, we conclude that disseminated mineralization, chloritization, carbonatization and silicification of the wall rocks are associated with fluids migrating along shearing, fracturing and foliation of the metamorphosed wall rocks.

  15. Application of thorium-normalized airborne radiospectrometric survey data of Wadi Araba area, North-eastern Desert, Egypt, as a guide to the recognition of probable subsurface petroleum accumulations.

    PubMed

    El-Sadek, Mohamed A

    2002-07-01

    A new exploration method has been developed by Saunders et al. (Geophysics 58(10) (1993) 1417) using surface and aerial gamma-ray spectral measurements in prospecting for petroleum in stratigraphic and structural traps. Wadi Araba area, North-eastern Desert, Egypt, was selected to apply this method on its recorded aerial gamma-ray spectrometric survey data, due to its distinct stratigraphic and structural setting as well as its situation in close connection with the Gulf of Suez, which represents one of the important sites of oil production in Egypt. The three variables (eU, eTh, and K) registered for the whole study area, in the form of three contour maps, were digitized along the flight paths every 1.0 km. The DRAD arithmetic means plus three standard deviations for the data set were computed. Any single profile value greater than this quantity should have a probability of 99.87% that it represents a valid anomaly and is not caused by random variations in the background values. The use of these criteria has identified one flight line which has a valid anomaly that is not caused by random variations in the background values. This might indicate a prospective possibility for petroleum accumulation in the Wadi Araba area. North-eastern Desert, Egypt.

  16. Ground-Water Recharge from Small Intermittent Streams in the Western Mojave Desert, California

    USGS Publications Warehouse

    Izbicki, John A.; Johnson, Russell U.; Kulongoski, Justin T.; Predmore, Steven

    2007-01-01

    Population growth has impacted ground-water resources in the western Mojave Desert, where declining water levels suggest that recharge rates have not kept pace with withdrawals. Recharge from the Mojave River, the largest hydrographic feature in the study area, is relatively well characterized. In contrast, recharge from numerous smaller streams that convey runoff from the bounding mountains is poorly characterized. The current study examined four representative streams to assess recharge from these intermittent sources. Hydraulic, thermal, geomorphic, chemical, and isotopic data were used to study recharge processes, from streamflow generation and infiltration to percolation through the unsaturated zone. Ground-water movement away from recharge areas was also assessed. Infiltration in amounts sufficient to have a measurable effect on subsurface temperature profiles did not occur in every year in instrumented study reaches. In addition to streamflow availability, results showed the importance of sediment texture in controlling infiltration and eventual recharge. Infiltration amounts of about 0.7 meters per year were an approximate threshold for the occurrence of ground-water recharge. Estimated travel times through the thick unsaturated zones underlying channels reached several hundred years. Recharging fluxes were influenced by stratigraphic complexity and depositional dynamics. Because of channel meandering, not all water that penetrates beneath the root zone can be assumed to become recharge on active alluvial fans. Away from study washes, elevated chloride concentrations and highly negative water potentials beneath the root zone indicated negligible recharge from direct infiltration of precipitation under current climatic conditions. In upstream portions of washes, generally low subsurface chloride concentrations and near-zero water potentials indicated downward movement of water toward the water table, driven primarily by gravity. Recharging conditions did not

  17. Concentrations of mineral aerosol from desert to plains across the central Rocky Mountains, western United States

    NASA Astrophysics Data System (ADS)

    Reynolds, Richard L.; Munson, Seth M.; Fernandez, Daniel; Goldstein, Harland L.; Neff, Jason C.

    2016-12-01

    Mineral dusts can have profound effects on climate, clouds, ecosystem processes, and human health. Because regional dust emission and deposition in western North America are not well understood, measurements of total suspended particulate (TSP) from 2011 to 2013 were made along a 500-km transect of five remote sites in Utah and Colorado, USA. The TSP concentrations in μg m-3 adjusted to a 24-h period were relatively high at the two westernmost, dryland sites at Canyonlands National Park (mean = 135) and at Mesa Verde National Park (mean = 99), as well as at the easternmost site on the Great Plains (mean = 143). The TSP concentrations at the two intervening montane sites were less, with more loading on the western slope of the Rocky Mountains (Telluride, mean = 68) closest to the desert sites compared with the site on the eastern slope (Niwot Ridge, mean = 58). Dust concentrations were commonly highest during late winter-late spring, when Pacific frontal storms are the dominant causes of regional wind. Low concentrations (<7 wt%) of organic matter indicated that rock-derived mineral particles composed most TSP. Most TSP mass was carried by particle sizes larger than 10 μm (PM>10), as revealed by relatively low average daily concentrations of fine (<5 μg m-3; PM2.5) and coarse (<10 μg m-3; PM2.5-10) fractions monitored at or near four sites. Standard air-quality measurements for PM2.5 and PM10 apparently do not capture the large majority of mineral-particulate pollution in the remote western interior U.S.

  18. Concentrations of mineral aerosol from desert to plains across the central Rocky Mountains, western United States

    USGS Publications Warehouse

    Reynolds, Richard L.; Munson, Seth M.; Fernandez, Daniel; Goldstein, Harland L.; Neff, Jason C.

    2016-01-01

    Mineral dusts can have profound effects on climate, clouds, ecosystem processes, and human health. Because regional dust emission and deposition in western North America are not well understood, measurements of total suspended particulate (TSP) from 2011 to 2013 were made along a 500-km transect of five remote sites in Utah and Colorado, USA. The TSP concentrations in μg m−3 adjusted to a 24-h period were relatively high at the two westernmost, dryland sites at Canyonlands National Park (mean = 135) and at Mesa Verde National Park (mean = 99), as well as at the easternmost site on the Great Plains (mean = 143). The TSP concentrations at the two intervening montane sites were less, with more loading on the western slope of the Rocky Mountains (Telluride, mean = 68) closest to the desert sites compared with the site on the eastern slope (Niwot Ridge, mean = 58). Dust concentrations were commonly highest during late winter-late spring, when Pacific frontal storms are the dominant causes of regional wind. Low concentrations (<7 wt%) of organic matter indicated that rock-derived mineral particles composed most TSP. Most TSP mass was carried by particle sizes larger than 10 μm (PM>10), as revealed by relatively low average daily concentrations of fine (<5 μg m−3; PM2.5) and coarse (<10 μg m−3; PM2.5–10) fractions monitored at or near four sites. Standard air-quality measurements for PM2.5 and PM10 apparently do not capture the large majority of mineral-particulate pollution in the remote western interior U.S.

  19. Structural evolution and Cenozoic tectonostratigraphy of the Cairo-Suez district, north Eastern Desert of Egypt: Field-structural data from Gebel Qattamiya-Gebel Um Reheiat area

    NASA Astrophysics Data System (ADS)

    Hagag, Wael

    2016-06-01

    Detailed field mapping reveals that continental rifting is strongly deforming the Gebel Qattamiya-Gebel Um Reheiat area and the entire Cairo-Suez district, in north Eastern Desert of Egypt. Rift-related structures are predominantly represented by E to WNW, NNW and NW oriented faults. The E to WNW oriented faults are small and build up the Gebel Qattamiya en echelon fault belt, whereas the faults trending NNW and NW establish a pervasive horst and graben structural style involving some rhomb-shape horsts as Gebel Qattamiya (GQRH), Gebel Um Reheiat (GURRH) and south Gebel Um Reheiat (SGURRH). Rock units of the Eocene succession and Oligocene sediments are well exposed and highly controlled by rift-related structures. Rifting was developed through two rift-phases; initial and major ones. The initial phase (a newly recognized phase in this contribution) has been occurred in Late Eocene (Priabonian), while the main phase was prevailing during Late Oligocene-Early Miocene time and is characterized by hydrothermal veins and basaltic eruptions. Continental transtension in the Cairo-Suez district, including the study area, was probably synchronous with a major tectonic stage (Pyrenean-Atlasic movement) of continental collision between African-Arabian and Eurasian plates in Late Eocene-Oligocene time. Field investigation suggests that the transfer of displacement (slip) from the Gulf of Suez proto-rift into the E-W oriented faults ''relays'' is an important mechanism, which helps to explain the current structural framework and tectonic evolution of the Cairo-Suez district. Reactivation of such faults with right-lateral divergent wrenching with NE-SW oriented extension deformed the Cairo-Suez district with several E-W oriented en echelon fault belts (e.g. Gebel Qattamiya fault belt in the study area). Thus the Cairo-Suez district represents an accommodation or transfer zone in northeastern Egypt, intercepting the ''far-field stresses'' from the Arabian-Nubian Shield, the Red

  20. The Release of Chromium in Aquifers Underlying the Western Mojave Desert

    NASA Astrophysics Data System (ADS)

    Khachikian, C. S.; Plotkin, C.; Monterrosa, A.; Ramirez, P.

    2004-12-01

    Recent studies suggest that chromium (Cr) in aquifers underlying the western part of the Mojave Desert may be naturally occurring, resulting from the release of this element from aquifer materials in oxic ground water with pH > 8.0. In order to test this hypothesis, we studied the kinetic release of Cr from aquifer material collected from the Sheep Creek fan near Victorville, CA. Pulverized and untreated aquifer material were incubated in 15mL Falcon tubes with water at three different pH values (2, 7, and 9) for 227 days. Duplicate samples were incubated in a heating bath at temperatures 20oC above ambient, in order to accelerate the kinetics of Cr release. Samples from each tube were collected, filtered through a 0.22 μ m filter, and analyzed using a graphite furnace atomic absorption photospectrometer using EPA Method 7199. Due to the heterogeneity of the aquifer material an accurate measure of Cr release kinetics was not possible; results presented here represent equilibrium values at the end of the incubation period. For untreated aquifer material incubated at ambient temperatures, Cr was found at concentrations of 26.0 ± 8.0 ppb at pH = 2, 5.2 ± 0.6 ppb at pH=7, and 9.1 ± 0.9 ppb at pH=9. As expected, the highest value of Cr was found for the samples incubated at pH=2. Pulverization of the samples resulted in an increase in Cr release by a factor of 1.5, 2.4, and 1.6 at pH values of 2, 7, and 9, respectively. Heating the pulverized samples at pH 7 and 9 resulted in an increase in the concentration of Cr released (by 25% and 9% respectively). However, heating the pulverized sample at pH=2 resulted in an almost 95% decrease in the concentration of released Cr (from 37.8 ppb to 2.2 ppb). The reason for this decrease is not known at this point. Our results indicate that significant concentrations of Cr are released naturally in Western Mojave Desert aquifers under various geochemical conditions. Additional studies are underway to study the kinetic release of

  1. Unique chemistry of a diamond-bearing pebble from the Libyan Desert Glass strewnfield, SW Egypt: Evidence for a shocked comet fragment

    NASA Astrophysics Data System (ADS)

    Kramers, Jan D.; Andreoli, Marco A. G.; Atanasova, Maria; Belyanin, Georgy A.; Block, David L.; Franklyn, Chris; Harris, Chris; Lekgoathi, Mpho; Montross, Charles S.; Ntsoane, Tshepo; Pischedda, Vittoria; Segonyane, Patience; Viljoen, K. S. (Fanus); Westraadt, Johan E.

    2013-11-01

    We have studied a small, very unusual stone, here named “Hypatia”, found in the area of southwest Egypt where an extreme surface heating event produced the Libyan Desert Glass 28.5 million years ago. It is angular, black, shiny, extremely hard and intensely fractured. We report on exploratory work including X-ray diffraction, Raman spectroscopy, transmission electron microscopy, scanning electron microscopy with EDS analysis, deuteron nuclear reaction analysis, C-isotope and noble gas analyses. Carbon is the dominant element in Hypatia, with heterogeneous O/C and N/C ratios ranging from 0.3 to 0.5 and from 0.007 to 0.02, respectively. The major cations of silicates add up to less than 5%. The stone consists chiefly of apparently amorphous, but very hard carbonaceous matter, in which patches of sub-μm diamonds occur. δ13C values (ca. 0‰) exclude an origin from shocked terrestrial coal or any variety of terrestrial diamond. They are also higher than the values for carbonaceous chondrites but fall within the wide range for interplanetary dust particles and comet 81P/Wild2 dust. In step heating, 40Ar/36Ar ratios vary from 40 to the air value (298), interpreted as a variable mixture of extraterrestrial and atmospheric Ar. Isotope data of Ne, Kr and Xe reveal the exotic noble gas components G and P3 that are normally hosted in presolar SiC and nanodiamonds, while the most common trapped noble gas component of chondritic meteorites, Q, appears to be absent. An origin remote from the asteroid belt can account for these features. We propose that the Hypatia stone is a remnant of a cometary nucleus fragment that impacted after incorporating gases from the atmosphere. Its co-occurrence with Libyan Desert Glass suggests that this fragment could have been part of a bolide that broke up and exploded in the airburst that formed the Glass. Its extraordinary preservation would be due to its shock-transformation into a weathering-resistant assemblage.

  2. Characterization of the thermally metamorphosed mantle-crust transition zone of the Neoproterozoic ophiolite at Gebel Mudarjaj, south Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Ahmed, Ahmed Hassan; Gharib, Moustafa E.; Arai, Shoji

    2012-06-01

    A suite of mantle-crust transition zone (Moho transition zone = MTZ) rocks are exceptionally well exposed in Gebel Mudarjaj area, southeastern desert of Egypt. The MTZ rocks were thermally metamorphosed by younger granitic intrusion, forming mafic-ultramafic hornfels with characteristic metamorphic mineral assemblages. The MTZ rocks are remarkably thin (30-50 m thick) and are composed mainly of dunites, troctolites, gabbroic rocks and pyroxenite masses overlying a basal serpentinized mantle harzburgite section. The Cr# of spinels of the basal serpentinized harzburgites and the MTZ dunites are on average 0.76 and 0.74, respectively, which is consistent with the range for arc peridotite spinels. The melt in equilibrium with these MTZ rocks is compositionally similar to boninitic magmas produced by high degrees of partial melting. The basal harzburgites and MTZ dunites have been produced by 19-23% mantle melting, and are compositionally similar to supra-subduction zone (SSZ) peridotites. The mantle melt in equilibrium with pyroxenites was formed after 16-17% partial melting, which subsequently reacted with the lower crustal gabbroic rocks to produce pyroxenites. The occurrence of pyroxenite masses at the crust-mantle boundary suggests a medium- to high-pressure accumulation of pyroxenes in mid- to lower crustal magma chambers. The original MTZ rocks were partially or fully hydrated, prior to the granitic intrusion, during the regional metamorphism, tectonic disruption and emplacement as various fragments of a dismembered ophiolite, to form antigorite-bearing serpentinized mafic-ultramafic rocks. Progressive metamorphic assemblages then overprinted the primary features due to the contact metamorphism of the MTZ rocks. The resultant metamorphic mineral assemblages are: (1) olivine + anthophyllite + tremolite ± chlorite ± talc (in the basal serpentinites), (2) olivine + enstatite ± chlorite (in the MTZ dunites), and (3) olivine + aluminous spinel (pleonaste

  3. Variations in eruptive style and depositional processes of Neoproterozoic terrestrial volcano-sedimentary successions in the Hamid area, North Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Khalaf, Ezz El Din Abdel Hakim

    2013-07-01

    Two contrasting Neoproterozoic volcano-sedimentary successions of ca. 600 m thickness were recognized in the Hamid area, Northeastern Desert, Egypt. A lower Hamid succession consists of alluvial sediments, coherent lava flows, pyroclastic fall and flow deposits. An upper Hamid succession includes deposits from pyroclastic density currents, sills, and dykes. Sedimentological studies at different scales in the Hamid area show a very complex interaction of fluvial, eruptive, and gravitational processes in time and space and thus provided meaningful insights into the evolution of the rift sedimentary environments and the identification of different stages of effusive activity, explosive activity, and relative quiescence, determining syn-eruptive and inter-eruptive rock units. The volcano-sedimentary deposits of the study area can be ascribed to 14 facies and 7 facies associations: (1) basin-border alluvial fan, (2) mixed sandy fluvial braid plain, (3) bed-load-dominated ephemeral lake, (4) lava flows and volcaniclastics, (5) pyroclastic fall deposits, (6) phreatomagmatic volcanic deposits, and (7) pyroclastic density current deposits. These systems are in part coeval and in part succeed each other, forming five phases of basin evolution: (i) an opening phase including alluvial fan and valley flooding together with a lacustrine period, (ii) a phase of effusive and explosive volcanism (pulsatory phase), (iii) a phase of predominant explosive and deposition from base surges (collapsing phase), and (iv) a phase of caldera eruption and ignimbrite-forming processes (climactic phase). The facies architectures record a change in volcanic activity from mainly phreatomagmatic eruptions, producing large volumes of lava flows and pyroclastics (pulsatory and collapsing phase), to highly explosive, pumice-rich plinian-type pyroclastic density current deposits (climactic phase). Hamid area is a small-volume volcano, however, its magma compositions, eruption styles, and inter

  4. Multi-stage emerald formation during Pan-African regional metamorphism: The Zabara, Sikait, Umm Kabo deposits, South Eastern desert of Egypt

    NASA Astrophysics Data System (ADS)

    Grundmann, G.; Morteani, G.

    2008-02-01

    The genesis of gem-quality deep green emeralds of Zabara, Sikait and Umm Kabo (South Eastern Desert, Egypt) is to date a controversial topic. The emerald-bearing biotite schists and quartz lenses are interpreted alternatively as a product of (i) thrust-fault-shear zone - controlled large scale alkali-metasomatism driven by post-magmatic fluid flow or of (ii) a large scale interaction between syntectonic pegmatitic magma or hydrothermal fluids with pre-existing basic to ultrabasic rocks, or of (iii) a syn- to post-tectonic regional metamorphism and small scale blackwall metasomatism. Detailed microstructural and chemical analyses of the Egyptian emeralds and their host rocks show that three generations of beryl can be distinguished: a colourless pegmatitic beryl; a pale green Cr-poor beryl crystallized from pegmatite-related hydrothermal fluids; and a deep green Cr- and Mg-rich emerald. The crystallization of the Cr- and Mg-rich emerald was controlled by the very local availability of Cr, Mg and Be-rich metamorphic fluids during the Pan-African tectono-thermal event. Emerald-rich quartz lenses demonstrate that those fluids locally did mobilize quartz, too. The pale green emeralds found within the pegmatites in association with colourless beryl are the product of a mobilization of colourless pegmatitic beryl and/or phenakite by late pegmatitic fluids slightly enriched in Cr by an interaction with the Cr-rich country rocks. The late pegmatitic fluids are typically Na-rich as is demonstrated by the pervasive albitization of the pegmatites. The complex interplay of magmatic and regional metamorphic events during the genesis of the Egyptian emeralds/beryls makes it impossible through stable oxygen isotope data to relate their genesis to the one or the other event.

  5. Processing and interpretation of ASTER TIR data for mapping of rare-metal-enriched albite granitoids in the Central Eastern Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Aboelkhair, Hatem; Ninomiya, Yoshiki; Watanabe, Yasushi; Sato, Isao

    2010-08-01

    ASTER level 1B (radiance at the sensor) TIR-bands and level 2B04 (surface emissivity) data were analyzed to detect four of 14 rare-metal-enriched albite granite, which are classified as I-type magnetite-series (G3 type) granites in the Central Eastern Desert of Egypt. Analysis of the shapes of laboratory emissivity spectrum of albite granite samples measured by portable emission spectrometer and albite mineral spectra from ASTER spectral library at the website of JPL of NASA showed that, albite granite samples has a higher emissivity in bands 12, 13 and 14 than in bands 10 and 11. To identify and map this type of granite, Quartz Index, as well as band ratios, band ratio combination and band combinations were used, based on the shapes of the analyzed emissivity spectrum of albite granite samples and albite mineral. The Quartz Index (QI) was high for quartz-rich/feldspar poor rocks and was low for K-feldspar or gypsum-rich rocks. Albite rich granites were detected as dark pixels in the QI image. The proposed band ratio b12/b11 clearly identified the albite granite bodies as dark regions. False color images of band combination of 14:12:10 and 12:13:11 in R:G:B clearly mapped the albite granite bodies as light brownish yellow and light greenish regions respectively. A new ASTER colored composite band ratio combination b12/b13:b11/b12:b14/b13 as R:G:B is applied successfully for mapping albite granite in the study area. This new combination clearly separated albite granite as pinkish magenta color. An ASTER scene covering the study area acquired on a different date was used to determine the effect of atmospheric and surface temperature conditions on the ratio and the mathematical band operation. The results indicated no significance differences.

  6. Upper Oligocene evaporites in basin fill of Sevier Desert region, western Utah

    SciTech Connect

    Lindsey, D.A.; Glanzman, R.K.; Naeser, C.W.; Nichols, D.J.

    1981-02-01

    The basin fill beneath the Sevier Desert of western Utah contains evaporites of late Oligocene age that were deposited in a broad closed basin. All of the basin fill penetrated by the Gulf Oil 1 Gronning (2458 m TD), one of only three deep holes in the basin, contains abundant volcanic detritus and its alteration products of Cenozoic age, when volcanism was intense in western Utah. Fission-track dating of tuffaceous sandstone, interbedded with evaporite minerals and representative of sandstone in the lower formations penetrated, yields ages of 26 to 28 m.y.; concordance of ages indicates no thermal resetting. Fossil pollen from mudstone in the evaporite-bearing strata includes forms no older than late Oligocene, in good agreement with the fission-track ages. Thus the age of the evaporites, and of all the basin fill penetrated by drilling, is late Oligocene and younger; previous work had assigned them ages ranging from Triassic to Eocene. Evaporite-bearing rocks were deposited during late Oligocene time in a broad closed basin under arid or semiarid conditions much like those of the Great Basin today. Anhydrite is present throughout approximately 900 m of volcaniclastic rocks in the lower part of the section cut by the Gulf hole, and more than 1500 m of anhydrite and halite is present in possibly equivalent strata in the nearby Argonaut dry hole. Fossil pollen from anhydrite-bearing rocks in the Gulf hole are indicative of an arid to semiarid flora, including plants similar to Mormon tea and possibly saltbush or buffalo berry. Evaporite minerals formed in the basin during dry periods; tuff was erupted from nearby volcanic centers, reworked by water, and deposited in the basin.

  7. Holocene freshwater carbonate structures in the hyper-arid Gebel Uweinat region of the Sahara Desert (Southwestern Egypt)

    NASA Astrophysics Data System (ADS)

    Marinova, Margarita M.; Meckler, A. Nele; McKay, Christopher P.

    2014-01-01

    The eastern part of the Sahara is at present the driest region of the desert. Yet the extensive animal rock art in the area, presumed to depict real activities in the lives of the painters, suggests that environmental conditions were significantly different when the rock art was produced. Here we report on exploration of the area, which led to the discovery of morphologically-distinct carbonate structures that line the walls of two valleys in Gebel Uweinat, and were likely formed in standing water. The carbonate structures comprise what appear to be shoreline carbonate formations, and date back to 8100 and 9400 years BP. The chemical and morphological similarity of these formations to carbonate structures from modern lakes suggests that these lakes contained fresh, standing water suitable for human and animal use. However, the significant quartz content suggests that windblown sand was pervasive, and thus the vegetation cover may have been sparse. This discovery supports the possibility of grasslands in the area, which may have been able to support human habitation, and adds to the evidence for a wetter climate in the area in the early Holocene.

  8. Evaluation of heat generation by radioactive decay of sedimentary rocks in Eastern Desert and Nile Valley, Egypt.

    PubMed

    Abbady, Adel G E

    2010-10-01

    Radioactive heat-production (RHP) data of sedimentary outcrops in Gebel Anz (Eastern Desert) and Gebel Sarai (Nile Valley) are presented. A total of 103 rock samples were investigated, covering all major rock types of the areas. RHP were derived from uranium, thorium and potassium concentrations measured from gamma-radiation originating from the decay of (214)Bi ((238)U series), (208)Tl ((232)Th series) and the primary decay of (40)K, obtained with a NaI (Tl) detector. The heat-production rate of Gebel Anz ranges from 0.94 (Nubai Sandstone ) to 5.22 microW m(-3) (Duwi Formation). In Gebel Sarai it varies from 0.82 (Esna Shale) to 7 microW m(-3) (Duwi Formation). The contribution due to U is about 62%, from Th is 34% and 4% from K in Gebel Anz. The corresponding values in Gebel Sarai are 69.6%, 26.9% and 3.5%, respectively. These data can be used to discuss the effects of the lateral variation of the RHP rate on the heat flux and the temperature fields in the upper crust.

  9. Effect of kaolinite as a key factor controlling the petrophysical properties of the Nubia sandstone in central Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Kassab, Mohamed A.; Abu Hashish, Mohamed F.; Nabawy, Bassem S.; Elnaggar, Osama M.

    2017-01-01

    This paper presents the results of a comprehensive petrographical and petrophysical investigation for the Late Cretaceous Nubia sandstone from Wadi Kareem in central Eastern Desert to measure their fluid flow properties and to investigate the effect of kaolinite on their petrophysical characteristics. From the petrographical analyses, scanning electron microscope 'SEM' and the X-ray diffraction 'XRD' analysis, it is shown that the studied sandstone samples are quite homogeneous in mineralogy and can be distinguished into four sedimentary microfacies: quartz arenite as a clean sandstone as well as three kaolinitic microfacies; namely they are kaolinitic quartz arenite, kaolinitic subarkose, and calcareous to kaolinitc quartz arenite. The main recognized diagenetic processes that prevailed during the post-depositional history of the Nubia sandstone are; compaction, cementation, alteration and dissolution of feldspar into kaolinite. The petrophysical potentiality of the studied sandstones was studied using the helium pycnometer, gas permeability and mercury injection confining pressure 'MICP' techniques. The investigated sandstones can be classified into three petrophysical facies with varying reservoir performances. The petrophysical behaviour of these facies is dependent mostly on their kaolinite content and its impact on porosity, permeability, irreducible water saturation, R35 (pore aperture corresponding to mercury saturation of 35% pore volume), R50 (median pore-throat radius), and MHR (the mean hydraulic radius). Therefore, the studied petrophysical facies are comparable to the distinguished petrographical facies.

  10. The first occurrence of platinum group minerals (PGM) in a chromite deposit in the Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Elhaddad, M. A.

    1996-07-01

    The platinum-group mineralogy (PGM) of the chromitite from Gebel Lawi, in the southeastern desert has been investigated. The most abundant base metal sulfides (BMS) associated with the Lawi chromite are pentlandite, millerite and heazlewoodite. The major platinum-group minerals identified were as follows: laurite (IrOsRu)S2, osmian iridium (OsIr), hollingworthite (RhAsS), tellurian arsenopalladinite (PdTeSbAs), potarite (PdHg) besides cuprian palladian gold (CuPdAu), a Pd-Sb-Hg and HgTe phases. Laurite and osmian iridium occur preferentially in chromite. Os-Ir commonly forms composite PGM with laurite. Hollingworthite and tellurian arsenopalladinite are included within serpentine and, close to the base-metal sulfides, the cuprian palladian gold shares boundaries with chromite. Potarite together with the Pd-Sb-Hg and HgTe phases are embedded in serpentine. Palladium is the most abundant PGE in the Gebel Lawi chromite. A paragenetic sequence of PGM formation is described. Textural evidence indicates that Os-, Ir- and Ru-bearing PGM formed early and were followed by Rh- and Pd-bearing PGM. The concentration of all five PGE could be magmatic, but much of the PGE mineralogy except for laurite and osmian iridium in the center of chromite grains, has been modified by subsequent processes. At later stages, the environment became Te-, Sb-, As- and Hg-rich, which finally led to the formation of low-temperature alteration minerals.

  11. Mesozoic evolution of northeast African shelf margin, Libya and Egypt

    SciTech Connect

    Aadland, R.K.; Schamel, S.

    1989-03-01

    The present tectonic features of the northeast African shelf margin between the Nile delta and the Gulf of Sirte are products of (1) precursory late Paleozoic basement arches, (2) early Mesozoic rifting and plate separation, and (3) Late Cretaceous structural inversion. The 250 km-wide and highly differentiated Mesozoic passive margin in the Western Desert region of Egypt is developed above a broad northwest-trending Late Carboniferous basement arch. In northeastern Libya, in contrast, the passive margin is restricted to just the northernmost Cyrenaica platform, where subsidence was extremely rapid in the Jurassic and Early Cretaceous. The boundary between the Western Desert basin and the Cyrenaica platform is controlled by the western flank of the basement arch. In the middle Cretaceous (100-90 Ma), subsidence accelerated over large areas of the Western desert, further enhancing a pattern of east-west-trending subbasins. This phase of rapid subsidence was abruptly ended about 80 Ma by the onset of structural inversion that uplifted the northern Cyrenaica shelf margin and further differentiated the Western Desert subbasin along a northeasterly trend.

  12. Effects of protective fencing on birds, lizards, and black-tailed hares in the Western Mojave Desert

    USGS Publications Warehouse

    Brooks, M.

    1999-01-01

    Effects of protective fencing on birds, lizards, black-tailed hares (Lepus californicus), perennial plant cover, and structural diversity of perennial plants were evaluated from spring 1994 through winter 1995 at the Desert Tortoise Research Natural Area (DTNA), in the Mojave Desert, California. Abundance and species richness of birds were higher inside than outside the DTNA, and effects were larger during breeding than wintering seasons and during a high than a low rainfall year. Ash-throated flycatchers (Myiarchus cinerascens), cactus wrens (Campylorhynchus brunneicapillus), LeConte's thrashers (Toxostoma lecontei), loggerhead shrikes (Lanius ludovicianus), sage sparrows (Amphispiza belli), and verdins (Auriparus flaviceps) were more abundant inside than outside the DTNA. Nesting activity was also more frequent inside. Total abundance and species richness of lizards and individual abundances of western whiptail lizards (Cnemidophorous tigris) and desert spiny lizards (Sceloporus magister) were higher inside than outside. In contrast, abundance of black-tailed hares was lower inside. Structural diversity of the perennial plant community did not differ due to protection, but cover was 50% higher in protected areas. Black-tailed hares generally prefer areas of low perennial plant cover, which may explain why they were more abundant outside than inside the DTNA. Habitat structure may not affect bird and lizard communities as much as availability of food at this desert site, and the greater abundance and species richness of vertebrates inside than outside the DTNA may correlate with abundances of seeds and invertebrate prey.

  13. Geothermal resources of the western arm of the Black Rock Desert, northwestern Nevada. Part I. Geology and geophysics

    SciTech Connect

    Schaefer, D.H.; Welch, A.H.; Maurer, D.K.

    1983-01-01

    Studies of the geothermal potential of the western arm of the Black Rock Desert in northwestern Nevada included a compilation of existing geologic data on a detailed map, a temperature survey at 1-meter depth, a thermal-scanner survey, and gravity and seismic surveys to determine basin geometry. The temperature survey showed the effects of heating at shallow depths due to rising geothermal fluids near the known hot spring areas. Lower temperatures were noted in areas of probable near-surface ground-water movement. The thermal-scanner survey verified the known geothermal areas and showed relatively high-temperature areas of standing water and ground-water discharge. The upland areas of the desert were found to be distinctly warmer than the playa area, probably due to the low thermal diffusivity of upland areas caused by low moisture content. Surface geophysical surveys indicated that the maximum thickness of valley-fill deposits in the desert is about 3200 meters. Gravity data further showed that changes in the trend of the desert axis occurred near thermal areas. 53 refs., 8 figs., 3 tabs.

  14. Geothermal resources of the western arm of the Black Rock Desert, northwestern Nevada; Part I, geology and geophysics

    USGS Publications Warehouse

    Schaefer, Donald H.; Welch, Alan H.; Mauzer, Douglas K.

    1983-01-01

    Studies of the geothermal potential of the western arm of the Black Rock Desert in northwestern Nevada included a compilation of existing geologic data on a detailed map, a temperature survey at 1-meter depth, a thermal-scanner survey, and gravity and seismic surveys to determine basin geometry. The temperature survey showed the effects of heating at shallow depths due to rising geothermal fluids near the known hot spring areas. Lower temperatures were noted in areas of probable near-surface ground-water movement. The thermal-scanner survey verified the known geothermal areas and showed relatively high-temperature areas of standing water and ground-water discharge. The upland areas of the desert were found to be distinctly warmer than the playa area, probably due to low thermal diffusivity resulting from low moisture content. The surface geophysical surveys indicated that the maximum thickness of valley-fill deposits in the desert is about 3,200 meters. Gravity data further showed that changes in the trend of the desert axis occurred near thermal areas. (USGS)

  15. Bistatic GPR Measurements in the Egyptian Western Desert - Measured and Simulated data

    NASA Astrophysics Data System (ADS)

    Ciarletti, V.; Le Gall, A.; Berthelier, J.; Ney, R.; Corbel, C.; Dolon, F.

    2006-12-01

    The TAPIR (Terrestrial And Planetary Investigation Radar) instrument has been designed at CETP (Centre d'etude des Environnements Terrestre et Planetaires) to explore the deep Martian subsurface (down to a few kilometers) and to detect liquid water reservoirs. TAPIR is an impulse ground penetrating radar operating at central frequencies ranging from 2 to 4 MHz operating from the surface. In November 2005, an updated version of the instrument working either in monostatic or in bi-static mode was tested in the Egyptian Western Desert. The work presented here focuses on the bi-static measurements performed on the Abou Saied plateau which shows a horizontally layered sub-surface. The electromagnetic signal was transmitted using one of the two orthogonal 70 m loaded electrical dipole antennas of the transmitting GPR. A second GPR, 50 or 100 meters apart, was dedicated to the signal reception. The received waves were characterized by a set of 5 measurements performed on the receiving GPR : the two horizontal components of the electric field and the three composants of the magnetic field. They were used to compute the direction of arrival of the incoming waves and to retrieve more accurately their propagation path and especially to discriminate between waves due to some sub-surface reflecting structure and those due to interaction with the surface clutter. A very efficient synchronization between the two radars enabled us to perform coherent additions up to 2^{31} which improves dramatically the obtained signal to noise ratio. Complementary electromagnetic measurements were conducted on the same site by the LPI (Lunar and Planetary Institute) and the SwRI (Southwest Research Institute). They provided independent information which helped the interpretation of the TAPIR data. Accurate simulations obtained by FDTD taking into account the information available are presented and used for both the interpretation of the measured data and the validation of the instrument.

  16. Effects of Protective Fencing on Birds, Lizards, and Black-Tailed Hares in the Western Mojave Desert.

    PubMed

    BROOKS

    1999-04-01

    / Effects of protective fencing on birds, lizards, black-tailed hares (Lepus californicus), perennial plant cover, and structural diversity of perennial plants were evaluated from spring 1994 through winter 1995 at the Desert Tortoise Research Natural Area (DTNA), in the Mojave Desert, California. Abundance and species richness of birds were higher inside than outside the DTNA, and effects were larger during breeding than wintering seasons and during a high than a low rainfall year. Ash-throated flycatchers (Myiarchus cinerascens), cactus wrens (Campylorhynchus brunneicapillus), LeConte's thrashers (Toxostoma lecontei), loggerhead shrikes (Lanius ludovicianus), sage sparrows (Amphispiza belli), and verdins (Auriparus flaviceps) were more abundant inside than outside the DTNA. Nesting activity was also more frequent inside. Total abundance and species richness of lizards and individual abundances of western whiptail lizards (Cnemidophorous tigris) and desert spiny lizards (Sceloporus magister) were higher inside than outside. In contrast, abundance of black-tailed hares was lower inside. Structural diversity of the perennial plant community did not differ due to protection, but cover was 50% higher in protected areas. Black-tailed hares generally prefer areas of low perennial plant cover, which may explain why they were more abundant outside than inside the DTNA. Habitat structure may not affect bird and lizard communities as much as availability of food at this desert site, and the greater abundance and species richness of vertebrates inside than outside the DTNA may correlate with abundances of seeds and invertebrate prey. KEY WORDS: Birds; Fenced protection; Lepus californicus, Lizards; Mojave Desert; Off-highway vehicles; Protected area management; Sheep grazing

  17. Chemistry of serpentine "polymorphs" in the Pan-African serpentinites from the Eastern Desert of Egypt, with an emphasis on the effect of superimposed thermal metamorphism

    NASA Astrophysics Data System (ADS)

    Surour, Adel A.

    2016-08-01

    The present work deals with some Pan-African serpentinites of Neoproterozoic age from five localities in the Eastern Desert of Egypt namely, Abu Fannani, Fawakhir, Barramiya, Ras Shait and Wadi Ghadir that derivedmostly from lherzolite to harzburgite protoliths. The M-value of antigorite is anindicator of the metamorphic grade which is lowest at Fawakhir (greenschist facies) and highest at Abu Fannani (lower amphibolite facies). Antigoritization during progressive regional metamorphism at Fawakhir is limited and its M-value is much higher than 8.52 indicating crystallization temperatures of 220-250 °C whereas it is ≥300 °C in the rest. Antigorite recrystallized at T ≈ 400-450 °C in the contact metamorphic aureoles due to the emplacement of post-orogenic leucogranites at Fawakhir and Gebel Ghadir. Towards the contact with the granites, M-value of antigorite is low (6.48) compared to 8.52 in the least recrystallized antigorite due to the thermal effect. Antigorite that forms in the thermal aureoles is characterized by two types of substitution; Tschermak substitution (Al3+ and Cr3+ for Si4+ in the tetrahedral sites and Mg2+ in the octahedral sites) and non-Tschermak substitutionin the octahedral sites (2R3+ = 3R2+). Generally, both ortho- and clinochrysotiles are common with MgO contents of 41-41.13 wt% and 39.38-40.93 wt%, respectively. In addition to chlorite, high- and low-Al lizardites are present with almost constant total iron (~0.24 cations) as Fe2+(vi) and variable Mg2+. This suggests that significant R3+ in the octahedral sites are mostly occupied by Al3+ and Cr3+ and not iron. In the lizardite structure, there is Tschermak substitution of Si4+ by some trivalent cations in the tetrahedral sites. Using the TEM images, antigorite is distinguishable from chrysotile and they suggest the presence of polyhedral or polygonal serpentine (spherical or circular with alternating sectors of lizardite). Crack-seal microstructures are displayed by chrysotile and

  18. Utilization of airborne gamma ray spectrometric data for geological mapping, radioactive mineral exploration and environmental monitoring of southeastern Aswan city, South Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Youssef, Mohamed A. S.; Elkhodary, Shadia T.

    2013-12-01

    The present work utilizes airborne gamma ray spectrometric data in a trial to refine surface geology of igneous, metamorphic and sedimentary rocks, detect any radioactive mineralization and monitor environment at southeastern Aswan city, South Eastern Desert, Egypt. This area is mainly covered with igneous rocks (younger granites, older granites, metasediments, metavolcanics, metagabbro, Tertiary basalt and ring complex), metamorphic rocks as well as sedimentary rocks (Um Barmil Formation, Timsah Formation, Abu Aggag Formation and wadi sediments). Airborne gamma ray spectrometry can be very helpful in mapping surface geology. This provides estimates of the apparent surface concentrations of the most common naturally occurring radioactive elements, such as potassium (K), equivalent uranium (eU) and equivalent thorium (eTh). This is based on the assumption that, the absolute and relative concentrations of these radioelements vary measurably and significantly with lithology. The composite image technique is used to display simultaneously three parameters of the three radioelement concentrations and their three binary ratios on one image. The technique offers much in terms of lithological discrimination, based on colour differences and showed efficiency in defining areas, where different lithofacies occur within areas mapped as one continuous lithology. The integration between surface geological information and geophysical data led to detailing the surface geology and the contacts between different rock units. Significant locations or favourable areas for uranium exploration are defined, where the measurements exceed (X + 2S), taking X as the arithmetic mean of eU, eU/eTh and eU/K measurements and S as the standard deviation corresponding to each variables. The study area shows the presence of four relatively high uraniferous zones. These zones cannot be ignored and need further ground follow-up. In addition, the trend analysis based on the three radioelement maps and

  19. Mid-Eocene alluvial-lacustrine succession at Gebel El-Goza El-Hamra (Shabrawet area, NE Eastern Desert, Egypt): Facies analysis, sequence stratigraphy and paleoclimatic implications

    NASA Astrophysics Data System (ADS)

    Wanas, H. A.; Sallam, E.; Zobaa, M. K.; Li, X.

    2015-11-01

    This study aims to provide the depositional facies, sequence stratigraphic and paleoclimatic characteristics of the Mid-Eocene (Bartonian) continental succession exposed at Gebel El-Goza El-Hamra (Shabrawet Area, NE Eastern Desert, Egypt). The studied succession consists of siliciclastic rocks followed upward by carbonate rocks. Detailed field observation and petrographic investigation indicate accumulation in floodplain-dominated alluvial and shallow lacustrine systems. The floodplain-dominated alluvial facies (45 m thick) is composed mainly of carbonate nodules-bearing, mottled mudrock with subordinate sandstone and conglomerate beds. The conglomerate and pebbly sandstone bodies interpreted as ephemeral braided channel deposits. The massive, laminated, planner cross-bedded, fine- to medium-grained sandstone bodies interlayered within mudstone reflect sheet flood deposits. The mudrocks associated with paleosols represent distal floodplain deposits. The shallow lacustrine facies (15 m thick) is made up of an alternation of marlstone, micritic limestone, dolostone and mudrock beds with charophytes and small gastropods. Both the alluvial and lacustrine facies show evidence of macro-and micro-pedogenic features. Pollen assemblages, stable δ18O and δ13C isotopes, and paleopedogenic features reflect prevalence of arid to semi-arid climatic conditions during the Bartonian. The sequence stratigraphic framework shows an overall fining-upward depositional sequence, consisting of Low- and High-accommodation Systems Tracts (LAST, HAST), and is bounded by two sequence boundaries (SB-1, SB-2). Conglomerate and pebbly sandstone deposits (braided channel and sheet flood deposits) of the lower part of the alluvial facies reflect a LAST. Mudrock and silty claystone facies (distal floodplain deposits) of the upper part of alluvial facies and its overlying lacustrine facies correspond to a HAST. The LAST, HAST and SB were formed during different accommodation-to-sediment supply (A

  20. Chemistry of serpentine "polymorphs" in the Pan-African serpentinites from the Eastern Desert of Egypt, with an emphasis on the effect of superimposed thermal metamorphism

    NASA Astrophysics Data System (ADS)

    Surour, Adel A.

    2017-02-01

    The present work deals with some Pan-African serpentinites of Neoproterozoic age from five localities in the Eastern Desert of Egypt namely, Abu Fannani, Fawakhir, Barramiya, Ras Shait and Wadi Ghadir that derivedmostly from lherzolite to harzburgite protoliths. The M-value of antigorite is anindicator of the metamorphic grade which is lowest at Fawakhir (greenschist facies) and highest at Abu Fannani (lower amphibolite facies). Antigoritization during progressive regional metamorphism at Fawakhir is limited and its M-value is much higher than 8.52 indicating crystallization temperatures of 220-250 °C whereas it is ≥300 °C in the rest. Antigorite recrystallized at T ≈ 400-450 °C in the contact metamorphic aureoles due to the emplacement of post-orogenic leucogranites at Fawakhir and Gebel Ghadir. Towards the contact with the granites, M-value of antigorite is low (6.48) compared to 8.52 in the least recrystallized antigorite due to the thermal effect. Antigorite that forms in the thermal aureoles is characterized by two types of substitution; Tschermak substitution (Al3+ and Cr3+ for Si4+ in the tetrahedral sites and Mg2+ in the octahedral sites) and non-Tschermak substitutionin the octahedral sites (2R3+ = 3R2+). Generally, both ortho- and clinochrysotiles are common with MgO contents of 41-41.13 wt% and 39.38-40.93 wt%, respectively. In addition to chlorite, high- and low-Al lizardites are present with almost constant total iron ( 0.24 cations) as Fe2+(vi) and variable Mg2+. This suggests that significant R3+ in the octahedral sites are mostly occupied by Al3+ and Cr3+ and not iron. In the lizardite structure, there is Tschermak substitution of Si4+ by some trivalent cations in the tetrahedral sites. Using the TEM images, antigorite is distinguishable from chrysotile and they suggest the presence of polyhedral or polygonal serpentine (spherical or circular with alternating sectors of lizardite). Crack-seal microstructures are displayed by chrysotile and

  1. P-T path and timing of crustal thickening during amalgamation of East and West Gondwana: A case study from the Hafafit Metamorphic Complex, Eastern Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Abu El-Enen, Mahrous M.; Abu-Alam, Tamer S.; Whitehouse, Martin J.; Ali, Kamal A.; Okrusch, Martin

    2016-10-01

    The southeastern sector of the Hafafit Metamorphic Complex, southern Eastern Desert of Egypt comprises infrastructural orthogneisses of tonalite and syenogranite parentage, amphibolites, and a volcano-sedimentary association. These are overthrust by an obducted suprastructural ophiolite nappes via the Nugrus thrust. The protolith of the biotite-hornblende-gneisses was formed during island-arc accretion, while that of the garnet-biotite gneisses were formed in a within-plate regime, consistent with a transition to a post-collisional setting. The volcano-sedimentary association comprises interbedded and intercalated highly foliated metapelitic schists, metabasites, and leucocratic gneisses, deposited in a back-arc basin. The metapelites and the leucocratic gneisses originated from immature Fe-shales and arkoses derived from intermediate-mafic and acidic igneous rocks, respectively, via weak chemical weathering in a tectonically active island arc terrane. The intercalated amphibolites were derived from tholeiitic basalts generated in a back-arc setting. The volcano-sedimentary association was metamorphosed under upper-amphibolite facies conditions with pressures of 9-13 kbar and temperatures of 570-675 °C, as derived from conventional geothermobarometry and pseudosection calculation. A steep, tight clockwise P-T path is constrained and a geothermal gradient around 20 °C/km is estimated for the peak metamorphism. We assume that deformation and metamorphism are due to crustal thickening during the collision of East and West Gondwana, where peak metamorphism took place in the middle to lower crust at 33 km average crustal depth. This was followed by a subsequent quasi-isothermal decompression due to rapid exhumation during wrench tectonics. Sinistral transcurrent shearing with extensional denudation resulted in vertical ductile thinning that was accompanied by heat input from magmatism, as indicated by a higher geothermal gradient during retrograde metamorphism and

  2. Chromium, chromium isotopes and selected trace elements, western Mojave Desert, USA

    USGS Publications Warehouse

    Izbicki, J.A.; Ball, J.W.; Bullen, T.D.; Sutley, S.J.

    2008-01-01

    Chromium(VI) concentrations in excess of the California Maximum Contaminant Level (MCL) of 50 ??g/L occur naturally in alkaline, oxic ground-water in alluvial aquifers in the western Mojave Desert, southern California. The highest concentrations were measured in aquifers eroded from mafic rock, but Cr(VI) as high as 27 ??g/L was measured in aquifers eroded from granitic rock. Chromium(VI) concentrations did not exceed 5 ??g/L at pH < 7.5 regardless of geology. ??53Cr values in native ground-water ranged from 0.7 to 5.1??? and values were fractionated relative to the average ??53Cr composition of 0??? in the earth's crust. Positive ??53Cr values of 1.2 and 2.3??? were measured in ground-water recharge areas having low Cr concentrations, consistent with the addition of Cr(VI) that was fractionated on mineral surfaces prior to entering solution. ??53Cr values, although variable, did not consistently increase or decrease with increasing Cr concentrations as ground-water flowed down gradient through more oxic portions of the aquifer. However, increasing ??53Cr values were observed as dissolved O2 concentrations decreased, and Cr(VI) was reduced to Cr(III), and subsequently removed from solution. As a result, the highest ??53Cr values were measured in water from deep wells, and wells in discharge areas near dry lakes at the downgradient end of long flow paths through alluvial aquifers. ??53Cr values at an industrial site overlying mafic alluvium having high natural background Cr(VI) concentrations ranged from -0.1 to 3.2???. Near zero ??53Cr values at the site were the result of anthropogenic Cr. However, mixing with native ground-water and fractionation of Cr within the plume increased ??53Cr values at the site. Although ??53Cr was not necessarily diagnostic of anthropogenic Cr, it was possible to identify the extent of anthropogenic Cr at the site on the basis of the ??53Cr values in conjunction with major-ion data, and the ??18O and ??D composition of water from wells.

  3. Occurrence of hexavalent chromium in ground water in the western Mojave Desert, California

    USGS Publications Warehouse

    Ball, J.W.; Izbicki, J.A.

    2004-01-01

    About 200 samples from selected public supply, domestic, and observation wells completed in alluvial aquifers underlying the western Mojave Desert were analyzed for total dissolved Cr and Cr(VI). Because Cr(VI) is difficult to preserve, samples were analyzed by 3 methods. Chromium(VI) was determined in the field using both a direct colorimetric method and EPA method 218.6, and samples were speciated in the field for later analysis in the laboratory using a cation-exchange method developed for the study described in this paper. Comparison of the direct colorimetric method and EPA method 218.6 with the new cation-exchange method yielded r2 values of 0.9991 and 0.9992, respectively. Total dissolved Cr concentrations ranged from less than the 0.1 ??g/l detection limit to 60 ??g/l, and almost all the Cr present was Cr(VI). Near recharge areas along the mountain front pH values were near neutral, dissolved O2 concentrations were near saturation, and Cr(VI) concentrations were less than the 0.1 ??g/l detection limit. Chromium(VI) concentrations and pH values increased downgradient as long as dissolved O 2 was present. However, low Cr(VI) concentrations were associated with low dissolved O2 concentrations near ground-water discharge areas along dry lakes. Chromium(VI) concentrations as high as 60 ??g/l occurred in ground water from the Sheep Creek fan alluvial deposits weathered from mafic rock derived from the San Gabriel Mountains, and Cr(VI) concentrations as high as about 36 ??g/l were present in ground water from alluvial deposits weathered from less mafic granitic, metamorphic, and volcanic rocks. Chromium(III) was the predominant form of Cr only in areas where dissolved O2 concentrations were less than 1 mg/l and was detected at a median concentration of 0.1 ??g/l, owing to its low solubility in water of near-neutral pH. Depending on local hydrogeologic conditions and the distribution of dissolved O2, Cr(VI) concentrations may vary considerably with depth. Samples

  4. Phylogeographic structure and historical demography of the western diamondback rattlesnake (Crotalus atrox): A perspective on North American desert biogeography.

    PubMed

    Castoe, Todd A; Spencer, Carol L; Parkinson, Christopher L

    2007-01-01

    The western diamondback rattlesnake (Crotalus atrox) is a prominent member of North American desert and semi-arid ecosystems, and its importance extends from its impact on the region's ecology and imagery, to its medical relevance as a large deadly venomous snake. We used mtDNA sequences to identify population genetic structure and historical demographic patterns across the range of this species, and relate these to broader patterns of historical biogeography of desert and semi-arid regions of the southwestern USA and adjacent Mexico. We inferred a Late Pliocene divergence between peninsular and continental lineages of Crotalus, followed by an Early Mid Pleistocene divergence across the continental divide within C. atrox. Within desert regions (Sonoran and Chihuahuan Deserts, Southern Plains, and Tamaulipan Plain) we observed population structure indicating isolation of populations in multiple Pleistocene refugia on either side of the continental divide, which we attempt to identify. Evidence of post-glacial population growth and range expansion was inferred, particularly in populations east of the continental divide. We observed clear evidence of (probably recent) gene flow across the continental divide and secondary contact of haplotype lineages. This recent gene flow appears to be particularly strong in the West-to-East direction. Our results also suggest that Crotalus tortugensis (Tortuga Island rattlesnake) and a population of 'C. atrox' inhabiting Santa Cruz Island (in the Gulf of California) previously suggested to be an unnamed species, are in fact deeply phylogenetically nested within continental lineages of C. atrox. Accordingly, we suggest C. tortugensis and 'C. atrox' from Santa Cruz Island be placed in the synonymy of C. atrox.

  5. Morphologic-anthropological investigations in tomb K93.12 at Dra' Abu el-Naga (Western Thebes, Egypt).

    PubMed

    Lösch, Sandra; Moghaddam, Negahnaz; Paladin, Alice; Rummel, Ute; Hower-Tilmann, Estelle; Zink, Albert

    2014-01-01

    In this study we present the analysis of the human remains from tomb K93.12 in the Ancient Egyptian necropolis of Dra' Abu el-Naga, located opposite the modern city of Luxor in Upper Egypt on the western bank of the Nile. Archaeological findings indicate that the rock tomb was originally built in the early 18th dynasty. Remains of two tomb-temples of the 20th dynasty and the looted burial of the High Priest of Amun Amenhotep have been identified. After the New Kingdom the tomb was reused as a burial place until the 26th dynasty. The skeletal and mummified material of the different tomb areas underwent a detailed anthropological and paleopathological analysis. The human remains were mostly damaged and scattered due to extensive grave robberies. In total, 79 individuals could be partly reconstructed and investigated. The age and sex distribution revealed a male predominance and a high percentage of young children (< 6 years) and adults in the range of 20 to 40 years. The paleopathological analysis showed a high prevalence of stress markers such as cribra orbitalia in the younger individuals, and other pathological conditions such as dental diseases, degenerative diseases and a possible case of ankylosing spondylitis. Additionally, 13 mummies of an intrusive waste pit could be attributed to three different groups belonging to earlier time periods based on their style of mummification and materials used. The study revealed important information on the age and sex distribution and diseases of the individuals buried in tomb K93.12.

  6. Multiprocess evolution of landforms in the Kharga Region, Egypt: Applications to Mars

    NASA Technical Reports Server (NTRS)

    Breed, C. S.; Mccauley, J. F.; Grolier, M. J.

    1984-01-01

    In order to understand better the polygenetic evolution of landforms on the martian surface, field studies were conducted in and around the Kharga Depression, Egypt. The Kharga region, on the eastern edge of Egypt's Western Desert, was subject to erosion under mostly hyperarid climatic conditions, punctuated by brief pluvial episodes of lesser aridity, since early Pleistocene time. The region contains numerous landforms analogous to features on the martian surface: yardangs carved in layered surficial deposits and in bedrock, invasive dune trains, wind-modified channels and interfluves, and depressions bounded by steep scarps. Like many of the topographic depresions on Mars, the Kharga Depression was invaded by crescentic dunes. In Egypt, stratigraphic relations between dunes, yardangs, mass-wasting debris, and wind-eroded flash-flood deposits record shifts in the relative effectiveness of wind, water, and mass-wasting processes as a function of climate change.

  7. Variations in water balance and recharge potential at three western desert sites

    USGS Publications Warehouse

    Gee, G.W.; Wierenga, P.J.; Andraski, B.J.; Young, M.H.; Fayer, M.J.; Rockhold, M.L.

    1994-01-01

    Radioactive and hazardous waste landfills exist at numerous desert locations in the USA. At these locations, annual precipitation is low and soils are generally dry, yet little is known about recharge of water and transport of contaminants to the water table. Recent water balance measurements made at three desert locations, Las Cruces, NM, Beatty, NV, and the U.S. Department of Energy's Hanford Site in the state of Washington, provide information on recharge potential under three distinctly different climate and soil conditions. All three sites show water storage increases with time when soils are coarse textured and plants are removed from the surface, the rate of increase being influenced by climatic variables such as precipitation, radiation, temperature, and wind. Lysimeter data from Hanford and Las Cruces indicate that deep drainage (recharge) from bare, sandy soils can range from 10 to >50% of the annual precipitation. At Hanford, when desert plants are present on sandy or gravelly surface soils, deep drainage is reduced but not eliminated. When surface soils are silt loams, deep drainage is eliminated whether plants are present or not. At Las Cruces and Beatty, the presence of plants eliminated deep drainage at the measurement sites. Differences in water balance between sites are attributed to precipitation quantity and distribution and to soil and vegetation types. The implication for waste management at desert locations is that surface soil properties and plant characteristics must be considered in waste site design in order to minimize recharge potential.

  8. Subduction-related cryptic metasomatism in fore-arc to nascent fore-arc Neoproterozoic mantle peridotites beneath the Eastern Desert of Egypt: mineral chemical and geochemical evidences

    NASA Astrophysics Data System (ADS)

    Hamdy, Mohamed; Salam Abu El-Ela, Abdel; Hassan, Adel; Kill, Youngwoo; Gamal El Dien, Hamed

    2013-04-01

    Mantle spinel peridotites beneath the Arabian Nubian Shield (ANS) in the Eastern Desert (ED) of Egypt were formed in arc stage in different tectonic setting. Thus they might subject to exchange with the crustal material derived from recycling subducting oceanic lithosphere. This caused metasomatism enriching the rocks in incompatible elements and forming non-residual minerals. Herein, we present mineral chemical and geochemical data of four ophiolitic mantle slice serpentinized peridotites (W. Mubarak, G. El-Maiyit, W. Um El Saneyat and W. Atalla) widely distributed in the ED. These rocks are highly serpentinized, except some samples from W. Mubarak and Um El-Saneyat, which contain primary olivine (Fo# = 90-92 mol %) and orthopyroxene (En# = 86-92 mol %) relics. They have harzburgite composition. Based on the Cr# and Mg# of the unaltered spinel cores, all rocks formed in oceanic mantle wedge in the fore-arc setting, except those from W. Atalla formed in nascent fore-arc. This implies that the polarity of the subduction during the arc stage was from the west to the east. These rocks are restites formed after partial melting between 16.58 in W. Atalla to 24 % in G-El Maiyit. Melt extraction occurred under oxidizing conditions in peridotites from W. Mubarak and W. Atalla and under reducing conditions in peridotites from G. El-Maiyit and Um El-Saneyat. Cryptic metasomatism in the studied mantle slice peridotites is evident. This includes enrichment in incompatible elements in minerals and whole rocks if compared with the primitive mantle (PM) composition and the trend of the depletion in melt. In opx the Mg# doesn't correlate with TiO2, CaO, MnO, NiO and Cr2O3concentrations. In addition, in serpentinites from W. Mubarak and W. Atalla, the TiO2spinel is positively correlated with the TiO2 whole-rock, proposing enrichment by the infiltration of Ti-rich melts, while in G. El- Maiyit and Um El-Saneyat serpentinites they are negatively correlated pointing to the reaction

  9. Zonation of primary haloes of Atud auriferous quartz vein deposit, Central Eastern Desert of Egypt: A potential exploration model targeting for hidden mesothermal gold deposits

    NASA Astrophysics Data System (ADS)

    Harraz, Hassan Z.; Hamdy, Mohamed M.

    2015-01-01

    The Atud gold mine located in the Neoproterozoic diorite and metagabbro of the Central Eastern Desert of Egypt has been initially excavated during Pharaonic times. Between 1953 and 1969, the Egyptian Geological Survey and Mining Authority performed underground prospection in the auriferous quartz vein and metasomatic alteration zones in the main Atud area, estimating a principal gold lode of 19,000 tones (16.28 g/ton), and 1600 tons of damp (1.24 g/ton). Yet the potentiality of the deposit has not been exhausted. However, for exploration of hidden ore, quantitative characterization using trace elements zoning of mineralization haloes with 280 samples from surface and three underground mining levels is applied. This was through multivariate statistical analysis (Factor analysis) of 11 selected trace elements. Axial (vertical) extents of primary haloes above and beneath gently dipping orebody are also visualized to interpret the level of erosion, determine the direction of mineralizing solutions as well as to examine whether the hidden orebody is promising at the Atud mine. Axial zones of primary dispersion aureoles of trace elements are: Ag, As, S and U around the auriferous quartz veins; Cu, and Pb in the surface horizons; and Zn, Ni, Co, and U along the lower margin of mineralization zone. Gold contents in bedrock and quartz vein samples from level-42M are the highest (5.7 and 40.3 ppm, respectively). In the transverse (lateral) direction, the maximum relative accumulation of Au and Zn occurs at the Northern Shaft; Pb, Cu, As, and U at the Main Shaft; and Ag, S, Co, and Ni at the Southern Shaft. The estimated axial zonation sequence of indicator elements using the variability index is Pb → Cu → Ag → Au → As → S → Ni → Co → U → Zn. According to this zonation, an index such as (Pb × Cu)D/(U × Zn)D can be a significant for predicting the Au potentiality at a particular depth. In addition, the Pb/U zonality index is an appropriate indicator for the

  10. Calcareous nannofossil and planktonic foraminifera biostratigraphy through the Middle to Late Eocene transition of Fayum area, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Marzouk, Akmal Mohamed; El Shishtawy, Ahmed Moustafa; Kasem, Atef Masoud

    2014-12-01

    The Eocene sequence exposed at Gebel Naalun (Fayum-Nile divide), Guta section-I (West of Birket Qarun near Guta Village) and Guta section-II (Northwest of Birket Qarun near Guta Village) is differentiated, from base to top, into two formations; Gehannam Formation (Middle-Late Eocene) and Birket Qarun Formation (Late Eocene), respectively. Two calcareous nannofossil zones were recognized from the Eocene succession at Gebel Naalun; Discoaster saipanensis (NP17) and Chiasmolithus oamaruensis (NP18) zones as well as one planktonic foraminiferal zone; Truncorotaloides (Acaranina) rohri (P14) zone. However, at Guta section-I, two nannofossil zones were defined; Discoaster saipanensis (NP17) and Chiasmolithus oamaruensis (NP18) zones; the preservation of planktonic foraminiferal assemblage is too poor to enable us to recognize marker species as a result of many diagenetic processes. At Guta section-II, two nannofossil zones; Chiasmolitus oamaruensis (NP18) and Isthmolithus recurvus (NP19) and two planktonic foraminiferal zones; T. pseudoampliapertura zone and G. semiinvoluta zone are recorded. Several authors found that the lowest occurrence of Chiasmolithus oamaruensis is a poor criterion for defining the base of NP18 Zone, which is confirmed here. The same criticism has been applied to the lowest occurrence of Isthmolithus recurvus which defines the NP18/NP19 zonal boundary. It is generally agreed that NP19 Zone falls in the Priabonian (Late Eocene). As a result of the occurrence of the nannofossil marker species; Isthmolithus recurvus only in side views below and above the first appearance of Chiasmolithus oamaruensis at both Naalun and Guta section-I, this species is not reliable to define the NP18/NP19 zonal boundary. At Guta section-II, the Middle/Upper Eocene boundary can be delineated by the first appearance of Globigerinatheka semiinvoluta above the first occurrence of Isthmolithus recurvus in both plane and side views.

  11. Thermal treatment for separating quartz from geethitic iron ore of Gebel Ghorabi, Bahariya oasis, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Monen, H. M. Abdel; Kamel, A. F.

    1993-07-01

    Gebel Ghorabi is located at the extreme northern end of Bahariya Oasis and the mineralized area covers an area of about 2 km 2. Geologically, the iron ore is composed of random alternations of three main yellow, brown and dark brown colored bands. The former band is relatively thicker than the others. The iron particles range in size from a (pisolitic ≫) fraction > 2 mm to earthy (the so-called pisolites may grade down from coarse to about 0.25 mm in size). A bulk sample corresponding more or less to the yellow iron ore band contains 54.16% Fe 2O 3, 26.13% SiO 2 and 5.39% Al 2O 3 as major components. Technologically, the combined effect of a thermal reduction and of a quenching shock on the crushed iron sample (-12 mm) has been investigated. This technique has been found to sufficiently enhance the magnetic properties of the iron minerals which could be easily separated by using a low intensity magnetic separator. The maximum severance of quartz grains from the reduced iron oxides was reached for samples subjected to a slow heating at 700°C for 60 min. and to a fast cooling by quenching in water. A flow sheet for handling the yellow iron ore is here proposed to produce a magnetic iron concentrate with 87.63% Fe 3O 3 and 1.40% SiO 2, and with a recovery of 97.21%.

  12. Childhood illnesses and malnutrition in under five children in drought affected desert area of western Rajasthan, India.

    PubMed

    Singh, Madhu B; Lakshminarayana, J; Fotedar, R; Anand, P K

    2006-03-01

    The study was undertaken to asses the impact of drought on childhood illnesses and nutrition in under five children of rural population using three stage sampling design. The study has been carried out in 24 villages belonging to 6 tehsils of Jodhpur district which was a drought affected desert district of Western Rajasthan in 2003. A total of 914 under five children (0-5 years) could be examined for their childhood illnesses, malnutrition, dietary intake and clinical signs of nutritional deficiency. Childhood illnesses observed at the time of drought were respiratory (7.5 %), gastroentrological (7.5%), and 5.6% fever (viral, malaria and jaundice), higher in males than females. Children suffered from recent and long term malnutrition were 39% and 26% respectively as per National Centre for Health Statistics (NCHS) standards. The extent of malnutrition was significantly higher in females than in males (p<0.01). Vitamin A & B complex deficiencies were 0.7% and 3/% respectively. The protein energy malnutrition (PEM) was observed in 44.4%. Overall mean calorie and protein intake deficit was observed to be very high (76.0 & 54.0 %). The comparison of present drought results with earlier studies in normal and drought conditions showed higher prevalence of PEM and deficiencies of calories & proteins in their diet. Respiratory, gastroentrological and fever were main childhood illnesses observed and were higher in males at the time of drought. PEM, vitamin A & B- complex deficiencies, anemia along with deficit in calories and proteins in their diet was observed higher in present study as compared to non desert areas, which may be due to the harsh environmental conditions in desert areas and paucity in the consumption of daily food intake. Due to inadequate consumption of daily food, the children were suffering from PEM resulting in several childhood illnesses. Effective measures making availability of adequate calories and proteins to all age groups especially to under five

  13. Spermatogenesis and plasma testosterone levels in Western Australian burrowing desert frogs, Cyclorana platycephala, Cyclorana maini, and Neobatrachus sutor, during aestivation.

    PubMed

    Shalan, A G; Bradshaw, S D; Withers, P C; Thompson, G; Bayomy, M F F; Bradshaw, F J; Stewart, T

    2004-03-01

    Changes in testis size, histological status, and plasma levels of testosterone were monitored for males of three species of Western Australian desert frogs, Cyclorana maini, Cyclorana platycephala, and Neobatrachus sutor during aestivation. The frogs were induced to burrow and form cocoons soon after their capture and then disinterred at intervals in order to monitor changes in reproductive activity of the testes. All stages of spermatogenesis were evident in active frogs, which were collected a few days following rain from breeding choruses. Relative testis mass declined gradually in all species during the first 7 months of aestivation and then increased significantly at 16-19 months in the two species for which extended data were available (C. maini and N. sutor). A decrease in the number of sperm bundles 2-4 months after cocooning was associated with an initial increase in the number of free spermatazoa in all three species, which then returned to the levels seen in active animals after 7 months. Increases in the number of primary and secondary spermatogonia were most evident in C. platycephala after 4-7 months of aestivation, but early stages of spermatocytogenesis were evident in all species after 7 months of aestivation, especially in individuals that contained neither sperm bundles nor mature spermatazoa. Changes in plasma testosterone levels correlated significantly with variations in the diameter of the seminiferous tubules and the GSI, suggesting that this hormone plays a major role in controlling testicular recrudescence in aestivating, cocooned, desert frogs. Data from this study show that, in the absence of any external cues, testicular recrudescence is evident after approximately one year of aestivation in desert frogs which prepares them to breed again, once rain falls.

  14. Source and Movement of Ground Water in the Western Part of the Mojave Desert, Southern California, USA

    USGS Publications Warehouse

    Izbicki, John A.

    2004-01-01

    Delta oxygen-18 and delta deuterium composition of precipitation and water from wells in the Mojave River and the Morongo ground-water basins in the western part of the Mojave Desert show that ground-water recharge occurs primarily from winter precipitation near low-altitude passes in the San Bernardino and the San Gabriel Mountains?as opposed to runoff from higher altitudes in the mountains. The resulting deuterium composition of the ground water, about -64 per mil, contrasts sharply with the isotopic composition of water from wells recharged by runoff from higher altitudes of the San Gabriel and the San Bernardino Mountains, about -84 per mil. These differences define the 3-dimensional movement of ground water between aquifers especially downgradient from faults that act as barriers to ground-water flow. Water recharged from runoff in the mountains farther to the east in the Mojave Desert plots to the right of the meteoric water line and after accounting for evaporative effects had an isotopic composition lighter than present-day precipitation.

  15. Movement and Age of Ground Water in the Western Part of the Mojave Desert, Southern California, USA

    USGS Publications Warehouse

    Izbicki, John A.; Michel, Robert L.

    2004-01-01

    Tritium and carbon-14 data in water from wells in the Mojave River and the Morongo ground-water basins in the western part of the Mojave Desert show recent recharge focused in the floodplain aquifer along the Mojave River. Older ground water was present in parts of the regional aquifer that surround and underlie the floodplain aquifer. Movement of water between the floodplain and the regional aquifers occurs near on the upgradient side of faults as water from the regional aquifer discharges to the floodplain aquifer and on the downgradient side of the faults where water from the floodplain aquifer recharges the regional aquifer. On the basis of carbon-14 ages, corrected for mineralogic reactions with aquifer materials, water from some wells was recharged more than 20,000 years ago. Geochemical data show ground-water recharge has gradually decreased as the climate changed since that time.

  16. Implications of high altitude desert dust transport from Western Sahara to Nile Delta during biomass burning season.

    PubMed

    Prasad, Anup K; El-Askary, Hesham; Kafatos, Menas

    2010-11-01

    The air over major cities and rural regions of the Nile Delta is highly polluted during autumn which is the biomass burning season, locally known as black cloud. Previous studies have attributed the increased pollution levels during the black cloud season to the biomass or open burning of agricultural waste, vehicular, industrial emissions, and secondary aerosols. However, new multi-sensor observations (column and vertical profiles) from satellites, dust transport models and associated meteorology present a different picture of the autumn pollution. Here we show, for the first time, the evidence of long range transport of dust at high altitude (2.5-6 km) from Western Sahara and its deposition over the Nile Delta region unlike current Models. The desert dust is found to be a major contributor to the local air quality which was previously considered to be due to pollution from biomass burning enhanced by the dominant northerly winds coming from Europe.

  17. Mirages in the Desert: Theorizing Western Muslim Identity across 60 Years

    ERIC Educational Resources Information Center

    El-Sherif, Lucy

    2016-01-01

    Theorizations on Western Muslim identity that are multi-layered and grounded in actual Western Muslim experiences are hard to find. Two exceptions to this are "The Road to Mecca" by Muhammad Asad (1954/2005), and "Islam is a Foreign Country" by Zareena Grewal (2014), rich texts that span across six decades. Asad's classic…

  18. Seasonal metabolic acclimatization in the herbivorous desert lizard Uromastyx philbyi (Reptilia: Agamidea) from western Saudi Arabia.

    PubMed

    Zari, Talal A

    2016-08-01

    Many ectotherms adjust their metabolic rate seasonally in association with variations in environmental temperatures. The range and direction of these seasonal changes in reptilian metabolic rates are thought to be linked to the seasonality of activity and energy requirements. The present study was conducted to measure the standard metabolic rate (SMR) of seasonally-acclimatized Uromastyx philbyi with different body masses at 20, 25, 30, 35 and 40°C using open-flow respirometry during the four seasons. SMR was mass-dependent. The mean exponent of mass, "b", in the metabolism-body mass relation was 0.76 (variance=0.0007). Likewise, SMR increased as temperature increased with low Q10 values at high temperatures and high Q10 values at low temperatures. The lowest and highest Q10 values were achieved for temperature ranges of 30-35°C for summer-acclimatized dhabbs (Q10=1.6) and 20-25°C for winter-acclimatized dhabbs (Q10=3.9). Seasonal acclimatization effects were obvious at all temperatures (20-40°C). Winter-acclimatized dhabbs had the lowest metabolic rates at all temperatures. The seasonal acclimatization patterns displayed by U. philbyi may represent a valuable adaptation for herbivorous desert lizards that inhabit subtropical deserts to facilitate activity during their active seasons and to conserve energy during inactivity at low temperatures.

  19. Extension of the Najd Shear System from Saudi Arabia to the central eastern desert of Egypt based on integrated field and LANDSAT observations

    NASA Astrophysics Data System (ADS)

    Sultan, Mohamed; Arvidson, Raymond E.; Duncan, Ian J.; Stern, Robert J.; El Kaliouby, Baher

    1988-12-01

    The Najd Shear System in Saudi Arabia extends over 1200 km in a NW-SE direction and has a width of approximately 300 km. A digital color mosaic, compiled from seven Landsat thematic mapper scenes, was used to delineate characteristic structural features of the Najd System in the Midyan region of Saudi Arabia and to search for similar features in the Egyptian Eastern Desert. The digital mosaic was generated using ratios of Landsat thematic mapper bands (bands 5/4 × 3/4, 5/1, 5/7) that are sensitive to the rock content of Fe-bearing aluminosilicates, spectrally opaque phases, and hydroxyl-bearing or carbonate minerals, respectively. The mosaic covers approximately 130,000 km² of late Proterozoic exposures of the Arabian-Nubian Shield and has the Eastern Desert and the Midyan region placed in their approximate pre-Red Sea locations. The Ajjaj Shear Zone (AJZ) marks the termination of the Najd System against the eastern margin of the Red Sea in the Midyan region. The AJZ aligns with the central Eastern Desert, based on analysis of pre-Red Sea locations. Analyses of Landsat data and field observations show that the Ajjaj Shear Zone and the central Eastern Desert exhibit the following features in common: (1) outcrops that are generally elongate in a NW-SE direction as a result of folding, with fine-scale lithologic heterogeneity at the outcrop scale related to deformation associated with faulting; (2) NW trending left-lateral faults and ductile shear zones; (3) subhorizontal, NW trending mineral lineations, and variably dipping NW trending foliations, with local changes in attitude around large competent (e.g., granitic) bodies; and (4) lithologic contacts that are generally tectonic in nature and related to faulting. These features are less common to the north and south of both the Ajjaj Shear Zone and the central Eastern Desert. Results are consistent with the Najd Shear System extending into the Eastern Desert and dominating the structural patterns within the

  20. Geothermal resources of the Western Arm of the Black Rock Desert, northwestern Nevada; Part II, Aqueous geochemistry and hydrology

    USGS Publications Warehouse

    Welch, A.H.; Preissler, A.M.

    1990-01-01

    The western arm of the Black Rock Desert, Nevada, includes several distinct hydrothermal systems, some of which exceed 150 C and may exceed 200 C at depth, determined on the basis of chemical geothermometry. The cation composition of the thermal water appears to be controlled by aluminosilicate minerals that are common in other active geothermal systems. Estimates of the equilibrium temperatures at which some mineral pairs are stable, when compared with the more commonly applied geothermometer estimates, indicate that thermodynamic data may be useful for estimating deep aquifer temperatures. Thermal water at Great Boiling and Mud Springs, which has a chloride concentration of about 2,000 mg/L and a total dissolved-solids concentration of 4 ,500 mg/L, appears to have been affected by shallow evapotranspiration in an adjacent playa prior to deep circulation. This model of recharge within the basin floor is distinctly different from models proposed for most other geothermal systems in the northern Great Basin. (USGS)

  1. Three-dimensional structure of Conrad and Moho discontinuities in Egypt

    NASA Astrophysics Data System (ADS)

    Abdelwahed, Mohamed F.; El-Khrepy, Sami; Qaddah, Atef

    2013-09-01

    The three-dimensional structures of Conrad and Moho discontinuities beneath Egypt are investigated by local earthquake travel time inversion. A number of 2513 events with 24,696 arrival time data recorded by the Egyptian National Seismic Network (ENSN) are used. The station corrections of P- and S-waves and the hypocentral parameters are simultaneously estimated with the Conrad and Moho depths. The results of this study show that the discontinuities form patterns of shallow and deep structures getting shallow toward the northern and eastern coast, and deeper toward western Desert and northeastern Sinai. The Conrad and Moho discontinuities are located within the depth range 9-17 km and 27-41 km, respectively. The depth ranges of Conrad and Moho discontinuities are respectively: 15-16 km and 31-33 km in greater Cairo and Dahshour; 15-18 km and 32-35 km in Sinai; 16-17 and 33-35 km along the Nile River; 9 and 30 km near the Red Sea coast; 15 and 39 km toward the western desert. The comprehensive comparison with previous crustal studies suggests that the main patterns of Moho undulations and the range of Moho depths are in good agreement with the previous crustal models in Egypt, as well as with the Bouguer gravity anomalies that well explain the Nile River sediments, Red Sea mountain belts and Western Desert depression and Oasis. The model of the Moho and Conrad discontinuities improves knowledge of the three dimensional structure of the crust beneath Egypt in wide areas where geophysical data is sparse.

  2. The meaning of desert color in earth orbital photographs

    NASA Technical Reports Server (NTRS)

    El-Baz, F.

    1978-01-01

    The color of desert surfaces as seen in earth orbital photographs is indicative of soil composition. Apollo-Soyuz photographs of the Sturt and Simpson Deserts of Australia confirm that sand grains become redder as the distance from the source increases. Reddening is caused by a thin iron-oxide coating on individual sand grains and can be used, in some cases, to map relative-age zones. Photographs of the Western (Libyan) Desert of Egypt indicate three distinct and nearly parallel color zones that have been correlated in the field with: (1) arable soil composed of quartz, clay, and calcium carbonate particles; (2) relatively active sand with or without sparse vegetation; and (3) relatively inactive sand mixed with dark (desert-varnished) pebbles. The youngest sands are in the form of longitudinal dunes, which are migrating to the south-southeast along the prevailing wind direction. Some of the young dune fields are encroaching on the western boundary of the fertile Nile Valley.

  3. Atmospheric aerosols size distribution properties in winter and pre-monsoon over western Indian Thar Desert location

    NASA Astrophysics Data System (ADS)

    Panwar, Chhagan; Vyas, B. M.

    2016-05-01

    The first ever experimental results over Indian Thar Desert region concerning to height integrated aerosols size distribution function in particles size ranging between 0.09 to 2 µm such as, aerosols columnar size distribution (CSD), effective radius (Reff), integrated content of total aerosols (Nt), columnar content of accumulation and coarse size aerosols particles concentration (Na) (size < 0.5 µm) and (Nc) (size between 0.5 to 2 µm) have been described specifically during winter (a stable weather condition and intense anthropogenic pollution activity period) and pre-monsoon (intense dust storms of natural mineral aerosols as well as unstable atmospheric weather condition period) at Jaisalmer (26.90°N, 69.90°E, 220 m above surface level (asl)) located in central Thar desert vicinity of western Indian site. The CSD and various derived other aerosols size parameters are retrieved from their average spectral characteristics of Aerosol Optical Thickness (AOT) from UV to Infrared wavelength spectrum measured from Multi-Wavelength solar Radiometer (MWR). The natures of CSD are, in general, bio-modal character, instead of uniformly distributed character and power law distributions. The observed primary peaks in CSD plots are seen around about 1013 m2 μm-1 at radius range 0.09-0.20 µm during both the seasons. But, in winter months, secondary peaks of relatively lower CSD values of 1010 to 1011 m2/μm-1 occur within a lower radius size range 0.4 to 0.6 µm. In contrast to this, while in dust dominated and hot season, the dominated secondary maxima of the higher CSD of about 1012 m2μm-3 is found of bigger aerosols size particles in a rage of 0.6 to 1.0 µm which is clearly demonstrating the characteristics of higher aerosols laden of bigger size aerosols in summer months relative to their prevailed lower aerosols loading of smaller size aerosols particles (0.4 to 0.6 µm) in cold months. Several other interesting features of changing nature of monthly spectral AOT

  4. Magnetostratigraphy of the Western Borrego Badlands, Anza-Borrego Desert, California - Implications for Tectonics and Litho- and Biostratigraphic Control

    NASA Astrophysics Data System (ADS)

    Remeika, P.; Liddicoat, J. C.; Beske-Diehl, S.

    2008-12-01

    Over 200 meters of non-marine fluvial-floodplain sediments and volcanic ashes are exposed in the Borrego Badlands as part of the northwest margin of the Borrego-San Filipe Basin in the Anza-Borrego Desert, Califorinia. Our stratigraphic and paleomagnetic investigations provide data regarding the age and character of the sediments and tectonics of the region. The intrabasin sediments in Mammoth Cove and Rainbow Wash are especially favorable for paleomagnetic and biostratigraphic analysis due to their fine-grained lithology, abundant vertebrate fossils (Borrego Local Fauna) of Irvingtonian Land Mammal Age, and a continuous syndepositional record of alluvial fan, lacustrine, and playa-margin deposition in response to wrench tectonics associated with the seismogenic San Jacinto Fault Zone. The mean paleomagnetic directions following thermal demagnetization to 600°C are Incl. = 44.9°, Decl. = 11.6°, alpha-95 = 10.4°, k = 13.5, n = 16 for samples from the Brunhes Normal Chron, and Incl. = -46.5°, Decl. = 201.3°, alpha-95 = 8.6°, k = 18.1, n = 17 for samples from the Matuyama Reverse Chron. Those directions are reasonable when compared to the directions reported for older deposits in the Vallecito-Fish Creek Basin in the eastern part of the Anza-Borrego Desert (Johnson et al., 1983); those directions are Incl. = 41.6°, Decl. = 30.6°, alpha-95 = 7.4°, k = 13.1 for samples that record normal polarity, and Incl. = -35.1°, Decl. = 219.4°, alpha-95 = 7.4°, k = 9.6 for samples that record reverse polarity. By contrast, sediments deposited during the lower Matuyama Reverse Chron and upper Gauss Normal Chron where we sampled in Rainbow Wash are rotated clockwise by a greater amount - almost 90°. That rotation patterns the nearly 90° of clockwise rotation of volcanic rocks in the Western Transverse Ranges (Luyendyk, 1991) and non-marine Sespe Fm. (Liddicoat, 1990; 2001) north of the Los Angeles Basin that began about 15 million years ago (Luyendyk, 1991).

  5. Remote sensing and geochemical investigations of selected surface processes in Egypt and Missouri

    NASA Astrophysics Data System (ADS)

    Crombie, Mary Katherine

    This thesis consists of three studies of surface processes on Earth: 1. Age and isotopic constraints of pluvial episodes in the Western Desert of Egypt. North Africa has undergone drastic climatic change over the past several hundred thousand years. Timing of humid intervals called pluvials was investigated by uranium- series disequilibrium dating of travertines from the Kurkur Oasis, Western Desert, Egypt. Stable oxygen isotopes of the travertines were used in equilibrium oxygen isotope fractionation calculations indicating the Kurkur travertines have δ18O values similar to ancient Western Desert groundwaters (~[- ]11/perthous). The ages of the of the travertines correspond to times of monsoonal maxima, eustatic sea level high stands and interglacial maxima. Increased precipitation, recharge of Western Desert groundwaters, and resultant travertine deposition are interpreted to be consequences of Milankovitch cycle forcing, through enhanced Atlantic and Indian Ocean monsoons during periods of enhanced northern summer insolation. 2. Identification of soil moisture as an environmental risk factor for filariasis in Egypt. Bancroftian filariasis is a deforming illness transmitted by mosquitoes (Culex. pipiens) and caused by the parasite Wuchereria bancrofti (WHO technical report 821; Neva and Brown, 1994). Environmental variables, such as humidity, play an important role in the transmission cycle of filariasis. Landsat Thematic Mapper data were used to model the surface soil moisture conditions of the southern Nile Delta region of Egypt as a proxy for environmental humidity. Filariasis infection rates were found to be negligible for areas with low surface soil moisture availability (>20%). Variable infection rates were observed for regions with higher surface soil moisture content, possibly due to anthropogenic influences such as insect control and the use of anti- filarial drugs. 3. Monitoring of Pb aerosol fallout in the vicinity of the Glover smelter, Southeastern

  6. Nile River, Lake Nasser, Aswan Dam, Egypt

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Egypt's High Aswan Dam on the Nile River at the first cataracts, Nile River, (24.0N, 33.0E) was completed in 1971 to provide cheap hydroelectric power and to regulate the historically uneven flow of the Nile River. The contrast between the largely base rock desert east of the Nile versus the sand covered desert west of the river and the ancient irrigated floodplain downstream from the damsite is clearly shown.

  7. Evidence for population fragmentation within a subterranean aquatic habitat in the Western Australian desert.

    PubMed

    Guzik, M T; Cooper, S J B; Humphreys, W F; Ong, S; Kawakami, T; Austin, A D

    2011-09-01

    The evolution of subterranean animals following multiple colonisation events from the surface has been well documented, but few studies have investigated the potential for species diversification within cavernicolous habitats. Isolated calcrete (carbonate) aquifers in central Western Australia have been shown to contain diverse assemblages of aquatic subterranean invertebrate species (stygofauna) and to offer a unique model system for exploring the mechanisms of speciation in subterranean ecosystems. In this paper, we investigated the hypothesis that microallopatric speciation processes (fragmentation and isolation by distance (IBD)) occur within calcretes using a comparative phylogeographic study of three stygobiontic diving beetle species, one amphipod species and a lineage of isopods. Specimens were sequenced for the mitochondrial cytochrome c oxidase 1 gene from three main sites: Quandong Well, Shady Well (SW) and Mt. Windarra (MW), spanning a 15 km region of the Laverton Downs Calcrete. Phylogenetic and haplotype network analyses revealed that each species possessed a single divergent clade of haplotypes that were present only at the southern MW site, despite the existence of other haplotypes at MW that were shared with SW. IBD between MW and SW was evident, but the common phylogeographic pattern most likely resulted from fragmentation, possibly by a salt lake adjacent to MW. These findings suggest that microallopatric speciation within calcretes may be a significant diversifying force, although the proportion of stygofauna species that may have resulted from in situ speciation in this system remains to be determined.

  8. Bioprospecting of plant growth promoting psychrotrophic Bacilli from the cold desert of north western Indian Himalayas.

    PubMed

    Yadav, Ajar Nath; Sachan, Shashwati Ghosh; Verma, Priyanka; Saxena, Anil Kumar

    2016-02-01

    The plant growth promoting psychrotrophic Bacilli were investigated from different sites in north western Indian Himalayas. A total of 247 morphotypes were obtained from different soil and water samples and were grouped into 43 clusters based on 16S rDNA-RFLP analysis with three restriction endonucleases. Sequencing of representative isolates has revealed that these 43 Bacilli belonged to different species of 11 genera viz., Desemzia, Exiguobacterium, Jeotgalicoccus, Lysinibacillus, Paenibacillus, Planococcus, Pontibacillus, Sinobaca, Sporosarcina, Staphylococcus and Virgibacillus. With an aim to develop microbial inoculants that can perform efficiently at low temperatures, all representative isolates were screened for different plant growth promoting traits at low temperatures (5-15 degrees C). Among the strains, variations were observed for production (%) of indole-3-acetic acid (20), ammonia (19), siderophores (11), gibberellic acid (4) and hydrogen cyanide (2); solubilisation (%) of zinc (14), phosphate (13) and potassium (7); 1-aminocyclopropane-1-carboxylate deaminase activity (6%) and biocontrol activity (4%) against Rhizoctonia solani and Macrophomina phaseolina. Among all the strains, Bacillus licheniformis, Bacillus muralis, Desemzia incerta, Paenibacillus tylopili and Sporosarcina globispora were found to be potent candidates to be developed as inoculants as they exhibited multiple PGP traits at low temperature.

  9. Evidence for population fragmentation within a subterranean aquatic habitat in the Western Australian desert

    PubMed Central

    Guzik, M T; Cooper, S J B; Humphreys, W F; Ong, S; Kawakami, T; Austin, A D

    2011-01-01

    The evolution of subterranean animals following multiple colonisation events from the surface has been well documented, but few studies have investigated the potential for species diversification within cavernicolous habitats. Isolated calcrete (carbonate) aquifers in central Western Australia have been shown to contain diverse assemblages of aquatic subterranean invertebrate species (stygofauna) and to offer a unique model system for exploring the mechanisms of speciation in subterranean ecosystems. In this paper, we investigated the hypothesis that microallopatric speciation processes (fragmentation and isolation by distance (IBD)) occur within calcretes using a comparative phylogeographic study of three stygobiontic diving beetle species, one amphipod species and a lineage of isopods. Specimens were sequenced for the mitochondrial cytochrome c oxidase 1 gene from three main sites: Quandong Well, Shady Well (SW) and Mt. Windarra (MW), spanning a 15 km region of the Laverton Downs Calcrete. Phylogenetic and haplotype network analyses revealed that each species possessed a single divergent clade of haplotypes that were present only at the southern MW site, despite the existence of other haplotypes at MW that were shared with SW. IBD between MW and SW was evident, but the common phylogeographic pattern most likely resulted from fragmentation, possibly by a salt lake adjacent to MW. These findings suggest that microallopatric speciation within calcretes may be a significant diversifying force, although the proportion of stygofauna species that may have resulted from in situ speciation in this system remains to be determined. PMID:21343944

  10. Combining molecular-marker and chemical analysis of Capparis decidua (Capparaceae) in the Thar Desert of Western Rajasthan (india).

    PubMed

    Kumar, Sushil; Sharma, Ramavtar; Kumar, Vinod; Vyas, Govind K; Rathore, Abhishek

    2013-03-01

    The Thar Desert, a very inhospitable place, accommodates only plant species that survive acute drought, unpredictable precipitation, and those can grow in the limited moisture of sandy soils. Capparis decidua is among one of the few plants able to grow well under these conditions. This species is highly exploited and has been naturally taken, as local people use it for various purposes like food, timber and fuel, although, no management or conservation efforts have been established. The present study was conducted in this arid area of Western Rajasthan (India) with the aim to obtain preliminary molecular information about this group of plants. We evaluated diversity among 46 samples of C. decidua using chemical parameters and random amplified polymorphic DNA (RAPD) markers. Fourteen chemical parameters and eight minerals (total 22 variables) of this species fruits were estimated. A total of 14 RAPD primers produced 235 band positions, of which 81.27% were polymorphic. Jaccard's similarity coefficients for RAPD primers ranged from 0.34 to 0.86 with a mean genetic similarity of 0.50. As per observed coefficient of variation, NDF (Neutral Detergent Fiber) content was found to be the most variable trait followed by starch and soluble carbohydrate. The Manhattan dissimilarity coefficient values for chemical parameters ranged between 0.02-0.31 with an average of 0.092. The present study revealed a very low correlation (0.01) between chemical parameters and RAPD-based matrices. The low correlation between chemical- and RAPD-based matrices indicated that the two methods were different and highly variable. The chemical-based diversity will assist in selection of nutritionally rich samples for medicinal purpose, while genetic diversity to face natural challenges and find sustainable ways to promote conservation for future use.

  11. Methanogens at the top of the world: occurrence and potential activity of methanogens in newly deglaciated soils in high-altitude cold deserts in the Western Himalayas

    PubMed Central

    Aschenbach, Katrin; Conrad, Ralf; Řeháková, Klára; Doležal, Jiří; Janatková, Kateřina; Angel, Roey

    2013-01-01

    Methanogens typically occur in reduced anoxic environments. However, in recent studies it has been shown that many aerated upland soils, including desert soils also host active methanogens. Here we show that soil samples from high-altitude cold deserts in the western Himalayas (Ladakh, India) produce CH4 after incubation as slurry under anoxic conditions at rates comparable to those of hot desert soils. Samples of matured soil from three different vegetation belts (arid, steppe, and subnival) were compared with younger soils originating from frontal and lateral moraines of receding glaciers. While methanogenic rates were higher in the samples from matured soils, CH4 was also produced in the samples from the recently deglaciated moraines. In both young and matured soils, those covered by a biological soil crust (biocrust) were more active than their bare counterparts. Isotopic analysis showed that in both cases CH4 was initially produced from H2/CO2 but later mostly from acetate. Analysis of the archaeal community in the in situ soil samples revealed a clear dominance of sequences related to Thaumarchaeota, while the methanogenic community comprised only a minor fraction of the archaeal community. Similar to other aerated soils, the methanogenic community was comprised almost solely of the genera Methanosarcina and Methanocella, and possibly also Methanobacterium in some cases. Nevertheless, ~103 gdw−1 soil methanogens were already present in the young moraine soil together with cyanobacteria. Our results demonstrate that Methanosarcina and Methanocella not only tolerate atmospheric oxygen but are also able to survive in these harsh cold environments. Their occurrence in newly deglaciated soils shows that they are early colonizers of desert soils, similar to cyanobacteria, and may play a role in the development of desert biocrusts. PMID:24348469

  12. Methanogens at the top of the world: occurrence and potential activity of methanogens in newly deglaciated soils in high-altitude cold deserts in the Western Himalayas.

    PubMed

    Aschenbach, Katrin; Conrad, Ralf; Reháková, Klára; Doležal, Jiří; Janatková, Kateřina; Angel, Roey

    2013-01-01

    Methanogens typically occur in reduced anoxic environments. However, in recent studies it has been shown that many aerated upland soils, including desert soils also host active methanogens. Here we show that soil samples from high-altitude cold deserts in the western Himalayas (Ladakh, India) produce CH4 after incubation as slurry under anoxic conditions at rates comparable to those of hot desert soils. Samples of matured soil from three different vegetation belts (arid, steppe, and subnival) were compared with younger soils originating from frontal and lateral moraines of receding glaciers. While methanogenic rates were higher in the samples from matured soils, CH4 was also produced in the samples from the recently deglaciated moraines. In both young and matured soils, those covered by a biological soil crust (biocrust) were more active than their bare counterparts. Isotopic analysis showed that in both cases CH4 was initially produced from H2/CO2 but later mostly from acetate. Analysis of the archaeal community in the in situ soil samples revealed a clear dominance of sequences related to Thaumarchaeota, while the methanogenic community comprised only a minor fraction of the archaeal community. Similar to other aerated soils, the methanogenic community was comprised almost solely of the genera Methanosarcina and Methanocella, and possibly also Methanobacterium in some cases. Nevertheless, ~10(3) gdw(-1) soil methanogens were already present in the young moraine soil together with cyanobacteria. Our results demonstrate that Methanosarcina and Methanocella not only tolerate atmospheric oxygen but are also able to survive in these harsh cold environments. Their occurrence in newly deglaciated soils shows that they are early colonizers of desert soils, similar to cyanobacteria, and may play a role in the development of desert biocrusts.

  13. Scale insects and mealy bugs (Homoptera: Coccoidea) attacking deciduous fruit trees in the western north coast of Alexandria, Egypt.

    PubMed

    Mourad, A K; Moursi Khadiga, S; Mesbah, H A; Abdel-Razak Soad, I

    2008-01-01

    This investigation covered a survey of scale insects and mealy bugs infesting ten growing species of deciduous fruit trees in three localities in Alexandria govemorate. These localities were Merghem, Burg El-Arab, and El-Nahda about 50 Km. West of Alexandria under both rain-fed and irrigation system conditions. The common inspected fruit trees were fig, white mulberry, pomegranate, apple, pear, apricot, European plum, peach, almond, and persimmon. It was shown that a group of twenty scale insects and meaty bug species pertaining to fifteen genera belonging to six families of the super family: Coccoidea were collected and identified during the elapsing period from January to December, 2004. Among these species, Diaspidiotus perniciosus (Comstock) was recorded for the first time in Egypt. In the present study, many insect and non-insect parasitoids and predators were also found associated with these scale insects and mealy bugs on deciduous fruit trees in the three concerned localities throughout this investigation. These natural enemies were identified and recorded.

  14. PIXE micro-mapping of minor elements in Hypatia, a diamond bearing carbonaceous stone from the Libyan Desert Glass area, Egypt: Inheritance from a cold molecular cloud?

    NASA Astrophysics Data System (ADS)

    Andreoli, M. A. G.; Przybylowicz, W. J.; Kramers, J.; Belyanin, G.; Westraadt, J.; Bamford, M.; Mesjasz-Przybylowicz, J.; Venter, A.

    2015-11-01

    Matter originating from space, particularly if it represents rare meteorite samples, is ideally suited to be studied by Particle Induced X-ray Emission (PIXE) as this analytical technique covers a broad range of trace elements and is per se non-destructive. We describe and interpret a set of micro-PIXE elemental maps obtained on two minute (weighing about 25 and 150 mg), highly polished fragments taken from Hypatia, a controversial, diamond-bearing carbonaceous pebble from the SW Egyptian desert. PIXE data show that Hypatia is chemically heterogeneous, with significant amounts of primordial S, Cl, P and at least 10 elements with Z > 21 (Ti, V, Cr, Mn, Fe, Ni, Os, Ir) locally attaining concentrations above 500 ppm. Si, Al, Ca, K, O also occur, but are predominantly confined to cracks and likely represent contamination from the desert environment. Unusual in the stone is poor correlation between elements within the chalcophile (S vs. Cu, Zn) and siderophile (i.e.: Fe vs. Ni, Ir, Os) groups, whereas other siderophiles (Mn, Mo and the Platinum group elements (PGEs)) mimic the distribution of lithophile elements such as Cr and V. Worthy of mention is also the presence of a globular domain (Ø ∼ 120 μm) that is C and metals-depleted, yet Cl (P)-enriched (>3 wt.% and 0.15 wt.% respectively). While the host of the Cl remains undetermined, this chemical unit is enclosed within a broader domain that is similarly C-poor, yet Cr-Ir rich (up to 1.2 and 0.3 wt.% respectively). Our data suggest that the pebble consists of shock-compacted, primitive carbonaceous material enriched in cold, pre-solar dust.

  15. Timing and characteristics of Late Pleistocene and Holocene wetter periods in the Eastern Desert and Sinai of Egypt, based on 14C dating and stable isotope analysis of spring tufa deposits

    NASA Astrophysics Data System (ADS)

    Hamdan, Mohamed A.; Brook, George A.

    2015-12-01

    There is very little dated evidence on wet periods in the Eastern Desert and Sinai Peninsula of Egypt during the Late Pleistocene and Holocene. To obtain such information, we have studied the petrography, isotope geochemistry and AMS radiocarbon ages of mostly relict tufas deposited by springs draining perched ground water bodies in metamorphic and volcanic rocks. The tufas unconformably overly Precambrian basic igneous rocks (basalt, diabase and gabbro). As the ages of tufa carbonate are frequently older than the true ages of the deposits because of the incorporation of old, 14C-dead carbon, we have dated both the carbonate matrix and insoluble organic material of the tufas. These ages show that the tufas were largely formed during two broad time periods, the most recent from 12,058 to 6678 cal yr BP (African Humid Period), and the other from ˜31,200-22,500 cal yr BP, with preferential growth during the coldest times of this period namely during Heinrich Events 2 and 3 (H2 and H3) and the Last Glacial Maximum (LGM). The time span between 19,000-9000 cal yr BP, including the YD and H1, appears to have been relatively more arid than the earlier LGM or H2 periods or the later Holocene. The Late Pleistocene tufas are depleted in 18O relative to the Holocene tufas and were deposited at a lower temperature (˜14.0°-20.8 °C vs. 18.4°-23.4 °C). We believe that the Holocene tufas in the Sinai were formed by rainfall from the Mediterranean and those in the southern part of the Eastern Desert by African monsoon rainfall derived from the Red Sea-Gulf of Aden and Indian Ocean. In contrast, the moisture that fed the Late Pleistocene tufas, which are depleted in 18O relative to Holocene deposits, and progressively depleted from north to south, was probably brought by the Westerlies from the Atlantic-Mediterranean Sea when the Westerly circulation was pushed southwards during the coldest periods of the Late Pleistocene. Periods of tufa deposition correlate with major

  16. Water movement through a thick unsaturated zone underlying an intermittent stream in the western Mojave Desert, southern California, USA

    USGS Publications Warehouse

    Izbicki, J.A.; Radyk, J.; Michel, R.L.

    2000-01-01

    Previous studies indicated that small amounts of recharge occur as infiltration of intermittent streamflow in washes in the upper Mojave River basin, in the western Mojave Desert, near Victorville, California. These washes flow only a few days each year after large storms. To reach the water table, water must pass through an unsaturated zone that is more than 130 m thick. Results of this study, done in 1994-1998, showy that infiltration to depths below the root zone did not occur at control sites away from the wash. At these sites, volumetric water contents were as low as 0.01 and water potentials (measured as the combination of solute and matric potentials using a water activity meter) were as negative as -14,000 kPa. Water-vapor movement was controlled by highly negative solute potentials associated with the accumulation of soluble salts in the unsaturated zone. Highly negative matric potentials above and below the zone of maximum solute accumulation result from movement of water vapor toward the highly negative solute potentials at that depth. The ??18O and ??D (delta oxygen-18 and delta deuterium) isotopic composition of water in coarse-grained deposits plots along a Rayleigh distillation line consistent with removal of water in coarse-grained layers by vapor transport. Beneath Oro Grande Wash, water moved to depths below the root zone and, presumably, to the water table about 130 m below land surface. Underneath Oro Grande Wash, volumetric water contents were as high as 0.27 and water potentials (measured as matric potential using tensiometers) were between -1.8 and -50 kPa. On the basis of tritium data, water requires at least 180-260 years to infiltrate to the water table. Clay layers impede the downward movement of water. Seasonal changes in water vapor composition underneath the wash are consistent with the rapid infiltration of a small quantity of water to great depths and subsequent equilibration of vapor with water in the surrounding material. It may be

  17. Thermodynamic modelling of Sol Hamed serpentinite, South Eastern Desert of Egypt: Implication for fluid interaction in the Arabian-Nubian Shield ophiolites

    NASA Astrophysics Data System (ADS)

    Abu-Alam, Tamer S.; Hamdy, Mohamed M.

    2014-11-01

    The Arabian-Nubian Shield is the largest tract of juvenile continental crust of the Neoproterozoic. This juvenile crust is composed of intra-oceanic island arc/back arc basin complexes and micro-continents welded together along sutures as the Mozambique Ocean was closed. Some of these sutures are marked by ophiolite decorated linear belts. The Sol Hamed ophiolite (808 ± 14 Ma) in southeastern Egypt at the Allaqi-Heiani-Onib-Sol Hamed-Yanbu arc-arc suture represents an uncommon example of rocks that might be less deformed than other ophiolites in the Arabian-Nubian Shield. In order to understand fluid-rock interactions before and during arc-arc collision, petrological, mineral chemistry, whole-rock chemistry and thermodynamic studies were applied to the Sol Hamed serpentinized ophiolitic mantle fragment. These studies reveal that the protolith had a harzburgite composition that probably originated as forearc mantle in the subducted oceanic slab. We propose that these rocks interacted with Ti-rich melts (boninite) in suprasubduction zone, which latter formed the Sol Hamed cumulates. Spinel's Cr# associated with the whole rock V-MgO composition suggest that the harzburgites are highly refractory residues after partial melting up to 29%. The melt extraction mostly occurred under reducing conditions, similar to peridotites recovered from the subducted lithosphere. Protolith alteration resulted from two stages of fluid-rock interaction. The first stage occurred as a result of infiltration of concentrated CO2-rich fluid released from carbonate-bearing sediments and altered basalt at the subduction zone. The alteration occurred during isobaric cooling at a pressure of 1 kbar. The fluid composition during the isobaric cooling was buffered by the metamorphic reactions. The second stage of fluid-rock interactions took place through prograde metamorphism. The increase in pressure during this stage occurred as a result of thrusting within the oceanic crust. In this process the

  18. Spectroscopy of olivine basalts using FieldSpec and ASTER data: A case study from Wadi Natash volcanic field, south Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Madani, Ahmed

    2015-10-01

    This paper aims at revealing the spectral characteristics of the olivine basalts exposed at Wadi Natash area, Egypt, using FieldSpec spectroradiometer. It also evaluates band ratios and fusion techniques for mapping purposes using ASTER data. Several volcanic episodes occurred during Early- to Late-Cretaceous are recorded in the study area. Early-Cretaceous olivine basalts are highly carbonated. Late-Cretaceous eruptions took place throughout several volcanic cones aligned in NW direction. Based on FieldSpec measurements and petrographic data, two groups of olivine basalt namely `A' and `B' are recognized. Fresh olivine basalt (group A) is characterized by low flat spectral profile with overall low reflectance values (˜20%). Spectral profile of altered olivine basalt (group B) shows moderate reflectance values (˜37%) with four little absorption features around the 1.10, 1.40, 2.00 and 2.35 μm wavelength regions. These absorption features are attributed mainly to the presence of chlorite and carbonate alteration products as indicated by petrographic examination. ASTER false colour composite band ratio image (3/2:R, 8/1:G and 8/5:B) discriminates easily the fresh and altered basalts by deep blue and reddish blue colours respectively. Image fusion between previously mentioned FCC ratios image and high spatial resolution ASTER panchromatic image are carried out using brovey and HSV transformation methods. Visual and statistical assessment methods proved that HSV fusion image yields better image interpretability results compared to brovey image. It improves the spatial resolution of original FCC ratios image with acceptable spectral preservation. The present study proved the usefulness of FieldSpec spectral profiles and the processed ASTER data for discriminating different olivine basalt groups exposed at the study area.

  19. Use of the subsurface thermal regime as a groundwater-flow tracer in the semi-arid western Nile Delta, Egypt

    NASA Astrophysics Data System (ADS)

    Salem, Zenhom E.; Bayumy, Dina A.

    2016-06-01

    Temperature profiles from 25 boreholes were used to understand the spatial and vertical groundwater flow systems in the Western Nile Delta region of Egypt, as a case study of a semi-arid region. The study area is located between the Nile River and Wadi El Natrun. The recharge areas, which are located in the northeastern and the northwestern parts of the study area, have low subsurface temperatures. The discharge areas, which are located in the western (Wadi El Natrun) and southern (Moghra aquifer) parts of the study area, have higher subsurface temperatures. In the deeper zones, the effects of faults and the recharge area in the northeastern direction disappear at 80 m below sea level. For that depth, one main recharge and one main discharge area are recognized. The recharge area is located to the north in the Quaternary aquifer, and the discharge area is located to the south in the Miocene aquifer. Two-dimensional groundwater-flow and heat-transport models reveal that the sealing faults are the major factor disturbing the regional subsurface thermal regime in the study area. Besides the main recharge and discharge areas, the low permeability of the faults creates local discharge areas in its up-throw side and local recharge areas in its down-throw side. The estimated average linear groundwater velocity in the recharge area is 0.9 mm/day to the eastern direction and 14 mm/day to the northwest. The average linear groundwater discharge velocities range from 0.4 to 0.9 mm/day in the southern part.

  20. Nature and composition of gold-forming fluids at Umm Rus area, Eastern Desert, Egypt: evidence from fluid inclusions in vein materials

    NASA Astrophysics Data System (ADS)

    Harraz, H. Z.; El-Dahhar, M. A.

    1993-04-01

    The Umm Rus gold lode is housed along fractures in granitoid-gabbroic rocks, being largely controlled by a NE-SW trending fracture system that affected the Eastern Desert. Mineralogically, the gold lode consists of quartz and carbonate gangue enclosing minor amounts of auriferous pyrite and arsenopyrite. Trace amounts of sphalerite, galena, marcasite and pyrrhotite are also present. The lode can be divided into: (i) Au-poor, pyrite-quartz vein, (ii) Au-rich, pyrite-arsenopyrite-quartz vein and (iii) gangue dominant. Inspection of primary inclusions from the Umm Rus gold lode showed that the ore was formed from CO 2-H 2O-rich fluids (ca. 30-46 mol % CO 2) of low salinity (6.75-7.75 wt. % NaCl equiv.) and alkaline to neutral pH with a density of 0.76-0.85 g/cc. These data are consistent with dissolution of gold as a bisulphide complex. Deposition of Au most likely occurred over a temperature range of 250-300°C and at pressures around 0.35 Kbars. The deposition may have occurred in response to separation of a liquid CO 2-phase from an originally CO 2-H 2O-rich aqueous fluids. The style of mineralization at Umm Rus bears certain resemblances to Au-bearing quartz veins in the Archaean deposits of Canada and Australia and the "Mother Lode" deposits of the U.S.A.

  1. Solar Energy for Rural Egypt

    NASA Astrophysics Data System (ADS)

    Abdelsalam, Tarek I.; Darwish, Ziad; Hatem, Tarek M.

    Egypt is currently experiencing the symptoms of an energy crisis, such as electricity outage and high deficit, due to increasing rates of fossil fuels consumption. Conversely, Egypt has a high solar availability of more than 18.5 MJ daily. Additionally, Egypt has large uninhabited deserts on both sides of the Nile valley and Sinai Peninsula, which both represent more than 96.5 % of the nation's total land area. Therefore, solar energy is one of the promising solutions for the energy shortage in Egypt. Furthermore, these vast lands are advantageous for commissioning large-scaled solar power projects, not only in terms of space availability, but also of availability of high quality silicon (sand) required for manufacturing silicon wafers used in photovoltaic (PV) modules. Also, rural Egypt is considered market a gap for investors, due to low local competition, and numerous remote areas that are not connected to the national electricity grid. Nevertheless, there are some obstacles that hinder the progress of solar energy in Egypt; for instance, the lack of local manufacturing capabilities, security, and turbulent market in addition to other challenges. This paper exhibits an experience of the authors designing and installing decentralized PV solar systems, with a total rated power of about 11 kW, installed at two rural villages in at the suburbs of Fayoum city, in addition to a conceptual design of a utility scale, 2 MW, PV power plant to be installed in Kuraymat. The outcomes of this experience asserted that solar PV systems can be a more technically and economically feasible solution for the energy problem in rural villages.

  2. Marine pollution as indicated by oil accumulated on clams collected from the western coasts of the Red Sea, Egypt

    SciTech Connect

    Shimy, T.M.

    1997-02-01

    In order to save the environment from pollution, many techniques are used for identifying oil accumulated on clams along the western coast of the Red Sea. Gas chromatography (GC), infrared (IR), and ultraviolet (UV) absorption spectrophotometry are three different techniques used to analyze the collected samples, GC chromatograms for oil extracted from these animals indicate that the source of pollution is petroleum, and a few peaks reveal a mixture of biogenic and petrogenic hydrocarbons. These results are confirmed by the characteristic IR spectra profiles, high concentrations of the aromatic compounds, and the UV absorption spectra of these samples.

  3. Ancient Egypt.

    ERIC Educational Resources Information Center

    Evers, Virginia

    This four-week fourth grade social studies unit dealing with religious dimensions in ancient Egyptian culture was developed by the Public Education Religion Studies Center at Wright State University. It seeks to help students understand ancient Egypt by looking at the people, the culture, and the people's world view. The unit begins with outlines…

  4. Extension-related buttress-like folds, the western side of the Gulf of Suez rift, Egypt

    NASA Astrophysics Data System (ADS)

    Abu Sharib, A. S. A. A.; Abdel-Fattah, M. M.; Salama, Y. F.; Abdel-Gawad, G. I.

    2017-02-01

    The wedge-shaped St. Paul block, western side of the Gulf of Suez rift, exposes Late Cretaceous beds that are folded into transverse folds. The block is bounded from the east and west by east- and southeast-dipping rift-related normal faults, respectively. This study reveals that the transverse folds are extension-related, and formed due to the buttress-like effect that was created during the movement along the rift-related normal faults. The more competent Eocene hanging-wall block of the N-S-striking fault buttressed against the moving less competent Cretaceous hanging-wall block of the NE-SW-striking fault. A localized zone of shortening developed between the two fault trends causing the intervening wedge-shaped block to be crumpled and folded into a series of kilometer-scale, gentle SSE-plunging folds. The buttressing, within block internal localized strain caused by the zigzag geometry of the NE-SW-striking fault, and the effect of the minor cross fault explain the SSE-to-ESE plunges of the mesoscopic folds. This study turns the attention to the buttress-like effect as one of the mechanisms of extension-related folds during rifting.

  5. Nile behaviour and Late Palaeolithic humans in Upper Egypt during the Late Pleistocene

    NASA Astrophysics Data System (ADS)

    Vermeersch, Pierre M.; Van Neer, Wim

    2015-12-01

    The reconstruction of the environment and the human population history of the Nile Valley during the Late Pleistocene have received a lot of attention in the literature thus far. There seems to be a consensus that during MIS2 extreme dry conditions prevailed over north-eastern Africa, which was apparently not occupied by humans. The Nile Valley seems to be an exception; numerous field data have been collected suggesting an important population density in Upper Egypt during MIS2. The occupation remains are often stratified in, or at least related to, aeolian and Nile deposits at some elevation above the present-day floodplain. They are rich in lithics and animal bones, mainly fish, illustrating the exploitation of the Nile Valley by the Late Palaeolithic inhabitants. The fluvial processes active during that period have traditionally been interpreted as a continuously rising highly braided river. In this paper we summarize the evidence thus far available for the Late Pleistocene on the population densities in the Nile Valley, and on the models of Nilotic behaviour. In the discussion we include data on the environmental conditions in Eastern Africa, on the aeolian processes in the Western Desert of Egypt derived from satellite images, 14C and OSL dates, in order to formulate a new model that explains the observed high remnants of aeolian and Nilotic deposits and the related Late Palaeolithic sites. This model hypothesizes that, during the Late Pleistocene, and especially the LGM, dunes from the Western Desert invaded the Nile Valley at several places in Upper Egypt. The much reduced activity of the White Nile and the Blue Nile was unable to evacuate incoming aeolian sand and, as a consequence, several dams were created in the Upper Egyptian Nile Valley. Behind such dams the created lakes offered ideal conditions for human subsistence. This model explains the occurrence of Late Palaeolithic hunter-fisher-gatherers in a very arid environment with very low Nile flows

  6. The formation of the patterns of desert shrub communities on the Western Ordos Plateau, China: the roles of seed dispersal and sand burial.

    PubMed

    Wang, Yange; Yang, Xiaohui; Shi, Zhongjie

    2013-01-01

    The western Ordos Plateau is a key area of shrub diversity and a National Nature Reserve of endangered shrub species in north-west China. Desert expansion is becoming the most important threat to these endangered species. However, little is known about the effects of sand burial on the dynamics of the shrub community. This study aims to investigate how the shrubs as a community and as different individual shrubs respond to the disturbances caused by the desert expansion. The approach used by this study is to separate the seed-dispersal strategy from the sand-burial forces that are involved in structuring the shrub communities at different disturbance stages. Four communities for different disturbance stages were surveyed by using 50×50 m plots. The individual shrubs were classified into coloniser and successor groups at the seed-dispersal stage and strong and weak sand-burial tolerance groups at the sand-expansion stage. We employed spatial point pattern analysis with null models for each community to examine the seed-dispersal strategy and sand-burial forces affecting community distribution patterns. At the seed-dispersal stage, the interactions between the colonisers and the successors showed significant positive correlation at a scale of 0-1 m and significant negative correlation at a scale of 2 m; significant negative correlations between the groups with strong and weak sand-burial tolerance in the early stage of sand expansion at scales of 3-6 m, and significant positive correlation in the later stage of sand expansion at a scale of 13 m, were found. Seed-dispersal strategy is a reasonable mechanism to explain the shrub community pattern formation in the earlier stages, whereas sand burial is the primary reason for the disappearance of shrubs with weak sand-burial tolerance, this irreversible disturbance causes homogenisation of the community structure and produces aging populations of shrub species. This has an important influence on the succession direction

  7. Effect of the temperature variation between Mediterranean Sea and Syrian deserts on the dust storm occurrence in the western half of Iran

    NASA Astrophysics Data System (ADS)

    Amanollahi, Jamil; Kaboodvandpour, Shahram; Qhavami, Samira; Mohammadi, Bakhtiyar

    2015-03-01

    Recent dust storms have caused crises in western Iran, which necessitate the prediction of these storms a few days before their occurrence. This is the first study of its type that analyzes the effect of temperature differences between the Mediterranean Sea surface and Syrian deserts (creation zone of the dusts storms) on the formation of dust storms in the west of Iran. The study also seeks to identify any changes in the atmospheric temperature created by the extreme dust storm of July 5, 2009 in west of Iran (Sanandaj City). In this study, the MODIS images from 2000 to 2008, and particulate matter data of the Sanandaj station from 2008 to 2012 were utilized to identify the dust storm days. The Mediterranean Sea surface temperature data were extracted from NOAA satellites for dust storm days up to four days preceding them. The web site of world weather was used to obtain the temperature of Damascus, Syria station as the selected land station. According to the results, significant differences were acquired between surface temperatures of Damascus station and the Mediterranean Sea in the dust storm days and up to three days before them. As the dust storm days approached, a rising trend was observed in changes of the temperature difference between land and sea. Thermal map analysis of the atmosphere of the Syrian deserts on July 5, 2009 showed significant decrease in the levels of 1000 hPa and 500 hPa but for the days preceding it no significant changes were observed. It can be concluded that the temperature difference between the Mediterranean Sea surface and the Syrian deserts four days before the dust storm occurrences is the important factor in predicting this event.

  8. Groundwater studies in arid areas in Egypt using LANDSAT satellite images

    NASA Technical Reports Server (NTRS)

    Elshazly, E. M.; Abdelhady, M. A.; Elshazly, M. M.

    1977-01-01

    Various features are interpreted which have strong bearing on groundwater in the arid environment. These include the nature of geological and lithologic units, structural lineaments, present and old drainage systems, distribution and form of water pools, geomorphologic units, weathering surfaces and other weathering phenomena, desert soils, sand dunes and dune sand accumulations, growths of natural vegetation and agriculture, and salt crusts and other expressions of salinization. There are many impressive examples which illustrate the significance of satellite image interpretation on the regional conditions of groundwater which could be traced and interconnected over several tens or even several hundreds of kilometers. This is especially true in the northern Western Desert of Egypt where ground water issuing from deep strata comes to the surface along ENE-WSW and ESE-WNW fault lines and fracture systems. Another striking example is illustrated by the occurrence of fresh to brackish groundwater on the Mediterranean Sea Coastal Zone of the Western Desert where the groundwater is found in the form of lenses floating on the saline sea water.

  9. Current status of phytoparasitic nematodes and their host plants in Egypt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Egypt many phytoparasitic nematodes constitute a major constraint to agricultural production, especially in sandy soil and reclaimed desert lands. Nematological surveys were conducted to determine the genera and species of phytoparasitic nematodes on associated host plants in Egypt. The results i...

  10. An Investigation into the Processes and Quantity of Dust Emissions over Gravel and Sand Deserts in North-Western China

    NASA Astrophysics Data System (ADS)

    Zhang, Zhengcai; Dong, Zhibao; Qian, Guangqian; Wu, Guoxi; Cui, Xujia

    2017-01-01

    Year-long field observations have shown that there are spatial and temporal variations in the quantity of dust emissions for particulate matter {<} 10 μm (PM10), particulate matter {<} 63 μm (PM63) and vertical dust flux over different gravel surfaces (with loose sand, without loose sand, with a crust, and without a crust), with the greatest emissions occurring in the spring. The largest quantity of PM10 and PM63 emissions occurred over gravel with a loose sand surface (1.1 × 10^{-3} and 10.2 × 10^{-3} kg m^{-1} day^{-1} , respectively). The gravel surface without loose sand and without a crust presents the lowest values of PM63 (1.6 × 10^{-3} kg m^{-1} day^{-1} ) and PM10 (3.3 × 10^{-4}{ kg m^{-1} day^{-1} ). However, the vertical dust flux was largest at over sandy surface (373 × 10^{-3} kg m^{-2} day^{-1} ). Multivariate correlation analysis indicates that the quantity of PM10 is strongly negatively correlated to gravel coverage (R^{2 }= 0.55 ). The quantity of PM10 dust emissions over a gravel surface with loose sand is approximately three times greater than that of a gravel surface with a crust. The mean quantity of PM10, PM63 and vertical dust flux over a gravel surface decreased with increasing gravel coverage. By comparing the quantity of PM10 dust emissions over gravel and sandy deserts, we found that gravel deserts and sandy deserts are both major sources of dust for dust storms in this region.

  11. Integrated biostratigraphy, stage boundaries and Paleoclimatology of the Upper Cretaceous-Lower Eocene successions in Kharga and Dakhala Oases, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Khalil, H.; Al Sawy, S.

    2014-08-01

    The Upper Cretaceous-Lower Eocene succession in the studied sections is divided into four rock units that arranged from base to top: the Dakhla, Tarawan, Esna and the Thebes formations. Detailed study of the foraminifera and calcareous nannofossils has led to the recognition of 58 and 82 species, respectively. Based on planktonic foraminifera and calcareous nannofossils 8 planktonic foraminiferal biozones (CF4, P2, P3, P4, E1, E2, E3 and E4) have been recognized as well as 8 calcareous nannofossil biozones (CC25b, NP3, NP4, NP5, NP6, NP7/8, NP9, and NP10). At Gabal Teir/Tarawan section, Kharga Oasis, the Paleocene can be divided into three stages; Danian, Selandian and Thanetian. The Danian/Selandian boundary is placed at P3a/P3b zonal boundary (LO of Igorina albeari) which corresponds to the level of LO of Lithoptychius ulii, Fasciculithus pileatus, Fasciculithus involutus and Lithoptychius janii (upper part of Zone NP4). The Selandian/Thanetian boundary, on the other hand, can be traced within the foraminiferal Zone P4 (Globanomalina pseudomenardii Zone) and between the nannofossil zones NP6 and NP7/8 (LO of Discoaster mohleri). At Gabal Ghanima section, the Paleocene/Eocene boundary is located within the lower part of the Esna Formation. It can be traced at the base of planktonic foraminiferal Zone E1 (LOs of Acarinina africana, A sibaiyaensis and Morozovella allinsoensis), and at the NP9a/NP9b subzonal boundary (LO of Rhomboaster spp). However, the lower Eocene succession seems to be condensed and punctuated by minor hiatus (absence of Subzone NP10a). The dominance of cool water nannofossil species in the late Maastrichtian and early Danian interval suggests a gradual decrease in the surface water paleotemperature. However, a slight warming condition prevailed around the Danian/Selandian transition as evidenced by the warm water nannofossil species. At the P/E boundary interval, the high abundance of warm-water taxa (e.g. Discoaster, Sphenolithus, Rhomboaster, Tribrachiatus and Pontosphaera species) indicates a warm-water paleotemperatures.

  12. Comparative study of factors controlling the groundwater occurrence in Bir Kiseiba and Bir El Shab areas, south western desert, Egypt using hydrogeological and geophysical techniques

    NASA Astrophysics Data System (ADS)

    Abu Risha, U. A.; Al Temamy, A. M. M.

    2016-05-01

    This research presents a clear example of the significant role of basement relief on the formation of aquifers and the impact of geologic structures on groundwater occurrence. A basement relief map was constructed using the depth to basement data acquired from 20 vertical electrical soundings (VESes), 3 land magnetic profiles, and 27 drilled wells tapping the basement rocks in addition to the elevations of the basement outcrops in the area of study. The map shows three basins underlying the area. The geoelectric survey shows that these basins were formed as a result of series of step faults. The largest basin underlies El-Shab area. The medium basin underlies the area of Bir Kiseiba whereas the smallest one underlies Bir Abu El-Hussein area. The Nubian Sandstone aquifer occurs only in El-Shab basin whereas the other basins are filled completely with the confining layer of Kiseiba Formation. The depth to basement in El-Shab basin ranges from 11 m. (ves-20) to 197 m. (ves-1) m.b.g.s. The depth to basement in Kiseiba basin ranges from 20 m. (Bir Kurayim magnetic profile) to 122 m. (ves-13) m.b.g.s. The depth to basement in Abu El-Husein basin ranges from 0 (basement outcrops) to 64 m. (Abu El-Husein magnetic profile) m.b.g.s. The aquifer thickness ranges from 0 m (where the aquitard rests directly on the basement) to 153 m. (El Shab well No. 79). The aquifer is uncoformably overlain by Kiseiba Formation which represents the aquitard layer at Bir El-Shab. The thickness of the aquitard ranges from 0 (in areas covered by the Nubian Sandstone) to 120 m (ves-13). Each of the aquifer and aquitard consist of three layers. Two of the aquitard layers are water-bearing. However, the estimated transmissivity of the aquitard is very low (11.9 m2/d). The groundwater moves vertically into the overlying aquitard at Bir El-Shab and subsequently flows in concentric pattern into the surrounding areas. Faulting controls groundwater occurrence and quality. Some springs lie on the basement high associated with step faulting at the edges of El-Shab basin. An ENE low-salinity zone is associated with the basement high which separates El-Shab basin from Kiseiba basin. Focused groundwater recharge through the faults and fractures from paleo playas could be the mechanism of the formation of this anomaly. The isotope data shows local recharge of the groundwater most likely during the Pleistocene time. Two-dimension (2D) Electrical Resistivity Tomography (ERT) profiles reveal that the evaporation process has the main role in increasing the salinity of some water points. It is highly recommended to delineate the southern boundary of El-Shab basin which is expected to extend into Sudan.

  13. Morphology and development of pahoehoe flow-lobe tumuli and associated features from a monogenetic basaltic volcanic field, Bahariya Depression, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Khalaf, Ezz El Din Abdel Hakim; Hammed, Mohamed Saleh

    2016-01-01

    The dimensions, landforms, and structural characteristics of pahoehoe flow-lobe tumuli from Bahariya Depression are collectively reported here for the first time. The flow-lobe tumuli documented here characterize hummocky flow surfaces. These tumuli are characterized by low, dome-like mounds, lava-inflation clefts, and squeeze ups. Flow-lobe tumuli are of various shapes and sizes, which are affected by the mechanism of inflation because they formed in response to the increase of pressure within the flow when the flow's crust becomes thicker. The tumuli often appear isolated or in small groups in the middle sectors of the lava flows, whereas in the distal sectors they form large concentration, suggesting the presence of complex lava tubes inside of the flow. Tumuli exhibited by El Bahariya lava flows are between 3.0 and 50 m in length and up to 5.0 m in height with lenticular geometry in aerial view. The flow emplacement of flow-lobe tumuli is controlled by variations in local characteristics such as nature of the substrate, flow orientation, slope, interferrence with other lobes, and rate of lava supply. Their presence generally towards the terminal ends of flow fields suggests that they seldom form over the clogged portions of distributary tubes or pathways. Thus, localized inflations that formed over blockages in major lava tubes result in formation of flow-lobe tumuli. The three-tiered (crust-core-basal zone) internal structure of the flow-lobe tumuli, resembling the typical distribution of vesicles in P-type lobes, confirms emplacement by the mechanism of inflation. All the available data show that the morphology and emplacement mechanism of the studied flow-lobe tumuli may be analogous to similar features preserved within topographically confined areas of the Hawaiian and Deccan hummocky lava flows. Considering the age of the studied volcanic fields (˜22 Ma) it is most probable that the structures described here may be amongst the oldest recognized examples of lava inflation.

  14. Mesozoic and Cenozoic thermal history of the eastern Mojave Desert, California and western Arizona, with emphasis on the Old Woman Mountains area and the Chemehuevi metamorphic core complex

    SciTech Connect

    Foster, D.A.

    1989-01-01

    Mesozoic thickening and Cenozoic extension resulted in the juxtaposition of upper and middle crustal rocks in the eastern Mojave Desert, southeastern California and western Arizona. The application of {sup 40}Ar/{sup 39}Ar thermochronology and petrology/thermobarometry to rocks in this region provides information about the timing and nature of thrusting, plutonism, metamorphism, denudation, and detachment faulting. Orogenesis culminated during the Late Cretaceous when rocks exposed in the Old Woman-Piute, Chemehuevi, and Sacramento Mountains attained temperatures > 500C. High grade metamorphism of the Old Woman Mountains area was caused by the intrusion of the Old Woman-Piute batholith at 73 {plus minus} 1 Ma; Cretaceous mineral assemblages in Proterozoic pelites increase in grade from greenschist to upper amphibolite facies, and {sup 40}Ar/{sup 39}Ar hornblende ages from Proterozoic amphibolites decrease in age from {approximately} 1,600 Ma to 73 {plus minus} 1 Ma, in the direction of 73 Ma plutons. Pluton emplacement and metamorphism occurred at 3 to 3.5 kbars and 400 > 600C in the Piute Mountains, and 3.5 to 4.5 kbars and 530 to > 650C in the Old Woman Mountains. Following the Cretaceous, the eastern Mojave Desert underwent a period of cooling at a rate of 2 to 10C/Ma between 65 and 25 Ma. By 30 Ma rocks exposed in the Old Woman-Piute, Marble Ship, Clipper and Turtle Mountains were below {approximately} 100C. {sup 40}/{sup 39}Ar ages from the Sacramento Mountains suggest that mylonitization caused by the onset of regional extension occurred at 23 {plus minus} 1 Ma. When extension started in the Chemehuevi Mountains, rocks exposed in the southwestern and northeastern portions of footwall to the Chemehuevi detachment fault were at {approximately} 180C and {approximately} 350C, respectively which suggests that this fault initiated at a dip of 5 to 30{degree}.

  15. The Formation of the Patterns of Desert Shrub Communities on the Western Ordos Plateau, China: The Roles of Seed Dispersal and Sand Burial

    PubMed Central

    Wang, Yange; Yang, Xiaohui; Shi, Zhongjie

    2013-01-01

    The western Ordos Plateau is a key area of shrub diversity and a National Nature Reserve of endangered shrub species in north-west China. Desert expansion is becoming the most important threat to these endangered species. However, little is known about the effects of sand burial on the dynamics of the shrub community. This study aims to investigate how the shrubs as a community and as different individual shrubs respond to the disturbances caused by the desert expansion. The approach used by this study is to separate the seed-dispersal strategy from the sand-burial forces that are involved in structuring the shrub communities at different disturbance stages. Four communities for different disturbance stages were surveyed by using 50×50 m plots. The individual shrubs were classified into coloniser and successor groups at the seed-dispersal stage and strong and weak sand-burial tolerance groups at the sand-expansion stage. We employed spatial point pattern analysis with null models for each community to examine the seed-dispersal strategy and sand-burial forces affecting community distribution patterns. At the seed-dispersal stage, the interactions between the colonisers and the successors showed significant positive correlation at a scale of 0–1 m and significant negative correlation at a scale of 2 m; significant negative correlations between the groups with strong and weak sand-burial tolerance in the early stage of sand expansion at scales of 3–6 m, and significant positive correlation in the later stage of sand expansion at a scale of 13 m, were found. Seed-dispersal strategy is a reasonable mechanism to explain the shrub community pattern formation in the earlier stages, whereas sand burial is the primary reason for the disappearance of shrubs with weak sand-burial tolerance, this irreversible disturbance causes homogenisation of the community structure and produces aging populations of shrub species. This has an important influence on the succession

  16. Cultural Diversity or Cultural Imperialism: Liberal Education in Egypt.

    ERIC Educational Resources Information Center

    Blanks, David R.

    1998-01-01

    A faculty member's experience at the American University in Cairo (Egypt) reveals that pluralism and tolerance are western concepts, even within the college curriculum. National identity affords cultural stability: where the American melting-pot experience is reinforced by the notion of cultural diversity, the national identity of Egypt is…

  17. Resilience to stress and disturbance, and resistance to Bromus tectorum l. invasion in cold desert shrublands of western North America

    USGS Publications Warehouse

    Chambers, Jeanne C.; Bradley, Bethany A.; Brown, Cynthia S.; D'Antonio, Carla; Germino, Matthew J.; Grace, James B.; Hardegree, Stuart P.; Miller, Richard F.; Pyke, David A.

    2013-01-01

    Alien grass invasions in arid and semi-arid ecosystems are resulting in grass–fire cycles and ecosystem-level transformations that severely diminish ecosystem services. Our capacity to address the rapid and complex changes occurring in these ecosystems can be enhanced by developing an understanding of the environmental factors and ecosystem attributes that determine resilience of native ecosystems to stress and disturbance, and resistance to invasion. Cold desert shrublands occur over strong environmental gradients and exhibit significant differences in resilience and resistance. They provide an excellent opportunity to increase our understanding of these concepts. Herein, we examine a series of linked questions about (a) ecosystem attributes that determine resilience and resistance along environmental gradients, (b) effects of disturbances like livestock grazing and altered fire regimes and of stressors like rapid climate change, rising CO2, and N deposition on resilience and resistance, and (c) interacting effects of resilience and resistance on ecosystems with different environmental conditions. We conclude by providing strategies for the use of resilience and resistance concepts in a management context. At ecological site scales, state and transition models are used to illustrate how differences in resilience and resistance influence potential alternative vegetation states, transitions among states, and thresholds. At landscape scales management strategies based on resilience and resistance—protection, prevention, restoration, and monitoring and adaptive management—are used to determine priority management areas and appropriate actions.

  18. AIRSAR Data for Geological and Geomorphological Mapping in the Great Sandy Desert and Pilbara Regions of Western Australia

    NASA Technical Reports Server (NTRS)

    Tapley, Ian J.

    1996-01-01

    Enhancements of AIRSAR data have demonstrated the benefits of synthetic aperture radar (SAR) for revealing an additional and mich higher level of information about the composition of the terrain than enhancements f either SPOT-PAN or Landsat TM data. With appropriate image processing techniques, surface and near surface geological structures, hydrological systems (both current and ancient) and landform features, have been evidenced in a diverse range of landscapes. In the Great Sandy Desert region where spectral variability is minimal, radar's sensitivity to the micromorphology of sparse exposures of subcrop and lag gravels has provided a new insight into the region's geological framework, its landforms, and their evolution. In the Pilbara region, advanced processing of AIRSAR data to unmix the backscatter between and within the three frequencies of data has highlighted subsurface extensions of greenstone lithologies below sand cover and morphological evidence of past flow conditions under former climate regimes. On the basis of these observations, it is recommend that radar remote sensing technology involving the use of high resolution, polarimetric data be seriously considered as a viable tool for exploration in erosional and depositional environments located within Australia's mineral and oil-prospective provinces.

  19. Management of Egypt's Surface and Groundwater Resources: Present and Future

    NASA Astrophysics Data System (ADS)

    Sultan, M.; Ahmed, M.; Yan, E.; Milewski, A.; Mohamed, L.; Farag, A. Z. A.

    2014-12-01

    The River Nile is the main source of fresh water in Egypt. Most of Egypt's River Nile water (>85%) originates as precipitation over the Ethiopian highlands and is channeled by the Blue Nile. The construction (years: 2011 to 2017) of the Renaissance Dam (reservoir capacity: 70 x 109m3) on the Blue Nile poses an extreme threat to Egypt's population. If the reservoir was to be filled in 7 years, Egypt will lose (during each of 7 years following dam completion) a minimum of 15 x 109m3 of its annual allocation (55 x 109m3) to reservoir filling (10 x 109m3), evaporation (3.5 x 109m3), and infiltration (1.5 x 109m3). Three solutions are proposed: Solution I takes advantage of the cyclicity of Nile floods and is based on findings from a calibrated (against temporal head data) unconfined 2-dimensional transient groundwater flow model for Lake Nasser and surroundings and a calibrated (against lake levels) surface water model. Models show with time: (1) losses to infiltration will decrease (1975-193: 58.4 109m3; 1993-2001: 43.6 x 109m3) due to silting of Lake bottom and encroachment of excess Lake Nasser water will increase (e.g., 1975-1993: none; 1993-2001: 17 x 109m3). We propose to develop sustainable agricultural in the Western Desert: (1) In high flood years, excess Lake Nasser water (e.g., 1993-2001: 17 x 109m3) is channeled across the plateau bounding (from west) the River Nile valley to artificially recharge the Nubian Sandstone Aquifer System (NSAS) that crops out west of the plateau and, (2) in low flood years, we extract the recharged groundwater. Solution II calls on mining the NSAS at reasonable rates. Using temporal (January 2003 - September 2012) Gravity Recovery and Climate Experiment (GRACE) data we estimate the annual depletion rates at 2 x 109m3 due to artificial extraction (1.5 x 109m3) and natural discharge (0.5 x 109m3). Assuming current GRACE depletion rates, the recoverable groundwater (5,180 x 109m3) will last for 2500 years; if we were to quadruple

  20. Data from a thick unsaturated zone underlying Oro Grande and Sheep Creek washes in the western part of the Mojave Desert, near Victorville, San Bernardino County, California

    USGS Publications Warehouse

    Izbicki, John A.; Clark, Dennis A.; Pimental, Maria I.; Land, Michael; Radyk, John C.; Michel, Robert L.

    2000-01-01

    This report presents data on the physical properties of unsaturated alluvial deposits and on the chemical and isotopic composition of soil water and soil gas collected at 12 monitoring sites in the western part of the Mojave Desert, near Victorville, California. Sites were installed using the ODEX air-hammer method. Seven sites were located in the active channels of Oro Grande and Sheep Creek Washes. The remaining five sites were located away from the active washes. Most sites were drilled to a depth of about 100 feet below land surface; two sites were drilled to the water table almost 650 feet below land surface. Drilling procedures, lithologic and geophysical data, and site construction and instrumentation are described. Core material was analyzed for water content, bulk density, water potential, particle size, and water retention. The chemical composition of leachate from almost 1,000 subsamples of cores and cuttings was determined. Water extracted from selected subsamples of cores was analyzed for tritium and the stable isotopes of oxygen and hydrogen. Water from suction-cup lysimeters and soil-gas samples also were analyzed for chemical and isotopic composition. In addition, data on the chemical and isotopic composition of bulk precipitation from five sites and on ground water from two water-table wells are reported.

  1. Movement of water through the thick unsaturated zone underlying Oro Grande and Sheep Creek Washes in the western Mojave Desert, USA

    USGS Publications Warehouse

    Izbicki, J.A.; Radyk, J.; Michel, R.L.

    2002-01-01

    Previous studies indicate that a small quantity of recharge occurs from infiltration of streamflow in intermittent streams in the upper Mojave River basin, in the western Mojave Desert, near Victorville, California. Chloride, tritium, and stable isotope data collected in the unsaturated zone between 1994 and 1998 from boreholes drilled in Oro Grande and Sheep Creek Washes indicate that infiltration of streamflow occurs to depths below the root zone, and presumably to the water table, along much of Oro Grande Wash and near the mountain front along Sheep Creek Wash. Differences in infiltration at sites along each wash are the result of hydrologic variables such as proximity to the mountain front, quantity of streamflow, and texture of the subsurface deposits. Differences in infiltration between the washes are the result of large-scale geomorphic processes. For example, Oro Grande wash is incised into the Victorville fan and infiltration has occurred at approximately the same location over recent geologic time. In contrast, Sheep Creek Wash overlies an active alluvial fan and the stream channel can move across the fan surface through time. Infiltration does not occur to depths below the root zone at control sites outside of the washes.

  2. Movement of water through the thick unsaturated zone underlying Oro Grande and Sheep Creek Washes in the western Mojave Desert, USA

    NASA Astrophysics Data System (ADS)

    Izbicki, John A.; Radyk, John; Michel, Robert L.

    2002-06-01

    Previous studies indicate that a small quantity of recharge occurs from infiltration of streamflow in intermittent streams in the upper Mojave River basin, in the western Mojave Desert, near Victorville, California. Chloride, tritium, and stable isotope data collected in the unsaturated zone between 1994 and 1998 from boreholes drilled in Oro Grande and Sheep Creek Washes indicate that infiltration of streamflow occurs to depths below the root zone, and presumably to the water table, along much of Oro Grande Wash and near the mountain front along Sheep Creek Wash. Differences in infiltration at sites along each wash are the result of hydrologic variables such as proximity to the mountain front, quantity of streamflow, and texture of the subsurface deposits. Differences in infiltration between the washes are the result of large-scale geomorphic processes. For example, Oro Grande wash is incised into the Victorville fan and infiltration has occurred at approximately the same location over recent geologic time. In contrast, Sheep Creek Wash overlies an active alluvial fan and the stream channel can move across the fan surface through time. Infiltration does not occur to depths below the root zone at control sites outside of the washes.

  3. Ancient Egypt

    NASA Astrophysics Data System (ADS)

    Swamy, Ashwin Balegar

    This thesis involves development of an interactive GIS (Geographic Information System) based application, which gives information about the ancient history of Egypt. The astonishing architecture, the strange burial rituals and their civilization were some of the intriguing questions that motivated me towards developing this application. The application is a historical timeline starting from 3100 BC, leading up to 664 BC, focusing on the evolution of the Egyptian dynasties. The tool holds information regarding some of the famous monuments which were constructed during that era and also about the civilizations that co-existed. It also provides details about the religions followed by their kings. It also includes the languages spoken during those periods. The tool is developed using JAVA, a programing language and MOJO (Map Objects Java Objects) a product of ESRI (Environmental Science Research Institute) to create map objects, to provide geographic information. JAVA Swing is used for designing the user interface. HTML (Hyper Text Markup Language) pages are created to provide the user with more information related to the historic period. CSS (Cascade Style Sheets) and JAVA Scripts are used with HTML5 to achieve creative display of content. The tool is kept simple and easy for the user to interact with. The tool also includes pictures and videos for the user to get a feel of the historic period. The application is built to motivate people to know more about one of the prominent and ancient civilization of the Mediterranean world.

  4. Ghetto poverty and pollution in Egypt: a deadly threat for western countries caused by new and infectious mutants. A cultural, social and microbiological synopsis.

    PubMed

    Wassili, J H; Baradaeus, Cyril

    2012-10-01

    Egypt, whose soil germinated the first civilization, monotheism, refined ethics and culture of sharing the abundance of extracted natural resources among its populace became the crucible proliferating de-novo genotypes of organic and moral maladies. The enigma is these mutations are synchronized by several factors, namely; failing medical health, if there is any, abundant filth, cultural bankruptcy, over population, dogmatic militarism, societal deprivation and characterization, etc. These domineering ingredients fossilized Egypt as of 1952 coup in an irrevocable national apoptosis, together with the crippled social justice and imbalanced distribution of wealth among Egyptians, rates of bacterial and viral evolution to second generation resistant to known medical interventions are expected to exponentially accelerate. Therefore, it deemed essential to elaborate on pollution and psychosis-induced inflammations and grievous crimes evoked by dogmatic cults at the breeding source, e.g., ghettos and sporadic locations of the homeless in Cairo, Alexandria and Upper Egyptian villages. While this second generation of viral and bacterial diseases could labor plagues threatening the precariously maintained so-called social fabric of Middle Eastern countries, that are uniquely segregating its populace according to their dogmatic affiliations and soaked into intolerance, it would definitely compromise the integrity of the expensively managed medical care system of developed countries.

  5. Magnetic measurements with fluxgate 3-components magnetometers in archaeology. Multi-sensor device and associated potential field operators for large scale to centimetre investigations on the 1st millennium BC site of Qasr ʿAllam in the western desert of

    NASA Astrophysics Data System (ADS)

    Gavazzi, Bruno; Alkhatib-Alkontar, Rozan; Munschy, Marc; Colin, Frédéric; Duvette, Catherine

    2016-04-01

    Fluxgate 3-components magnetometers allow vector measurements of the magnetic field. Moreover, they are the magnetometers measuring the intensity of the magnetic field with the lightest weight and the lowest power consumption. Vector measurements make them the only kind of magnetometer allowing compensation of magnetic perturbations due to the equipment carried with the magnetometer. Fluxgate 3-components magnetometers are common in space magnetometry and in aero-geophysics but are never used in archaeology due to the difficulty to calibrate them. This problem is overcome by the use of a simple calibration and compensation procedure on the field developed initially for space research (after calibration and compensation, rms noise is less than 1 nT). It is therefore possible to build a multi-sensor (up to 8) and georeferenced device for investigations at different scales down to the centimetre: because the locus of magnetic measurements is less than a cubic centimetre, magnetic profiling or mapping can be performed a few centimetres outside magnetized bodies. Such an equipment is used in a context of heavy sediment coverage and uneven topography on the 1st millennium BC site of Qasr ʿAllam in the western desert of Egypt. Magnetic measurements with a line spacing of 0.5 m allow to compute a magnetic grid. Interpretation using potential field operators such as double reduction to the pole and fractional vertical derivatives reveals a widespread irrigation system and a vast cultic facility. In some areas, magnetic profiling with a 0.1 m line spacing and at 0.1 m above the ground is performed. Results of interpretations give enough proof to the local authorities to enlarge the protection of the site against the threatening progression of agricultural fields.

  6. Megaliths and Neolithic astronomy in southern Egypt

    NASA Astrophysics Data System (ADS)

    Malville, J. Mckim; Wendorf, Fred; Mazar, Ali A.; Schild, Romauld

    1998-04-01

    The Sahara west of the Nile in southern Egypt was hyperarid and unoccupied during most of the Late Pleistocene epoch. About 11,000 years ago the summer monsoons of central Africa moved into Egypt, and temporary lakes or playas were formed. The Nabta Playa depression, which is one of the largest in southern Egypt, is a kidney-shaped basin of roughly 10km by 7km in area. We report the discovery of megalithic alignments and stone circles next to locations of Middle and Late Neolithic communities at Nabta, which suggest the early development of a complex society. The southward shift of the monsoons in the Late Neolithic age rendered the area once again hyperarid and uninhabitable some 4,800 radiocarbon years before the present (years BP). This well-determined date establishes that the ceremonial complex of Nabta, which has alignments to cardinal and solstitial directions, was a very early megalithic expression of ideology and astronomy. Five megalithic alignments within the playa deposits radiate outwards from megalithic structures, which may have been funerary structures. The organization of the megaliths suggests a symbolic geometry that integrated death, water, and the Sun. An exodus from the Nubian Desert at ~4,800 years BP may have stimulated social differentiation and cultural complexity in predynastic Upper Egypt.

  7. Isolation and Pharmacological Characterization of α-Elapitoxin-Ot1a, a Short-Chain Postsynaptic Neurotoxin from the Venom of the Western Desert Taipan, Oxyuranus temporalis

    PubMed Central

    Barber, Carmel M.; Ahmad Rusmili, Muhamad Rusdi; Hodgson, Wayne C.

    2016-01-01

    Taipans (Oxyuranus spp.) are elapids with highly potent venoms containing presynaptic (β) and postsynaptic (α) neurotoxins. O. temporalis (Western Desert taipan), a newly discovered member of this genus, has been shown to possess venom which displays marked in vitro neurotoxicity. No components have been isolated from this venom. We describe the characterization of α-elapitoxin-Ot1a (α-EPTX-Ot1a; 6712 Da), a short-chain postsynaptic neurotoxin, which accounts for approximately 30% of O. temporalis venom. α-Elapitoxin-Ot1a (0.1–1 µM) produced concentration-dependent inhibition of indirect-twitches, and abolished contractile responses to exogenous acetylcholine and carbachol, in the chick biventer cervicis nerve-muscle preparation. The inhibition of indirect twitches by α-elapitoxin-Ot1a (1 µM) was not reversed by washing the tissue. Prior addition of taipan antivenom (10 U/mL) delayed the neurotoxic effects of α-elapitoxin-Ot1a (1 µM) and markedly attenuated the neurotoxic effects of α-elapitoxin-Ot1a (0.1 µM). α-Elapitoxin-Ot1a displayed pseudo-irreversible antagonism of concentration-response curves to carbachol with a pA2 value of 8.02 ± 0.05. De novo sequencing revealed the main sequence of the short-chain postsynaptic neurotoxin (i.e., α-elapitoxin-Ot1a) as well as three other isoforms found in O. temporalis venom. α-Elapitoxin-Ot1a shows high sequence similarity (i.e., >87%) with other taipan short-chain postsynaptic neurotoxins. PMID:26938558

  8. Desert Communities.

    ERIC Educational Resources Information Center

    NatureScope, 1985

    1985-01-01

    Provides: (1) background information on desert communities, their similarities, and differences; (2) student activities on this topic; and (3) ready-to-copy student pages with pictures of desert animals and plants. Each activity includes objective(s), recommended age level(s), subject area(s), list of materials needed, and procedures. (DH)

  9. Geochemical modeling of evaporation process in Lake Qarun, Egypt

    NASA Astrophysics Data System (ADS)

    Abdel Wahed, Mahmoud S. M.; Mohamed, Essam A.; El-Sayed, Mohamed I.; M'nif, Adel; Sillanpää, Mika

    2014-09-01

    Lake Qarun is an inland closed saline lake. It lies within the Fayoum Depression in the Western Desert of Egypt. Evaporation modeling has been carried out using PHREEQC to simulate the geochemical evolution of surface drainage waters inflow towards lake water. In the case of Lake Qarun, it is the first attempt to carry out such kind of modeling. Performance of this model helped to address the different sources of dissolved major ions to Lake Qarun and to identify the mechanisms control the lake's water chemistry. The model demonstrated that evaporation-crystallization process is the main mechanism controlling the evolution of lake water chemistry where major ions Na+, Mg2+, Cl- and SO42- have been built up in the lake by evaporation while Ca2+ and HCO3- are depleted by calcite precipitation. Moreover, the simulated model reproduced the real data observed in Lake Qarun except in the case of SO42- which is in real more enriched in the lake than the model output. The additional source of SO42- is reported to be from groundwater. The models result agreed well with the modified evolutionary Hardie and Eugster's scheme (1970) in which the final major composition of Lake Qarun water is Na-Mg-SO4-Cl type. In future, the monitoring of Lake Qarun chemistry with detection of any other sources of elements and/or local reactions inside the lake can be detected by performing the simulated evaporation model reported by the present study.

  10. Lake Nasser and Toshka Lakes, Egypt

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Lake Nasser (center) and the Toshka Lakes (center left) glow emerald green and black in this MODIS true-color image acquired March 8, 2002. Located on and near the border of Egypt and Norther Sudan, these lakes are an oasis of water in between the Nubian (lower right) and Libyan Deserts (upper left). Also visible are the Red Sea (in the upper right) and the Nile River (running north from Lake Nasser). Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  11. Whole-Genome Optical Mapping and Finished Genome Sequence of Sphingobacterium deserti sp. nov., a New Species Isolated from the Western Desert of China

    PubMed Central

    Molnár, István; Li, Xinna; Tang, Ran; Chen, Ming; Wang, Lin; Su, Shiyou; Zhang, Wei; Lin, Min

    2015-01-01

    A novel Gram-negative bacterium, designated ZWT, was isolated from a soil sample of the Western Desert of China, and its phenotypic properties and phylogenetic position were investigated using a polyphasic approach. Growth occurred on TGY medium at 5–42°C with an optimum of 30°C, and at pH 7.0–11.0 with an optimum of pH 9.0. The predominant cellular fatty acids were summed feature 3 (C16:1ω7c/C16:1ω6c or C16:1ω6c/C16:1ω7c) (39.22%), iso-C15:0 (27.91%), iso-C17:0 3OH (15.21%), C16:0 (4.98%), iso-C15:0 3OH (3.03%), C16:0 3OH (5.39%) and C14:0 (1.74%). The major polar lipid of strain ZWT is phosphatidylethanolamine. The only menaquinone observed was MK-7. The GC content of the DNA of strain ZWT is 44.9 mol%. rDNA phylogeny, genome relatedness and chemotaxonomic characteristics all indicate that strain ZWT represents a novel species of the genus Sphingobacterium. We propose the name S. deserti sp. nov., with ZWT (= KCTC 32092T = ACCC 05744T) as the type strain. Whole genome optical mapping and next-generation sequencing was used to derive a finished genome sequence for strain ZWT, consisting of a circular chromosome of 4,615,818 bp in size. The genome of strain ZWT features 3,391 protein-encoding and 48 tRNA-encoding genes. Comparison of the predicted proteome of ZWT with those of other sphingobacteria identified 925 species-unique proteins that may contribute to the adaptation of ZWT to its native, extremely arid and inhospitable environment. As the first finished genome sequence for any Sphingobacterium, our work will serve as a useful reference for subsequent sequencing and mapping efforts for additional strains and species within this genus. PMID:25830331

  12. Dust Plume off the Coast of Egypt

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Dwarfing the Nile, a river of dust flowed out of the deserts of northern Egypt on May 19, 2007. As the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite passed overhead at 12:05 p.m. local time in Cairo, the sensor captured this image of the dust spreading northward over the Mediterranean Sea from the sandy deserts that span the country. At the margins of the plume, ribbons and ripples of dust are translucent, allowing a glimpse of the desert and water beneath, but in the center, the cloud is opaque, revealing nothing of the surface below. The part of north-central Egypt hidden by the dust plume is the Qattara Depression, the country's lowest point. Dipping down to 133 meters below sea level (436 feet), the depression is home to sandy deserts and dry lake beds that occasionally flood. The sand and fine, lake bed sediments are easily lofted into the air by strong winds that scour the area in late winter and early spring. In the eastern (right-hand) part of the image, the Nile River is lined by narrow ribbons of dull green vegetation. The fan-shaped delta is dotted with tan-colored spots, marking the location of cities and towns. The Nile Valley and Delta make up only a small fraction of the country's total land area, yet they support almost the entire population. The large image provided above has a spatial resolution (level of detail) of 250 meters per pixel. The MODIS Rapid Response Team provides this image in additional resolutions. The Earth Observatory also provides a 250-meter-resolution KMZ file of this image for use with Google Earth.

  13. Napoleon in Egypt.

    ERIC Educational Resources Information Center

    Fagan, Brian

    1989-01-01

    Recounts the 1798 Egyptian campaign of Napoleon Bonaparte, whose Scientific and Artistic Commission documented and described the glories of ancient Egypt. The expedition was a disaster by military standards, but the cultural legacies included the Rosetta Stone, and a chronicle entitled "Description de L'Egypte," which did much to…

  14. Ancient Egypt: History 380.

    ERIC Educational Resources Information Center

    Turk, Laraine D.

    "Ancient Egypt," an upper-division, non-required history course covering Egypt from pre-dynastic time through the Roman domination is described. General descriptive information is presented first, including the method of grading, expectation of student success rate, long-range course objectives, procedures for revising the course, major…

  15. Education in Egypt, 1978.

    ERIC Educational Resources Information Center

    Youssef, Youssef Khalil, Ed.; Ibrahim, Fawzia El-Sayed, Ed.

    This publication of the National Center for Educational Research of Egypt describes the status of education in Egypt in 1978, with respect to administration, structure, the educational ladder including university education, as well as the quantitative side of education. It also briefly presents the historical background of Egyptian education, its…

  16. Education in Egypt, 1979.

    ERIC Educational Resources Information Center

    Youssef, Youssef Khalil, Ed.

    This publication of the National Center for Educational Research of Egypt describes the status of education in Egypt in 1979, with respect to administration, structure, the educational ladder including university education, as well as the quantitative side of education. It also briefly presents the historical background of Egyptian education, its…

  17. Calcareous nannofossils and paleoenvironments of the Paleocene-Eocene thermal maximum (PETM) interval in central Egypt

    NASA Astrophysics Data System (ADS)

    Youssef, Mohamed

    2016-02-01

    The Paleocene-Eocene Thermal Maximum (PETM) interval was examined from four outcrops in Central Egypt to document the response of the floral communities across the PETM. The four outcrops are: Gebel Taramsa west of Qena, Gebel Duwi in the Red Sea Coast, and Gebel Qeryia, Gebel Arras sections in Wadi Qena. The qualitative and quantitative analyses of calcareous nannofossils used samples on a high resolution scale. The PETM is characterized by distinguished lithological succession, the Dababyia Quarry Beds (DQB) which extend over the Nile Valley, the Eastern Desert and the Western Desert. The calcareous nannofossils changes across the Paleocene/Eocene boundary (NP9a/NP9b) is marked by the following events: 1) abrupt decreases in both diversity and abundance, 2) dramatic decrease of Fasciculithus both in diversity and abundance, 3) first acme of Coccolithus pelagicus/Coccolithus subpertusus, and 4) first occurrence of excursion taxa including Discoaster araneus, Discoaster. anartios, Discoaster aegyptiacus and Rhomboaster spp). These events may refer to relatively warm and oligotrophic surface waters. The abundance of Toweius spp. in the upper part of the PETM which associated with Campylosphaera characterizes the return to normal conditions.

  18. Heavy mineral concentrations in the sandstones of Amij Formation with particular emphasis on the mineral chemistry and petrographic characteristics of monazite, western desert of Iraq

    NASA Astrophysics Data System (ADS)

    Kettanah, Yawooz A.; Ismail, Sabah A.

    2016-11-01

    The heavy minerals in the clastic unit of the Lower Jurassic Amij Formation exposed in the western desert of Iraq were studied. The uppermost part of the clastic unit contains thin, placer-like black sandstone horizons that are radioactive and abnormally rich in heavy minerals (0.6-56%), dominated by opaque (65%) and transparent (35%) heavy minerals. The minerals, in the order of decreasing abundance are pseudorutile, goethite, zircon, hematite, magnetite, monazite, rutile, leucoxene, tourmaline, ilmenite, chromite, and few others. Electron probe microanalysis (EPMA), microscopic and autoradiographic observations and analysis showed that the monazite is monazite-(Ce) type with an average composition of (Ce0.39Nd0.16La0.19Pr0.04Sm0.02Gd0.02Eu0.01Y0·04Th0·06U0·01Ca0·05Fe0.01)(P0·98Si0.03)O4. Monazite consists predominantly of REE-oxides (57.93%) and P2O5 (29.31%), with minor amounts of ThO2 (6.60%), Y2O3 (1.92%), UO2 (0.76%), CaO (1.14%), SiO2 (0.69%), and FeOt (0.17%). The dominant compositional substitution operating between REE and P were a mixture of the complex cheralite type substitution ([REE]-2 [Th][Ca]) and the coupled huttonite type substitution ([REE]-1 [P]-1 [Th][Si]). The chondrite-normalized REE distribution patterns of monazite show enrichment in LREE with positive Eu- and Pr-anomalies of 1.46 and 9.13, respectively. The median values of (La/Sm)CN and (La/Nd)CN ratios are 4.35 and 1.97, respectively. Zircon which is the dominant transparent mineral is Hf-rich that is composed of 30.61% SiO2, 57.58% ZrO2, 7.03% HfO2, 2.04% Y2O3, 0.56% ThO2, 0.19% UO2, and 0.19% Al2O3 corresponding to a formula (Zr0.909Hf0.065Th0·004U0·001Y0.031)Σ1.011(Si3·966Al0.028)Σ0.999O4. Rutile and tourmaline form 7% and 4% of the heavy minerals. Ilmenite which is one of the predominant heavy minerals forms 2.5% of the opaques because it is pervasively altered to Ti-Fe oxides. In addition of zircon and monazite, the chemical compositions of most of the other heavy

  19. Desert Dermatoses (Thar Desert, India)

    PubMed Central

    Chatterjee, Col Manas

    2017-01-01

    Desert dermatology describes the cutaneous changes and the diseases affecting those living in the desert. Diurnal variation in temperature is high and is characteristic of the deserts. The lack of water affects daily activities and impacts dermatological conditions. Adaptation to the desert is, therefore, important to survival. Infections are the most common conditions seen among this population, and among them, fungal infections are the most common. The high incidence of these infections would be accounted for by the poor hygienic conditions due to lack of bathing facilities due to scarcity of water and the consequent sweat retention and overgrowth of cutaneous infective organisms. Pigmentary disorders, photodermatoses, leishmaniasis, and skin tumors are found to be more prevalent in this region. Desert sweat dermatitis was another specific condition found to have an increased incidence. The environment of the desert provides for a wide variety of dermatoses that can result in these regions with few of these dermatoses found in much higher incidence than in other regions. PMID:28216726

  20. Desert Dermatoses (Thar Desert, India).

    PubMed

    Chatterjee, Col Manas

    2017-01-01

    Desert dermatology describes the cutaneous changes and the diseases affecting those living in the desert. Diurnal variation in temperature is high and is characteristic of the deserts. The lack of water affects daily activities and impacts dermatological conditions. Adaptation to the desert is, therefore, important to survival. Infections are the most common conditions seen among this population, and among them, fungal infections are the most common. The high incidence of these infections would be accounted for by the poor hygienic conditions due to lack of bathing facilities due to scarcity of water and the consequent sweat retention and overgrowth of cutaneous infective organisms. Pigmentary disorders, photodermatoses, leishmaniasis, and skin tumors are found to be more prevalent in this region. Desert sweat dermatitis was another specific condition found to have an increased incidence. The environment of the desert provides for a wide variety of dermatoses that can result in these regions with few of these dermatoses found in much higher incidence than in other regions.

  1. Thar Desert

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This ASTER sub-scene covers an area of 12 x 15 km in NW India in the Thar Desert. The sand dunes of the Thar Desert constantly shift and take on new shapes. Located in northwestern India and eastern Pakistan, the desert is bounded on the south by a salt marsh known as the Rann of Kutch, and on the west by the Indus River plain. About 800 kilometers long and about 490 kilometers wide, the desert's terrain is mainly rolling sandhills with scattered growths of shrub and rock outcroppings. Only about 12 to 25 centimeters of rain fall on the desert each year, and temperatures rise as high as 52 degrees Celsius. Much of the population is pastoral, raising sheep for their wool. The image is located at 24.4 degrees north latitude and 69.3 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  2. Nile behaviour and Upper Palaeolithic humans in Upper Egypt

    NASA Astrophysics Data System (ADS)

    Vermeersch, Pierre M.

    2014-05-01

    There is evidence of a decreasing human occupation of the Upper Egyptian Nile valley during the MIS 5 to MIS 3 period. Whereas very large extraction sites of the Middle Stone Age have been recorded, only very few sites of the Upper Palaeolithic have been found. The best explanation of this fact is that during the Late Middle Stone Age and the Upper Palaeolithc there was nearly no need for raw materials because there was only a very restricted population present in Upper Egypt. From about 22 ka BP an important population increase is registered by the presence of numerous Late Palaeolithic sites. During the whole LGM there is abundant presence of humans along the Nile Valley in Upper Egypt. This population was mainly living from fishing. There seems to be an abrupt end of the Palaeolithic occupation after 12.8 ka BP. Until now, no sites were found in the Valley until some rare Epipaleolithic sites occur about 8.0 ka BP. It will be suggested that these population changes are influenced by the river Nile behaviour. The best interpretation of the observations in the Upper Egyptian Nile Valley is the hypothesis that at the same time that Nile flow was reduced because of the dryness in its source area, the impact of aeolian activity was increased over Northeast Africa. The increased aeolian activity by northern winds in the Fayum and Wadi Ryan during the LGM resulted in the accumulation of aeolian sand in the valley. That aeolian sand was transported along the western Nile valley cliffs until it was accumulated when the Nile Valley change it S-N direction, such as at Nag'Hammadi. At other places sand was invading the Nile valley, directly from the Western Desert, creating a damming of the Nile at several places such as Armant and Aswan. As Nile flow was quite reduced, the Nile was unable to erode all the incoming sand and the Nile water with its important clay content was dammed. At several places large lakes were created in the Nile Valley. Those lakes were an ideal

  3. Discovering Deserts.

    ERIC Educational Resources Information Center

    Braus, Judy, Ed.

    1985-01-01

    Ranger Rick's NatureScope is a creative education series dedicated to inspiring in children an understanding and appreciation of the natural world while developing the skills they will need to make responsible decisions about the environment. The topic of this issue is "Discovering Deserts." Contents are organized into the following…

  4. Desert Survivors!

    ERIC Educational Resources Information Center

    Horton, Jessica; Friedenstab, Steve

    2013-01-01

    This article describes a special third-grade classroom unit based on the reality show "Survivor." The goal of this engaging and interactive unit was to teach students about physical and behavioral adaptations that help animals survive in various desert biomes. The activity combines research, argument, and puppet play over one week of…

  5. Schools' Television in Egypt.

    ERIC Educational Resources Information Center

    Blezard, Dennis

    1980-01-01

    Chronicles the short (1970-77) and troubled history of instructional television in Egypt. Among the problems which led to the discontinuation of television programing for schools were production delays, inadequate repair service, and lack of training. (LLS)

  6. Nummulite biostratigraphy of the Eocene succession in the Bahariya Depression, Egypt: Implications for timing of iron mineralization

    NASA Astrophysics Data System (ADS)

    Afify, A. M.; Serra-Kiel, J.; Sanz-Montero, M. E.; Calvo, J. P.; Sallam, E. S.

    2016-08-01

    In the northern part of the Bahariya Depression (Western Desert, Egypt) the Eocene carbonate succession, unconformably overlying the Cretaceous deposits, consists of three main stratigraphic units; the Naqb, Qazzun and El Hamra formations. The Eocene carbonates are relevant as they locally host a large economic iron mineralization. This work revises the stratigraphic attribution of the Eocene formations on the basis of larger benthic foraminifers from both carbonate and ironstone beds. Eight Nummulites species spanning the late Ypresian - early Bartonian (SBZ12 to SBZ17) were identified, thus refining the chronostratigraphic framework of the Eocene in that region of Central Egypt. Moreover, additional sedimentological insight of the Eocene carbonate rocks is presented. The carbonate deposits mainly represent shallow marine facies characteristic of inner to mid ramp settings; though deposits interpreted as intertidal to supratidal are locally recognized. Dating of Nummulites assemblages from the youngest ironstone beds in the mines as early Bartonian provides crucial information on the timing of the hydrothermal and meteoric water processes resulting in the formation of the iron ore mineralization. The new data strongly support a post-depositional, structurally-controlled formation model for the ironstone mineralization of the Bahariya Depression.

  7. Geochemical and hydrological processes controlling groundwater quality in Assiut Governorate, Egypt

    NASA Astrophysics Data System (ADS)

    Mohammad, R. G.; Tempel, R.; Gomaa, M.; Korany, E.

    2011-12-01

    Groundwater in Assiut area, Egypt, is an important source of fresh water for human consumption, agriculture, and domestic and industrial purposes. Due to a growing population and expansion of agricultural reclamation projects in the desert fringes of the Nile Valley, there is an increasing water demand in this arid region. This study has investigated the geochemical and hydrological processes that control groundwater quality within the Pleistocene, Plio-Pleistocene, and Eocene aquifers in Assiut, in addition to the hydraulic relationships between surface and groundwater systems and the relations among the defined groundwater aquifers. A total of 28 surface and 160 groundwater samples were collected for geochemical analysis (major and minor element chemistry, and stable isotope analyses). Total dissolved solids = 182 to 5657 mg/L, water-delta 18O = -7.5 to +6.5%, and water-delta D = -55 to +32%. Geochemical and stable isotope data indicate that the principal source of recharge to the Pleistocene and Plio-Pleistocene aquifers is the surface water system (irrigation canals), while the prevalence of Na-Cl type waters in the Eocene aquifer indicates recharge by upward leakage from the underlying Nubian sandstone aquifer which contains the same Na-Cl water type. Evaporation prior to infiltration, mixing, and mineral equilibria (dissolution and precipitation) are the main factors that affect water quality. Ion exchange plays a secondary role in controlling the water chemistry of the Pleistocene aquifer, but is more effective in controlling water quality within the Plio-Pleistocene and Eocene aquifers due to the prevalence of clay minerals within the matrices. The fresh water exploited from the Eocene aquifer may be of great importance for land reclamation projects not only at the western desert fringes, but also at the eastern desert fringes of Assiut and similar settings around the River Nile south of Assiut Governorate. Results of this study will be helpful for

  8. Gold of the Pharaohs 6000 years of gold mining in Egypt and Nubia

    NASA Astrophysics Data System (ADS)

    Klemm, Dietrich; Klemm, Rosemarie; Murr, Andreas

    2001-08-01

    The legendary wealth in gold of ancient Egypt seems to correspond with an unexpected high number of gold production sites in the Eastern Desert of Egypt and Nubia. This contribution introduces briefly the general geology of these vast regions and discusses the geology of the different varieties of the primary gold occurrences (always related to auriferous quartz mineralization in veins or shear zones) as well as the variable physico-chemical genesis of the gold concentrations. The development of gold mining over time, from Predynastic (ca. 3000 BC) until the end of Arab gold production times (about 1350 AD), including the spectacular Pharaonic periods is outlined, with examples of its remaining artefacts, settlements and mining sites in remote regions of the Eastern Desert of Egypt and Nubia. Finally, some estimates on the scale of gold production are presented.

  9. The Cretaceous glauconitic sandstones of Abu Tartur, Egypt

    NASA Astrophysics Data System (ADS)

    Pestitschek, Brigitte; Gier, Susanne; Essa, Mahmoud; Kurzweil, Johannes

    2010-05-01

    The Abu Tartur mine is located in the Western Desert of Egypt, 50 km west of El Kharga City. Geologically, the Abu Tartur plateau is built by a sequence of Upper Cretaceous (Campanian - Maastrichtian) phosphorites, black shales and glauconitic sandstones. The phosphate deposits are of great economic importance and have been mined since their discovery in 1967. Outcrop sections were measured, sampled, sedimentologically characterized and described. One specific glaucony layer was investigated mineralogically and chemically in detail and compared to a subsurface sample from the mine. Two depositional regimes can be interpreted based on sedimentary architecture and structures: 1) a deeper-water hemipelagic environment, where phosphorites and organic carbon-rich shales were deposited and 2) a shallower, prograding higher energy shelf environment with glauconies. From a sequence stratigraphic perspective 1) was deposited during the transgressive systems tract and the early highstand while 2) was deposited during the remaining highstand and a lowstand prograding wedge (Glenn & Arthur, 1990). Petrographic and SEM investigations show that the glaucony grains are of authochtonous origin. XRF, EMPA and thin-section analyses show that the glaucony grains from the outcrop differ significantly in their chemical composition, morphology and color from the grains of the mine sample. The fresh glauconies are enriched in Fe2O3 and K2O compared to the surface samples. XRD analyses of the clay fraction of the six outcrop samples and the mine sample show that the grains consist of illite(glauconite)/smectite mixed-layers, with more illite layers (80 %) in the mine sample. The charge distribution diagram muscovite-pyrophyllite-celadonite shows a clear trend from smectitic glaucony to illitic glaucony, the mine sample plots exactly in the field for glauconites. All these features indicate that the surface samples are strongly altered by weathering and that glauconite progressively

  10. Safsaf Oasis, Egypt

    NASA Technical Reports Server (NTRS)

    1998-01-01

    These images show two views of a region of south-central Egypt, each taken by a different type of spaceborne sensor. On the left is an optical image from the Landsat Thematic Mapper, and on the right is a radar image from the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR). This comparison shows that the visible and infrared wavelengths of Landsat are only sensitive to the materials on the surface, while the radar wavelengths of SIR-C/X-SAR can penetrate the thin sand cover in this arid region to reveal details hidden below the surface. Field studies in this area indicate that the L-band radar can penetrate as much as 2 meters (6.5 feet) of very dry sand to image buried rock structures. Ancient drainage channels, shown at the bottom of this image, are filled with sand more than 2 meters (6.5 feet) thick and therefore appear dark because the radar waves cannot penetrate them. Only the most recently active channels are visible in the Landsat scene. Some geologic structures at the surface are visible in both images. However, many buried features, such as rock fractures and the blue circular granite bodies in the upper center of the image on the right, are visible only to the radar. The Safsaf Oasis is located near the bright yellow feature in the lower left center of the Landsat image. Scientists are using the penetrating capabilities of radar imaging in desert areas to study structural geology, mineral exploration, ancient climates, water resources and archaeology. Each image is 30.8 kilometers by 25.6 kilometers (19.1 miles by 15.9 miles) and is centered at 22.7 degrees north latitude, 29.3 degrees east longitude. North is toward the upper right. In the Landsat image, the colors are assigned as follows: red is Band 7 (mid-infrared); green is Band 4 (near infrared); and blue is Band 1 (visible blue light). The colors assigned to the radar frequencies and polarizations are as follows: red is L-band, horizontally transmitted and received; green

  11. Animal brucellosis in Egypt.

    PubMed

    Wareth, Gamal; Hikal, Ahmed; Refai, Mohamed; Melzer, Falk; Roesler, Uwe; Neubauer, Heinrich

    2014-11-13

    Brucellosis is a highly contagious zoonosis that affects the public health and economic performance of endemic as well as non-endemic countries. In developing nations, brucellosis is often a very common but neglected disease. The purpose of this review is to provide insight about brucellosis in animal populations in Egypt and help to understand the situation from 1986 to 2013. A total of 67 national and international scientific publications on serological investigations, isolation, and biotyping studies from 1986 to 2013 were reviewed to verify the current status of brucellosis in animal populations in Egypt. Serological investigations within the national surveillance program give indirect proof for the presence of brucellosis in cattle, buffaloes, sheep, goats, and camels in Egypt. Serologic testing for brucellosis is a well-established procedure in Egypt, but most of the corresponding studies do not follow the scientific standards. B. melitensis biovar (bv) 3, B. abortus bv 1, and B. suis bv 1 have been isolated from farm animals and Nile catfish. Brucellosis is prevalent nationwide in many farm animal species. There is an obvious discrepancy between official seroprevalence data and data from scientific publications. The need for a nationwide survey to genotype circulating Brucellae is obvious. The epidemiologic situation of brucellosis in Egypt is unresolved and needs clarification.

  12. Phytomonitoring the unique colonization of oil-contaminated saline environment by Limoniastrum monopetalum (L.) Boiss in Egypt.

    PubMed

    Hussein, Hussein S; Terry, Norman

    2002-04-01

    A site that covers over 20 acres of coastal saline depression in the western Mediterranean coastal desert of Egypt (El-Hammra station, the main crude oil pipeline terminal in Al-Alamein) is contaminated with crude oil spill as a result of activities from refineries, oilfield blowouts, tanker and pipeline break-ups. This area, prior to contamination, was dominated by different common halophytes. However, Limoniastrum monopetalum is now the only species found growing in the oil-contaminated soil. A specific question addressed in the present study was: what are the biochemical changes occurring in a desert plant growing in oil-contaminated soils? Major metabolites such as proline, betaine, free amino acids, fatty acid esters and mineral elements were studied. The plant samples were collected from the oil-contaminated, as well as noncontaminated, sites. The higher concentration in the selected organic metabolites in the plants growing in the contaminated site compared to those in noncontaminated site may be due to differences in a number of receptors. The sensitivity of such receptors for the environmental signal that cause differences in genetic expression leads to differences in physiological processes. The change in the landscape of the contaminated area and the elimination of the natural vegetation, except L. monopetalum, may explain the competitive balance toward the oil-resistant species.

  13. Dwarfs in ancient Egypt.

    PubMed

    Kozma, Chahira

    2006-02-15

    Ancient Egypt was one of the most advanced and productive civilizations in antiquity, spanning 3000 years before the "Christian" era. Ancient Egyptians built colossal temples and magnificent tombs to honor their gods and religious leaders. Their hieroglyphic language, system of organization, and recording of events give contemporary researchers insights into their daily activities. Based on the record left by their art, the ancient Egyptians documented the presence of dwarfs in almost every facet of life. Due to the hot dry climate and natural and artificial mummification, Egypt is a major source of information on achondroplasia in the old world. The remains of dwarfs are abundant and include complete and partial skeletons. Dwarfs were employed as personal attendants, animal tenders, jewelers, and entertainers. Several high-ranking dwarfs especially from the Old Kingdom (2700-2190 BCE) achieved important status and had lavish burial places close to the pyramids. Their costly tombs in the royal cemeteries and the inscriptions on their statutes indicate their high-ranking position in Egyptian society and their close relation to the king. Some of them were Seneb, Pereniankh, Khnumhotpe, and Djeder. There were at least two dwarf gods, Ptah and Bes. The god Ptah was associated with regeneration and rejuvenation. The god Bes was a protector of sexuality, childbirth, women, and children. He was a favored deity particularly during the Greco-Roman period. His temple was recently excavated in the Baharia oasis in the middle of Egypt. The burial sites and artistic sources provide glimpses of the positions of dwarfs in daily life in ancient Egypt. Dwarfs were accepted in ancient Egypt; their recorded daily activities suggest assimilation into daily life, and their disorder was not shown as a physical handicap. Wisdom writings and moral teachings in ancient Egypt commanded respect for dwarfs and other individuals with disabilities.

  14. Nile River Delta, Egypt

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The Nile River Delta of Egypt (30.0N, 31.0E) irrigated by the Nile River and its many distributaries, is some of the richest farm land in the world and home to some 45 million people, over half of Egypt's population. The capital city of Cairo is at the apex of the delta. Just across the river from Cairo can be seen the ancient three big pyramids and sphinx at Giza and the Suez Canal is just to the right of the delta.

  15. Surgery in Egypt.

    PubMed

    el-Zawahry, M D; Ramzy, A F; el-Sahwi, E; Bahnasy, A F; Khafaga, M; Rizk-Allah, M A; Abou el-Hoda, M F

    1997-07-01

    The history of medicine can never be complete without referral to ancient Egyptian medicine. Imhotep has been identified as the god of medicine. There are 13 faculties of medicine in Egypt; the oldest is the Kasr El Aini Faculty, which started in 1925. We review undergraduate and postgraduate education in Egypt. The Egyptian Society of Surgeons organizes the scientific surgical activities. Schistosomiasis is a national health problem. Health care is provided by many types of hospitals, including university, teaching, Ministry of Public Health, military, and private hospitals.

  16. The Politics of Educational Transfer and Policymaking in Egypt

    ERIC Educational Resources Information Center

    Ibrahim, Ali S.

    2010-01-01

    For the past two centuries, western modern education has informed education policies and practices in Egypt. However, few researchers have analyzed the historical or current politics of educational transfer in this country. This article investigates the ways in which foreign transfer has influenced Egyptian education, both historically and…

  17. Desert Test Site Uniformity Analysis

    NASA Technical Reports Server (NTRS)

    Kerola, Dana X.; Bruegge, Carol J.

    2009-01-01

    Desert test sites such as Railroad Valley (RRV) Nevada, Egypt-1, and Libya-4 are commonly targeted to assess the on-orbit radiometric performance of sensors. Railroad Valley is used for vicarious calibration experiments, where a field-team makes ground measurements to produce accurate estimates of top-of-atmosphere (TOA) radiances. The Sahara desert test sites are not instrumented, but provide a stable target that can be used for sensor cross-comparisons, or for stability monitoring of a single sensor. These sites are of interest to NASA's Atmospheric Carbon Observation from Space (ACOS) and JAXA's Greenhouse Gas Observation SATellite (GOSAT) programs. This study assesses the utility of these three test sites to the ACOS and GOSAT calibration teams. To simulate errors in sensor-measured radiance with pointing errors, simulated data have been created using MODIS Aqua data. MODIS data are further utilized to validate the campaign data acquired from June 22 through July 5, 2009. The first GOSAT vicarious calibration experiment was conducted during this timeframe.

  18. Ancient Egypt: Personal Perspectives.

    ERIC Educational Resources Information Center

    Wolinski, Arelene

    This teacher resource book provides information on ancient Egypt via short essays, photographs, maps, charts, and drawings. Egyptian social and religious life, including writing, art, architecture, and even the practice of mummification, is conveniently summarized for the teacher or other practitioner in a series of one to three page articles with…

  19. Egypt's National Education Debate.

    ERIC Educational Resources Information Center

    Cook, Bradley James

    2000-01-01

    Examines the vigorous dialectic occurring among intellectuals, religious leaders, and politicians trying to define the appropriate role of Islam in Egyptian education. Discusses the call for the Islamization of education in contemporary Egypt, aspects of Islamic law, the position of the state on religious education, and the influence of a small…

  20. Phylogeographic Structure of a Tethyan Relict Capparis spinosa (Capparaceae) Traces Pleistocene Geologic and Climatic Changes in the Western Himalayas, Tianshan Mountains, and Adjacent Desert Regions

    PubMed Central

    Wang, Qian; Zhang, Ming-Li; Yin, Lin-Ke

    2016-01-01

    Complex geological movements more or less affected or changed floristic structures, while the alternation of glacials and interglacials is presumed to have further shaped the present discontinuous genetic pattern of temperate plants. Here we consider Capparis spinosa, a xeromorphic Tethyan relict, to discuss its divergence pattern and explore how it responded in a stepwise fashion to Pleistocene geologic and climatic changes. 267 individuals from 31 populations were sampled and 24 haplotypes were identified, based on three cpDNA fragments (trnL-trnF, rps12-rpl20, and ndhF). SAMOVA clustered the 31 populations into 5 major clades. AMOVA suggests that gene flow between them might be restricted by vicariance. Molecular clock dating indicates that intraspecific divergence began in early Pleistocene, consistent with a time of intense uplift of the Himalaya and Tianshan Mountains, and intensified in mid-Pleistocene. Species distribution modeling suggests range reduction in the high mountains during the Last Glacial Maximum (LGM) as a result of cold climates when glacier advanced, while gorges at midelevations in Tianshan appear to have served as refugia. Populations of low-altitude desert regions, on the other hand, probably experienced only marginal impacts from glaciation, according to the high levels of genetic diversity. PMID:27314028

  1. Geologic and hydrologic controls on the movement of water through a thick, heterogeneous unsaturated zone underlying an intermittent stream in the western Mojave Desert, southern California

    NASA Astrophysics Data System (ADS)

    Izbicki, John A.

    2002-03-01

    A two-dimensional, axially symmetric, unsaturated flow model was developed to test hypotheses about geologic and hydrologic controls on the movement of water through the thick, heterogeneous, unsaturated zone underlying Oro Grande Wash in the Mojave Desert, California. Heterogeneity within the unsaturated zone was simulated with multiple realizations of subsurface geology estimated on the basis of transition probability/Markov chain statistics. Model results show lateral spreading of water away from the wash was best approximated by realizations that include thin, horizontally extensive clay layers that impede the downward movement of water. There was a wide range in model responses for these realizations, and the movement of water through unsaturated zones containing thin, horizontally extensive clay layers may be more difficult to predict than water movement through unsaturated zones where clay layers are less extensive. For realizations having less extensive clay layers, the range of model responses decreased with time, and model results became increasingly similar as water encountered larger volumes of material.

  2. Phylogeographic Structure of a Tethyan Relict Capparis spinosa (Capparaceae) Traces Pleistocene Geologic and Climatic Changes in the Western Himalayas, Tianshan Mountains, and Adjacent Desert Regions.

    PubMed

    Wang, Qian; Zhang, Ming-Li; Yin, Lin-Ke

    2016-01-01

    Complex geological movements more or less affected or changed floristic structures, while the alternation of glacials and interglacials is presumed to have further shaped the present discontinuous genetic pattern of temperate plants. Here we consider Capparis spinosa, a xeromorphic Tethyan relict, to discuss its divergence pattern and explore how it responded in a stepwise fashion to Pleistocene geologic and climatic changes. 267 individuals from 31 populations were sampled and 24 haplotypes were identified, based on three cpDNA fragments (trnL-trnF, rps12-rpl20, and ndhF). SAMOVA clustered the 31 populations into 5 major clades. AMOVA suggests that gene flow between them might be restricted by vicariance. Molecular clock dating indicates that intraspecific divergence began in early Pleistocene, consistent with a time of intense uplift of the Himalaya and Tianshan Mountains, and intensified in mid-Pleistocene. Species distribution modeling suggests range reduction in the high mountains during the Last Glacial Maximum (LGM) as a result of cold climates when glacier advanced, while gorges at midelevations in Tianshan appear to have served as refugia. Populations of low-altitude desert regions, on the other hand, probably experienced only marginal impacts from glaciation, according to the high levels of genetic diversity.

  3. Desert dust aerosol air mass mapping in the western Sahara, using particle properties derived from space-based multi-angle imaging

    NASA Astrophysics Data System (ADS)

    Kahn, Ralph; Petzold, Andreas; Wendisch, Manfred; Bierwirth, Eike; Dinter, Tilman; Esselborn, Michael; Fiebig, Marcus; Heese, Birgit; Knippertz, Peter; Müller, Detlef; Schladitz, Alexander; von Hoyningen-Huene, Wolfgang

    2009-02-01

    ABSTRACT Coincident observations made over the Moroccan desert during the Sahara mineral dust experiment (SAMUM) 2006 field campaign are used both to validate aerosol amount and type retrieved from multi-angle imaging spectroradiometer (MISR) observations, and to place the suborbital aerosol measurements into the satellite's larger regional context. On three moderately dusty days during which coincident observations were made, MISR mid-visible aerosol optical thickness (AOT) agrees with field measurements point-by-point to within 0.05-0.1. This is about as well as can be expected given spatial sampling differences; the space-based observations capture AOT trends and variability over an extended region. The field data also validate MISR's ability to distinguish and to map aerosol air masses, from the combination of retrieved constraints on particle size, shape and single-scattering albedo. For the three study days, the satellite observations (1) highlight regional gradients in the mix of dust and background spherical particles, (2) identify a dust plume most likely part of a density flow and (3) show an aerosol air mass containing a higher proportion of small, spherical particles than the surroundings, that appears to be aerosol pollution transported from several thousand kilometres away.

  4. Desert Dust Air Mass Mapping in the Western Sahara, using Particle Properties Derived from Space-based Multi-angle Imaging

    NASA Technical Reports Server (NTRS)

    Kahn, Ralph; Petzold, Andreas; Wendisch, Manfred; Bierwirth, Eike; Dinter, Tilman; Fiebig, Marcus; Schladitz, Alexander; von Hoyningen-Huene, Wolfgang

    2008-01-01

    Coincident observations made over the Moroccan desert during the SAhara Mineral dUst experiMent (SAMUM) 2006 field campaign are used both to validate aerosol amount and type retrieved from Multi-angle Imaging SpectroRadiometer (MISR) observations, and to place the sub-orbital aerosol measurements into the satellite's larger regional context. On three moderately dusty days for which coincident observations were made, MISR mid-visible aerosol optical thickness (AOT) agrees with field measurements point-by-point to within 0.05 to 0.1. This is about as well as can be expected given spatial sampling differences; the space-based observations capture AOT trends and variability over an extended region. The field data also validate MISR's ability to distinguish and to map aerosol air masses, from the combination of retrieved constraints on particle size, shape, and single-scattering albedo. For the three study days, the satellite observations (a) highlight regional gradients in the mix of dust and background spherical particles, (b) identify a dust plume most likely part of a density flow, and (c) show an air mass containing a higher proportion of small, spherical particles than the surroundings, that appears to be aerosol pollution transported from several thousand kilometers away.

  5. Desert Dust Aerosol Air Mass Mapping in the Western Sahara, Using Particle Properties Derived from Space-Based Multi-Angle Imaging

    NASA Technical Reports Server (NTRS)

    Kahn, Ralph; Petzold, Andreas; Wendisch, Manfred; Bierwirth, Eike; Dinter, Tilman; Esselborn, Michael; Fiebig, Marcus; Heese, Birgit; Knippertz, Peter; Mueller, Detlef; Schladitz, Alexander; Von Hoyningen-Huene, Wolfgang

    2008-01-01

    Coincident observations made over the Moroccan desert during the Sahara mineral dust experiment (SAMUM) 2006 field campaign are used both to validate aerosol amount and type retrieved from multi-angle imaging spectroradiometer (MISR) observations, and to place the suborbital aerosol measurements into the satellite s larger regional context. On three moderately dusty days during which coincident observations were made, MISR mid-visible aerosol optical thickness (AOT) agrees with field measurements point-by-point to within 0.05 0.1. This is about as well as can be expected given spatial sampling differences; the space-based observations capture AOT trends and variability over an extended region. The field data also validate MISR s ability to distinguish and to map aerosol air masses, from the combination of retrieved constraints on particle size, shape and single-scattering albedo. For the three study days, the satellite observations (1) highlight regional gradients in the mix of dust and background spherical particles, (2) identify a dust plume most likely part of a density flow and (3) show an aerosol air mass containing a higher proportion of small, spherical particles than the surroundings, that appears to be aerosol pollution transported from several thousand kilometres away.

  6. The Regional Environmental Impacts of Atmospheric Aerosols over Egypt

    NASA Astrophysics Data System (ADS)

    Zakey, Ashraf; Ibrahim, Alaa

    2015-04-01

    Identifying the origin (natural versus anthropogenic) and the dynamics of aerosols over Egypt at varying temporal and spatial scales provide valuable knowledge on the regional climate impacts of aerosols and their ultimate connections to the Earth's regional climate system at the MENA region. At regional scale, Egypt is exposed to air pollution with levels exceeding typical air-quality standards. This is particularly true for the Nile Delta region, being at the crossroads of different aerosol species originating from local urban-industrial and biomass-burning activities, regional dust sources, and European pollution from the north. The Environmental Climate Model (EnvClimA) is used to investigate both of the biogenic and anthropogenic aerosols over Egypt. The dominant natural aerosols over Egypt are due to the sand and dust storms, which frequently occur during the transitional seasons (spring and autumn). In winter, the maximum frequency reaches 2 to 3 per day in the north, which decreases gradually southward with a frequency of 0.5-1 per day. Monitoring one of the most basic aerosol parameters, the aerosol optical depth (AOD), is a main experimental and modeling task in aerosol studies. We used the aerosol optical depth to quantify the amount and variability of aerosol loading in the atmospheric column over a certain areas. The aerosols optical depth from the model is higher in spring season due to the impacts of dust activity over Egypt as results of the westerly wind, which carries more dust particles from the Libyan Desert. The model result shows that the mass load of fine aerosols has a longer life-time than the coarse aerosols. In autumn season, the modelled aerosol optical depth tends to increase due to the biomass burning in the delta of Egypt. Natural aerosol from the model tends to scatter the solar radiation while most of the anthropogenic aerosols tend to absorb the longwave solar radiation. The overall results indicate that the AOD is lowest in winter

  7. Astronomy at Nabta Playa, Southern Egypt

    NASA Astrophysics Data System (ADS)

    McKim Malville, J.

    Nabta Playa may contain the oldest human-made features with astronomical alignments in Egypt. In the Late and Terminal Neolithic (7,500-5,400 BP), nomadic pastoralists built a ceremonial center on the western shore of Nabta Playa, consisting of some 30 complex megalithic structures, stone circles, and lines of megaliths crossing the playa. The megaliths may once have aligned with Arcturus, the Belt of Orion, Sirius, and α Cen. Reorientations of the northern set of megaliths suggest a response to precession. Elaborate burials at the nearby cemetery at Gebel Ramlah indicate the nomads consisted of Mediterranean and sub-Saharan populations with little social stratification.

  8. Statistical methods to study soil infiltration rate in Kharga Oasis, Egypt.

    NASA Astrophysics Data System (ADS)

    Gamie, Rasha; De Smedt, Florimond

    2016-04-01

    Agricultural expansion in the Kahrga oasis, located in the western desert of Egypt, strongly depends on irrigation. Hence, the infiltration rate is a key parameter for further development. The infiltration rate was measured in the field using a double ring infiltrometer at 20 m intervals in a 120 m by 120 m plot, together with 12 other relevant physical and chemical soil parameters. The resulting data were statistically analyzed using principal component and linear regression analyses. Results show that the infiltration rate is highly variable in the study area, and strongly positively correlated with hydraulic conductivity and negatively with silt, clay and carbonates contents of the soil. Principle component analysis showed that most of the variation in the data is assigned in the first 3 principle components. The first component explains 36% of the total variation and is strongly linked with soil structure; the second component explains 18% of the total variation and is linked to soil texture; the third component explains 13% and is linked to chemical properties but has no link with infiltration rate; all other components just represent noise in the data and must be attributed to measurement errors, randomness and soil heterogeneity. Multiple linear regression analysis shows that the only relevant factors to predict infiltration rate are hydraulic conductivity, and silt and carbonate content of the soil. The regression equation is only able to predict about half of the variation of the infiltrations rate, while the other half remains unexplained.

  9. Petrophysical Properties of Clastic Reservoirs Using NMR Relaxometry and Mercury Injection Data: Bahariya Formation, Egypt

    NASA Astrophysics Data System (ADS)

    El Sayed, Abdel Moktader A.; El Sayed, Nahla A.

    2016-10-01

    The Bahariya Formation is a sedimentary sequence, which was deposited under fluvial to shallow marine conditions at the beginning of the Upper Cretaceous (Cenomanian) transgression in the Western Desert of Egypt. Thirty sandstone core samples, obtained from the Bahariya Formation, are conducted to NMR measurements and the relaxation time T2 = 100 μs and 600 μs were estimated. Application of a model related core-porosity and transverse relaxation time (T2) measured from NMR spectrum; the cementation exponent of Wyllie's type is outlined with high accuracy. Consequently, the water saturation and hydrocarbon saturation will be significantly enhanced. The irreducible water saturation (Swirr) calculated from the mercury injection capillary pressure (MICP) measurements is related to the normalized area under < 4 μs of transverse relaxation time (T2) and a regression model is calculated with a reliable coefficient of correlation permitting calculation of (Swirr) with high accuracy. Lithologic laminations presented in some intervals of the Bahariya Formation have great consequences on both the Mercury injection capillary pressure (MICP) measurements and nuclear magnetic Relaxometry (T2) as well. Thin sections and SEM-micrographs were made for some selected core samples in order to recognize petrography and mineralogy of the Bahariya sandstones. Glauconitic, mica, zircon, rutile and pyrite minerals are predominant in the laminated sandstones intervals.

  10. SHUTTLE IMAGING RADAR PROVIDES FRAMEWORK FOR SUBSURFACE GEOLOGIC EXPLORATION IN EGYPT AND SUDAN.

    USGS Publications Warehouse

    Breed, Carol S.; McCauley, John F.; Schaber, Gerald G.

    1984-01-01

    Shuttle Imaging Radar provides a pictorial framework to guide exploration for mineral resources (potential placers), groundwater sources, and prehistoric archaeological sites in the Western Desert of Egypt and Sudan. Documented penetration by the SIR-A signal of dry surficial sediment to depths of a meter or more revealed bedrock geologic features and networks of former stream valleys otherwise concealed beneath windblown sand, alluvium, and colluvial deposits. 'Radar units' mapped on SIR-A images according to relative brightness and degree of mottling correspond to subsurface geologic and topographic features identified in more than 50 test pits. Petrologic examination of pit samples confirms that a variety of depositional environments existed in this now hyper-arid region before it was mantled by windblown sand sheets and dunes. Wet sand was discovered in two buried valleys shown on the radar images and located in the field with the aid of co-registered maps and Landsat images, and a satellite navigation device. Buried valleys whose streams once traversed mineralized zones are potential sites of placers (gold, tin).

  11. Desert Voices: Southwestern Children's Literature.

    ERIC Educational Resources Information Center

    Polette, Keith

    1997-01-01

    Examines three books with different ways of writing about the desert. Discusses: "Here Is the Southwestern Desert" by Madeline Dunphy, "The Desert Is My Mother" by Pat Mora, and "The Desert Mermaid" by Alberto Blanco. (PA)

  12. Mental health in Egypt.

    PubMed

    Okasha, Ahmed

    2005-01-01

    The concepts and management of mental health in Egypt are presented from the Pharaonic era through the Islamic Renaissance until today. Papyri from the Pharaonic period show that Soma and Psyche were not differentiated and mental disorders were described as symptoms of the heart and uterus. Although theories of causation were of a mystical nature, mental disorders were treated on a somatic basis. In the Islamic era, mental patients were neither maltreated nor tortured as a consequence of the belief that they may be possessed by a good Moslem genie. In the 14th century mental disorders was one of the four departments in Cairo's Kalawoon Hospital, a precursor of the place of psychiatry in general hospitals that was accepted in Europe six centuries later. The mental health services in Egypt today are described, and transcultural studies carried out in Egypt of the prevalence and phenomenology of anxiety, schizophrenia, depression, suicide, conversion and obsessive compulsive disorders are reviewed. The psychiatric services for children are in their infancy. Since 1983 the common and semi-accepted use of hashish has been joined by abuse by heroin and other substances.

  13. Data from a Thick Unsaturated Zone Underlying Two Artificial Recharge Sites along Oro Grande Wash in the Western Part of the Mojave Desert, near Victorville, San Bernardino County, California, 2001-2006

    USGS Publications Warehouse

    Clark, Dennis A.; Izbicki, John A.; Johnson, Russell D.; Land, Michael

    2009-01-01

    This report presents data on the physical and hydraulic properties of unsaturated alluvial deposits and on the chemical and isotopic composition of water collected at two recharge sites in the western part of the Mojave Desert, near Victorville, California, from 2001 to 2006. Unsaturated-zone monitoring sites were installed adjacent to the two recharge ponds using the ODEX air-hammer and air rotary method to depths of about 460 feet and 269 feet below land surface. Each of the two unsaturated-zone monitoring sites included a water-table well, matric-potential sensors, and suction-cup lysimeters installed in a single bore hole. Drilling procedures, lithologic and geophysical data, and site construction and instrumentation are described. Core material was analyzed for water content, bulk density, water potential, particle size, and water retention. The chemical composition of leachate from almost 400 samples of cores and cuttings was determined. Water from suction-cup lysimeters also was analyzed for chemical and isotopic composition. In addition, data on the chemical and isotopic composition of groundwater from the two water-table wells are reported along with chemical and isotopic composition of the surface water in the recharge ponds.

  14. Nubian Complex strategies in the Egyptian high desert.

    PubMed

    Olszewski, Deborah I; Dibble, Harold L; McPherron, Shannon P; Schurmans, Utsav A; Chiotti, Laurent; Smith, Jennifer R

    2010-08-01

    Systematic survey by the Abydos Survey for Paleolithic Sites project has recorded Nubian Complex artifact density, distribution, typology, and technology across the high desert landscape west of the Nile Valley in Middle Egypt. Our work contrasts with previous investigations of Nubian Complex settlement systems in Egypt, which focused on a small number of sites in the terraces of the Nile Valley, the desert oases, and the Red Sea Mountains. Earlier research interpreted the Nubian Complex, in particular, as a radiating settlement system that incorporated a specialized point production. Our high desert data, however, indicate that the Nubian Complex associated with early modern humans in this region of the high desert reflects a circulating, rather than a radiating, settlement system, and that point production has been over-emphasized. Data available from our work, as well as sites investigated by others, do not conclusively identify Nubian Complex behavioral strategies as modern. These data, however, do contribute to the understanding of landscape use by early modern human populations living along the Nile Valley Corridor route out of Africa.

  15. Modern Egypt: A Development Perspective.

    ERIC Educational Resources Information Center

    Scott, Rosalind; And Others

    Egypt is a culture which combines the traditional with the modern. This text aims to foster an appreciation of Egypt as a changing culture facing the challenges of development. Topics included are: (1) Village Life; (2) Urban Life; (3) Nile; (4) Government; (5) Agriculture; (6) Economy; (7) Health/Games; (8) Education; (9) Religion; (10)…

  16. Hydrogeochemical analysis and evaluation of groundwater in the reclaimed small basin of Abu Mina, Egypt

    NASA Astrophysics Data System (ADS)

    Salem, Zenhom E.; Atwia, Mohamed G.; El-Horiny, Mohamed M.

    2015-12-01

    Agricultural reclamation activities during the last few decades in the Western Nile Delta have led to great changes in the groundwater levels and quality. In Egypt, changing the desert land into agricultural land has been done using transferred Nile water (through irrigation canal systems) or/and groundwater. This research investigates the hydrogeochemical changes accompanying the reclamation processes in the small basin of Abu Mina, which is part of the Western Nile Delta region. In summer 2008, 23 groundwater samples were collected and groundwater levels were measured in 40 observation wells. Comparing the groundwater data of the pre-reclamation (1974) and the post-reclamation (2008) periods, groundwater seems to have been subjected to many changes: rise in water level, modification of the flow system, improvement of water quality, and addition of new salts through dissolution processes. Generally, Abu Mina basin is subdivided into two areas, recharge and discharge. The dissolution and mixing were recognized in the recharge areas, while the groundwater of the discharge region carries the signature of the diluted pre-reclamation groundwater. The salts of soil and aquifer deposits play an important role in the salt content of the post and pre-reclamation groundwater. NaCl was the predominant water type in the pre-reclamation groundwater, while CaSO4, NaCl and MgSO4 are the common chemical facies in the post-reclamation groundwater. The post-reclamation groundwater mostly indicates mixing between the pre-reclamation groundwater and the infiltrated freshwater with addition of some ions due to interaction with soil and sediments.

  17. New paleocene sepiid coleoids (cephalopoda) from Egypt: evolutionary significance and origin of the sepiid 'rostrum'.

    PubMed

    Košťák, Martin; Jagt, John W M; Speijer, Robert P; Stassen, Peter; Steurbaut, Etienne

    2013-01-01

    New coleoid cephalopods, assignable to the order Sepiida, are recorded from the Selandian/Thanetian boundary interval (Middle to Upper Paleocene transition, c. 59.2 Ma) along the southeastern margin (Toshka Lakes) of the Western Desert in Egypt. The two genera recognised, Aegyptosaepia n. gen. and ?Anomalosaepia Weaver and Ciampaglio, are placed in the families Belosaepiidae and ?Anomalosaepiidae, respectively. They constitute the oldest record to date of sepiids with a 'rostrum-like' prong. In addition, a third, generically and specifically indeterminate coleoid is represented by a single rostrum-like find. The taxonomic assignment of the material is based on apical parts (as preserved), i.e., guard, apical prong (or 'rostrum-like' structure), phragmocone and (remains of) protoconch, plus shell mineralogy. We here confirm the shell of early sepiids to have been bimineralic, i.e., composed of both calcite and aragonite. Aegyptosaepia lugeri n. gen., n. sp. reveals some similarities to later species of Belosaepia, in particular the possession of a distinct prong. General features of the phragmocone and protoconch of the new form are similar to both Belocurta (Middle Danian [Lower Paleocene]) and Belosaepia (Eocene). However, breviconic coiling and the presence of a longer ventral conotheca indicate closer ties with late Maastrichtian-Middle Danian Ceratisepia. In this respect, Aegyptosaepia n. gen. constitutes a link between Ceratisepia and the Eocene Belosaepia. The occurrence of the new genus near the Selandian/Thanetian boundary suggests an earlier origin of belosaepiids, during the early to Middle Paleocene. These earliest known belosaepiids may have originated in the Tethyan Realm. From northeast Africa, they subsequently spread to western India, the Arabian Plate and, probably via the Mediterranean region, to Europe and North America.

  18. Anthropogenic wetlands due to over-irrigation of desert areas; A challenging hydrogeological investigation with extensive geophysical input

    NASA Astrophysics Data System (ADS)

    Behroozmand, A. A.; Teatini, P.; Pedersen, J. B. B.; Auken, E.; Tosatto, O.; Christiansen, A. V.

    2015-12-01

    During the last century, many large irrigation projects have been initiated in arid lands worldwide. Despite a tremendous increase in food production, a common problem when characterizing these zones is land degradation in form of waterlogging. As results, large volumes of water are lost due to surplus irrigation in regions where water availability is extremely challenging for both population survival and economic development. The Nubariya depression, Western Desert (Egypt), is a clear example of this mechanism. Following the reclamation of desert lands for agricultural production, an artificial brackish and contaminated lake developed in the area in the late 1990s and presently extends for about 2.5 km2. Available data provide evidence of a simultaneous general deterioration of the groundwater system. With the main objectives of understanding the hydrological evolution of the area, characterizing the hydrogeological setting and developing scenarios for artificial aquifer remediation and recharge, an extensive hydrogeophysical investigation was carried out in this challenging environment using Magnetic Resonance Sounding (MRS, also called surface NMR) and ground-based Transient EM (TEM). The integrated interpretation of the geophysical surveys, properly calibrated with a number of boreholes, provides a clear hydrogeological picture of the upper 100 m sedimentary structure, in terms of both lithology and groundwater quality. The information is then used to set up a regional groundwater flow and a local density-dependent flow and transport numerical model to reproduce the past evolution of the aquifer system and develop a few scenarios for artificial aquifer recharge using the treated waters provided by a nearby waste-water treatment plant. The research outcomes point the hydrological challenges that emerge for an effective management of water resources in reclaimed desert areas and highlight the effectiveness of integrating advanced geophysical and modeling

  19. Organ transplantation in Egypt.

    PubMed

    Paris, Wayne; Nour, Bakr

    2010-09-01

    Concern has increasingly been expressed about the growing number of reports of medical personnel participating in the transplantation of human organs or tissues taken from the bodies of executed prisoners, handicapped patients, or poor persons who have agreed to part with their organs for commercial purposes. Such behavior has been universally considered as ethically and morally reprehensible, yet in some parts of the world the practice continues to flourish. The concept of justice demands that every person have an equal right to life, and to protect this right, society has an obligation to ensure that every person has equal access to medical care. Regrettably, the Egyptian system does not legally recognize brain death and continues to allow the buying and selling of organs. For more than 30 years in Egypt, the ability to pay has determined who receives an organ and economic need has determined who will be the donor. As transplant professionals, it is important that we advocate on behalf of all patients, potential recipients, and donors and for those who are left out and not likely to receive a donor organ in an economically based system. Current issues associated with this debate are reviewed and recommendations about how to address them in Egypt are discussed.

  20. The schistosomiasis problem in Egypt.

    PubMed

    Mobarak, A B

    1982-01-01

    This report provides an overview of past and current efforts to control schistosomiasis in Egypt, describes recent trends, and analyzes factors responsible for changes in transmission. For the purpose of long-term planning and developing control strategies, the country has been divided into eight geographic zones: Suez Canal Zone, Sainai, Nile Delta, Guiza, Fayoum, Middle Egypt, Upper Egypt, and the High Dam Lake Zone. Overall control priorities are examined and the strategy for each zone is described. The most recent information on changes in epidemiologic patterns of schistosomiasis in Egypt is mentioned, as well as the introduction of newer therapeutic agents. Lastly, the role of outside funding agencies in supporting schistosomiasis control is examined.

  1. Transport of dust and anthropogenic aerosols across Alexandria, Egypt

    NASA Astrophysics Data System (ADS)

    El-Askary, H.; Farouk, R.; Ichoku, C.; Kafatos, M.

    2009-07-01

    The flow of pollutants from Europe and desert dust to Europe from the Sahara desert both affects the air quality of the coastal regions of Egypt. As such, measurements from both ground and satellite observations assume great importance to ascertain the conditions and flow affecting the Nile Delta and the large city of Alexandria. We note that special weather conditions prevailing in the Mediterranean Sea result in a westerly wind flow pattern during spring and from North to South during the summer. Such flow patterns transport dust-loaded and polluted air masses from the Sahara desert and Europe, respectively, through Alexandria, and the Nile Delta in Egypt. We have carried out measurements acquired with a ground- based portable sun photometer (Microtops II) and the satellite-borne TERRA/Moderate Resolution Imaging Spectroradiometer (MODIS) sensor during the periods of October 1999-August 2001 and July 2002-September 2003. These measurements show a seasonal variability in aerosol optical depth (AOD) following these flow patterns. Maximum aerosol loadings accompanied by total precipitable water vapor (W) enhancements are observed during the spring and summer seasons. Pronounced changes have been observed in the Ångström exponent (α) derived from ground-based measurements over Alexandria (31.14° N, 29.59° E) during both dust and pollution periods. We have followed up the observations with a 3-day back-trajectories model to trace the probable sources and pathways of the air masses causing the observed aerosol loadings. We have also used other NASA model outputs to estimate the sea salt, dust, sulfates and black carbon AOD spatial distributions during different seasons. Our results reveal the probable source regions of these aerosol types, showing agreement with the trajectory and Ångström exponent analysis results. It is confirmed that Alexandria is subjected to different atmospheric conditions involving dust, pollution, mixed aerosols and clean sky.

  2. Mesozoic carbonate-siliciclastic platform to basin systems of a South Tethyan margin (Egypt, East Mediterranean)

    NASA Astrophysics Data System (ADS)

    Tassy, Aurélie; Crouzy, Emmanuel; Gorini, Christian; Rubino, Jean-Loup

    2015-04-01

    The Mesozoïc Egyptian margin is the south margin of a remnant of the Neo-Tethys Ocean, at the African northern plate boundary. East Mediterranean basin developed during the late Triassic-Early Jurassic rifting with a NW-SE opening direction (Frizon de Lamotte et al., 2011). During Mesozoïc, Egypt margin was a transform margin with a NW-SE orientation of transform faults. In the Eastern Mediterranean basin, Mesozoïc margins are characterized by mixed carbonate-siliciclastics platforms where subsidence and eustacy are the main parameters controlling the facies distribution and geometries of the platform-to-basin transition. Geometries and facies on the platform-slope-basin system, today well constrained on the Levant area, where still poorly known on the Egyptian margin. Geometries and stratigraphic architecture of the Egyptian margin are revealed, thanks to a regional seismic and well data-base provided by an industrial-academic group (GRI, Total). The objective is to understand the sismostratigraphic architecture of the platform-slope-basin system in a key area from Western Desert to Nile delta and Levant margin. Mapping of the top Jurassic and top Cretaceous show seismic geomorphology of the margin, with the cartography of the hinge line from Western Desert to Sinaï. During the Jurassic, carbonate platform show a prograding profile and a distally thickening of the external platform, non-abrupt slope profiles, and palaeovalleys incisions. Since the Cretaceous, the aggrading and retrograding mixed carbonate-siliciclastic platform show an alternation of steep NW-SE oblique segments and distally steepened segments. These structures of the platform edge are strongly controlled by the inherited tethyan transform directions. Along the hinge line, embayments are interpreted as megaslides. The basin infilling is characterised by an alternation of chaotic seismic facies and high amplitude reflectors onlaping the paleoslopes. MTC deposits can mobilize thick sedimentary

  3. [The wild boar of Egypt].

    PubMed

    Manlius, N; Gautier, A

    1999-07-01

    The wild boar, Sus scrofa, is not a typical member of the Egyptian wild fauna, although it appears to have lived in the Nile Delta and other suitable regions in the north of the country. However, historic populations were probably of mixed origin, including feral domestic pigs. It is incorrect, as is sometimes still done, to include the wild boar in the iconographic bestiary of Ancient Egypt and assume that the domestic pigs of Ancient Egypt derive from local wild boars.

  4. Calcareous benthonic foraminifera across the Cretaceous/Paleocene transition of Gebel Um El-Ghanayem, Kharga Oasis, Egypt

    NASA Astrophysics Data System (ADS)

    Orabi, Orabi H.; Khalil, Hamza M.

    2014-08-01

    The studies of benthic calcareous foraminifera of the Maastrichtian-early Paleocene Dakhla Formation in Gebel Um El-Ghanayem (Western Desert, Egypt), improve reconstruction of depositional environments of these successions. In total, 68 taxa of benthic foraminifera were identified in the studied succession. The late Maastrichtian assemblages (Zone CF3) are dominated by calcareous foraminifera with tapered tests, this tapered taxon Loxostomum applinae, Lox. tegulatum various dentalinid taxa, and Buliminella cushmani dominate in CF3 Biozone. We thus interpret these faunas as being dominated by infaunal morphogroups, suggesting a moderately eutrophic environment. Danian assemblages are characterized by abundant epifaunal trochospiral species, such as Cibicidoides abudurbensis, Cibicidoides farafraensis, and Gyroidinoides girardanus. The infaunal morphogroups make up 25-47% of fauna in the Danian, in contrast to 62-76% in the Upper Maastrichtian. This dominance of the Danian benthic foraminiferal assemblages by epifaunal or mixed epifaunal/infaunal morphogroups suggests that the food supply to the benthos was less abundant than in the latest Cretaceous. The Cretaceous/Paleocene boundary (K/Pg) is within the upper unit of the Lower Kharga Member and marked by a hiatus in at least the top of CF3 Zone of the Upper Maastrichtian to the Lower Paleocene (base Plc Zone).

  5. Depositional environments and sequence architecture of the Raha and Abu Qada formations (Cenomanian-Turonian), west central Sinai, Egypt

    NASA Astrophysics Data System (ADS)

    Anan, Tarek I.; El-Shahat, Adam; Genedi, Adel; Grammer, Michael

    2013-06-01

    Cenomanian-Turonian deposits are important reservoirs for many oil fields in the Western Desert and the Gulf of Suez region of Egypt. Study of the Raha and Abu Qada formations (Cenomanian-Turonian), from five dip-oriented outcrop locations in west central Sinai; indicates deposition of a mixed siliciclastic-carbonate system on a ramp setting. The inner ramp facies (bivalve and benthonic foraminiferal wackestone) grades northward to the mid ramp facies (echinoderm calcisphere packstone, and oyster floatstone), and outer ramp facies (planktonic foraminiferal wackestone and calcisphere wackestone). The two studied formations comprise one second-order depositional sequence (duration of approximately 10 Million years). This large scale sequence includes four third-order depositional sequences, three of which are observed in the Raha Formation, with the other one recorded in the Abu Qada Formation. Because west central Sinai was tectonically stable during the Cenomanian and Turonian, the main factor controlling the lateral and vertical distribution of facies tracts is likely due to changes in the relative sea level. The Cenomanian-Turonian boundary event is known as the largest oceanic anoxic event during the Cretaceous. This global event has been documented in three of the studied sections. The recorded δ13C excursions range from +3.04‰ to +5.24‰. These high positive excursions in δ13C are associated with highly negative values of δ18O (values range from -6.01‰ to -1.38‰).

  6. New insights into microbially induced sedimentary structures in alkaline hypersaline El Beida Lake, Wadi El Natrun, Egypt

    NASA Astrophysics Data System (ADS)

    Taher, Amany G.; Abdel-Motelib, Ali

    2015-10-01

    Microbially induced sedimentary structures (MISS) were studied in detail in the alkaline hypersaline El Beida Lake of Wadi El Natrun in the western desert sector of Egypt, based on field observations and sampling performed in 2013 and 2014. Geomorphologically, the lake can be subdivided into three zones, each with characteristic sedimentary and biosedimentary structures. The marginal elevated zone that borders the lake is characterized by thick blocky crusts devoid of microbial mats. The middle-lower supratidal zone has luxuriant microbial mats associated with knotty surfaces, mat cracks and wrinkle structures. A zone of ephemeral shallow pools and channels is characterized by reticulate surfaces, pinnacle mats, sieve-like surfaces, gas domes and mat chips. In the microbial mats, authigenic minerals include thenardite Na2SO4, trona Na3(CO3)(HCO3)•2H2O and halite NaCl. Scanning electron microscopy (SEM) analyses revealed that the minerals are closely associated with the MISS, suggesting some influence of microorganisms on mineral precipitation. Complex interactions between regional hydrological cycles and diagenetic processes imply low preservation potential. MISS signatures of such saline lakes can serve as key analogues for interpreting the geologic record.

  7. New Lakes in the Egyptian Desert

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Four lakes formed recently in southern Egypt in an area that was previously desert. Fed by unusually high levels of rainfall and water overflowing from the Aswan High Dam on the Nile River, the first lake appeared in 1998. The Aswan's overflowing waters are channeled through an arroyo into a reservoir, as expected, but as the high rains have continued, so has the overflow. Consequently, the reservoir has grown in size and three more lakes have formed. Authorities in Egypt estimate that, together, the lakes now hold about 700 billion cubic feet of water--one quarter the Nile's total water supply. Scientist don't know whether or not the lakes will remain, or will dry up within a few years. In this true-color image acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS), on October 10, 2000, the lakes are the areas of dark pixels located about 50 km west of Lake Nasser. Image by Robert Simmon Reto Stockli, and Brian Montgomery, NASA GSFC

  8. Reclaiming freshwater sustainability in the Cadillac Desert

    USGS Publications Warehouse

    Sabo, John L.; Sinha, Tushar; Bowling, Laura C.; Schoups, Gerrit H.W.; Wallender, Wesley W.; Campana, Michael E.; Cherkauer, Keith A.; Fuller, Pam L.; Graf, William L.; Hopmans, Jan W.; Kominoski, John S.; Taylor, Carissa; Trimble, Stanley W.; Webb, Robert H.; Wohl, Ellen E.

    2010-01-01

    Increasing human appropriation of freshwater resources presents a tangible limit to the sustainability of cities, agriculture, and ecosystems in the western United States. Marc Reisner tackles this theme in his 1986 classic Cadillac Desert: The American West and Its Disappearing Water. Reisner's analysis paints a portrait of region-wide hydrologic dysfunction in the western United States, suggesting that the storage capacity of reservoirs will be impaired by sediment infilling, croplands will be rendered infertile by salt, and water scarcity will pit growing desert cities against agribusiness in the face of dwindling water resources. Here we evaluate these claims using the best available data and scientific tools. Our analysis provides strong scientific support for many of Reisner's claims, except the notion that reservoir storage is imminently threatened by sediment. More broadly, we estimate that the equivalent of nearly 76% of streamflow in the Cadillac Desert region is currently appropriated by humans, and this figure could rise to nearly 86% under a doubling of the region's population. Thus, Reisner's incisive journalism led him to the same conclusions as those rendered by copious data, modern scientific tools, and the application of a more genuine scientific method. We close with a prospectus for reclaiming freshwater sustainability in the Cadillac Desert, including a suite of recommendations for reducing region-wide human appropriation of streamflow to a target level of 60%.

  9. Reclaiming freshwater sustainability in the Cadillac Desert

    PubMed Central

    Sabo, John L.; Sinha, Tushar; Bowling, Laura C.; Schoups, Gerrit H. W.; Wallender, Wesley W.; Campana, Michael E.; Cherkauer, Keith A.; Fuller, Pam L.; Graf, William L.; Hopmans, Jan W.; Kominoski, John S.; Taylor, Carissa; Trimble, Stanley W.; Webb, Robert H.; Wohl, Ellen E.

    2010-01-01

    Increasing human appropriation of freshwater resources presents a tangible limit to the sustainability of cities, agriculture, and ecosystems in the western United States. Marc Reisner tackles this theme in his 1986 classic Cadillac Desert: The American West and Its Disappearing Water. Reisner's analysis paints a portrait of region-wide hydrologic dysfunction in the western United States, suggesting that the storage capacity of reservoirs will be impaired by sediment infilling, croplands will be rendered infertile by salt, and water scarcity will pit growing desert cities against agribusiness in the face of dwindling water resources. Here we evaluate these claims using the best available data and scientific tools. Our analysis provides strong scientific support for many of Reisner's claims, except the notion that reservoir storage is imminently threatened by sediment. More broadly, we estimate that the equivalent of nearly 76% of streamflow in the Cadillac Desert region is currently appropriated by humans, and this figure could rise to nearly 86% under a doubling of the region's population. Thus, Reisner's incisive journalism led him to the same conclusions as those rendered by copious data, modern scientific tools, and the application of a more genuine scientific method. We close with a prospectus for reclaiming freshwater sustainability in the Cadillac Desert, including a suite of recommendations for reducing region-wide human appropriation of streamflow to a target level of 60%. PMID:21149727

  10. Mapping perennial vegetation cover in the Mojave Desert

    USGS Publications Warehouse

    Wallace, Cynthia S.A.

    2011-01-01

    Scientists with the U.S. Geological Survey's Western Geographic Science Center have recently created a regional map of perennial vegetation cover for the Mojave Desert. The scientists used existing field data collected for a variety of previous studies and satellite data available for free through USGS archives to create a calibrated model of percent vegetation cover, an important attribute of desert ecosystems. This map is being used to inform ongoing scientific investigations and land-management efforts, including endangered species habitat mapping and vulnerability and recoverability studies of desert landscapes in the arid Southwest.

  11. The Nile floodplain, hydroclimatic variability, and its relation with cultural dynamics in ancient Thebes (Luxor, Egypt)

    NASA Astrophysics Data System (ADS)

    Toonen, Willem H. J.; Graham, Angus; Pennington, Ben; Hunter, Morag; Strutt, Kris; Barker, Dominic; Masson, Aurelia; Emery, Virginia

    2016-04-01

    The western bank of the river Nile in the Luxor region (Egypt) separates New Kingdom divine temple complexes in the central axis of the river valley from contemporaneous sites on the desert edge and limestone plateau. The intermediate Nile floodplain features relatively few known archaeological sites, but played an important role in the ancient ritual landscape by connecting the focal region of the living (floodplain) with that of the dead (desert). All Royal Funerary Temple Complexes of the New Kingdom period (1539-1077 BCE), which played a central role in the cosmogonical landscape, are positioned within a confined 3.5 km long strip of land on the western edge of the present floodplain. This preferential location, together with contemporary textual sources and tomb scenes suggesting the nearby presence of canals, have led to the hypothesis that natural and human-made waterways may have once connected the main channel of the Nile with the desert edge. Until the present research took place, no detailed study of pre-existing channel networks existed in the region, leaving a gap in current knowledge on the configuration and use of the ancient floodplain. This study presents the results of a multi-disciplinary study aimed at mapping and dating ancient waterways in the Theban region and aims to find evidence for the natural or human origin of such channels. Boreholes and Electric Resistivity Tomography (ERT) were carried out along a transect that connects the edge of the Holocene floodplain with the current position of the river Nile. Satellite imagery and textual sources were also used to augment the fieldwork. The data indicate the presence of an infilled abandoned channel of the Nile in the western distal part of the current floodplain, adjoining the Funerary Temple complexes. Over 2100 ceramic fragments were analysed from the sedimentary infilling of the silted-up river course, dating it to the end of the New Kingdom, and indicating that the channel and temples

  12. Negev: Land, Water, and Life in a Desert Environment

    NASA Astrophysics Data System (ADS)

    Back, William

    In view of the continuing increased concern about the extreme fragility of deserts and desert margins, Negev provides a timely discussion of land-use practices compatible with the often conflicting goals of preservation and development. The success o f agricultural and hydrologic experiments in the Negev desert of Israel offers hope to the large percentage of the world's population that lives with an unacceptably low quality of life in desert margins. Deserts are the one remaining type of open space that, with proper use, has the potential for alleviating the misery often associated with expanding population.In addition to the science in the book, the author repeatedly reinforces the concept that “western civilization is inextricably bound to the Negev and its environs, from which it has drawn, via its desert-born religions—Judasium, Christianity, and Islam—many of the mores and concepts, and much of the imagery and love of the desert, including man's relation to nature and to ‘God’.” Deserts often are erroneously perceived to be areas of no water: In reality, these are areas in which a little rainfall occurs sporadically and unpredictably over time. This meager water supply can be meticulously garnered to produce nutritious crops and forage.

  13. Operational Aspects of Desert Shield and Desert Storm

    DTIC Science & Technology

    1992-03-12

    Battalion (MIB), 3d Armored Division leading up to and during Desert Shield and Desert Storm. This paper represents the personal assessment of the author...DESERT SHIELD A$DDESERT STORM ...J BY Lieutenant Colonel Henry C. Shirah United States Army DISTRIBUTION STATEMENT A: Approved for public release...Classification) OPERATIONAL ASPECTS OF DESERT SHIELD AND DESERT STORM 12. PERSONAL AUTHOR(S) 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (Year

  14. Deserts : geology and resources

    USGS Publications Warehouse

    Walker, Alta S.

    1996-01-01

    Approximately one-third of the Earth's land surface is desert, arid land with meager rainfall that supports only sparse vegetation and a limited population of people and animals. Deserts stark, sometimes mysterious worlds have been portrayed as fascinating environments of adventure and exploration from narratives such as that of Lawrence of Arabia to movies such as "Dune." These arid regions are called deserts because they are dry. They may be hot, they may be cold. They may be regions of sand or vast areas of rocks and gravel peppered with occasional plants. But deserts are always dry. Deserts are natural laboratories in which to study the interactions of wind and sometimes water on the arid surfaces of planets. They contain valuable mineral deposits that were formed in the arid environment or that were exposed by erosion. Because deserts are dry, they are ideal places for human artifacts and fossils to be preserved. Deserts are also fragile environments. The misuse of these lands is a serious and growing problem in parts of our world.

  15. Infectious diseases in ancient Egypt.

    PubMed

    Brier, Bob

    2004-03-01

    Techniques for studying infectious disease in the ancient world are discussed. A brief survey of infectious diseases, such as schistosomiasis and malaria, in ancient Egypt is presented, and the physical traces of these diseases are examined. A discussion of the ancient Egyptian physician's response to infectious disease is included. There are two substantial sources of evidence for infectious diseases-physical remains and descriptions in Egyptian medical papyri. This preliminary survey suggests that ancient Egypt was far from the idyllic paradise on the Nile that some historians would like to imagine.

  16. Cryptogenic Tuberculosis - 1990 Cairo - Egypt

    DTIC Science & Technology

    1993-01-01

    AD-A269 664 i l•l lI ,iI I i h4Ji PUBLICATION REPORT 1753 SEP TE5195, 31/93EYP CRYPTOGENIC TUBERCULOSIS - 1990 CAIRO - EGYPT BY Z. Farid, M.E...FUNDING NUMBERS Cryptogenic Tuberculosis - 1990 Cairo - Egypt PE- 61102A WU- 3M161102BS13.AK.311 6. AUTHORjS) Farid, Z., Kilpatrick, M.E. and Kamal...is unlimited. 13- A8B TRACT %’ 4 , n ;.’ Please see attached. DTIC 7T-3 t A 2-d~~t (r’ oa Dist__ _._ .S pecial. Cryptogenic tuberculosis ; Prolonged

  17. Anthropogenic wetlands due to over-irrigation of desert areas: a challenging hydrogeological investigation with extensive geophysical input from TEM and MRS measurements

    NASA Astrophysics Data System (ADS)

    Behroozmand, Ahmad Ali; Teatini, Pietro; Bjergsted Pedersen, Jesper; Auken, Esben; Tosatto, Omar; Vest Christiansen, Anders

    2017-03-01

    During the last century, many large irrigation projects were carried out in arid lands worldwide. Despite a tremendous increase in food production, a common problem when characterizing these zones is land degradation in the form of waterlogging. A clear example of this phenomenon is in the Nubariya depression in the Western Desert of Egypt. Following the reclamation of desert lands for agricultural production, an artificial brackish and contaminated pond started to develop in the late 1990s, which at present extends for about 2.5 km2. The available data provide evidence of a simultaneous general deterioration of the groundwater system. An extensive hydrogeophysical investigation was carried out in this challenging environment using magnetic resonance sounding (MRS) and ground-based time-domain electromagnetic (TEM) techniques with the following main objectives: (1) understanding the hydrological evolution of the area; (2) characterizing the hydrogeological setting; and (3) developing scenarios for artificial aquifer remediation and recharge. The integrated interpretation of the geophysical surveys provided a hydrogeological picture of the upper 100 m sedimentary setting in terms of both lithological distribution and groundwater quality. The information is then used to set up (1) a regional groundwater flow and (2) a local density-dependent flow and transport numerical model to reproduce the evolution of the aquifer system and develop a few scenarios for artificial aquifer recharge using the treated water provided by a nearby wastewater treatment plant. The research outcomes point to the hydrological challenges that emerge for the effective management of water resources in reclaimed desert areas, and they highlight the effectiveness of using advanced geophysical and modeling methodologies.

  18. The use of multifrequency and polarimetric SIR-C/X-SAR data in geologic studies of Bir Safsaf, Egypt

    USGS Publications Warehouse

    Schaber, G.G.; McCauley, J.F.; Breed, C.S.

    1997-01-01

    Bir Safsaf, within the hyperarid 'core' of the Sahara in the Western Desert of Egypt, was recognized following the SIR-A and SIR-B missions in the 1980s as one of the key localities in northeast Africa, where penetration of dry sand by radar signals delineates previously unknown, sand-buried paleodrainage valleys ('radar-rivers') of middle Tertiary to Quaternary age. The Bir Safsaf area was targeted as a focal point for further research in sand penetration and geologic mapping using the multifrequency and polarimetric SIR-C/X-SAR sensors. Analysis of the SIR-C/X-SAR data from Bir Safsaf provides important new information on the roles of multiple SAR frequency and polarimetry in portraying specific types of geologic units, materials, and structures mostly hidden from view on the ground and on Landsat TM images by a relatively thin, but extensive blanket of blow sand. Basement rock units (granitoids and gneisses) and the fractures associated with them at Bir Safsaf are shown here for the first time to be clearly delineated using C- and L-band SAR images. The detectability of most geologic features is dependent primarily on radar frequency, as shown for wind erosion patterns in bedrock at X-band (3 cm wavelength), and for geologic units and sand and clay-filled fractures in weathered crystal-line basement rocks at C-band (6 cm) and L-band (24 cm). By contrast, Quaternary paleodrainage channels are detectable at all three radar frequencies owing, among other things, to an usually thin cover of blow sand. The SIR-C/X-SAR data investigated to date enable us to make specific recommendations about the utility of certain radar sensor configurations for geologic and paleoenvironmental reconnaissance in desert regions.Analysis of the shuttle imaging radar-C/X-synthetic aperture radar (SIR-C/X-SAR) data from Bir Safsaf provides important new information on the roles of multiple SAR frequency and polarimetry in portraying specific types of geologic units, materials, and

  19. Impact of highway geometry and posted speed on operating speed at multi-lane highways in Egypt.

    PubMed

    Semeida, Ahmed M

    2013-11-01

    The paper presents an analysis of roadway factors and posted speed limits that affect the operating speed at multi-lane highways in Egypt. Field data on multi-lane highways in Egypt are used in this investigation. The analysis considers two categories of highways. The first consists of two desert roads (Cairo-Alexandria and Cairo-Ismailia desert roads) and the second consists of two agricultural roads (Cairo-Alexandria and Tanta-Damietta agricultural roads). The paper includes three separate relevant analyses. The first analysis uses the regression models to investigate the relationships between operating speed (V 85) as dependent variable, and roadway factors and posted speed as independent variables. The road factors are lane width, shoulder width, pavement width, median width, number of lanes in each direction, and existence of side access along each section. The second analysis uses the Artificial Neural Network (ANN) to explore the previous relationships while the third one examines the suitability of the posted speed limits on the roads under study. It is found that the ANN modeling gives the best model for predicting the operating speed and the most influential variables on V 85 are the pavement width, followed by the median width and the existence of side access along section. It is also found that the posted speed limit has a very small effect on the operating speed due to the bad behavior of drivers in Egypt. These results are so important for controlling V 85 on multi-lane rural highways in Egypt.

  20. Response to comment on "A reservoir of nitrate beneath desert soils"

    USGS Publications Warehouse

    Walvoord, Michelle A.; Phillips, Fred M.; Stonestrom, David A.; Evans, R. Dave; Hartsough, Peter C.; Newman, Brent D.; Striegl, Robert G.

    2004-01-01

    We appreciate the comment by Jackson et al. (1), which underscores two points made in our recent paper (2): (i) that desert subsoil nitrate (NO–3) inventories are spatially highly variable, and thereby warrant substantial measurement efforts to reduce uncertainty in global extrapolations, and (ii) that Chihuahuan Desert subsoil NO–3 inventories tend to be much smaller than inventories in other western U.S. deserts.

  1. Alexandria (Al Iskandariya), Egypt

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image of Alexandria was taken by astronauts on board the International Space Station in December 2000 using an Electronic Still Camera. A wider-angle view (STS088-739-90) taken from the Space Shuttle in December 1998 is available for context. Alexandria (Al Iskandariya) occupies a T-shaped peninsula and strip of land separating the Mediterranean from Lake Mariout. Originally the town was built upon a mole (stone breakwater) called Heptastadium, which joined the island of Pharos (see referenced website, below) to the mainland. Since then sedimentary deposits have widened the mole. Since 1905, when the 370,000 Alexandrians lived in an area of about 4 sq km between the two harbors, the city (population 4 million; see referenced website, below) has grown beyond its medieval walls and now occupies an area of about 300 sq km. The Mahmudiya Canal, connecting Alexandria with the Nile, runs to the south of the city and, by a series of locks, enters the harbor of the principal port of Egypt (note ships). The reddish and ochre polygons west of Lake Mariout are salt-evaporation, chemical-storage, and water-treatment ponds within the coastal lagoon. Reference Youssef Halim and Fatma Abou Shouk, 2000, Human impacts on Alexandria's marine environment: UNESCO, Coastal Regions and Small Islands Unit (CSI), Coastal Management Sourcebooks 2 (accessed December 20, 2000) Additional photographs taken by astronauts can be viewed at NASA-JSC's Gateway to Astronaut Photography of Earth. Image ISS001-ESC-5025 provided by the Earth Sciences and Image Analysis Laboratory, Johnson Space Center.

  2. New Paleocene Sepiid Coleoids (Cephalopoda) from Egypt: Evolutionary Significance and Origin of the Sepiid ‘Rostrum’

    PubMed Central

    Košťák, Martin; Jagt, John W. M.; Speijer, Robert P.; Stassen, Peter; Steurbaut, Etienne

    2013-01-01

    New coleoid cephalopods, assignable to the order Sepiida, are recorded from the Selandian/Thanetian boundary interval (Middle to Upper Paleocene transition, c. 59.2 Ma) along the southeastern margin (Toshka Lakes) of the Western Desert in Egypt. The two genera recognised, Aegyptosaepia n. gen. and ?Anomalosaepia Weaver and Ciampaglio, are placed in the families Belosaepiidae and ?Anomalosaepiidae, respectively. They constitute the oldest record to date of sepiids with a ‘rostrum-like’ prong. In addition, a third, generically and specifically indeterminate coleoid is represented by a single rostrum-like find. The taxonomic assignment of the material is based on apical parts (as preserved), i.e., guard, apical prong (or ‘rostrum-like’ structure), phragmocone and (remains of) protoconch, plus shell mineralogy. We here confirm the shell of early sepiids to have been bimineralic, i.e., composed of both calcite and aragonite. Aegyptosaepia lugeri n. gen., n. sp. reveals some similarities to later species of Belosaepia, in particular the possession of a distinct prong. General features of the phragmocone and protoconch of the new form are similar to both Belocurta (Middle Danian [Lower Paleocene]) and Belosaepia (Eocene). However, breviconic coiling and the presence of a longer ventral conotheca indicate closer ties with late Maastrichtian–Middle Danian Ceratisepia. In this respect, Aegyptosaepia n. gen. constitutes a link between Ceratisepia and the Eocene Belosaepia. The occurrence of the new genus near the Selandian/Thanetian boundary suggests an earlier origin of belosaepiids, during the early to Middle Paleocene. These earliest known belosaepiids may have originated in the Tethyan Realm. From northeast Africa, they subsequently spread to western India, the Arabian Plate and, probably via the Mediterranean region, to Europe and North America. PMID:24348918

  3. Eyewitness introduction to Egypt: "The gift of the Nile".

    PubMed

    Brown, Geraldine

    2009-01-01

    Northeastern corner of Africa, lying at the crossroads between the two continents of Europe and Asia (in the Sinai Peninsula), while bordering Libya, Sudan, Israel and the Red Sea. Egypt is the most ancient tourist country in the world. Several health fact-finding missions in the last few years were made to this small country that is frequently defined by the Valley of the Nile. With the spreading deserts on either side, or a very rich heritage of ancient relics, these scenic vistas are without equal elsewhere in the world. Although there are significant cultural differences among the population, Egypt has a long history of ethnic and religious compassion. Among the many rarities, main tourist attractions include the three great Pyramids of Giza and the Sphinx, amazing ancient wonders of the world. These fact-finding missions included how health and medical care are defined, how people and culture are intertwined with its physical features, land use, and the economy and its resources.

  4. Schistosomiasis and cancer in egypt: review.

    PubMed

    Khaled, Hussein

    2013-09-01

    Schistosomiasis is not known to be associated with any malignant disease other than bladder cancer. Bladder cancer is still the most common malignant tumor among males in Egypt and some African and Middle East countries. However, the frequency rate of bladder cancer has declined significantly during the last 25 years. This drop is mainly related to the control of Schistosomiasis. Many studies have elucidated the pathogenic events of Schistosomal-related bladder cancer with a suggested theory of pathogenesis. Furthermore, the disease presents with a distinct clinicopathologic profile that is quite different from bladder cancer elsewhere with younger age at presentation, more male predominance, more invasive stages, and occurrence of squamous cell carcinoma pathologic subtype. However, recent data suggest that this profile has been dramatically changed over the past 25 years leading to minimization of the differences between its features in Egypt and that in Western countries. Management of muscle-invasive localized disease is mainly surgery with 5-year survival rates of 30-50%. Although still a debatable issue, adjuvant and neoadjuvant chemotherapy and radiotherapy have improved treatment outcomes including survival and bladder preservation rates in most studies. This controversy emphasizes the need of individualized treatment options based on a prognostic index or other factors that can define the higher risk groups where more aggressive therapy is needed. The treatment for locally advanced and/or metastatic disease has passed through a series of clinical trials since 1970s. These phase II and III trials have included the use of single agent and combination of chemotherapy and radiotherapy regimens. The current standard of systemic chemotherapy of generally fit patients is now the gemcitabine-cisplatin combination. In conclusion, a changing pattern of bladder cancer in Egypt is clearly observed. This is mainly due to the success in the control of Schistosomiasis

  5. What is Desert RATS?

    NASA Video Gallery

    The mission manager and test coordinators for the 2011 mission explain why Desert RATS was started 14 years ago, questions being studied in this year's activities, technologies being tested and the...

  6. Team Egypt! Integrating the Disciplines.

    ERIC Educational Resources Information Center

    Greenwald, Amanda Welsh

    2000-01-01

    Describes a unit on Egypt used in an interdisciplinary curriculum that involves activities in social studies, art, science, language (Latin), and computers. Explains that each discipline is assessed separately in order to reward students' strengths. Highlights the benefits of interdisciplinary curricula. (CMK)

  7. Skeletal dysplasia in ancient Egypt.

    PubMed

    Kozma, Chahira

    2008-12-01

    The ancient Egyptian civilization lasted for over 3000 years and ended in 30 BCE. Many aspects of ancient Egyptian culture, including the existence of skeletal dysplasias, and in particular achondroplasia, are well known through the monuments and records that survived until modern times. The hot and dry climate in Egypt allowed for the preservation of bodies and skeletal anomalies. The oldest dwarf skeleton, the Badarian skeleton (4500 BCE), possibly represents an epiphyseal disorder. Among the remains of dwarfs with achondroplasia from ancient Egypt (2686-2190 BCE), exists a skeleton of a pregnant female, believed to have died during delivery with a baby's remains in situ. British museums have partial skeletons of dwarfs with achondroplasia, humeri probably affected with mucopolysaccharidoses, and a skeleton of a child with osteogenesis imperfecta. Skeletal dysplasia is also found among royal remains. The mummy of the pharaoh Siptah (1342-1197 BCE) shows a deformity of the left leg and foot. A mummified fetus, believed to be the daughter of king Tutankhamun, has scoliosis, spina bifida, and Sprengel deformity. In 2006 I reviewed the previously existing knowledge of dwarfism in ancient Egypt. The purpose of this second historical review is to add to that knowledge with an expanded contribution. The artistic documentation of people with skeletal dysplasia from ancient Egypt is plentiful including hundreds of amulets, statues, and drawing on tomb and temple walls. Examination of artistic reliefs provides a glance of the role of people with skeletal dysplasia and the societal attitudes toward them. Both artistic evidence and moral teachings in ancient Egypt reveal wide integration of individuals with disabilities into the society.

  8. ASTER View of Sharm El Sheik, Egypt

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Red Sea golf resort in Sharm El Sheik, Egypt, where President Clinton met with Israeli Prime Minister Ehud Barak and Palestinian Authority President Yasser Arafat, stands out against the desert landscape in this image acquired on August 25, 2000.

    This image of the southern tip of the Sinai Peninsula shows an area about 30 by 40 kilometers (19 by 25 miles) in the visible and near infrared wavelength region. Vegetation appears in red. The blue areas in the water at the top and bottom of the image are coral reefs. The airport is visible just to the north of the golf resort.

    Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. Science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface.

    The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands Evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology

  9. Palynology and Stratigraphy of the Nubian Sandstone in Libya and Comparison with Egypt

    NASA Astrophysics Data System (ADS)

    Tekbali, Ali; Hlal, Osama

    2013-04-01

    The so-called "Nubian Sandstone" outcrops along a wide area from Algeria to the Red Sea, forming two regressive phases. The lower phase is represented in Egypt by the Basal Clastic Unit, the Desert Rose Unit, the Abu Ballas Formation and the Matruh Shale. In Libya it is represented by the Mesak Sandstone, Sarir Sandstone, Cabao Sandstone and Kiklah Formation. In both countries, these successions are covered by a carbonate sequence, resulting from the Tethyan transgression during the Cenomanian. In Egypt however, the upper regressive phase is represented by the Taref Sandstone which was deposited during a brief period of active progradation, following the Tethyan incursion. This is not observed in Libya. Comparison of palynological studies in Libya with those documented by several authors in Egypt reveals that the "Nubian" facies in Libya were deposited before equivalent facies in Egypt. The Basal Clastic Unit, dated as Hautrauvian-Barremian, may be equivalent, at least to a part of the Neocomian Cabao Sandstone in NW Libya. Jarmah Member of the Mesak Formation in Libya was dated as Berriasian on the basis of Pilosisporites and Trilobosporites. This makes it older than any "Nubian" unit in Egypt. The Matruh Shale was assigned to the Aptian on the basis of Tricolpites, and the Abu Balls Formation 34 as Aptian-Albian on the basis of Tricolpites and Rousisporites radiatus. Whereas, there is no equivalent to the Aptian in NW Libya, the Aptian-Albian of Egypt is similar to Zone 1 of the Kiklah Formation and As Sarir Sandstone, which were dated as early Albian on the basis of Afropollis spp., and Perotriletes pannuceus, an Albian element not recorded in Egypt. The Plant Beds in southwestern Egypt were dated as Cenomanian on the basis of advanced angiosperm pollen. In Libya, equivalent bodies were considered Vraconian, representing the uppermost Albian, because it lacks Cenomanian pollen (e.g. Tricolpites mutabilis). Comparison of local sea-level changes with global sea

  10. Egypt: Background and U.S. Relations

    DTIC Science & Technology

    2012-09-13

    visited Egypt, promising to “help Egypt deal with its economic challenges, including meeting immediate financial concerns, providing debt relief...MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT ...negotiating with Egypt the terms for obligating funds that have already been appropriated by Congress, such as up to $1 billion in bilateral debt

  11. DISTRIBUTIONAL CHANGES AND POPULATION STATUS FOR AMPHIBIANS IN THE EASTERN MOJAVE DESERT

    EPA Science Inventory

    A number of amphibian species historically inhabited sparsely distributed wetlands in the Mojave Desert of western North America, habitats that have been dramatically altered or eliminated as a result of human activities. The population status and distributional changes for amphi...

  12. Sonoran Desert: Fragile Land of Extremes

    USGS Publications Warehouse

    Produced and Directed by Wessells, Stephen

    2003-01-01

    'Sonoran Desert: Fragile Land of Extremes' shows how biologists with the U.S. Geological Survey work with other scientists in an effort to better understand native plants and animals such as desert tortoises, saguaro cacti, and Gila monsters. Much of the program was shot in and around Saguaro National Park near Tucson, Arizona. Genetic detective work, using DNA, focuses on understanding the lives of tortoises. Studies of saguaros over many decades clarify how these amazing plants reproduce and thrive in the desert. Threats from fire, diseases in tortoises, and a growing human population motivate the scientists. Their work to identify how these organisms live and survive is a crucial step for the sound management of biological resources on public lands. This 28-minute program, USGS Open-File Report 03-305, was shot entirely in high definition video and produced by the USGS Western Ecological Research Center and Southwest Biological Science Center; produced and directed by Stephen Wessells, Western Region Office of Communications.

  13. Range and habitats of the desert tortoise

    USGS Publications Warehouse

    Germano, D.J.; Bury, R.B.; Esque, T.C.; Fritts, T.H.; Bury, R.B.; Germano, D.J.

    1994-01-01

    We determined the current range of the desert tortoise (Gopherus agassizii) based on the available latest data from government agencies, the literature, and our experience. We developed the first detailed range map of this species and summarized information about habitat preferences. New records of occurrences were incorporated, and some peripheral localities of questionable authenticity were deleted. The distribution oCG. agassizii covers the broadest range of latitude, climatic regimes, habitats, and biotic regions of any North American tortoise. The northern portion ofits range is in the Mojave Desert of sDuth"eastern California, southern Nevada, southwestern Utah, and northwestern Arizona. The central portion of the range consists of several subdivisions of the Sonaran Desert in southeastern California, western and southern Arizona, and western Sonora, Mexico. The southern edge of its range is in the semitropical Sinaloan thornscrub and Sinaloan deciduous forest of eastern Sonora and northern Sinaloa, Mexico. This species has marked geogi-aphic differences but seems to construct burrows throughout its range.

  14. Regional geothermal exploration in Egypt

    NASA Technical Reports Server (NTRS)

    Morgan, P.; Boulos, F. K.; Swanberg, C. A.

    1983-01-01

    A study is presented of the evaluation of the potential geothermal resources of Egypt using a thermal gradient/heat flow technique and a groundwater temperature/chemistry technique. Existing oil well bottom-hole temperature data, as well as subsurface temperature measurements in existing boreholes, were employed for the thermal gradient/heat flow investigation before special thermal gradient holes were drilled. The geographic range of the direct subsurface thermal measurements was extended by employing groundwater temperature and chemistry data. Results show the presence of a regional thermal high along the eastern margin of Egypt with a local thermal anomaly in this zone. It is suggested that the sandstones of the Nubian Formation may be a suitable reservoir for geothermal fluids. These findings indicate that temperatures of 150 C or higher may be found in this reservoir in the Gulf of Suez and Red Sea coastal zones where it lies at a depth of 4 km and deeper.

  15. Desert Shield/Storm Logistics

    DTIC Science & Technology

    1993-04-15

    Wc This document may not be retee for open publiarion until it has bm deaed by the Vproprnite military service or gmeanen agency. DESERT SHIELD /STORM...capture what had occurred during Operations DESERT SHIELD and STORM, the commanders of the Division Support Command of the 24th Infantry Division...Mechanized) held a ful. day of discussion centering on what occurted during Operation DESERT STORM and its preceding operation, DESERT SHIELD . The entire

  16. Cataract surgery in ancient Egypt.

    PubMed

    Blomstedt, Patric

    2014-03-01

    Ophthalmology was one of the most important specialties in Egyptian medicine, and more specialists are known in this field than in any other. This specialization seems, however, to have been of a purely noninvasive nature. Even though it has been claimed that cataract surgery was performed in pharaonic Egypt, careful analysis of the sources does not support the claim. No example of cataract surgery or of any other invasive ophthalmologic procedure can be found in the original sources.

  17. Abdominal Tuberculosis in Cairo, Egypt

    DTIC Science & Technology

    1994-01-01

    COW 03 PUBLICATION REPORT 94-30227 * ABDOMINAL TUBERCULOSIS IN CAIRO, BY RWIavni 0. IHibbs6 M. Kuanmm ad Z. Fun .Y .~ ... W I Form ApprovedREPORT...Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED 8 April 1993 4. TITLE AND SUBTITLE S. FUNDING NUMBERS Abdominal Tuberculosis in Cairo...abdominal tuberculosis patients seen at Abbassia Fever Hospital in Cairo, Egypt from January 1990 to August 1992 are described; their mean age was 21.5

  18. Orthopedic surgery in ancient Egypt

    PubMed Central

    Blomstedt, Patric

    2014-01-01

    Background — Ancient Egypt might be considered the cradle of medicine. The modern literature is, however, sometimes rather too enthusiastic regarding the procedures that are attributed an Egyptian origin. I briefly present and analyze the claims regarding orthopedic surgery in Egypt, what was actually done by the Egyptians, and what may have been incorrectly ascribed to them. Methods — I reviewed the original sources and also the modern literature regarding surgery in ancient Egypt, concentrating especially on orthopedic surgery. Results — As is well known, both literary sources and the archaeological/osteological material bear witness to treatment of various fractures. The Egyptian painting, often claimed to depict the reduction of a dislocated shoulder according to Kocher’s method, is, however, open to interpretation. Therapeutic amputations are never depicted or mentioned in the literary sources, while the specimens suggested to demonstrate such amputations are not convincing. Interpretation — The ancient Egyptians certainly treated fractures of various kinds, and with varying degrees of success. Concerning the reductions of dislocated joints and therapeutic amputations, there is no clear evidence for the existence of such procedures. It would, however, be surprising if dislocations were not treated, even though they have not left traces in the surviving sources. Concerning amputations, the general level of Egyptian surgery makes it unlikely that limb amputations were done, even if they may possibly have been performed under extraordinary circumstances. PMID:25140982

  19. Astronomy Education Challenges in Egypt

    NASA Astrophysics Data System (ADS)

    El Fady Beshara Morcos, Abd

    2015-08-01

    One of the major challenges in Egypt is the quality of education. Egypt has made significant progress towards achieving the Education for All and the Millennium Development Goals (MDGs). Many associations and committees as education reform program and education support programs did high efforts in supporting scientific thinking through the scientific clubs. The current state of astronomical education in Egypt has been developed. Astronomy became a part in both science and geography courses of primary, preparatory and secondary stages. Nowadays the Egyptian National Committee for Astronomy, put on its shoulders the responsibility of revising of astronomy parts in the education courses, beside preparation of some training programs for teachers of different stages of educations, in collaboration with ministry of education. General lectures program has been prepared and started in public places , schools and universities. Many TV and Radio programs aiming to spread astronomical culture were presented. In the university stage new astronomy departments are established and astrophysics courses are imbedded in physics courses even in some private universities.

  20. Desert Shield and Desert Storm Emerging Observations

    DTIC Science & Technology

    1991-10-07

    becomes much more apparent over relatively flat terrain. d. Recommended or Ongoing Action. The M577 CPV is scheduled to yo through a system conversion to...STORM Vehicle exchange policy at maintenanfce points. 9? 40115 4f996 (0017?) DESERT STORM Fretracide, peor ommunication. poor flank ceerdihutien. 24...02413 fll% yo (00M) DEIil SIONM Distribut ion of Wcom arM Iaf amon units 4??44 INAI8 (002 n) TILSll STORM Pro-combat trainfig V4 14145 U’,411 (00276

  1. Lessons from the Desert

    DTIC Science & Technology

    1993-04-14

    involvement in Operations DESERT SHIELD and STORM. The 498th was a unique unit, well-suited for the gamut of operations conducted by the 2AD (FWD) during its...Division (Forward), during that unit’s involvement in Operations DESERT SHIELD and STORM. The 498th was a unique unit, well-suited for the gamut of...well-suited fir the gamut of operations conducted by 2AD (FWD) during its stay in Southwest Asia (SWA) . I commanded the 498th Support Battalion from

  2. Egypt: Beyond Pharaohs, Feluccas and Fellahin.

    ERIC Educational Resources Information Center

    Holt, Evelyn R.

    In a random study of five middle school social studies textbooks available for adoption in the state of Indiana in 1984, great variation in the treatment of Egypt was noted. Coverage of contemporary history was incomplete in all cases. All texts dealt with Egypt's ancient history, but what was reported was questionable. Only one text addressed in…

  3. Women--Sex Objects in Ancient Egypt.

    ERIC Educational Resources Information Center

    Mutimer, Brian T. P.

    Although it has been said that the women in Ancient Egypt enjoyed a reasonable state of social and professional equality with men, this paper presents an alternate theory--that women were second-class citizens whose physical prowess was secondary to their role as sex objects. It appears that men and women in Ancient Egypt often participated in the…

  4. Gender, Sibship Composition, and Education in Egypt

    ERIC Educational Resources Information Center

    Tfaily, Rania

    2016-01-01

    This article examines the relationship between gender, sibship, and education over time in Egypt, focusing on how the number, sex, and birth order configuration of siblings affected boys' and girls' education during 1991-2008, a period characterized by significant social and economic changes in Egypt. This study disaggregates schooling into…

  5. Inclusiveness in Higher Education in Egypt

    ERIC Educational Resources Information Center

    Cupito, Emily; Langsten, Ray

    2011-01-01

    In Egypt, before 1952, education, especially higher education, was the province of a privileged few. After the 1952 Revolution, in pursuit of social justice and economic development, Egypt's leaders eliminated fees, instituted a universal admission examination, promised government employment to all graduates of higher education, and expanded the…

  6. Egypt: Background and U.S. Relations

    DTIC Science & Technology

    2007-12-12

    smuggling of illegal workers, prostitutes, and even Palestinian brides for grooms inside Gaza. It is not uncommon for Palestinian smugglers to bribe security...Egypt in a difficult diplomatic position. On the one hand, Egypt has attempted to symbolically support international efforts to alleviate the

  7. Probabilistic earthquake hazard analysis for Cairo, Egypt

    NASA Astrophysics Data System (ADS)

    Badawy, Ahmed; Korrat, Ibrahim; El-Hadidy, Mahmoud; Gaber, Hanan

    2016-04-01

    Cairo is the capital of Egypt and the largest city in the Arab world and Africa, and the sixteenth largest metropolitan area in the world. It was founded in the tenth century (969 ad) and is 1046 years old. It has long been a center of the region's political and cultural life. Therefore, the earthquake risk assessment for Cairo has a great importance. The present work aims to analysis the earthquake hazard of Cairo as a key input's element for the risk assessment. The regional seismotectonics setting shows that Cairo could be affected by both far- and near-field seismic sources. The seismic hazard of Cairo has been estimated using the probabilistic seismic hazard approach. The logic tree frame work was used during the calculations. Epistemic uncertainties were considered into account by using alternative seismotectonics models and alternative ground motion prediction equations. Seismic hazard values have been estimated within a grid of 0.1° × 0.1 ° spacing for all of Cairo's districts at different spectral periods and four return periods (224, 615, 1230, and 4745 years). Moreover, the uniform hazard spectra have been calculated at the same return periods. The pattern of the contour maps show that the highest values of the peak ground acceleration is concentrated in the eastern zone's districts (e.g., El Nozha) and the lowest values at the northern and western zone's districts (e.g., El Sharabiya and El Khalifa).

  8. 75 FR 58353 - Business Development Mission to Egypt and Morocco

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-24

    ... International Trade Administration Business Development Mission to Egypt and Morocco Mission Description The U.S... Business Development Mission to explore ports and infrastructure development opportunities in Egypt (Cairo... Eastern and Southern European markets. Commercial Setting Egypt Egypt is strategically located at...

  9. Mojave Desert Diary

    ERIC Educational Resources Information Center

    Breed, Allen F.

    1974-01-01

    This is an account of a trip to the Mojave Desert sponsored by the California Youth Authority's Community Parole Center for wards who are selected on the basis of their potential for growth and their ability to make a connection between what they do in the wilderness and what they do on the streets. (PD)

  10. Geochronologic and isotopic evidence for involvement of pre-Pan-African crust in the Nubian shield, Egypt

    SciTech Connect

    Sultan, M.; Chamberlain, K.R.; Bowring, S.A.; Arvidson, R.E. ); Abuzied, H. ); El Kaliouby, B. )

    1990-08-01

    Two Late Proterozoic granitic bodies from the Eastern Desert of Egypt, the ca. 578 Ma Nakhil and the ca. 595 Ma Aswan granites, provide insights into processes of crust formation in the Arabian-Nubian shield. Evidence for involvement of an older crustal component in the formation of the Nakhil granite includes (1) U/Pb zircon data that establish a crystallization age of 578 {plus minus} 15 Ma and indicate the presence of inherited zircons possibly as old as 1.6 Ga; (2) an elevated model initial {sup 87}Sr/{sup 86}Sr (0.7136); and (3) an elevated initial {sup 207}Pb/{sup 204}Pb (15.561) relative to model mantle compositions at 578 Ma. Evidence for involvement of an older crustal component in the Aswan granite comes from the elevated initial {sup 207}Pb/{sup 204}Pb (15.611). In contrast, extensive crustal contamination is not reflected in the high initial {epsilon}{sub Nd} (+5.7) for the Nakhil and the low initial {sup 87}Sr/{sup 86}Sr (0.7029) for the Aswan granite. The contrasting inferences from the different isotopic systems can be explained by the high whole-rock Nd and Sr concentration for the the Nakhil (87 ppm Nd) and the Aswan (173 ppm Sr) granites, respectively, that suggest that the Nd and Sr isotopic composition of the older component has been overshadowed by the more primitive material. Similar contrasts in Pb, Sr, and Nd isotopic data from the eastern and western shield margins can be interpreted in the same manner and might suggest widespread involvement of older crustal components in the formation of the Late Proterozoic Arabian-Nubian shield.

  11. Metal and fluid sources in a potential world-class gold deposit: El-Sid mine, Egypt

    NASA Astrophysics Data System (ADS)

    Helmy, Hassan; Zoheir, Basem

    2015-04-01

    Lode gold mineralization at the El-Sid mine area is associated with the ca. 600 Ma Fawakhir granite intrusion, which cuts the ~737 Ma ophiolite nappes in the Central Eastern Desert of Egypt. The mineralized quartz veins are hosted by ~E- and NE-trending fault/fracture sets cutting the western boundary of the intrusion and sheared ophiolites. The results of electron microprobe analyses of gold-associated hydrothermal sulfide and silicate minerals suggest that Au was mobilized alongside Ni, Co, Cr and As from the adjacent ophiolitic serpentinite. After granite emplacement, hydrothermal fluids interacted with the sheared serpentinite, leaching metals and re-depositing them in the faults/fractures and adjacent wall rock in a cyclic process. Low-salinity aqueous-carbonic fluids with significant quantities of volatile species (CO2, CH4, and N2 ± H2S) leached and transported Au from deep to shallow crustal levels. Carbon dioxide had a buffering effect on the Au-bearing hydrothermal solution, maintaining its pH within a narrow near-neutral range, where elevated gold concentration was transported by complexation with reduced magmatic sulfur in a reducing environment. Gold deposition along fault/fracture conduits in the Fawakhir granite and adjacent serpentinite resulted from interplay of pressure drop, fluctuations in oxygen and sulfur fugacities, and exsolution of the volatile phases. Infiltration of meteoric water may have contributed to the formation of the late stage gold-sulfide mineralization that formed at shallower levels during terrane uplift. Sulfidation of the Fe-rich magmatic minerals was, on the other hand, the overriding process in the wall rock as evidenced by abundant disseminated sulfides with gold inclusions. Considering the structural control by regional shear zones (fluid conduits) and the voluminous granitic and ophiolitic rocks (metal sources), a high tonnage gold deposit amenable to open pit mining at the El-Sid mine area is very likely.

  12. Hydrogeochemical evolution of inland lakes’ water: A study of major element geochemistry in the Wadi El Raiyan depression, Egypt

    PubMed Central

    Mohamed, Essam A.; El-Kammar, Ahmed M.; Yehia, Mohamed M.; Abu Salem, Hend S.

    2015-01-01

    Wadi El Raiyan is a great depression located southwest of Cairo in the Western Desert of Egypt. Lake Qarun, located north of the study area, is a closed basin with a high evaporation rate. The source of water in the lake is agricultural and municipal drainage from the El Faiyum province. In 1973, Wadi El Raiyan was connected with the agricultural wastewater drainage system of the Faiyum province and received water that exceeded the capacity of Lake Qarun. Two hydrogeological regimes have been established in the area: (i) higher cultivated land and (ii) lower Wadi El Raiyan depression lakes. The agricultural drainage water of the cultivated land has been collected in one main drain (El Wadi Drain) and directed toward the Wadi El Raiyan depression, forming two lakes at different elevations (upper and lower). In the summer of 2012, the major chemical components were studied using data from 36 stations distributed over both hydrogeological regimes in addition to one water sample collected from Bahr Youssef, the main source of freshwater for the Faiyum province. Chemical analyses were made collaboratively. The major ion geochemical evolution of the drainage water recharging the El Raiyan depression was examined. Geochemically, the Bahr Youssef sample is considered the starting point in the geochemical evolution of the studied surface water. In the cultivated area, major-ion chemistry is generally influenced by chemical weathering of rocks and minerals that are associated with anthropogenic inputs, as well as diffuse urban and/or agricultural drainage. In the depression lakes, the water chemistry generally exhibits an evaporation-dependent evolutionary trend that is further modified by cation exchange and precipitation of carbonate minerals. PMID:26644942

  13. Hydrogeochemical evolution of inland lakes' water: A study of major element geochemistry in the Wadi El Raiyan depression, Egypt.

    PubMed

    Mohamed, Essam A; El-Kammar, Ahmed M; Yehia, Mohamed M; Abu Salem, Hend S

    2015-11-01

    Wadi El Raiyan is a great depression located southwest of Cairo in the Western Desert of Egypt. Lake Qarun, located north of the study area, is a closed basin with a high evaporation rate. The source of water in the lake is agricultural and municipal drainage from the El Faiyum province. In 1973, Wadi El Raiyan was connected with the agricultural wastewater drainage system of the Faiyum province and received water that exceeded the capacity of Lake Qarun. Two hydrogeological regimes have been established in the area: (i) higher cultivated land and (ii) lower Wadi El Raiyan depression lakes. The agricultural drainage water of the cultivated land has been collected in one main drain (El Wadi Drain) and directed toward the Wadi El Raiyan depression, forming two lakes at different elevations (upper and lower). In the summer of 2012, the major chemical components were studied using data from 36 stations distributed over both hydrogeological regimes in addition to one water sample collected from Bahr Youssef, the main source of freshwater for the Faiyum province. Chemical analyses were made collaboratively. The major ion geochemical evolution of the drainage water recharging the El Raiyan depression was examined. Geochemically, the Bahr Youssef sample is considered the starting point in the geochemical evolution of the studied surface water. In the cultivated area, major-ion chemistry is generally influenced by chemical weathering of rocks and minerals that are associated with anthropogenic inputs, as well as diffuse urban and/or agricultural drainage. In the depression lakes, the water chemistry generally exhibits an evaporation-dependent evolutionary trend that is further modified by cation exchange and precipitation of carbonate minerals.

  14. A study of Desert Dermatoses in the Thar Desert Region

    PubMed Central

    Chatterjee, Manas; Vasudevan, Biju

    2015-01-01

    Introduction: Desert dermatology describes the cutaneous changes and the diseases affecting those living in the desert. Diurnal variation in temperature is high and is characteristic of the deserts. The lack of water affects daily activities and impacts dermatological conditions. Adaptation to the desert is therefore important to survival. This original article focuses on dermatoses occurring in a population in the Thar desert of India, predominantly located in Rajasthan. Materials and Methods: This is a descriptive study involving various dermatoses seen in patients residing in the Thar desert region over a duration of 3 years. Results: Infections were the most common condition seen among this population and among them fungal infections were the most common. The high incidence of these infections would be accounted for by the poor hygienic conditions due to lack of bathing facilities due to scarcity of water and the consequent sweat retention and overgrowth of cutaneous infective organisms. Pigmentary disorders, photodermatoses, leishmaniasis and skin tumors were found to be more prevalent in this region. Desert sweat dermatitis was another specific condition found to have an increased incidence. Conclusion: The environment of the desert provides for a wide variety of dermatoses that can result in these regions with few of these dermatoses found in much higher incidence than in other regions. The concept of desert dermatology needs to be understood in more details to provide better care to those suffering from desert dermatoses and this article is a step forward in this regard. PMID:25657392

  15. [Urinary schistosomiasis in ancient Egypt].

    PubMed

    Ziskind, Bernard

    2009-12-01

    First described by Theodor Bilharz in 1851, Schistosoma haematobium, the worm responsible for urinary schistosomiasis, was a major health problem along the Nile Valley until the present days. Haematuria, the main symptom of this parasitic disease, was known and treated in Egyptian medical papyri since 1550 B.C. A relationship between haematuria and the god Seth was envisaged. Sir Marc Armand Ruffer, pioneer of paleopathology, found (1910) calcified Schistosoma eggs in Egyptian mummies of the xxth dynasty, establishing that bilharzia plagued ancient Egypt people. The ELISA method demonstrated the Schistosoma circulating anodic antigen in 45% of mummies studied.

  16. Serious fungal infections in Egypt.

    PubMed

    Zaki, S M; Denning, D W

    2017-02-17

    We aimed to estimate the burden of serious fungal infections in Egypt, currently unknown, based on the size of the populations at risk and available epidemiological data. Data were obtained from the World Health Organization (WHO), the Joint United Nations Programme on HIV/AIDS (UNAIDS), and published reports with clearcut denominators. When no data existed, risk populations were used to estimate frequencies of fungal infections, using previously described methodology. The population of Egypt in 2011 was ∼82,500,000; 31% children, and 8% women >60 years of age. Amongst about 21.8 million women aged 15-50 years, recurrent vulvovaginal candidiasis (≥4 episodes/year) is estimated to occur in 1.3 million (3,169/100,000 females). Using a low international average rate of 5/100,000, we estimate 4,127 cases of candidaemia, and 619 patients with intra-abdominal candidiasis. Amongst the survivors of pulmonary tuberculosis (TB) in Egypt in 2012, 319 new cases of chronic pulmonary aspergillosis (CPA) are likely, a prevalence of 1,005 post-TB and a total prevalence estimate of 3,015 CPA patients in all. Asthma is common in Egypt, affecting 9.4% of adults, 5.35 million, and so ABPA and SAFS were estimated in around 162/100,000 and 214/100,000 respectively. Invasive aspergillosis is estimated to affect 495 patients following leukaemia therapy, there are an estimated 37 cases in renal and liver transplant recipients, and an estimated 132 patients develop IA in the context of lung cancer. Amongst 641,000 COPD admissions to hospital each year, 8,337 patients develop IA. The total HIV-infected population is small, with an estimated 6,500 patients, 2,500 not on antiretroviral therapy. Amongst HIV-infected patients, 38 (0.6%) cases of cryptococcal meningitis and 125 (1.9%) cases of Pneumocystis pneumonia are estimated each year. Fungal keratitis is common, with 28-55% (mean 40%) of corneal infections being fungal, an estimated total of 11,550 cases. The present study indicates

  17. Structural influence on the evolution of the pre-Eonile drainage system of southern Egypt: Insights from magnetotelluric and gravity data

    NASA Astrophysics Data System (ADS)

    Roden, Jeff; Abdelsalam, Mohamed G.; Atekwana, Estella; El-Qady, Gad; Tarabees, Elhamy Aly

    2011-12-01

    The Wadi Kubbaniya in the Western Desert of Egypt north of the City of Aswan has been interpreted as the downstream continuation of the Wadi Abu Subeira, comprising an ancient W- and NW-flowing river system originating from the Precambrian crystalline rocks of the Red Sea Hills which were uplifted during the Miocene in association with the opening of the Red Sea. This drainage system is thought to have been active before the onset of the N-flowing Egyptian Nile which started ˜6 Ma with the Eonile phase; an event that resulted in carving of ˜1000 km long canyon (the Eonile canyon) extending from the Mediterranean Sea in the north to Aswan in the south due to the Messinian Salinity Crisis. This study utilizes geophysical data to examine the role of regional tectonics and local structures in controlling the evolution of the pre-Eonile drainage system. Magnetotelluric (MT) and gravity surveys were conducted along two ˜5 km-long profiles across the NW-trending Wadi Kubbaniya. Two-dimensional (2D) inversion of MT data and gravity models indicate the Wadi Kubbaniya is filled with loosely-consolidated sandstone and conglomerate that extend to a depth of ˜150-200 m into Cretaceous sandstone formations which overlie Precambrian crystalline rocks. These results were evaluated in terms of two end-member models; an incision model in which the 150-200 m thick sedimentary rocks were considered as being deposited within an incised valley that was carved into bedrock, or a structural model in which the sedimentary rocks are considered as filling a NW-trending graben controlled by normal faults that deform the Cretaceous sandstone formations and the underlying Precambrian crystalline rocks. Geological observations as well as supporting seismic data favor the interpretation that the Wadi Kubbaniya is a NW-trending graben similar to other extensional structures found 400 km northwest along-strike of Wadi Kubbaniya. These structures are impressively parallel to the western

  18. Space Radar Image of Safsaf Oasis, Egypt

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This three-frequency space radar image of south-central Egypt demonstrates the unique capability of imaging radar to penetrate thin sand cover in arid regions to reveal hidden details below the surface. Nearly all of the structures seen in this image are invisible to the naked eye and to conventional optical satellite sensors. Features appear in various colors because the three separate radar wavelengths are able to penetrate the sand to different depths. Areas that appear red or orange are places that can be seen only by the longest wavelength, L-band, and they are the deepest of the buried structures. Field studies in this area indicate L-band can penetrate as much as 2 meters (6.5 feet) of very dry sand to image buried rock structures. Ancient drainage channels at the bottom of the image are filled with sand more than 2 meters (6.5 feet) thick and therefore appear dark because the radar waves cannot penetrate them. The fractured orange areas at the top of the image and the blue circular structures in the center of the image are granitic areas that may contain mineral ore deposits. Scientists are using the penetrating capabilities of radar imaging in desert areas in studies of structural geology, mineral exploration, ancient climates, water resources and archaeology. This image is 51.9 kilometers by 30.2 kilometers (32.2 miles by 18.7 miles) and is centered at 22.7 degrees north latitude, 29.3degrees east longitude. North is toward the upper right. The colors are assigned to different radar frequencies and polarizations as follows: red is L-band, horizontally transmitted and received; green is C-band, horizontally transmitted and received; and blue is X-band, vertically transmitted and received. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on April 16, 1994, on board the space shuttle Endeavour. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission

  19. Wind modeling of Chihuahuan Desert dust outbreaks

    NASA Astrophysics Data System (ADS)

    Rivera Rivera, Nancy I.; Gill, Thomas E.; Gebhart, Kristi A.; Hand, Jennifer L.; Bleiweiss, Max P.; Fitzgerald, Rosa M.

    The Chihuahuan Desert region of North America is a significant source of mineral aerosols in the Western Hemisphere, and Chihuahuan Desert dust storms frequently impact the Paso del Norte (El Paso, USA/Ciudad Juarez, Mexico) metropolitan area. A statistical analysis of HYSPLIT back trajectory residence times evaluated airflow into El Paso on all days and on days with synoptic (non-convective) dust events in 2001-2005. The incremental probability—a measure of the areas most likely to have been traversed by air masses arriving at El Paso during dusty days—was only strongly positively associated with the region west-southwest of the city, a zone of known dust source areas. Focused case studies were made of major dust events on 15 April and 15 December 2003. Trajectories approached the surface and MM5 (NCAR/Penn State Mesoscale Model) wind speeds increased at locations consistent with dust sources observed in satellite imagery on those dates. Back trajectory and model analyses suggested that surface cyclones adjacent to the Chihuahuan Desert were associated with the extreme dust events, consistent with previous studies of dust storms in the Southern High Plains to the northeast. The recognition of these meteorological patterns serves as a forecast aid for prediction of dust events likely to impact the Paso del Norte.

  20. Environmental Processes and Spectral Reflectance Characteristics Associated with Soil Erosion in Desert Fringe Regions

    NASA Technical Reports Server (NTRS)

    Jacobberger, P. A.

    1987-01-01

    Results of analysis of spectral variation of sand dunes in El Ghorabi, Bahariya, Egypt; Tombouctou/Azaouad, Mali; and Tsodilo Hills, western Botswana are presented. Seasonal variations in dune extent and location of dune crests and their relationship to such factors as wind and weather variations are emphasized.

  1. Desert Farming Benefits from Microbial Potential in Arid Soils and Promotes Diversity and Plant Health

    PubMed Central

    Köberl, Martina; Müller, Henry; Ramadan, Elshahat M.; Berg, Gabriele

    2011-01-01

    Background To convert deserts into arable, green landscapes is a global vision, and desert farming is a strong growing area of agriculture world-wide. However, its effect on diversity of soil microbial communities, which are responsible for important ecosystem services like plant health, is still not known. Methodology/Principal Findings We studied the impact of long-term agriculture on desert soil in one of the most prominent examples for organic desert farming in Sekem (Egypt). Using a polyphasic methodological approach to analyse microbial communities in soil as well as associated with cultivated plants, drastic effects caused by 30 years of agriculture were detected. Analysing bacterial fingerprints, we found statistically significant differences between agricultural and native desert soil of about 60%. A pyrosequencing-based analysis of the 16S rRNA gene regions showed higher diversity in agricultural than in desert soil (Shannon diversity indices: 11.21/7.90), and displayed structural differences. The proportion of Firmicutes in field soil was significantly higher (37%) than in the desert (11%). Bacillus and Paenibacillus play the key role: they represented 96% of the antagonists towards phytopathogens, and identical 16S rRNA sequences in the amplicon library and for isolates were detected. The proportion of antagonistic strains was doubled in field in comparison to desert soil (21.6%/12.4%); disease-suppressive bacteria were especially enriched in plant roots. On the opposite, several extremophilic bacterial groups, e.g., Acidimicrobium, Rubellimicrobium and Deinococcus-Thermus, disappeared from soil after agricultural use. The N-fixing Herbaspirillum group only occurred in desert soil. Soil bacterial communities were strongly driven by the a-biotic factors water supply and pH. Conclusions/Significance After long-term farming, a drastic shift in the bacterial communities in desert soil was observed. Bacterial communities in agricultural soil showed a higher

  2. Snow, the Great River, and the Desert

    NASA Astrophysics Data System (ADS)

    Rango, A.

    2005-12-01

    While many major rivers around the world originate from alpine snowpacks in mountain regions, some experience the extreme contrast of flowing through harsh desert environments downriver. One such stream is the Rio Grande which rises in the San Juan and the Sangre de Christo mountains of southern Colorado and northern New Mexico. Eventually, the snow fed Rio Grande flows through North America's largest desert, the Chihuahuan Desert in New Mexico, Texas, and Mexico, and simultaneously becomes part of the border between the United States and Mexico. As is often true, urban areas develop along the river corridors rather than in more inaccessible mountain regions. This demographic preference tends to isolate the vast majority of population in the Rio Grande, who are dependent on water for their livelihoods, from the mountain snowpacks where the flow is generated. Ironically then, snow is seldom viewed as the source of the much needed water flowing through the desert by the majority of the basin's population. In arid regions of the western U.S., water demand far exceeds the water supply, and water use is apportioned under the doctrine of prior appropriation with the oldest right getting the first use of water. The increasing population in urban areas does not usually have a right to use the water flowing through the desert unless water rights have been purchased by municipalities from the major category of water user in these basins, namely, irrigated agriculture. In the entire Rio Grande basin, irrigation makes up 80% of the consumptive use of water. Additionally, basin compacts and international treaties apportion water between states and countries. Because these formal agreements were based on above average runoff years, there is little flexibility in changing the use of water, particularly in dry to normal runoff years. Most of the older water rights in the Rio Grande, especially the upper basin, are supplied by snowmelt. This leaves the lower basin to depend upon

  3. Deserts of China

    USGS Publications Warehouse

    Walker, Alta S.

    1982-01-01

    Improving arid land quality requires an understanding of the original state of the land and its relationship to wind, water, and plant regimes, as well as understanding of interactions within the present ecosystem.  Chinese scientists and local residents have made significant advances in improving arid environments in gobi and sandy deserts and in less arid sandy lands.  Wind patterns are being changed by planting forest belts to protect oases and sandy lands, and on a smaller scale by planting grasses and shrubs or constructing straw grids.  Research on reclamation of deserts is now focusing on how sand-fixing plants may be adapted to local environments, and how the resources of grazing land and water may be effectively exploited without being overused.

  4. Southwestern desert resources

    USGS Publications Warehouse

    Halvorson, William L.; van Riper, Charles; Schwalbe, Cecil R.

    2010-01-01

    The southwestern deserts stretch from southeastern California to west Texas and then south to central Mexico. The landscape of this region is known as basin and range topography featuring to "sky islands" of forest rising from the desert lowlands which creates a uniquely diverse ecology. The region is further complicated by an international border, where governments have caused difficulties for many animal populations. This book puts a spotlight on individual research projects which are specific examples of work being done in the area and when they are all brought together, to shed a general light of understanding the biological and cultural resources of this vast region so that those same resources can be managed as effectively and efficiently as possible. The intent is to show that collaborative efforts among federal, state agency, university, and private sector researchers working with land managers, provides better science and better management than when scientists and land managers work independently.

  5. Space Radar Image of Giza Egypt - with enlargement

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This radar image shows the area west of the Nile River near Cairo, Egypt. The Nile River is the dark band along the right side of the image and it flows approximately due North from the bottom to the right. The boundary between dense urbanization and the desert can be clearly seen between the bright and dark areas in the center of the image. This boundary represents the approximate extent of yearly Nile flooding which played an important part in determining where people lived in ancient Egypt. This land usage pattern persists to this day. The pyramids at Giza appear as three bright triangles aligned with the image top just at the boundary of the urbanized area. They are also shown enlarged in the inset box in the top left of the image. The Great Pyramid of Khufu (Cheops in Greek) is the northern most of the three Giza pyramids. The side-looking radar illuminates the scene from the top, the two sides of the pyramids facing the radar reflect most of the energy back to the antenna and appear radar bright; the two sides away from the radar reflect less energy back and appear dark Two additional pyramids can be seen left of center in the lower portion of the image. The modern development in the desert on the left side of the image is the Sixth of October City, an area of factories and residences started by Anwar Sadat to relieve urban crowding. The image was taken on April 19, 1994 by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the shuttle Endeavour. SIR-C/X-SAR, a joint mission of the German, Italian and the United States space agencies, is part of NASA's Mission to Planet Earth. The image is centered on latitude 29.72 degrees North latitude and 30.83 degrees East longitude. The area shown is approximately 20 kilometers by 30 kilometers. The colors in the image are assigned to different frequencies and polarizations of the radar as follows: red is L-band horizontally transmitted, horizontally received; green is C

  6. Impact of Geoethics in Egypt

    NASA Astrophysics Data System (ADS)

    AbdelMakosud, kholoud Mohamed; Ezzat, Nada

    2016-04-01

    Geoethics, is a new term that could be unknown in the Arab world,where its translation in Arabic language make some kind of problems,with special emphasis on Egypt; spreading this term and the importance of it to professionals and un professionals is not an easy task.Culture and awareness problems face us on dealing with it. In this working paper the researchers study two levels of educational samples, the first one is of young geo-scientists and the other one is of young people of different disciplines to make over view survey (monitoring the base level) about knowing geoethics and another survey after applying some lectures and workshops to the same samples to monitor the second level. The aim of the research is to find out how people will accept this term and its application and how we can spread it through community with different effective ways. In Egypt there are some kind of culture problems could affect on spreading of any new concept, these problems could be overcome by some scientific, social and culture recommendations, these recommendations could be applied in both Arab countries and African Countries with few modifications.

  7. Dental surgery in ancient Egypt.

    PubMed

    Blomstedt, Patric

    2013-01-01

    Many different surgical procedures have over the years been attributed to the ancient Egyptians. This is also true regarding the field of dental surgery. The existence of dentists in ancient Egypt is documented and several recipes exist concerning dental conditions. However, no indications of dental surgery are found in the medical papyri or in the visual arts. Regarding the osteological material/mummies, the possible indications of dental surgery are few and weak. There is not a single example of a clear tooth extraction, nor of a filling or of an artificial tooth. The suggested examples of evacuation of apical abscesses can be more readily explained as outflow sinuses. Regarding the suggested bridges, these are constituted of one find likely dating to the Old Kingdom, and one possibly, but perhaps more likely, dating to the Ptolemaic era. Both seem to be too weak to have served any possible practical purpose in a living patient, and the most likely explanation would be to consider them as a restoration performed during the mummification process. Thus, while a form of dentistry did certainly exist in ancient Egypt, there is today no evidence of dental surgery.

  8. Aquaporins in desert rodent physiology.

    PubMed

    Pannabecker, Thomas L

    2015-08-01

    Desert rodents face a sizeable challenge in maintaining salt and water homeostasis due to their life in an arid environment. A number of their organ systems exhibit functional characteristics that limit water loss above that which occurs in non-desert species under similar conditions. These systems include renal, pulmonary, gastrointestinal, nasal, and skin epithelia. The desert rodent kidney preserves body water by producing a highly concentrated urine that reaches a maximum osmolality nearly three times that of the common laboratory rat. The precise mechanism by which urine is concentrated in any mammal is unknown. Insights into the process may be more apparent in species that produce highly concentrated urine. Aquaporin water channels play a fundamental role in water transport in several desert rodent organ systems. The role of aquaporins in facilitating highly effective water preservation in desert rodents is only beginning to be explored. The organ systems of desert rodents and their associated AQPs are described.

  9. Jeeps Penetrating a Hostile Desert

    ERIC Educational Resources Information Center

    Bailey, Herb

    2009-01-01

    Several jeeps are poised at base camp on the edge of a desert aiming to escort one of them as far as possible into the desert, while the others return to camp. They all have full tanks of gas and share their fuel to maximize penetration. In a friendly desert it is best to leave caches of fuel along the way to help returning jeeps. We solve the…

  10. Space Radar Image of Nile River Delta, Egypt

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This spaceborne radar image shows the area just north of the city of Cairo, Egypt, where the Nile River splits into two main branches. The Rosetta Branch is the curving dark line in the center of the image and the Damietta Branch is the curving dark line in the lower right of the image. The light blue area on the right half of the image is a portion of the Nile River Delta. The thinner, straighter lines and the small network of gold lines are irrigation canals. There are more than 10,000 kilometers of canals throughout the Nile Delta. A transition zone of irrigated fields is shown in blue and yellow between the irrigated delta and the surrounding desert. The desert is the dark blue area on the left side of the image lacking the pattern of irrigated fields. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on October 4, 1994, onboardthe space shuttle Endeavour. The image is 75 kilometers by 60 kilometers (46 miles by 37 miles) and is centered at 30.2 degreesnorth latitude, 31.1 degrees east longitude. North is toward the upper right. The colors are assigned to different radar frequencies and polarizations as follows: red is L-band, horizontally transmitted and received; green is C-band, horizontally transmitted and received; and blue is the ratio of C-band and L-band, horizontally transmitted and received. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission to PlanetEarth program.

  11. Impact of highway geometry and posted speed on operating speed at multi-lane highways in Egypt

    PubMed Central

    Semeida, Ahmed M.

    2012-01-01

    The paper presents an analysis of roadway factors and posted speed limits that affect the operating speed at multi-lane highways in Egypt. Field data on multi-lane highways in Egypt are used in this investigation. The analysis considers two categories of highways. The first consists of two desert roads (Cairo–Alexandria and Cairo–Ismailia desert roads) and the second consists of two agricultural roads (Cairo–Alexandria and Tanta–Damietta agricultural roads). The paper includes three separate relevant analyses. The first analysis uses the regression models to investigate the relationships between operating speed (V85) as dependent variable, and roadway factors and posted speed as independent variables. The road factors are lane width, shoulder width, pavement width, median width, number of lanes in each direction, and existence of side access along each section. The second analysis uses the Artificial Neural Network (ANN) to explore the previous relationships while the third one examines the suitability of the posted speed limits on the roads under study. It is found that the ANN modeling gives the best model for predicting the operating speed and the most influential variables on V85 are the pavement width, followed by the median width and the existence of side access along section. It is also found that the posted speed limit has a very small effect on the operating speed due to the bad behavior of drivers in Egypt. These results are so important for controlling V85 on multi-lane rural highways in Egypt. PMID:25685460

  12. Factors influencing the rates, processes and magnitude of accumulation of carbon in desert soils

    NASA Technical Reports Server (NTRS)

    Mcfadden, Leslie D.

    1994-01-01

    This report summarizes research funded through NASA's Soil Landscape Climate Program which includes studies of the systematics of carbon storage and flux in the terrestrial environment, specifically terrestrial soils. Efforts focussed on the nature of carbon behavior in arid environments, where the majority of the carbon is present as inorganic carbon stored as pedogenic carbonate in desert calcic soils. Studies were supported of soils in two areas of western North America's major deserts: the Mojave Desert and the Chihuahuan Desert. Part 1 of this report summarizes the results of research conducted in the area of the Providence Mountains, California in the eastern Mojave Desert. Part 2 of this report summarizes the results of research in the Sevilleta Wildlife Refuge in central New Mexico, one of the sites of the UMN Biology Department's Long Term Ecological Research.

  13. Area Handbook Series: Egypt: A Country Study

    DTIC Science & Technology

    1991-01-01

    has been unable to prevent young Coptic Christians from acting on their own to counter acts of violence against their religious centers and property...Party, and the Young Egypt (Misr al Fatah) Party became eligible to run for election. The Supreme Administrative Court rejected, however, the...state with an increase in the power of these provincial lords , particular- ly in Upper Egypt. The Old Kingdom ended when the central administration col

  14. Workshop on Extraterrestrial Materials from Cold and Hot Deserts

    NASA Technical Reports Server (NTRS)

    Schultz, Ludolf (Editor); Franchi, Ian A. (Editor); Reid, Arch M. (Editor); Zolensky, Michael E. (Editor)

    2000-01-01

    Since 1969 expeditions from Japan, the United States, and European countries have recovered more than 20,000 meteorite specimens from remote ice fields of Antarctica. They represent approximately 4000-6000 distinct falls, more than all non-Antarctic meteorite falls and finds combined. Recently many meteorite specimens of a new "population" have become available: meteorites from hot deserts. It turned out that suitable surfaces in hot deserts, like the Sahara in Africa, the Nullarbor Plain in Western and South Australia, or desert high plains of the U.S. (e.g., Roosevelt County, New Mexico), contain relatively high meteorite concentrations. For example, the 1985 Catalogue of Meteorites of the British Museum lists 20 meteorites from Algeria and Libya. Today, 1246 meteorites finds from these two countries have been published in MetBase 4.0. Four workshops in 1982, 1985, 1988, and 1989 have discussed the connections between Antarctic glaciology and Antarctic meteorites, and the differences between Antarctic meteorites and modem falls. In 1995, a workshop addressed differences between meteorites from Antarctica, hot deserts, and modem falls, and the implications of possible different parent populations, infall rates, and weathering processes. Since 1995 many more meteorites have been recovered from new areas of Antarctica and hot deserts around the world. Among these finds are several unusual and interesting specimens like lunar meteorites or SNCs of probable martian origin. The Annual Meeting of the Meteoritical Society took place in 1999 in Johannesburg, South Africa. As most of the recent desert finds originate from the Sahara, a special workshop was planned prior to this meeting in Africa. Topics discussed included micrometeorites, which have been collected in polar regions as well as directly in the upper atmosphere. The title "Workshop on Extraterrestrial Materials from Cold and Hot Deserts" was chosen and the following points were emphasized: (1) weathering

  15. Workshop on Extraterrestrial Materials from Cold and Hot Deserts

    NASA Technical Reports Server (NTRS)

    Schultz, Ludolf (Editor); Franchi, Ian A. (Editor); Reid, Arch M. (Editor); Zolensky, Michael E. (Editor)

    1999-01-01

    Since 1969 expeditions from Japan, the United States, and European countries have recovered more than 20,000 meteorite specimens from remote ice fields of Antarctica. They represent approximately 4000-6000 distinct falls, more than all non-Antarctic meteorite falls and finds combined. Recently many meteorite specimens of a new "population" have become available: meteorites from hot deserts. It turned out that suitable surfaces in hot deserts, like the Sahara in Africa, the Nullarbor Plain in Western and South Australia, or desert high plains of the U.S. (e.g., Roosevelt County, New Mexico), contain relatively high meteorite concentrations. For example, the 1985 Catalog of Meteorites of the British Museum lists 20 meteorites from Algeria and Libya. Today, 1246 meteorites finds from these two countries have been published in MetBase 4.0. Four workshops in 1982, 1985, 1988, and 1989 have discussed the connections between Antarctic glaciology and Antarctic meteorites, and the differences between Antarctic meteorites and modern falls. In 1995, a workshop addressed differences between meteorites from Antarctica, hot deserts, and modem falls, and the implications of possible different parent populations, infall rates, and weathering processes. Since 1995 many more meteorites have been recovered from new areas of Antarctica and hot deserts around the world. Among these finds are several unusual and interesting specimens like lunar meteorites or SNCs of probable martian origin. The Annual Meeting of the Meteoritical Society took place in 1999 in Johannesburg, South Africa. As most of the recent desert finds originate from the Sahara, a special workshop was planned prior to this meeting in Africa. Topics discussed included micrometeorites, which have been collected in polar regions as well as directly in the upper atmosphere. The title "Workshop on Extraterrestrial Materials from Cold and Hot Deserts" was chosen and the following points were emphasized: (1) weathering

  16. Enhancing and restoring habitat for the desert tortoise

    USGS Publications Warehouse

    Abella, Scott R.; Berry, Kristin H.

    2016-01-01

    Habitat has changed unfavorably during the past 150 y for the desert tortoise Gopherus agassizii, a federally threatened species with declining populations in the Mojave Desert and western Sonoran Desert. To support recovery efforts, we synthesized published information on relationships of desert tortoises with three habitat features (cover sites, forage, and soil) and candidate management practices for improving these features for tortoises. In addition to their role in soil health and facilitating recruitment of annual forage plants, shrubs are used by desert tortoises for cover and as sites for burrows. Outplanting greenhouse-grown seedlings, protected from herbivory, has successfully restored (>50% survival) a variety of shrubs on disturbed desert soils. Additionally, salvaging and reapplying topsoil using effective techniques is among the more ecologically beneficial ways to initiate plant recovery after severe disturbance. Through differences in biochemical composition and digestibility, some plant species provide better-quality forage than others. Desert tortoises selectively forage on particular annual and herbaceous perennial species (e.g., legumes), and forage selection shifts during the year as different plants grow or mature. Nonnative grasses provide low-quality forage and contribute fuel to spreading wildfires, which damage or kill shrubs that tortoises use for cover. Maintaining a diverse “menu” of native annual forbs and decreasing nonnative grasses are priorities for restoring most desert tortoise habitats. Reducing herbivory by nonnative animals, carefully timing herbicide applications, and strategically augmenting annual forage plants via seeding show promise for improving tortoise forage quality. Roads, another disturbance, negatively affect habitat in numerous ways (e.g., compacting soil, altering hydrology). Techniques such as recontouring road berms to reestablish drainage patterns, vertical mulching (“planting” dead plant material

  17. Desert landscape irrigation

    SciTech Connect

    Quinones, R.

    1995-06-01

    Industrialization can take place in an arid environment if a long term, overall water management program is developed. The general rule to follow is that recharge must equal or exceed use. The main problem encountered in landscape projects is that everyone wants a lush jungle setting, tall shade trees, ferns, with a variety of floral arrangements mixed in. What we want, what we can afford, and what we get are not always the same. Vegetation that requires large quantities of water are not native to any desert. Surprisingly; there are various types of fruit trees, and vegetables that will thrive in the desert. Peaches, plums, nut trees, do well with drip irrigation as well as tomatoes. Shaded berry plans will also do well, the strawberry being one. In summary; if we match our landscape to our area, we can then design our irrigation system to maintain our landscape and grow a variety of vegetation in any arid or semiarid environment. The application of science and economics to landscaping has now come of age.

  18. Distribution and vegetation reconstruction of the deserts of northern China during the mid-Holocene

    NASA Astrophysics Data System (ADS)

    Li, Qin; Wu, Haibin; Guo, Zhengtang; Yu, Yanyan; Ge, Junyi; Wu, Jianyu; Zhao, Deai; Sun, Aizhi

    2014-07-01

    Desertification is potentially a serious threat to society, and therefore, it is critical to understand how deserts may respond to future climate change. The mid-Holocene (6 ± 0.5 14C ka) was warmer than present, and the distribution of deserts at this time may have implications for understanding their response to future warming. Here we reconstruct the distribution of deserts in northern China during the mid-Holocene by combining data on vegetation type and the sedimentary facies of aeolian deposits. The results demonstrate that during the mid-Holocene, the deserts retreated northwestward to the location of the modern 300 mm isohyet. Most of the Eastern Desert was stabilized with steppe or forest-steppe vegetation, whereas the Western Desert exhibited no significant change and remained mobile, occupied by desert vegetation. The deserts in northern China were greatly reduced during the mid-Holocene because of the enhancement of the East Asian summer monsoon in a warmer climate than today.

  19. 77 FR 71777 - Trade Mission to Egypt and Kuwait

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-04

    ... International Trade Administration Trade Mission to Egypt and Kuwait AGENCY: International Trade Administration... Trade Mission to Egypt and Kuwait March 10-14, 2013, published at 77 FR 33439, June 6, 2012 to revise... Mission to Egypt and Kuwait March 10-14, 2013, published at 77 FR 33439, June 6, 2012. Due to...

  20. Military Review: Operation Desert Shield/Desert Storm

    DTIC Science & Technology

    1991-09-01

    stunrm by Lieutenant General William G. Pagonts, US Army and Major Harod E Raugh Jr., US Army OW61 6.3r -- 40 Moving an Army: Movement Control for Desert...headquarters to the controlling headquarters for three armies in one: the Army compo-~nent, the theater army nd a number d field army. Viwtory in the Desert...contingency, had just completed Central was bleak. Saddam Hussein had invaded Kuwait Command Exercise INTERNAL on 2 August, gaining control of that

  1. Tectonic architecture through Landsat-7 ETM+/SRTM DEM-derived lineaments and relationship to the hydrogeologic setting in Siwa region, NW Egypt

    NASA Astrophysics Data System (ADS)

    Masoud, Alaa; Koike, Katsuaki

    2006-08-01

    Fracture zones on the Earth's surface are important elements in the understanding of plate motion forces, the dynamics of the subsurface fluid flow, and earthquake distributions. However, good exposures of these features are always lacking in arid regions, characterized by flat topography and where sand dunes extensively cover the terrain. During field surveys these conditions, in many cases, hinder the proper characterization of such features. Therefore, an approach that identifies the regional fractures as lineaments on remotely-sensed images or shaded digital terrain models, with its large scale synoptic coverage, could be promising. In the present work, a segment tracing algorithm (STA), for lineament detection from Landsat-7 Enhanced Thematic Mapper Plus (ETM+) imagery, and the data from the Shuttle Radar Topographic Mission (SRTM) 30 m digital elevation model (DEM), has been applied in the Siwa region, located in the northwest of the Western Desert of Egypt. The objectives are to analyze the spatial variation in orientation of the detected linear features and its relation to the hydrogeologic setting in the area and the underlying geology, and to evaluate the performance of the algorithm applied to the ETM+ and the DEM data. Detailed structural analysis and better understanding of the tectonic evolution of the area could provide useful tools for hydrologists for reliable groundwater management and development planning. The results obtained have been evaluated by the structural analysis of the area and field observations. Four major vertical fracture zones were detected corresponding to two conjugate sets of strike-slip faults that governed the surface, and subsurface environments of the lakes in the region, and these correlate well with the regional tectonics.

  2. A new genus and species of marine catfishes (Siluriformes; Ariidae) from the upper Eocene Birket Qarun Formation, Wadi El-Hitan, Egypt

    PubMed Central

    2017-01-01

    Wadi El-Hitan, the UNESCO World Heritage Site, of the Fayum Depression in the northeast part of the Western Desert of Egypt, has produced a remarkable collection of Eocene vertebrates, in particular the fossil whales from which it derives its name. Here we describe a new genus and species of marine catfishes (Siluriformes; Ariidae), Qarmoutus hitanensis, from the base of the upper Eocene Birket Qarun Formation, based on a partial neurocranium including the complete left side, partial right dentary, left suspensorium, two opercles, left pectoral girdle and spine, nuchal plates, first and second dorsal spines, Weberian apparatus and a disassociated series of abdominal vertebrae. All of the elements belong to the same individual and some of them were found articulated. Qarmoutus gen. nov. is the oldest and the most complete of the Paleogene marine catfishes unearthed from the Birket Qarun Formation. The new genus exhibits distinctive features not seen in other African Paleogene taxa, such as different sculpturing on the opercle and pectoral girdle with respect to that on the neurocranium and nuchal plates, denticulate ornamentation on the skull bones arranged in longitudinal rows and forming a radiating pattern on the sphenotic, pterotic, extrascapular and the parieto-supraoccipital, indentations or pitted ornamentation on the nuchal plates as well as the parieto-supraoccipital process, strut-like radiating pattern of ornamentation on the opercle from the proximal articulation to margins, longitudinal, curved, reticulate ridges and tubercular ornamentations on the cleithrum, sinuous articulation between the parieto-supraoccipital process and the anterior nuchal plate, long, narrow, and arrowhead shaped nuchal shield, very small otic capsules restricted to the prootic. Multiple parsimony and Bayesian morphological phylogenetic analyses of Ariidae, run with and without “molecular scaffolds”, yield contradictory results for the placement of Qarmoutus; the genus is

  3. Diphtheria immunity status in Egypt.

    PubMed

    Redwan, El-Rashdy M; El-Awady, Mostafa K

    2004-01-01

    The aim of this study was to determine immune status to corynebacterium diphtheria by screening for protective antibodies in a sample of Egyptian population. The study population consisted of 709 healthy subjects aged from 2 months to 105 years, inhabitants of 6 regions of Egypt. The study utilized Enzyme linked immunosorbent assay (ELISA) to measure serum levels IgG antibodies reactive with diphtheria toxoid. Levels of diphtheria toxoid antibody > or = 0.1 IU/ ml were defined as immune/protected, 23.9 % of the population were found to be susceptible to diphtheria (IgG level < 0.01 IU/ml), 43% had basic protection (0.01-0.09 IU/ml), and 33.1% were fully protected (0.1 IU/ml). The results revealed that serum levels of antitoxin antibodies decreased in old ages (< 60 y) with the females being more susceptible then males. These results recommend a booster immunization for the susceptible age groups.

  4. Evolutionary hotspots in the Mojave Desert

    USGS Publications Warehouse

    Vandergast, Amy G.; Inman, Richard D.; Barr, Kelly R.; Nussear, Kenneth E.; Esque, Todd C.; Hathaway, Stacie A.; Wood, Dustin A.; Medica, Philip A.; Breinholt, Jesse W.; Stephen, Catherine L.; Gottscho, Andrew D.; Marks, Sharyn B.; Jennings, W. Bryan; Fisher, Robert N.

    2013-01-01

    Genetic diversity within species provides the raw material for adaptation and evolution. Just as regions of high species diversity are conservation targets, identifying regions containing high genetic diversity and divergence within and among populations may be important to protect future evolutionary potential. When multiple co-distributed species show spatial overlap in high genetic diversity and divergence, these regions can be considered evolutionary hotspots. We mapped spatial population genetic structure for 17 animal species across the Mojave Desert, USA. We analyzed these in concurrence and located 10 regions of high genetic diversity, divergence or both among species. These were mainly concentrated along the western and southern boundaries where ecotones between mountain, grassland and desert habitat are prevalent, and along the Colorado River. We evaluated the extent to which these hotspots overlapped protected lands and utility-scale renewable energy development projects of the Bureau of Land Management. While 30–40% of the total hotspot area was categorized as protected, between 3–7% overlapped with proposed renewable energy project footprints, and up to 17% overlapped with project footprints combined with transmission corridors. Overlap of evolutionary hotspots with renewable energy development mainly occurred in 6 of the 10 identified hotspots. Resulting GIS-based maps can be incorporated into ongoing landscape planning efforts and highlight specific regions where further investigation of impacts to population persistence and genetic connectivity may be warranted.

  5. Women's position and family planning in Egypt.

    PubMed

    Govindasamy, P; Malhotra, A

    1996-01-01

    In this report, data from the 1988 Egypt Demographic and Health Survey are used to address some of the most frequently raised questions about the relationship between gender inequality and reproductive behavior. The findings from binomial and multinomial logit models show that while the relationship between women's position and fertility control in Egypt is complex, some clear, broad patterns exist that have important theoretical and policy implications. First, although women's status in Egypt is clearly multidimensional, the reproductive aspect of women's position has a strong connection with the nonreproductive dimensions. Second, the case of the continued use of education and employment as proxies of women's position, especially in relationship to fertility control, is considerably discredited by the results. Finally, the findings indicate that Egyptian culture supports gender equality in the form of interaction and negotiation rather than women's autonomy.

  6. Keeping the desert at bay

    SciTech Connect

    El-Kassas, M.

    1981-02-01

    Man-made desert (areas that are no longer productive) has increased the world's deserts from 36.3 to 43% of the land surface. Desertification involves ecological degradation that makes the land less productive or allows an uneconomic type of vegetation, such as mesquite, to replace an economic plant. The process was first thought to be an encroachment by expanding deserts, but, except for the movement of sand dunes, desertification is now viewed as productive land that deteriorated and was added to the desert. Land is lost to agriculture by erosion, loss of nutrients, compaction, salination, urban development, and pollution. The interacting biosphere, technosphere, and social sphere form the framework of man's existence. An understanding of this framework is crucial to those offering technological assistance to developing countries. (DCK)

  7. Mate desertion in the snail kite

    USGS Publications Warehouse

    Beissinger, S.R.; Snyder, N.F.R.

    1988-01-01

    Mate desertion during the breeding cycle was documented at 28 of 36 (78%) snail kite, Rostrhamus sociabilis nests in Florida between 1979 and 1983. Offspring mortality occurred at only one deserted nest, however. Parents that were deserted by their mates continued to care for their young until independence (3?5 additional weeks) and provided snails at a rate similar to that of both parents combined before desertion. Males and females deserted with nearly equal frequency, except in 1982 when more females deserted. No desertion occurred during drought years, whereas desertion occurred at nearly every nest during favourable conditions. The occurrence of mate desertion was generally related to indirect measures of snail abundance: foraging range, snail delivery rates to the young and growth rates. Small broods were deserted more frequently by females than by males and tended to be deserted earlier than large ones. After desertion, deserters had the opportunity to re-mate and nest again since breeding seasons were commonly lengthy, but whether they did so was impossible to determine conclusively in most cases. The deserted bird sometimes incurred increased energetic costs and lost breeding opportunities during periods of monoparental care.

  8. Introduction to the special issue on the changing Mojave Desert

    USGS Publications Warehouse

    Berry, Kristin H.; Murphy, R.W.; Mack, Jeremy S.; Quillman, W.

    2006-01-01

    The Mojave Desert, which lies between the Great Basin Desert in the north and the Sonoran Desert in the south, covers an estimated 114 478–130 464 km2 of the south-western United States and includes parts of the states of Nevada, Utah, Arizona, and California, with the amount of land mass dependent on the definition (Fig. 1; Rowlands et al., 1982; McNab and Avers, 1994; Bailey, 1995; Groves et al., 2000). This desert is sufficiently diverse to be subdivided into five regions: northern, south-western, central, south-central, and eastern (Rowlands et al., 1982). It is a land of extremes both in topography and climate. Elevations range from below sea level at Death Valley National Park to 3633 m on Mt. Charleston in the Spring Range of Nevada. Temperatures exhibit similar extreme ranges with mean minimum January temperatures of −2.4 °C in Beatty, Nevada and mean maximum July temperatures of 47 °C in Death Valley. Mean annual precipitation varies throughout the regions (42–350 mm), is highest on mountain tops, but overall is low (Rowlands et al., 1982; Rowlands, 1995a). The distribution of precipitation varies from west to east and north to south, with >85% of rain falling in winter in the northern, south-western and south-central regions. In contrast, the central and eastern regions receive a substantial amount of precipitation in both winter and summer. The variability in topographic and climatic features contributes to regional differences in vegetation.

  9. 75 FR 61467 - Desert Southwest Power, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-05

    ... Energy Regulatory Commission Desert Southwest Power, LLC; Notice of Filing September 27, 2010. Take notice that on September 24, 2010, Desert Southwest Power, LLC (Desert Southwest) supplemented the... Commission's July 28, 2010 letter regarding Desert Southwest's petition for declaratory order...

  10. Phenolic Compounds from the Fruits of Medemia argun, a Food and Medicinal Plant of Ancient Egypt.

    PubMed

    Masullo, Milena; Hamed, Arafa I; Mahalel, Usama A; Pizza, Cosimo; Piacente, Sonia

    2016-03-01

    Medemia argun is a mysterious and little known monotypic fan palm from the Nubian Desert Oases of southern Egypt and northern Sudan. Its fruits have been found in the tombs from the 5th Dynasty (ca. 2500 BC) to Roman times (6-7th century AD), including the celebrated tomb of Tutankhamun. In ancient Egypt, the fruits of this palm were widely distributed and were highly valued, as confirmed by their frequent occurrence in offerings in the tombs. In order to elucidate the chemical composition of the phenolic fraction, phytochemical investigation of the BuOH extract of fruits was carried out to afford eight compounds (1-8), among which was the new 2,4-dihydroxy-6-methylacetophenone 2-0-β-D-glucopyranoside (1). With the aim to investigate if the high shelf life of M argun fruits could be related to the occurrence of antioxidant principles that were able to prevent oxidative reactions, the evaluation was carried out of the in vitro antioxidant activity by Trolox equivalent antioxidant capacity (TEAC) assay of the extract and isolated compounds.

  11. Desert and desertification in Iran

    NASA Astrophysics Data System (ADS)

    Bahrami, M.

    2009-04-01

    One of the greatest environmental concerns in Iran as in other arid and semiarid countries is the transformation of once productive, or marginally productive, land to deteriorated land and soil unable to support plants and animals. Because the land becomes barren and dry, the process is described as desertification, which occurs as a sequence of events. The area of deserts in Iran is about 340,000 Km2 (less than one fifth of its total area), of which 100,000 Km2 is being used for some cultivation, 120,000 Km2 is subjected to moving sands about 40 % of which is active sand dunes. Most of features and processes usual in world famous deserts are also observed in Iran: low precipitation, high evaporation, poor or lack of vegetation, saline and alkaline soils, low population and small and sparse oases. The deserts of Iran are generally classified in the subtropical, warm, arid and semiarid group, but the effect and presence of some geographical and geoclimatical factors such as height, vicinity to Indian Ocean and so on do some changes in climatic conditions and geographical features causing some local and regional differences in them. Geographically, two groups of deserts have been known in Iran: (1) Coastal deserts which, like a ribbon with variable width, stretch from extreme southeast to extreme southwest, at the north parts of Oman Sea and Persian Gulf. One important feature of these deserts is relatively high humidity which differentiates them from other deserts. This causes an increase in vegetation coverage and hence a decrease in eolian erosion and also a dominance of chemical weathering to that of physical. (2) internal deserts, which rest in central, eastern and southeastern plateau of the country and in independent and semi dependent depressions. This situation, which is due to the surrounding high mountains, blocks humidity entry and causes the aridity of these deserts. Wind as a dominant process in the area causes deflated features such as Reg (desert

  12. English Teaching Profile: Arab Republic of Egypt.

    ERIC Educational Resources Information Center

    British Council, London (England). English Language and Literature Div.

    This profile of the English language teaching situation in Egypt examines the role of English in society and in the educational system. The status of English as the main foreign language and as the medium of instruction in a small number of influential schools is discussed as well as the extent and content of the university English course. Also…

  13. Toward replacement fertility in Egypt and Tunisia.

    PubMed

    Eltigani, Eltigani E

    2009-09-01

    Egypt and Tunisia began their fertility transition at almost identical fertility levels and at roughly the same time period, yet the difference in the pace of decline has been such that the total fertility rate (TFR) in Tunisia reached replacement level by the year 2001, whereas the TFR in Egypt remains above three live births per woman. This article draws on the secondary literature and on several nationally representative surveys from the two countries between 1978 and 2005 to provide empirical evidence of the difference in the pace of fertility decline and to analyze the determinants of the differential. Findings include (a) variation across the two countries in the consistency of fertility decline among the segments of the population leading the transition; (b) that the success of each country's family planning program was influenced by the role of political leaders and the extent of the program's integration within socioeconomic development objectives; (c) that the impact of contraception on TFR decline became an important factor in the mid-1980s; and (d) that the greatest determinant of the discrepancy in the pace of fertility decline is the disparity in age at marriage, which rose more significantly in Tunisia than in Egypt. The latter finding indicates that reaching replacement fertility in Egypt hinges primarily on further declines in marital fertility, resulting from reduction of wanted fertility and from an expansion of family planning program coverage and improved efficiency of service delivery and use.

  14. Detection of Strawberry Viruses in Egypt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As part of a USAID-MERC funded project, ‘Disease-indexing and mass propagation of superior strawberry cultivars’, an effort was made to evaluate the virus status of strawberries in Egypt. Diagnostic reverse transcription-polymerase chain reaction (RT-PCR) tests for Strawberry mottle, Strawberry cri...

  15. Earth's motions in pharaonic Egypt: Religious interpretations

    NASA Astrophysics Data System (ADS)

    Jambon, Emmanuel

    This paper will deal with the representations of the earth's movements in pharaonic Egypt. At first, testimonies of an ancient literary pattern, the "sky and earth" figure, will be observed, and then, the pictures where earth is represented "alone". We will explore the different ways the Egyptians depicted and interpreted this phenomena through various texts.

  16. Women's "Justification" of Domestic Violence in Egypt

    ERIC Educational Resources Information Center

    Yount, Kathryn M.; Li, Li

    2009-01-01

    We explored the influences of women's social learning, marital resources and constraints, and exposure to norms about women's family roles on their views about wife hitting or beating among 5,450 participants in the 2005 Egypt Demographic and Health Survey. One half justified wife hitting or beating for some reason. Women from rural areas who were…

  17. Reading Habits of Adults in Egypt.

    ERIC Educational Resources Information Center

    Scales, Alice M.; Zikri, Lawrence B.

    Investigating the reading habits of adults in Egypt, East Africa, a study examined 294 Egyptians (233 males and 61 females) in post-secondary education in Cairo, and in the industrial cities of Shopra El-Khema, and Impapa, El-Giza. Marital status, sex, and occupation were used to group the subjects. Subjects completed a 29-item questionnaire…

  18. Multicenter study of brucellosis in Egypt.

    PubMed

    Samaha, Hassan; Al-Rowaily, Meshref; Khoudair, Ramadan M; Ashour, Hossam M

    2008-12-01

    Brucellosis causes appreciable economic losses in livestock. Examination of milk and tissues from animals in Egypt for Brucella spp. showed increased prevalence rates of serologically reactive animals. All isolates were B. melitensis biovar 3. One Brucella sp. was isolated from milk of serologically nonreactive buffaloes.

  19. Journey to Egypt: A Board Game

    ERIC Educational Resources Information Center

    Selvidge, Ellen

    2006-01-01

    This author describes how her elementary students first became interested in studying ancient Egypt. Her students' interest in the ancient Egyptian studies began when a student checked out a library book on Egyptology that contained colorful images and was soon swarmed by interested classmates. Many of her students began practicing writing…

  20. Censorship and Security Agents Pervade Egypt's Universities

    ERIC Educational Resources Information Center

    Mills, Andrew

    2008-01-01

    This article offers a glimpse into one of the many ways in which the Egyptian government and the campus administrators it appoints are slowly and persistently squeezing the life out of universities in Cairo, Egypt. Classroom discussions are monitored, faculty appointments and academic research are scrutinized, and faculty participation in outside…

  1. Review of Parasitic Zoonoses in Egypt

    PubMed Central

    Youssef, Ahmed I.; Uga, Shoji

    2014-01-01

    This review presents a comprehensive picture of the zoonotic parasitic diseases in Egypt, with particular reference to their relative prevalence among humans, animal reservoirs of infection, and sources of human infection. A review of the available literature indicates that many parasitic zoonoses are endemic in Egypt. Intestinal infections of parasitic zoonoses are widespread and are the leading cause of diarrhea, particularly among children and residents of rural areas. Some parasitic zoonoses are confined to specific geographic areas in Egypt, such as cutaneous leishmaniasis and zoonotic babesiosis in the Sinai. Other areas have a past history of a certain parasitic zoonoses, such as visceral leishmaniasis in the El-Agamy area in Alexandria. As a result of the implementation of control programs, a marked decrease in the prevalence of other zoonoses, such as schistosomiasis and fascioliasis has been observed. Animal reservoirs of parasitic zoonoses have been identified in Egypt, especially in rodents, stray dogs and cats, as well as vectors, typically mosquitoes and ticks, which constitute potential risks for disease transmission. Prevention and control programs against sources and reservoirs of zoonoses should be planned by public health and veterinary officers based on reliable information from systematic surveillance. PMID:24808742

  2. Video Usage in Egypt: Limits and Effects.

    ERIC Educational Resources Information Center

    El-Fawal, Nagwa Amin

    A review of research conducted in Egypt to assess the impact of videocassette recorders (VCRs) on society and on other communication media indicates that the use of VCRs--a new phenomenon in mass communication in that country--has been accelerating over the past five years as more people have been gradually exposed to the advantages of unlimited…

  3. Special Education in Egypt: An Overview.

    ERIC Educational Resources Information Center

    Ghobrial, Talaat Mansour; Vance, H. Robert

    During the past three decades, there has been a growing concern for handicapped children and youth in Egypt. Current legislation recognizes the rights of the handicapped, and the Egyptian government supports the care, education, rehabilitation, and personal/social adjustment of handicapped citizens. The responsibility for the disabled is divided…

  4. Directory of Adult Education Agencies in Egypt.

    ERIC Educational Resources Information Center

    El-Bashary, Ahmed, Comp.

    The directory of Adult Education Agencies in Egypt is a listing of six different types of organizations: national bodies and central agencies; teachers' training institutes and research institutions; adult education institutions (governmental); adult education institutions (non-governmental); central libraries and documentation centers; and…

  5. Original sounding and drifting balloon-borne measurements in the western Mediterranean with the aerosol counter/sizer LOAC during summer ChArMEx campaigns, with a focus on desert dust events

    NASA Astrophysics Data System (ADS)

    Renard, Jean-Baptiste; Dulac, François; Vignelles, Damien; Jeannot, Matthieu; Verdier, Nicolas; Chazette, Patrick; Crenn, Vincent; Sciare, Jean; Totems, Julien; Durand, Pierre; Barret, Brice; Jambert, Corinne; Mallet, Marc; Menut, Laurent; Mailler, Sylvain; Basart, Sara; Baldasano, José Maria

    2015-04-01

    LOAC (Light Optical Aerosol Counter) is a new small optical particle counter/sizer of ~250 grams designed to fly under all kinds of balloons. The measurements are conducted at two scattering angles (12° and 60°), allowing the determination of the aerosol particle concentrations in 19 size classes within a diameter range of ~0.2-100 µm and some identification of the nature of particles dominating different size classes. Following laboratory calibration, the sensor particularly discriminates wet or liquid particles, mineral dust, soot carbon particles and salts. Comparisons with other in situ sensors at the surface and with remote sensing measurements on the vertical were performed to give confidence in measurements. The instrument has been operated at the surface, under all kinds of balloons up to more than 35 km in altitude, including tethered, sounding, open stratospheric and new boundary-layer pressurized drifting balloons (BLPB) from CNES, and was tested on board a small UAV. Operations encompass a variety of environments including the Arctic (Reykjavik, Island, and Kiruna, Sweden), Brazil (Sao Paolo), the western Mediterranean Basin, southwestern France, peri-urban (Ile de France) and urban areas (Paris and Vienna). Presented results are focused on the LOAC balloon-borne measurements performed in the western Mediterranean basin during MISTRALS/ChArMEx campaigns (Mediterranean Integrated Studies aT Regional And Local Scales/the Chemistry-Aerosol Mediterranean Experiment; http://www.mistrals-hjome.org; http://charmex.lsce.ipsl.fr), with a focus on African dust events. Two test flights with a first version of LOAC under sounding balloons were first successfully performed in late June 2012 near Marseille during an intense dust event. In 2013, 19 LOAC flights have been performed under meteorological balloons and 12 under low altitude drifting balloons, most of them from Minorca Island (Spain) in June and early July and others from Levant Island (south of France

  6. A comprehensive study of noble gases and nitrogen in "Hypatia", a diamond-rich pebble from SW Egypt

    NASA Astrophysics Data System (ADS)

    Avice, Guillaume; Meier, Matthias M. M.; Marty, Bernard; Wieler, Rainer; Kramers, Jan D.; Langenhorst, Falko; Cartigny, Pierre; Maden, Colin; Zimmermann, Laurent; Andreoli, Marco A. G.

    2015-12-01

    This is a follow-up study of a work by Kramers et al. (2013) on a very unusual diamond-rich rock fragment found in the area of south west Egypt in the south-western side of the Libyan Desert Glass strewn field. This pebble, called Hypatia, is composed of almost pure carbon. Transmission Electron Microscopy (TEM) and X-ray diffraction (XRD) results reveal that Hypatia is mainly made of defect-rich diamond containing lonsdaleite and multiple deformation bands. These characteristics are compatible with an impact origin on Earth and/or in space. We also analyzed concentrations and isotopic compositions of all five noble gases and nitrogen in several ∼mg sized Hypatia samples. These data confirm the conclusion by Kramers et al. (2013) that Hypatia is extra-terrestrial. The sample is relatively rich in trapped noble gases with an isotopic composition being close to the Q component found in many types of meteorites. 40Ar/36Ar ratios in individual steps are as low as 0.4 ± 0.3. Cosmic-ray produced ;cosmogenic; 21Ne is present in concentrations corresponding to a nominal cosmic-ray exposure (CRE) age of roughly 0.1 Myr if produced in a typical meter-sized meteoroid. Such an atypically low nominal CRE age suggests high shielding in a considerably larger body. In addition to the Xe-Q composition, an excess of radiogenic 129Xe (from the decay of short-lived radioactive 129I) is observed (129Xe /132Xe = 1.18 + / - 0.03). Two isotopically distinct N components are present, an isotopically heavy component (δ15N ∼ + 20 ‰) released at low temperatures and a major isotopically light component (δ15N ∼ - 110 ‰) at higher temperatures. This disequilibrium in N suggests that the diamonds in Hypatia were formed in space rather than upon impact on Earth (δN15atm = 0 ‰). All our data are broadly consistent with concentrations and isotopic compositions of noble gases in at least three different types of carbon-rich meteoritic materials: carbon-rich veins in ureilites

  7. Analysis of utilization of desert habitats with dynamic simulation

    USGS Publications Warehouse

    Williams, B.K.

    1986-01-01

    The effects of climate and herbivores on cool desert shrubs in north-western Utah were investigated with a dynamic simulation model. Cool desert shrublands are extensively managed as grazing lands, and are defoliated annually by domestic livestock. A primary production model was used to simulate harvest yields and shrub responses under a variety of climatic regimes and defoliation patterns. The model consists of six plant components, and it is based on equations of growth analysis. Plant responses were simulated under various combinations of 20 annual weather patterns and 14 defoliation strategies. Results of the simulations exhibit some unexpected linearities in model behavior, and emphasize the importance of both the pattern of climate and the level of plant vigor in determining optimal harvest strategies. Model behaviors are interpreted in terms of shrub morphology, physiology and ecology.

  8. Biological soil crusts as an integral component of desert environments

    USGS Publications Warehouse

    Belnap, Jayne; Weber, Bettina

    2013-01-01

    The biology and ecology of biological soil crusts, a soil surface community of mosses, lichens, cyanobacteria, green algae, fungi, and bacteria, have only recently been a topic of research. Most efforts began in the western U.S. (Cameron, Harper, Rushforth, and St. Clair), Australia (Rogers), and Israel (Friedmann, Evenari, and Lange) in the late 1960s and 1970s (e.g., Friedmann et al. 1967; Evenari 1985reviewed in Harper and Marble 1988). However, these groups worked independently of each other and, in fact, were often not aware of each other’s work. In addition, biological soil crust communities were seen as more a novelty than a critical component of dryland ecosystems. Since then, researchers have investigated many different aspects of these communities and have shown that although small to microscopic, biological soil crusts are critical in many ecological processes of deserts. They often cover most of desert soil surfaces and substantially mediate inputs and outputs from desert soils (Belnap et al. 2003). They can be a large source of biodiversity for deserts, as they can contain more species than the surrounding vascular plant community (Rosentreter 1986). These communities are important in reducing soil erosion and increasing soil fertility through the capture of dust and the fixation of atmospheric nitrogen and carbon into forms available to other life forms (Elbert et al. 2012). Because of their many effects on soil characteristics, such as external and internal morphological characteristics, aggregate stability, soil moisture, and permeability, they also affect seed germination and establishment and local hydrological cycles. Covering up to 70% of the surface area in many arid and semi-arid regions around the world (Belnap and Lange 2003), biological soil crusts are a key component within desert environments.

  9. Phytoremediation for Oily Desert Soils

    NASA Astrophysics Data System (ADS)

    Radwan, Samir

    This chapter deals with strategies for cleaning oily desert soils through rhizosphere technology. Bioremediation involves two major approaches; seeding with suitable microorganisms and fertilization with microbial growth enhancing materials. Raising suitable crops in oil-polluted desert soils fulfills both objectives. The rhizosphere of many legume and non-legume plants is richer in oil-utilizing micro-organisms than non-vegetated soils. Furthermore, these rhizospheres also harbour symbiotic and asymbiotic nitrogen-fixing bacteria, and are rich in simple organic compounds exuded by plant roots. Those exudates are excellent nutrients for oil-utilizing microorganisms. Since many rhizospheric bacteria have the combined activities of hydrocarbon-utilization and nitrogen fixation, phytoremediation provides a feasible and environmentally friendly biotechnology for cleaning oil-polluted soils, especially nitrogen-poor desert soils.

  10. 75 FR 52776 - Notice of Availability of the Draft Environmental Impact Statement for the Desert Sunlight...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-27

    ... Desert Sunlight Holdings, LLC Desert Sunlight Solar Farm Project and Possible California Desert...) has prepared a Draft Environmental Impact Statement (EIS) and Draft California Desert Conservation Area (CDCA) Plan Amendment for the Desert Sunlight Holdings, LLC Desert Sunlight Solar Farm...

  11. Identification and interpretation of tectonic features from Skylab imagery. [Mojave Desert block of Texas, Arizona, and Chihuahua, Mexico

    NASA Technical Reports Server (NTRS)

    Abdel-Gawad, M. (Principal Investigator)

    1975-01-01

    The author has identified the following significant results. Two alternate models for the extension of the Texas zone through the Mojave Desert block have been developed: (1) along the Pisgah Line, and (2) along the eastern Transverse Ranges; this model suggests a counterclockwise rotation of the Mojave block. Analysis of S190B photographs of the western Mojave Desert provides strong evidence for the feasibility of identifying recent fault breaks.

  12. Quantifying dust emissions from desert landforms, eastern Mojave Desert, USA

    NASA Astrophysics Data System (ADS)

    Sweeney, Mark R.; McDonald, Eric V.; Etyemezian, Vicken

    2011-12-01

    The measurement of natural dust emissions from desert landforms is crucial in environmental hazard assessment and field checking the accuracy of global dust models. More than 500 individual dust measurements from eight common desert landforms in southern California were collected using the PI-SWERL (Portable In Situ Wind Erosion Lab). The largest emitters of dust are dry washes (13.787 to 0.007 mg m - 2 s - 1 ), dunes, playa margins, distal alluvial fans, and lacustrine beaches. Low emitters include salt-crusted playas (0.692 to 0.002 mg m - 2 s - 1 ), silt-clay-crusted playas, and desert pavements. High emissions are a function of saltating sand that bombards the surface, liberating dust-sized particles for entrainment. Low dust emissions are primarily a function of surface crusting, gravel armoring, and vegetation density. PI-SWERL measurements reveal that emission rates can vary by at least three orders of magnitude, reflecting local variability in soil texture and continuity of surface crusts. Shear-stress partitioning models can be applied to dust data measured by the PI-SWERL to account for large surface roughness features, such as vegetation. The results presented here give an approximation of the contributions to atmospheric dust loading by landforms in the Mojave Desert, and can potentially be used to improve atmospheric dust models.

  13. Exercise Desert Rock, Staff Memorandums. Army, Camp Desert Rock, Nevada.

    DTIC Science & Technology

    1957-01-01

    activities with the Safety Program. (2) Notifying the Exercise Safety Director of all fire@ involving government prcperty and equipment and for... Exercise Safety Director to the organization or activity conc- erned. o _ . _ . - : : , _ : ... .. ... .. . - _ . . .. . , ... .. .. ... ... . . ..7 memo...Nr 1, Exercise Desert Rocc4.WIVn’d VIII, 17 May 57 (Contd) (4) The officer in charge of the activity shall, within ten days after receiving the

  14. BIOGENIC VOLATILE ORGANIC COMPOUND EMISSIONS FROM DESERT VEGETATION OF THE SOUTHWESTERN U.S.

    EPA Science Inventory

    Thirteen common plant species in the Mojave and Sonoran Desert regions of the western United States were tested for emissions of biogenic non-methane volatile organic compounds (BVOCs). Only two of the species examined emitted isoprene at rates of 10 µgCg−1 ...

  15. Operation Iraqi Freedom: An Operational Opportunity to Complete the Strategic Objectives of Desert Storm

    DTIC Science & Technology

    2006-05-31

    Likely anticipating a repeat of Desert Storm, Iraqi leadership expected time to further work diplomatic initiatives. Given the vocal international and...made the House of Saud a “house of cards.” The same is true for many of its neighbors. Building an independent and strong pro- Western region not only

  16. Mesozoic evolution of the northeast African shelf margin, Libya and Egypt

    SciTech Connect

    Aadland, R.K.; Schamel, S.

    1988-08-01

    The present tectonic features of the northeast African shelf margin between the Nile delta and the Gulf of Sirte are products of (1) precursory late Paleozoic basement arches, (2) early Mesozoic rifting and plate separation, and (3) Late Cretaceous structural inversion. Isopach and structural maps, cross sections, and sediment accumulation (geohistory) curves constructed from 89 wells in the Western Desert and 27 wells in northeastern Libya depict the structural and stratigraphic development of the northeast African shelf margin.

  17. Instrumental neutron activation analysis of soil and sediment samples from Siwa Oasis, Egypt

    NASA Astrophysics Data System (ADS)

    Badawy, Wael M.; Ali, Khaled; El-Samman, Hussein M.; Frontasyeva, Marina V.; Gundorina, Svetlana F.; Duliu, Octavian G.

    2015-07-01

    Instrumental neutron activation analysis was used to study geochemical peculiarities of the Siwa Oasis in the Western Egyptian Desert. A total of 34 elements were determined in soil and sediment samples (Na, Mg, Al, Cl, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, As, Br, Rb, Sr, Zr, Sb, I, Cs, Ba, La, Ce, Nd, Eu, Tb, Dy, Tm, Yb, Hf, Ta, Th, and U). For data interpretation Cluster analysis was applied. Comparison with the available literature data was carried out.

  18. Management of Disused Radioactive Sealed Sources in Egypt - 13512

    SciTech Connect

    Mohamed, Y.T.; Hasan, M.A.; Lasheen, Y.F.

    2013-07-01

    The future safe development of nuclear energy and progressive increasing use of sealed sources in medicine, research, industry and other fields in Egypt depends on the safe and secure management of disused radioactive sealed sources. In the past years have determined the necessity to formulate and apply the integrated management program for radioactive sealed sources to assure harmless and ecological rational management of disused sealed sources in Egypt. The waste management system in Egypt comprises operational and regulatory capabilities. Both of these activities are performed under legislations. The Hot Laboratories and Waste Management Center HLWMC, is considered as a centralized radioactive waste management facility in Egypt by law 7/2010. (authors)

  19. Paleoclimatic and Tectonic History of the Eastern Desert, Egypt and Surroundings

    NASA Technical Reports Server (NTRS)

    Arvidson, Raymond E.

    1997-01-01

    This report covers work for the Planetary Geology and Geophysics Program, which has focused on three areas: analysis of the tectonics and paleoclimatic conditions in north eastern Africa, analysis of surficial geology and damage associated with the 1993 Missouri River floods and rates of lava flow degradation at Lunar Crater volcanic field in Nevada. Work has resulted in several dozen abstracts, several dissertations and a number of papers.

  20. Evaluation of airborne gamma-ray spectrometric data for the Missikat uranium deposit, Eastern Desert, Egypt.

    PubMed

    Abd El Nabi, S H

    2001-03-01

    The examination of gamma-ray spectrometric data of the Missikat area was found to be useful in locating areas worth exploring for uranium occurrence. The statistical treatment of these data shows that the uranium threshold level is 13 ppm. Such a value represents indirectly the presence of uranium mineralization and identifies anomalous areas on the eU contour map in the northern border of the Missikat-Ria El Gerra granitic plutons. This area should be of prime concern in uranium exploration of these plutons. The interpretation of the variation in the eU/eTh ratio with eU and eTh suggests that uranium redistribution has occurred within the Missikat-Ria El Gerra granitic plutons. Uranium may be reconcentrated in silicification, sericitization and kaolinization alterations which are geologically evident. eU, eTh and their ratio eU/eTh for the Missikat-Ria El Gerra granites exhibit a lognormal distribution which is in agreement with the general distribution of trace elements, whereas the K content tends towards a normal distribution.

  1. Fracture analysis and its relation to radioactivity around Gebel Um Risha, south eastern desert, Egypt

    NASA Astrophysics Data System (ADS)

    El Khateeb, S. O.; El Akraby, A. M.

    1994-07-01

    Analysis of radioactive fracture patterns prevailing in the study area revealed that there are a number of tectonic trends which show abnormal radioactivity. These trends can be arranged according to the degree of their importance as NW, NE, EW and NS. Meanwhile, they are applied in delineating interesting structural features that may serve as favourable loci of economic radioactive mineral deposits. Correlation of these radioactive fracture patterns with those deduced from surface geological map of the study area exhibits a good agreement assuring the importance of aeroradiometric survey data as an excellent tool in structural mapping.

  2. Basement structural control on Cretaceous pull-apart basins of the central Eastern Egypt Desert

    NASA Astrophysics Data System (ADS)

    McCaffrey, K.; El Kazzaz, Y.; Holdsworth, B.

    2006-12-01

    The present-day Red Sea / Gulf of Suez rift system is attributed to extensional block faulting with along-axis segmentation into sub-basins with different dip polarities. The northwestern margin of the Red Sea - Gulf of Suez rift system is exposed for about 400 km along the northwestern Red Sea coast near Quseir to the tip of the Gulf of Suez at Suez City. This area contains elements of the pre-Red Sea structural pattern which has been viewed in similar terms as one of fault-related basin formation. Four distinct depocenters (sub-basins) separated by complex accommodation zones are present containing 500-700m thick section ranging in age from the Late Cretaceous to the Middle Eocene. Each sub-basin is asymmetric, bounded on one side by a major NW-trending border fault system with large throws (3-6 km in general) with a dominant strata dip direction toward the border fault system. These basins are arranged in en echelon patterns and now form separate elongated ridges surrounded by basement rocks. Our study of the tectonic evolution of the central eastern section of the Gulf of Suez rift and the Northwestern Red Sea has focused on the interaction of pre-existing basement fabrics with the pre-Red Sea structural development. The study involved analysis of LandsatTM images and aerial photographs integrated with results from reconnaissance geological mapping. Our provisional results indicate that the Gebel Um Hammad/Duwi and Hammadat sub-basins were sited in pull-apart structures created by dextral reactivation of E-W to ENE-WSW trending basement fault zones. We show how the basin-bounding fault systems, lower order normal faults and folds in both hangingwall sequences and in basement are compatible with a Late Cretaceous to Early Eocene strike-slip regime. In contrast, the main Red Sea Gulf of Suez rift shows no evidence for strike-slip influence with the main boundary faults cutting across basement fabrics, however, as pointed out by previous authors, rift segmentation does appear to be basement-influenced.

  3. Biostratigraphy of the Middle Eocene succession at Gebel Mishgigah, Wadi Rayan, Libyan Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Allam, A.; Shamah, K.; Zalat, A.

    The present study deals with the biozonation of the exposed section at Gebel Mishgigah, which is mainly composed of highly fossiliferous limestones, dolostones and marls. These deposits belong to Mishgigah Member of Wadi Rayan Formation and are of Late Lutetian to Bartonian (Late Middle Eocene) age. The collected samples were investigated for their microfaunal and nannofloral content. Different associations of calcareous nannoplankton, planktonic foraminifers, ostracods and bryozoans were detected. The depositional environments and paleoecologic factors that prevailed during the sedimentation were also interpreted.

  4. Lower Miocene stratigraphy of the Gebel Shabrawet area, north Eastern desert Egypt

    NASA Astrophysics Data System (ADS)

    Abdelghany, Osman

    2002-05-01

    The Lower Miocene carbonate/siliciclastic sequence of the Shabrawet area, comprises a complex alternation of autochthonous and allogenic sediments. The sequence can be subdivided into two lithostratigraphic units. The lower unit (unit I) is equivalent to the Gharra Formation. It is mainly clastic and composed of sandstones, siltstones and shales with minor limestone intercalations. These sediments are rich in Clypeaster spp., Scutella spp., Miogypsina intermedia, Operculina complanata, and smaller foraminifera. The upper unit (unit II) was considered by previous workers as being equivalent to the Marmarica Formation. It consists mainly of non-clastic rocks, dominated by sandy and chalky limestones rich in larger foraminifera (miogypsinids and nummulitids). This unit is topped by a highly fossiliferous ( Heterostegina, Operculina and Planostegina) sandy limestone. The present study places both units in the Gharra Formation and reports for the first time M. intermedia from the Miocene sequence of the Shabrawet area.

  5. Geometry and texture of quartz veins in Wadi Atalla area, Central Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Akawy, Ahmed

    2007-02-01

    Several quartz vein sets with varying orientation, geometry and internal structure were recognized in the Atalla area. The veins were associated with the deformation phases affecting the area. En echelon and extensional veins are the main geometrical types. Syn-kinematic veins associated with the major northeast-over-southwest thrust faults were later boudinaged, folded and re-folded. En echelon veins, fibrous veins, and extensional veins are associated with the NNW-SSE faults. Other veins are associated with the NW-SE, N-S, NE-SW and E-W faults. Veins are concentrated at the intersection zones between faults. The internal structure of the veins comprises syntaxial, antitaxial, and composite types and reflects a change from a compressive stress regime to an extensional one. Chocolate-tablet structures and synchronous and co-genetic vein networks indicate later multi-directional extension of the area. Interaction between cracking and sealing of fractures is a common feature in the study area indicating that it was easy for the pore pressure to open pre-existing fractures instead of creating new ones. The reopening of pre-existing fractures rather than creating new ones is also indicated by the scattering of vein data around σ3. There is an alteration and change in characteristics of the wall rock due to increase in fluid flow rate. Fault-valving probably is also a cause of the complex geometry of some veins.

  6. Radiocarbon-based chronology for dynastic Egypt.

    PubMed

    Bronk Ramsey, Christopher; Dee, Michael W; Rowland, Joanne M; Higham, Thomas F G; Harris, Stephen A; Brock, Fiona; Quiles, Anita; Wild, Eva M; Marcus, Ezra S; Shortland, Andrew J

    2010-06-18

    The historical chronologies for dynastic Egypt are based on reign lengths inferred from written and archaeological evidence. These floating chronologies are linked to the absolute calendar by a few ancient astronomical observations, which remain a source of debate. We used 211 radiocarbon measurements made on samples from short-lived plants, together with a Bayesian model incorporating historical information on reign lengths, to produce a chronology for dynastic Egypt. A small offset (19 radiocarbon years older) in radiocarbon levels in the Nile Valley is probably a growing-season effect. Our radiocarbon data indicate that the New Kingdom started between 1570 and 1544 B.C.E., and the reign of Djoser in the Old Kingdom started between 2691 and 2625 B.C.E.; both cases are earlier than some previous historical estimates.

  7. Ostrich (Struthio camelus) production in Egypt.

    PubMed

    Cooper, R G; Mahrose, K M A; El-Shafei, M; Marai, I F M

    2008-06-01

    This review discusses the historical, developmental and practices of ostrich farming in Egypt. In the early 20th century, ostrich farming was very important for production of ostrich feathers and documents were produced to perfect the art of procuring the plumes from the birds and subsequently processing them. Pharaohs used ostrich feathers for adornment. Of 43 provinces, 12 were featured in 2003-2004 as farming ostriches: Alexandria, Al-Behera, Al-Dakahlia, Al-Wadi Al-Gadid, Aswan, Cairo, El-Sharkia, Geiza, Ismailia, Kafr-El-Sheikh, Matrouh and Nubaria. Abattoirs and tanneries specialising in ostrich handling are limited to two. Egypt has numerous strengths and opportunities to develop its ostrich sector. Rising meat prices suggest that fresh ostrich meat is unaffordable to many locals. Funds may be allocated to local advertising campaigns to promote ostrich meat; provision of incentives to farmers; and improving the capacity of abattoirs.

  8. Dental health and disease in ancient Egypt.

    PubMed

    Forshaw, R J

    2009-04-25

    In ancient Egypt the exceptionally dry climate together with the unique burial customs has resulted in the survival of large numbers of well-preserved skeletal and mummified remains. Examinations of these remains together with an analysis of the surviving documentary, archaeological and ethnographic evidence has enabled a detailed picture of the dental health of these ancient people to be revealed, perhaps more so than for any other civilisation in antiquity. In this, the first of two articles, the dental pathological conditions that afflicted the ancient Egyptians is considered. The commonest finding is that of tooth wear, which was often so excessive that it resulted in pulpal exposure. Multiple abscesses were frequently seen, but caries was not a significant problem. Overall the findings indicate that the various pathological conditions and non-pathological abnormalities of teeth evident in dentitions in the twenty-first century were also manifest in ancient Egypt, although the incidences of these conditions varies considerably between the civilisations.

  9. [Concepts of the heart in Ancient Egypt].

    PubMed

    Ziskind, Bernard; Halioua, Bruno

    2004-03-01

    The heart was regarded in Ancient Egypt as the organic motor of the body and also the seat of intelligence, an important religious and spiritual symbol. It was considered as one of the eight parts of human body. Counter to other organs it had to be kept carefully intact in the mummy to ensure its eternal life. In Ancient Egypt, the concept of heart included three constituents: heart-haty, heart-ib, and the spiritual seat of intelligence, emotion and memory. The hieroglyphs representing the heart early in the first dynasty were drawn with eight vessels attached to it. Egyptian doctors have elaborated an original conception of cardiovascular physiology which endured 30 centuries.

  10. Benchmarking performance: Environmental impact statements in Egypt

    SciTech Connect

    Badr, El-Sayed A.; Zahran, Ashraf A.; Cashmore, Matthew

    2011-04-15

    Environmental impact assessment (EIA) was formally introduced in Egypt in 1994. This short paper evaluates 'how well' the EIA process is working in practice in Egypt, by reviewing the quality of 45 environmental impact statements (EISs) produced between 2000 and 2007 for a variety of project types. The Lee and Colley review package was used to assess the quality of the selected EISs. About 69% of the EISs sampled were found to be of a satisfactory quality. An assessment of the performance of different elements of the EIA process indicates that descriptive tasks tend to be performed better than scientific tasks. The quality of core elements of EIA (e.g., impact prediction, significance evaluation, scoping and consideration of alternatives) appears to be particularly problematic. Variables that influence the quality of EISs are identified and a number of broad recommendations are made for improving the effectiveness of the EIA system.

  11. Monitoring Wadi El Raiyan lakes of the egyptian desert for inorganic pollutants by ion-selective electrodes, ion chromatography, and inductively coupled plasma spectroscopy.

    PubMed

    Saleh, M A; Ewane, E; Jones, J; Wilson, B L

    2000-03-01

    Wadi El Raiyan is a great depression located southwest of Cairo in the western desert of Egypt, one of the most arid regions of the world. In 1973, Wadi El Raiyan was connected with the agricultural wastewater drainage system of the El Faiyum province to provide a reservoir for the wastewater that exceeded the capacity of Lake Qarun north of the province. Pollutants from agricultural waste including pesticides and fertilizers as well as other effluents of industrial activities and runoffs certainly will pass into the biotic elements of the ecosystem. This report presents the status of inorganic pollutants including anions, cations, and trace metals in the two lakes and the surrounding springs of Wadi El Raiyan using ion chromatography, ion-selective electrodes, and inductively coupled plasma emission spectroscopy. The report also includes the levels of selected metals in the vegetation community of the area. The result of this investigation revealed a great improvement in water quality of the Wadi El Raiyan lakes compared to 1988 report by Saleh et al. Mercury was not detected in any of the samples and the level of lead was significantly reduced. Cadmium levels were much higher than those seen earlier. The higher level of cadmium might be used as an indicator to track the contamination of water by human waste. Concentrations of common anions were not significantly different from those reported earlier. However, an increase in the level of cyanide was observed. Levels of heavy metals in vegetation around the lakes were also found to be lower than previously reported.

  12. First evidence of enterobiasis in ancient Egypt.

    PubMed

    Horne, P D

    2002-10-01

    The oldest and most common parasite for which we have direct evidence, in the New World, is Enterobius vernicularis. Numerous archaeological sites, especially in the arid American southwest, have yielded fecal samples positive for pinworm ova, some of these dating back 10,000 yr. Reports of pinworm from the Old World are scarce. This article reports the first evidence of pinworm infection from Roman-occupied (30 BC-AD 395) Egypt.

  13. Living donor liver transplantation in Egypt

    PubMed Central

    Marwan, Ibrahim

    2016-01-01

    In Egypt there is no doubt that chronic liver diseases are a major health concern. Hepatitis C virus (HCV) prevalence among the 15−59 years age group is estimated to be 14.7%. The high prevalence of chronic liver diseases has led to increasing numbers of Egyptian patients suffering from end stage liver disease (ESLD), necessitating liver transplantation (LT). We reviewed the evolution of LT in Egypt and the current status. A single center was chosen as an example to review the survival and mortality rates. To date, deceased donor liver transplantation (DDLT) has not been implemented in any program though Egyptian Parliament approved the law in 2010. Living donor liver transplantation (LDLT) seemed to be the only logical choice to save many patients who are in desperate need for LT. By that time, there was increase in number of centers doing LDLT (13 centers) and increase in number of LDLT cases [2,400] with improvement of the results. Donor mortality rate is 1.66 per 1,000 donors; this comprised four donors in the Egyptian series. The exact recipient survival is not accurately known however, and the one-year, three-year and five-year survival were 73.17%, 70.83% and 64.16% respectively in the International Medical Center (IMC) in a series of 145 adult to adult living donor liver transplantation (AALDLT) cases. There was no donor mortality in this series. LDLT are now routinely and successfully performed in Egypt with reasonable donor and recipient outcomes. Organ shortage remains the biggest hurdle facing the increasing need for LT. Although LDLT had reasonable outcomes, it carries considerable risks to healthy donors. For example, it lacks cadaveric back up, and is not feasible for all patients. The initial success in LDLT should drive efforts to increase the people awareness about deceased organ donation in Egypt. PMID:27115003

  14. Living donor liver transplantation in Egypt.

    PubMed

    Amer, Khaled E; Marwan, Ibrahim

    2016-04-01

    In Egypt there is no doubt that chronic liver diseases are a major health concern. Hepatitis C virus (HCV) prevalence among the 15-59 years age group is estimated to be 14.7%. The high prevalence of chronic liver diseases has led to increasing numbers of Egyptian patients suffering from end stage liver disease (ESLD), necessitating liver transplantation (LT). We reviewed the evolution of LT in Egypt and the current status. A single center was chosen as an example to review the survival and mortality rates. To date, deceased donor liver transplantation (DDLT) has not been implemented in any program though Egyptian Parliament approved the law in 2010. Living donor liver transplantation (LDLT) seemed to be the only logical choice to save many patients who are in desperate need for LT. By that time, there was increase in number of centers doing LDLT (13 centers) and increase in number of LDLT cases [2,400] with improvement of the results. Donor mortality rate is 1.66 per 1,000 donors; this comprised four donors in the Egyptian series. The exact recipient survival is not accurately known however, and the one-year, three-year and five-year survival were 73.17%, 70.83% and 64.16% respectively in the International Medical Center (IMC) in a series of 145 adult to adult living donor liver transplantation (AALDLT) cases. There was no donor mortality in this series. LDLT are now routinely and successfully performed in Egypt with reasonable donor and recipient outcomes. Organ shortage remains the biggest hurdle facing the increasing need for LT. Although LDLT had reasonable outcomes, it carries considerable risks to healthy donors. For example, it lacks cadaveric back up, and is not feasible for all patients. The initial success in LDLT should drive efforts to increase the people awareness about deceased organ donation in Egypt.

  15. Egypt: Background and U.S. Relations

    DTIC Science & Technology

    2008-02-08

    December 6, 2005, U.S. State Department Deputy Spokesman Adam Ereli remarked that “We’ve also seen a number of developments over the past couple weeks...when Egypt hosted the signing of an Israeli-Palestinian agreement for implementing past commitments and meetings between then Secretary of State...Mubarak. Over the past several years, Mubarak’s forty-one year old son, Gamal, increasingly has become involved at the highest levels of the NDP, though

  16. Egypt: Background and U.S. Relations

    DTIC Science & Technology

    2013-06-27

    Egypt from sliding into a dark tunnel of conflict, internal fighting, criminality, accusations of treason, sectarian discord and the collapse of state...order to assist exports18 and tourism , the Central Bank has tried to manage the gradual devaluation of the currency (Egyptian Pound), which has slid...have the travel ban on the Americans who remained at the U.S. Embassy in Cairo lifted. Reportedly, U.S. officials and lawmakers threatened not only

  17. Egypt: Background and U.S. Relations

    DTIC Science & Technology

    2007-06-19

    Saudi Arabia as countries that “have a great distance still to travel” in making democratic reforms. Egyptian Foreign Minister Ahmed Abul Gheit...Egypt’s Inshas reactor and providing them to agents of Israel’s Mossad intelligence service in return for $17,000. Earlier in the year, Egypt asked the...genocide,” and has denounced the U.S. imposition of sanctions on the Sudanese government. According to Egyptian Foreign Minister Ahmed Abul Gheit, “Sanctions

  18. Modeling Soil Moisture in the Mojave Desert

    USGS Publications Warehouse

    Miller, David M.; Hughson, Debra; Schmidt, Kevin M.

    2008-01-01

    The Mojave Desert is an arid region of southeastern California and parts of Nevada, Arizona, and Utah; the desert occupies more than 25,000 square miles (fig. 1). Ranging from below sea level to over 5,000 feet (1,524 m) in elevation, the Mojave Desert is considered a ?high desert.? On the west and southwest it is bounded by the Sierra Nevada, the San Gabriel, and the San Bernardino Mountains. These imposing mountains intercept moisture traveling inland from the Pacific Ocean, producing arid conditions characterized by extreme fluctuations in daily temperatures, strong seasonal winds, and an average annual precipitation of less than six inches. The Mojave Desert lies farther south and at a lower elevation than the cooler Great Basin Desert and grades southward into the even lower and hotter Sonoran Desert.

  19. Integrated Human Futures Modeling in Egypt

    SciTech Connect

    Passell, Howard D.; Aamir, Munaf Syed; Bernard, Michael Lewis; Beyeler, Walter E.; Fellner, Karen Marie; Hayden, Nancy Kay; Jeffers, Robert Fredric; Keller, Elizabeth James Kistin; Malczynski, Leonard A.; Mitchell, Michael David; Silver, Emily; Tidwell, Vincent C.; Villa, Daniel; Vugrin, Eric D.; Engelke, Peter; Burrow, Mat; Keith, Bruce

    2016-01-01

    The Integrated Human Futures Project provides a set of analytical and quantitative modeling and simulation tools that help explore the links among human social, economic, and ecological conditions, human resilience, conflict, and peace, and allows users to simulate tradeoffs and consequences associated with different future development and mitigation scenarios. In the current study, we integrate five distinct modeling platforms to simulate the potential risk of social unrest in Egypt resulting from the Grand Ethiopian Renaissance Dam (GERD) on the Blue Nile in Ethiopia. The five platforms simulate hydrology, agriculture, economy, human ecology, and human psychology/behavior, and show how impacts derived from development initiatives in one sector (e.g., hydrology) might ripple through to affect other sectors and how development and security concerns may be triggered across the region. This approach evaluates potential consequences, intended and unintended, associated with strategic policy actions that span the development-security nexus at the national, regional, and international levels. Model results are not intended to provide explicit predictions, but rather to provide system-level insight for policy makers into the dynamics among these interacting sectors, and to demonstrate an approach to evaluating short- and long-term policy trade-offs across different policy domains and stakeholders. The GERD project is critical to government-planned development efforts in Ethiopia but is expected to reduce downstream freshwater availability in the Nile Basin, fueling fears of negative social and economic impacts that could threaten stability and security in Egypt. We tested these hypotheses and came to the following preliminary conclusions. First, the GERD will have an important short-term impact on water availability, food production, and hydropower production in Egypt, depending on the short- term reservoir fill rate. Second, the GERD will have a very small impact on

  20. Lyme borreliosis: A neglected zoonosis in Egypt.

    PubMed

    Elhelw, Rehab A; El-Enbaawy, Mona I; Samir, Ahmed

    2014-12-01

    Borrelia burgdorferi, the causal organism of Lyme borreliosis. In Egypt, available data about the occurrence of Lyme disease are scarce and no structured studies documented the presence of Lyme borreliosis in Egyptian animals and tick reservoirs verifying its zoonotic evidence. Besides, no successful trials to isolate B. burgdorferi from clinical samples have occurred. This study was conducted to investigate B. burgdorferi infection as an emerging zoonosis neglected in Egypt. A total number of 92 animals, tick and human companion specimens were collected and subjected for culture, PCR and/or serodetection. B. burgdorferi has been detected and isolated from Egyptian animal breeds. We also detected the presence of outer surface protein A gene of B. burgdorferi by PCR as well as anti-B. burgdorferi IgM by ELISA in human contacts who were suffering from fever of unknown origin. This report represents the first systematic study on animals associated with patients suffering from febrile illness to confirm the emerging of such neglected zoonosis in Egypt.

  1. Correlation of the major late Jurassic —early Tertiary low- and highstand cycles of south-west Egypt and north-west Sudan

    NASA Astrophysics Data System (ADS)

    Wycisk, Peter

    1994-12-01

    The mainly continental deposits of northwest Sudan and south-west Egypt have been correlated with coeval shallow marine and marine deposits in northern Egypt along a north-south running cross-section, based on surface and subsurface data. The palaeodepth curve of northern Egypt illustrates the gradual seal-level rise, reaching its maximum during the Late Cretaceous with conspicuous advances during the Aptian and late Cenomanian. A general highstand is also recorded during the Campanian-Maastrichtian in north-west Sudan. A detailed facies correlation is given for the Aptian and late Cenomanian highstand in western Egypt. The correlation of the Cenomanian Bahariya and Maghrabi formations displays short-term relative sealevel fluctuations. The interpretation illustrates the extensiveness of related erosional processes in the hinterland, partly intensified by temporarily uplift of the Uweinat-Aswan High in the south. Regional uplift and constant erosion took place in south-west Egypt during Coniacian and Santonian times. The regional stratigraphic gaps and uncertain interpretation of the Bahariya Uplift are induced by the influence of the Trans-African Lineament, especially during the Late Cretaceous. Low-stand fluvial sheet sandstones characterized by non-cyclic sequence development and high facies stability occur, especially in the Neocomian and early Turonian. During the Barremian and Albian, fluvial architecture changes to more cyclic fluvial sequences and increasing soil formation, due to increasing subsidence, more humid climatic conditions and the generally rising sea level, culminating in the extensive shallow marine Abu Ballas and Maghrabi formations.

  2. Hf-Nd-Sr isotopic fingerprinting of mineral dust from Asian and North African deserts

    NASA Astrophysics Data System (ADS)

    Ji, J.; Zhao, W.; Balsam, W.

    2015-12-01

    Mineral dust accounts for more than 50% of the atmospheric dust loading and plays an important role in the marine and terrestrial geochemical cycles. The deserts in North Africa, Northern China and Southern Mongolia are the major sources of mineral dust and have been studied intensively over past decades, especially with Sr, Nd and recently Hf isotopes which are seen as powerful tools to identify source areas. However, the isotopic compositions of dust are highly dependent on particle size hindering the ability to accurately identify dust provenance. The clay fraction (<2 μm) comprises about half of all mineral dust and has unique minerals phases dominanted by clay minerals. Once the clay-sized particles are deflated to the upper troposphere, they are transported over long distances and are removed from the atmosphere mainly by wet deposition. Thus, the clay-sized isotopic fingerprints from deserts may be ideal targets not only for tracking the provenance tracing of long-distance transported mineral dust, but also to provide an unparalleled window for understanding the global dust cycle, especially eolian dust preserved in deep-sea sediments and ice cores. In this work we investigate multivariate joint radiogenic Sr, Nd, and Hf isotopic compositions obtained from complete dissolution of clay-sized fractions of surface sediments from Asian and North African deserts. Asian dust source samples included the ten Northern China deserts and sandy lands - the Taklimakan, Gurbantunggut, Qaidam, Badaim Jaran, Tengger and Mu Us deserts, and the Hobq, Hulun Buirm, Onqin Daga and Horqin sandy land - and Mongolian Gobi desert. North African dust samples were from four transects in the Sahara and Sahel from Mali, Togo, Egypt and Morocco . Our results on the clay-sized isotopic measurements of these samples describe (1) the general characteristics of dusts from the Asian with ɛNd from -17.3 to 0.98, ɛHf from -5.95 to 3.68 and 87Sr/86Sr from 0.710113 to 0.73306, and North

  3. Western USA

    Atmospheric Science Data Center

    2014-05-15

    ... to the east of the Continental Divide, the Snake to the west, and the Colorado, which wends across Utah and Arizona. The Colorado ... southwestern portion of the image, California's San Joaquin Valley and the Mojave Desert of California and Nevada give way to the Los ...

  4. Integrate the Arts. The Art of Ancient Egypt.

    ERIC Educational Resources Information Center

    Parks, Mary

    1996-01-01

    Presents three art projects that can bring to life the study of ancient Egypt for elementary students. After researching Egypt's history and culture, students can create King Tut masks, make Cleopatra headdresses, and craft cartouche pendants. The article describes the materials needed and steps required to complete each project. (SM)

  5. Power and Gender in Ancient Egypt: The Case of Hatshepsut

    ERIC Educational Resources Information Center

    Hilliard, Kristina; Wurtzel, Kate

    2009-01-01

    Hatshepsut (1479-1458 B.C.E) ruled New Kingdom Egypt for roughly 20 years as one of the few female pharaohs in the history of ancient Egypt. Her rule began when her husband died and her stepson was too young to be pharaoh. To legitimize her role as pharaoh, Hatshepsut began a significant building campaign by constructing numerous images, temples,…

  6. Tech Talk for Social Studies Teachers: Ancient Egypt.

    ERIC Educational Resources Information Center

    Pahl, Ronald H.

    1998-01-01

    Presents an annotated bibliography of 10 Web sites concerning ancient Egypt that have materials appropriate for social studies classes. Includes virtual tours of Egypt and specific temples, explorations of the pyramids, archaeological and geographic information, and information on the Egyptian "Book of the Dead." (MJP)

  7. Resource Unit on Egypt for the Intermediate Grades.

    ERIC Educational Resources Information Center

    Husbands, Kenneth; Taylor, Bob

    Resources for teaching about modern and ancient Egypt are provided in this guide for intermediate grade social studies teachers. Material includes: a detailed outline for a unit on Egypt which contains a geographic overview followed by sections on the Nile River Valley, agriculture, the pharaohs, religion, architecture, science, hieroglyphics,…

  8. A SURVEY OF CYST NEMATODES (HETERODERA SPP.) IN NORTHERN EGYPT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Information concerning the occurrence and distribution of cyst nematodes (Heterodera spp.) in Egypt is important to assess their potential to cause economic damage to crop plants. A nematode survey was conducted in Alexandria and El-Behera Governorates in northern Egypt to identify the species of cy...

  9. Student Academic Freedom in Egypt: Perceptions of University Education Students

    ERIC Educational Resources Information Center

    Zain-Al-Dien, Muhammad M.

    2016-01-01

    The purpose of the present study was to investigate student academic freedom from the university education students' point of view in Egypt. This study adopted a survey research design in which the questionnaire was the main data collection instrument. The study participants comprised 800 university education students in Egypt. The result of the…

  10. Separate but Equal: Segregated Religious Education in Egypt's Public Schools

    ERIC Educational Resources Information Center

    Isaac, John

    2012-01-01

    The Arab Spring exposed the hidden secrets of Egyptian society to the global community. In spite of the insatiable media attention paid to the Mubarak regime and the toll it took on the entire country, Egypt's education system received little attention. For decades, Egypt's public schools have forced students to attend segregated classes, based on…

  11. Exercise Desert Rock Letter Orders. Army, Camp Desert Rock, Nevada.

    DTIC Science & Technology

    1957-08-01

    WILF.iED J MSGT A19032i3 HJ;,ŕWAY, ELLafGzJN 8FC Xf,37791267 INOZ W, P. 1. PVT2 US52401808 KELLEY, JESSIE J SFC R1� EVaS, LOUIS PFC .,53073109...Ord Co (HAM) Camo Desert Rock, Nevada You will preeeed to Reynolds Funeral Vome, Sigourney, Iowa 0/a 24 AU ist 1957 for apprx fourteen (14) days to

  12. Phylogeography of Beck's Desert Scorpion, Paruroctonus becki, reveals Pliocene diversification in the Eastern California Shear Zone and postglacial expansion in the Great Basin Desert.

    PubMed

    Graham, Matthew R; Jaeger, Jef R; Prendini, Lorenzo; Riddle, Brett R

    2013-12-01

    The distribution of Beck's Desert Scorpion, Paruroctonus becki (Gertsch and Allred, 1965), spans the 'warm' Mojave Desert and the western portion of the 'cold' Great Basin Desert. We used genetic analyses and species distribution modeling to test whether P. becki persisted in the Great Basin Desert during the Last Glacial Maximum (LGM), or colonized the area as glacial conditions retreated and the climate warmed. Phylogenetic and network analyses of mitochondrial cytochrome c oxidase 1 (cox1), 16S rDNA, and nuclear internal transcribed spacer (ITS-2) DNA sequences uncovered five geographically-structured groups in P. becki with varying degrees of statistical support. Molecular clock estimates and the geographical arrangement of three of the groups suggested that Pliocene geological events in the tectonically dynamic Eastern California Shear Zone may have driven diversification by vicariance. Diversification was estimated to have continued through the Pleistocene, during which a group endemic to the western Great Basin diverged from a related group in the eastern Mojave Desert and western Colorado Plateau. Demographic and network analyses suggested that P. becki underwent a recent expansion in the Great Basin. According to a landscape interpolation of genetic distances, this expansion appears to have occurred from the northwest, implying that P. becki may have persisted in part of the Great Basin during the LGM. This prediction is supported by species distribution models which suggest that climate was unsuitable throughout most of the Great Basin during the LGM, but that small patches of suitable climate may have remained in areas of the Lahontan Trough.

  13. A review of the emergence of Plasmodium falciparum-dominated malaria in irrigated areas of the Thar Desert, India.

    PubMed

    Tyagi, B K

    2004-01-01

    Recently, there has been a resurgence of malaria in several parts of India, and the Thar Desert in north-western India, is currently suffering from the impact of repeated annual epidemics. Nearly all malaria epidemics in the Thar Desert have come about with the progression of canal-irrigation work, particularly the massive Indira Gandhi Nahar Pariyojana (IGNP). Therefore, the Thar Desert provides an excellent model for understanding the underlying factors responsible for the exacerbation of malaria, pathways of evolution of the epidemics, succession in anopheline fauna, changes in the vector breeding and feeding preferences and, most importantly, the possible repercussions of mismanagement of irrigation systems. Before the initiation of canalised irrigation only Anopheles stephensi, breeding exclusively in household and community-based underground water reservoirs, and transmitting malaria at a low level, was prevalent in the interior of the Thar Desert. Since the 1980s, extensive irrigation with water from three different canal systems has altered the desert physiography, vector preponderance, distribution and vectorial capacity, whilst triggering the emergence of Plasmodium falciparum-dominated malaria in the virgin levees of the Thar Desert. The major objective of bringing the Himalayan waters to the xeric environment of the Thar was to transform it into verdure through growing irrigation-intensive crops like paddy, groundnut, cotton, mustard, wheat and sugarcane, besides providing drinking water to the desert dwellers. The change in crop pattern, retention of high surface moisture, and excessive canalisation rife with mismanagement of irrigation water have attracted several anophelines, including Anopheles culicifacies, which were earlier unknown in the desert. Thus, A. culicifacies has penetrated into the interior of the Thar Desert, along with irrigation and is now established in vast areas covered by the IGNP project. The distribution of P. falciparum

  14. Spatial and temporal changes in desertification in the southern region of the Tengger Desert from 1973 to 2009

    NASA Astrophysics Data System (ADS)

    Guan, Qingyu; Guan, Wenqian; Yang, Jing; Zhao, Shilei; Pan, Baotian; Wang, Lei; Song, Na; Lu, Min; Li, Fuchun

    2016-04-01

    The sandy land in the southern region of the Tengger Desert is adjacent to cities and towns, and land desertification poses a threat to the livelihood and production of local residents. To determine dynamic changes in local desertification, five periods (1973, 1987, 1992, 2001, and 2009) of remote sensing data are studied by remote sensing (RS) and geographic information system (GIS). The desert contraction area is primarily centered around three units (Wuwei, Gulang, and Jingtai) and nearby regions of Zhongwei City. The primary desert expansion areas include the west side of Helan Mountain (WSHM), the Central Mountainous Area (CMA), and the eastern and western Zhongwei units far from towns. From 1973 to 2009, the degree of change in the contracting part of the primary desert expansion unit showed an increasing trend; in brief, most of the desert (especially after 2001) has been developing in a direction in which desertification has been gradually controlled. The primary desert expansion areas are less affected by human activity, but they are primarily controlled by natural factors (especially wind and terrain). The desert contraction areas occur around the towns and nearby regions with frequent human activity; desertification is primarily controlled by human factors. With rapid economic development (especially after 2000), the scale of the cultivated area, town, and ecological protection engineering has gradually expanded, and the latter two are primarily built on a previous desert, which is the root cause of the reduction in the desert areas around the towns and the shrinkage toward north of border. Therefore, reasonable and effective human activity in the southern region of the Tengger Desert is playing a crucial role in preventing desertification.

  15. Desert Studies - A Global View

    DTIC Science & Technology

    1985-08-23

    Exploration, Dec. 6-10, 1982, Ft. Worth, TX, p. 39-40. 1983: 2 abs. published, 2 papers submitted for publication Breed, C. S., 1983, Subsurface imaging with...2-10 (in Chinese). Elachi, C., Roth, L. E., and Schaber, G. G., 1984, Spaceborne radar subsurface imaging in hyperarid regions, 1984: IEEE...are 55) km o. 18t BIBLIOGRAPHY (CITED REFERENCES) Breed, C. S., 1983, Subsurface imaging with SIR-A in the Egyptian Desert (abs.): Summaries, 17th

  16. Reference intervals and physiologic alterations in hematologic and biochemical values of free-ranging desert tortoises in the Mojave Desert

    USGS Publications Warehouse

    Christopher, Mary M.; Berry, Kristin H.; Wallis, I.R.; Nagy, K.A.; Henen, B.T.; Peterson, C.C.

    1999-01-01

    Desert tortoise (Gopherus agassizii) populations have experienced precipitous declines resulting from the cumulative impact of habitat loss, and human and disease-related mortality. Evaluation of hematologic and biochemical responses of desert tortoises to physiologic and environmental factors can facilitate the assessment of stress and disease in tortoises and contribute to management decisions and population recovery. The goal of this study was to obtain and analyze clinical laboratory data from free-ranging desert tortoises at three sites in the Mojave Desert (California, USA) between October 1990 and October 1995, to establish reference intervals, and to develop guidelines for the interpretation of laboratory data under a variety of environmental and physiologic conditions. Body weight, carapace length, and venous blood samples for a complete blood count and clinical chemistry profile were obtained from 98 clinically healthy adult desert tortoises of both sexes at the Desert Tortoise Research Natural area (western Mojave), Goffs (eastern Mojave) and Ivanpah Valley (northeastern Mojave). Samples were obtained four times per year, in winter (February/March), spring (May/June), summer (July/August), and fall (October). Years of near-, above- and below-average rainfall were represented in the 5 yr period. Minimum, maximum and median values, and central 95 percentiles were used as reference intervals and measures of central tendency for tortoises at each site and/or season. Data were analyzed using repeated measures analysis of variance for significant (P < 0.01) variation on the basis of sex, site, season, and interactions between these variables. Significant sex differences were observed for packed cell volume, hemoglobin concentration, aspartate transaminase activity, and cholesterol, triglyceride, calcium, and phosphorus concentrations. Marked seasonal variation was observed in most parameters in conjunction with reproductive cycle, hibernation, or seasonal

  17. Radiation, multiple dispersal and parallelism in the skinks, Chalcides and Sphenops (Squamata: Scincidae), with comments on Scincus and Scincopus and the age of the Sahara Desert.

    PubMed

    Carranza, S; Arnold, E N; Geniez, Ph; Roca, J; Mateo, J A

    2008-03-01

    Phylogenetic analysis using up to 1325 base pairs of mitochondrial DNA from 179 specimens and 30 species of Chalcides, Sphenops, Eumeces, Scincopus and Scincus indicates that Sphenops arose twice independently within Chalcides. It is consequently synonymized with that genus. Chalcides in this broader sense originated in Morocco, diversifying into four main clades about 10 Ma, after which some of its lineages dispersed widely to cover an area 40 times as large. Two separate lineages invaded the Canary Islands and at least five main lineages colonized southern Europe. At least five more spread across northern Africa, one extending into southwest Asia. Elongate bodies with reduced limbs have evolved at least four times in Chalcides, mesic 'grass-swimmers' being produced in one case and extensive adaptation to life in loose desert sand in two others. In clade, Chalcides striatus colonized SW Europe from NW Africa 2.6 Ma and C. chalcides mainland Italy 1.4 Ma, both invasions being across water, while C. c. vittatus reached Sardinia more recently, perhaps anthropogenically, and C. guentheri spread 1200km further east to Israel. C. minutus is a composite, with individuals from the type locality forming a long independent lineage and the remaining ones investigated being most closely related to C. mertensi. In the Northern clade, C. boulengeri and C. sepsoides spread east through sandy habitats north of the Sahara about 5 Ma, the latter reaching Egypt. C. bedriagai invaded Spain around the same time, perhaps during the Messinian period when the Mediterranean was dry, and shows considerable diversification. Although it is currently recognized as one species, the C. ocellatus clade exhibits as much phylogenetic depth as the other main clades of Chalcides, having at least six main lineages. These have independently invaded Malta and Sardinia from Tunisia and also southwest Arabia C. o. humilis appears to have spread over 4000 km through the Sahel, south of the Sahara quite

  18. Contributions of sandy lands and stony deserts to long-distance dust emission in China and Mongolia during 2000 2006

    NASA Astrophysics Data System (ADS)

    Zhang, Baolin; Tsunekawa, Atsushi; Tsubo, Mitsuru

    2008-02-01

    More than 400 Moderate Resolution Imaging Spectroradiometer (MODIS) images of dust storm events were collected and analyzed, and individual events were tracked back to their origins. Dust tracks were determined from color composite images, brightness temperature difference (BTD) and the NOAA Hybrid Single-Particle Lagrangian Integrated Trajectory model. The results showed that five regions (sandy lands in central Inner Mongolia and the adjacent area of Mongolia; the Gobi Desert in Xinjiang and Gansu provinces, western Inner Mongolia, and the adjacent southwestern area of Mongolia; the Gobi Desert in southern Mongolia and the adjoining area of northern Inner Mongolia; sandy lands and deserts around the middle reaches of the Yellow River; and the area rimming the Taklimakan Desert) were the main contributors to long-lived mineral dusts in northern China and Mongolia. Of these dust production areas, sandy lands and stony deserts, rather than the sandy deserts of Inner Mongolia and Mongolia, were found to be the dominant dust sources, accounting for more than 75% of regional dust emission events. Dust events in the Taklimakan Desert were often local phenomena, although they could also be transported eastward if they were uplifted high enough to escape the enclosing topographic highs. Dust sources in northwestern China are mainly alluvial fans and dry lake and river beds. Success in identifying the sources and trajectories of Asian dust storms would guide future ground-based research and steppe degradation countermeasures and help reduce the uncertainties in modern modeling of Asian dust.

  19. The age of the Taklimakan Desert.

    PubMed

    Sun, Jimin; Liu, Tungsheng

    2006-06-16

    The Taklimakan Desert is located in the foreland basin of the Tibetan Plateau. We report here the results of stratigraphic investigations of a 1626-meter-thick sequence with interbedded wind-blown silt from the southern marginal Taklimakan Desert. Because the studied section is located downwind of the desert, the eolian silt accumulation is closely linked to desert formation. Our new evidence indicates that shifting sand dunes prevailed in the Tarim Basin by at least 5.3 million years ago, as they do today. We attribute this event to late Cenozoic climatic deterioration, as well as to changes in atmospheric circulation induced by Tibetan Plateau uplift.

  20. Alternate Energy from the Desert

    NASA Astrophysics Data System (ADS)

    Malek, E.

    2003-12-01

    Due to rapid growth of the world's population and more demands for energy, and due to limited amount of fossil fuels (which provide 95 % of the world's energy needs), harnessing of alternate energy sources such as solar and wind power should be considered. In addition to the mountain passes with usually high wind, vast and flat desert areas could be good candidates for harvesting both solar and wind power. We set up a weather station in the middle of a desert, approximately 65 km east-west by 130 km north-south, located at Dugway (40\\deg 08' N, 113\\deg 27' W, 1124 m above mean sea level) in northwestern Utah, USA, in 1999. This station measured the incoming (Rsi) and outgoing (Rso) solar or shortwave radiation using two CM21 Kipp & Zonen pyranometers (one inverted), the incoming (Rli or atmospheric) and outgoing (Rlo or terrestrial) longwave radiation, using two CG1 Kipp & Zonen pyrgeometers (one inverted), and the net (Rn) radiation using a Q*7 net radiometer (Radiation Energy Balance System, REBS). We also measured the 3-m wind speed (U3) and direction (R.M. Young wind monitor) and precipitation (Campbell Sci., Inc.) and some other weather parameters. The measurements were taken every two seconds, and averaged into 20-min, continuously, throughout the year. The two-year (January 2000 - December 2001) period comparisons of global or solar radiation and windiness with two other stations in central (Hunter) and northern (Logan) Utah, indicate higher average solar radiation [Rsi,Dugway = 601 MJ / (m2-month) vs. Rsi, Hunter = 5371 MJ /(m2-month) and Rsi, Logan = 516 MJ /(m2-month)] and much higher 10-m average wind (UDugway = 478 km/d vs. UHunter = 323 km/d and ULogan = 275 km/d) throughout the period over the desert. These data reveal the possibility of simultaneously harvesting these two sources of clean energies at this vast and uniform desert area. Keywords: Desert, energy, radiation balance, solar and wind energies, windiness.

  1. Egypt site of first CSM marketing audit.

    PubMed

    1982-01-01

    The 1st application of the marketing audit concept to a CSM project was implemented in Egypt's Family of the Future (FOF) contraceptive social marketing program in 1982. The audit defined the basic mission of the FOF as one of assisting the government in achieving its long range family planning goals. The stated FOF objectives are as follows: to create an awareness or an increase in demand for family planning services, particularly among the lower socioeconomic strata in urban Egypt; to establish and maintain a reliable supply mechanism to make FOF products more readily acceptable and available from pharmacies; and to consolidate the CSM operations and services first in the greater Cairo area and then expand to other urban areas in Egypt. The core strategy of the FOF incorporates several elements, including intensive media based advertising and personal promotion to promote the concept of family planning and to educate the general public about contraceptive alternatives. FOF product prices are considerably lower than commercial prices. Dr. Alan R. Andreasen, who conducted the audit on behalf of the FOF technical assistance contractor, noted that the FOF is growing rapidly and stated that the audit recommendations were intended to help FOF management. Dr. Andreasen conducted interviews with all the senior personnel at FOF and met with various specialized staff members such as the Public Relations Manager. Dr. Andreasen noted that at the time of the audit the FOF could claim major accomplishments in creating an awareness of the need for family planning and in product sales. From the time products were launched in 1979 through 1981 condom sales increased 260%. Foaming tablet sales increased more than 320% and IUD sales increased nearly 330%. The introduction of the Copper 7 IUD accounted for 35% of the growth of IUD sales in 1981. Couple years of protection (CYP) provided by all products increased from 45,533 in 1979 to 190,831 in 1981, an increase over 300%. The

  2. Oedematous skin disease of buffalo in Egypt.

    PubMed

    Selim, S A

    2001-05-01

    This review covers a historical view and etiology of oedematous skin disease which affects buffalo in Egypt, the microbiology of Corynebacterium pseudotuberculosis causing the disease: its virulence; clinical signs; mechanism of pathogenesis; histopathology; mode of transmission; immunological aspects; treatment and control. It is concluded that C. pseudotuberculosis serotype II is the main cause of OSD and exotoxin phospholipase D and its lipid contents of the cell wall are the major causes of pathogenesis. After declaring the role of Hippobosca equina in transmission of the causative agent among buffaloes, control of OSD is now available.

  3. [The patients' view in Ancient Egypt].

    PubMed

    Herrmann, Sabine

    2008-01-01

    Although many medical texts are preserved from Ancient Egypt, these texts are giving only little information about the relationship between the Egyptian doctor and the patient. The aim of this article is to draw the reader's attention to personal documents such as letters between members of the royal court or private persons as well as to literary texts from the New Kingdom until the Roman Period. The article does also focus on Mesopotamian legal texts (Codex Hammurapi) and letters from the kingdom of Mari.

  4. Egypt: Background and U.S. Relations

    DTIC Science & Technology

    2009-05-12

    agricultural output, large domestic market , and strategic location between the Mediterranean and Red Seas. Most importantly, the British saw Egypt as vital to...the Fundación para las Relaciones Internacionales y el Diálogo Exterior (FRIDE), March 6, 2008. 17 Steven A. Cook, "Adrift on the Nile: The Limits of...widespread due to Israel’s total blockade of Gaza, Hamas’s demand for weapons, and the lack of viable economic alternatives to black market activity on

  5. Indirect determination of broadband turbidity coefficients over Egypt

    NASA Astrophysics Data System (ADS)

    El-Metwally, Mossad

    2013-01-01

    Long-term data from diffuse and global irradiances were used to calculate direct beam irradiance which was used to determine three atmospheric turbidity coefficients (Linke T L , Ångström β and Unsworth-Monteith δ a ) at seven sites in Egypt in the period from 1981 to 2000. Seven study sites (Barrani, Matruh, Arish, Cairo, Asyut, Aswan and Kharga) have been divided into three categories: Mediterranean climate (MC), desert Nile climate (DNC) and urban climate (UC, Cairo). The indirect method (i.e., global irradiance minus diffuse irradiance) used here allows to estimate the turbidity coefficients with an RMSE% ≤20 % (for β, δ a and T L ) and ~30 % (for β) if compared with those estimated by direct beam irradiance and sunphotometeric data, respectively. Monthly averages of T L , β and δ a show seasonal variations with mainly maxima in spring at all stations, due to Khamsin depressions coming from Sahara. Secondary maxima is observed in summer and autumn at DNC and MC (Barrani and Arish) stations in summer due to dust haze which prevails during that season and at UC (Cairo) in autumn, due to the northern extension of the Sudan monsoon trough, which is accompanied by small-scale depressions with dust particles. The mean annual values of β, δ a , and T L (0.216, 0.314, and 4.6, respectively) are larger in Cairo than at MC stations (0.146, 0.216, and 3.8, respectively) and DNC stations (0.153, 0.227, and 3.8, respectively). Both El-Chichon and Mt. Pinatubo eruptions were examined for all records data at MC, UC and DNC stations. The overburden caused by Mt. Pinatubo's eruption was larger than El-Chichon's eruption and overburden for β, and T L at DNC stations (0.06, and 0.58 units, respectively) was more pronounced than that at MC (0.02, and 0.26, respectively) and UC (0.05 and 0.52 units, respectively) stations. The annual variations in wind speed and turbidity parameters show high values for both low and high wind speed at all stations

  6. Unusual dominance by desert pupfish (Cyprinodon macularius) in experimental ponds within the Salton Sea Basin

    USGS Publications Warehouse

    Saiki, Michael K.; Martin, Barbara A.; Anderson, Thomas W.

    2011-01-01

    In October 2006, months after shallow experimental ponds in the Salton Sea Basin were filled with water from the Alamo River and Salton Sea, fish were observed in several ponds, although inlets had been screened to exclude fish. During October 2007November 2009, nine surveys were conducted using baited minnow traps to document species and relative abundance of fish. Surveys yielded 3,620 fish representing five species. Desert pupfish (Cyprinodon macularius), the only native species encountered, was the most numerous and comprised >93% of the catch. Nonnative species included western mosquitofish (Gambusia affinis, 4.1%), sailfin molly (Poecilia latipinna, 2.8%), and tilapia (a mixture of hybrid Mozambique tilapia Oreochromis mossambicus ?? O. urolepis and redbelly tilapia Tilapia zillii, <0.1%). Dominance by desert pupfish, which persisted over our 2 years of study, was unusual because surveys conducted in nearby agricultural drains yielded relatively few desert pupfish.

  7. Chapter 3: neurology in ancient Egypt.

    PubMed

    York, George K; Steinberg, David A

    2010-01-01

    Neurology, in the modern sense, did not exist in ancient Egypt, where medicine was a compound of natural, magical and religious elements, with different practitioners for each form of healing. Nevertheless, Egyptian doctors made careful observations of illness and injury, some of which involved the nervous system. Modern scholars have three sources of information about Egyptian medicine: papyri, inscriptions, and mummified remains. These tell us that the Egyptians had words for the skull, brain, vertebrae, spinal fluid and meninges, though they do not say if they assigned any function to them. They described unconsciousness, quadriparesis, hemiparesis and dementia. We can recognize neurological injuries, such as traumatic hemiparesis and cervical dislocation with paraplegia, in the well known Edwin Smith surgical papyrus. Similarly recognizable in the Ebers papyrus is a description of migraine. An inscription from the tomb of the vizier Weshptah, dated c. 2455 BCE, seems to describe stroke, and Herodotus describes epilepsy in Hellenistic Egypt. We have very little understanding of how Egyptian physicians organized these observations, but we may learn something of Egyptian culture by examining them. At the same time, modern physicians feel some connection to Egyptian physicians and can plausibly claim to be filling a similar societal role.

  8. Transnasal excerebration surgery in ancient Egypt.

    PubMed

    Fanous, Andrew A; Couldwell, William T

    2012-04-01

    Ancient Egyptians were pioneers in many fields, including medicine and surgery. Our modern knowledge of anatomy, pathology, and surgical techniques stems from discoveries and observations made by Egyptian physicians and embalmers. In the realm of neurosurgery, ancient Egyptians were the first to elucidate cerebral and cranial anatomy, the first to describe evidence for the role of the spinal cord in the transmission of information from the brain to the extremities, and the first to invent surgical techniques such as trepanning and stitching. In addition, the transnasal approach to skull base and intracranial structures was first devised by Egyptian embalmers to excerebrate the cranial vault during mummification. In this historical vignette, the authors examine paleoradiological and other evidence from ancient Egyptian skulls and mummies of all periods, from the Old Kingdom to Greco-Roman Egypt, to shed light on the development of transnasal surgery in this ancient civilization. The authors confirm earlier observations concerning the laterality of this technique, suggesting that ancient Egyptian excerebration techniques penetrated the skull base mostly on the left side. They also suggest that the original technique used to access the skull base in ancient Egypt was a transethmoidal one, which later evolved to follow a transsphenoidal route similar to the one used today to gain access to pituitary lesions.

  9. Risk factors for developing hepatocellular carcinoma in Egypt.

    PubMed

    Omar, Ashraf; Abou-Alfa, Ghassan K; Khairy, Ahmed; Omar, Heba

    2013-12-01

    Hepatocellular carcinoma (HCC) is a common disorder worldwide and ranks 2nd and 6th most common cancer among men and women in Egypt. HCC has a rising incidence in Egypt mostly due to high prevalence of viral hepatitis and its complications. Proper management requires the interaction of multidisciplinary HCC clinic to choose the most appropriate plan. The different modalities of treatment include resection (surgery or transplantation), local ablation, chemoembolization, radioembolization and molecular targeted therapies. This paper summarizes both the environmental and host related risk factors of HCC in Egypt including well-established risk factors such as hepatitis virus infection, aflatoxin, as well as possible risk factors.

  10. Characterization of the Sonoran desert as a radiometric calibration target for Earth observing sensors

    USGS Publications Warehouse

    Angal, Amit; Chander, Gyanesh; Xiong, Xiaoxiong; Choi, Tae-young; Wu, Aisheng

    2011-01-01

    To provide highly accurate quantitative measurements of the Earth's surface, a comprehensive calibration and validation of the satellite sensors is required. The NASA Moderate Resolution Imaging Spectroradiometer (MODIS) Characterization Support Team, in collaboration with United States Geological Survey, Earth Resources Observation and Science Center, has previously demonstrated the use of African desert sites to monitor the long-term calibration stability of Terra MODIS and Landsat 7 (L7) Enhanced Thematic Mapper plus (ETM+). The current study focuses on evaluating the suitability of the Sonoran Desert test site for post-launch long-term radiometric calibration as well as cross-calibration purposes. Due to the lack of historical and on-going in situ ground measurements, the Sonoran Desert is not usually used for absolute calibration. An in-depth evaluation (spatial, temporal, and spectral stability) of this site using well calibrated L7 ETM+ measurements and local climatology data has been performed. The Sonoran Desert site produced spatial variability of about 3 to 5% in the reflective solar regions, and the temporal variations of the site after correction for view-geometry impacts were generally around 3%. The results demonstrate that, barring the impacts due to occasional precipitation, the Sonoran Desert site can be effectively used for cross-calibration and long-term stability monitoring of satellite sensors, thus, providing a good test site in the western hemisphere.

  11. African Historical Religions: A Conceptual and Ethnical Foundation for "Western Religions."

    ERIC Educational Resources Information Center

    Alexander, E. Curtis

    This paper attempts to set the record straight with regard to the following assumptions: (1) the Africans of the antiquities of Ethiopia and Egypt were black people; and (2) the same black people developed the foundation that provides the basis for the so-called major Western religions of Judaism, Christianity, and Islam. There are two parts to…

  12. On carbon sequestration in desert ecosystems

    USGS Publications Warehouse

    Schlesinger, W.H.; Belnap, J.; Marion, G.

    2009-01-01

    Recent reports of net ecosysytem production >100 g C m-2 yr-1 in deserts are incompatible with existing measurements of net primary production and carbon pools in deserts. The comparisions suggest that gas exchange measurements should be used with caution and better validation if they are expected to indicate the magnitude of carbon sink in these ecosysytems. ?? 2009 Blackwell Publishing.

  13. Magnetic Analysis Techniques Applied to Desert Varnish

    NASA Technical Reports Server (NTRS)

    Schmidgall, E. R.; Moskowitz, B. M.; Dahlberg, E. D.; Kuhlman, K. R.

    2003-01-01

    Desert varnish is a black or reddish coating commonly found on rock samples from arid regions. Typically, the coating is very thin, less than half a millimeter thick. Previous research has shown that the primary components of desert varnish are silicon oxide clay minerals (60%), manganese and iron oxides (20-30%), and trace amounts of other compounds [1]. Desert varnish is thought to originate when windborne particles containing iron and manganese oxides are deposited onto rock surfaces where manganese oxidizing bacteria concentrate the manganese and form the varnish [4,5]. If desert varnish is indeed biogenic, then the presence of desert varnish on rock surfaces could serve as a biomarker, indicating the presence of microorganisms. This idea has considerable appeal, especially for Martian exploration [6]. Magnetic analysis techniques have not been extensively applied to desert varnish. The only previous magnetic study reported that based on room temperature demagnetization experiments, there were noticeable differences in magnetic properties between a sample of desert varnish and the substrate sandstone [7]. Based upon the results of the demagnetization experiments, the authors concluded that the primary magnetic component of desert varnish was either magnetite (Fe3O4) or maghemite ( Fe2O3).

  14. Notes from the Great American Desert

    ERIC Educational Resources Information Center

    Grady, Marilyn L.; LaCost, Barbara Y.

    2005-01-01

    In the good old days, the state that is Nebraska was identified as part of the Great American Desert. In many ways, in climate and terrain, it still bears a resemblance to a desert. As a frontier or a land of pioneers, it deserves recognition. Invisibility may be one of the greatest challenges women face. One of the great flaws in the writing of…

  15. On-line measurements of ozone surface fluxes: Part II. Surface-level ozone fluxes onto the Sahara desert

    NASA Astrophysics Data System (ADS)

    Güsten, Hans; Heinrich, Günther; Mönnich, Erbo; Sprung, Detlev; Weppner, Joseph; Ramadan, Abou Bakr; Ezz El-Din, Mohammed R. M.; Ahmed, Darwish M.; Hassan, Galal K. Y.

    Surface-level ozone concentrations, the vertical turbulent ozone flux as well as the fluxes of sensible and latent heat were continuously monitored by the eddy covariance method in the Lybian desert, 30 km south of the Dakhla Oasis in Egypt, from 23 March until 9 April 1993. An automatic station powered by a photovoltaics generator system was used to measure the vertical turbulent ozone flux to the desert ecosystem. Fairly high ozone volume fractions up to 60 ppb were recorded when northerly winds prevailed. When southerly winds were blowing, the ozone volume fractions were lower and reached maximum values slightly above 40 ppb. On-line eddy correlation measurements of the vertical turbulent ozone flux to the desert were performed with a novel fast-response ozone sensor. The fairly small ozone fluxes were corrected for effects of micro-turbulent density fluctuations caused by the concomitant fluxes of heat and water vapour in the air volume (Webb correction). While ozone fluxes to the desert ecosystem are below 2 ppb cm s - in the night, maximum daytime ozone fluxes of 20 ppb cm s -1 were measured which yielded a maximum daily dry deposition velocity of 0.15 cm s -1. During the whole measurement campaign of 16 d a mean deposition velocity of Vd = 0.065 cm s -1 for ozone is calculated. For global numerical models in which the sources and sinks of ozone in the troposphere are taken into account, a daytime Vdof 0.1 cm s -1 and a nighttime value of 0.04 cm s -1 are recommended for the desert ecosystem.

  16. Mitigation options for the industrial sector in Egypt

    SciTech Connect

    Gelil, I.A.; El-Touny, S.; Korkor, H.

    1996-12-31

    Though its contribution to the global Greenhouse gases emission is relatively small, Egypt has signed and ratified the United Nations Framework Convention on Climate Change (UN FCCC) and has been playing an active role in the international efforts to deal with such environmental challenges. Energy efficiency has been one of the main strategies that Egypt has adopted to improve environmental quality and enhance economic competitiveness. This paper highlights three initiatives currently underway to improve energy efficiency of the Egyptian industry. The first is a project that has been recently completed by OECP to assess potential GHG mitigation options available in Egypt`s oil refineries. The second initiative is an assessment of GHG mitigation potential in the Small and Medium size Enterprises (SME) in the Mediterranean city of Alexandria. The third one focuses on identifying demand side management options in some industrial electricity consumers in the same city.

  17. PHYLOGEOGRAPHY OF BUFO PUNCTATUS: LONG TERM EVOLUTION WITHIN THE WARM DESERTS OF NORTH AMERICA AND LATE QUATERNARY RANGE SHIFTING

    EPA Science Inventory

    Bufo punctatus, the red-spotted toad, is a widespread anuran of the warm-desert regions of western North America. This distribution makes this species ideal for evaluating biotic response to geotectonically and climatically mediated episodes of landscape transformation (e.g., ear...

  18. Nile River, Lake Nasser, Aswan High Dam, Egypt, Africa

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Lake Nasser, (24.0N, 33.0E) at the Aswan High Dam on the Nile River, in Egypt is the world's second largest artificial lake, extending 500 km, in length and about 5000 sq. km. in area. The lake has a storage capacity sufficient to irrigate farms in Egypt and Sudan year round allowing up to three harvests per year. Other benefits include year round river navagation, hydroelectric power, more fish harvests, reduced flooding and more industrial employment. opportunites.

  19. Selfhood and social distance: toward a cultural understanding of psychiatric stigma in Egypt.

    PubMed

    Coker, Elizabeth M

    2005-09-01

    Psychiatric stigma is a concept that is often used uncritically by policy-makers to explain the underutilization of professional psychiatric services in non-Western societies. Stigma, however, is a multi-determined process manifestations and effects of which cannot be viewed separately from the larger social and cultural context. The present paper presents the results of a qualitative study of psychiatric stigma in Egypt from the perspective of lay respondents. A vignette method was used to elicit judgments of social distance and qualitative responses to stories depicting psychosis, depression, alcohol abuse and a 'possession state' from 208 respondents recruited through their places of work. The results indicated that while stigma does exist in Egypt, the form that it takes must be understood with reference to Egyptian notions of selfhood that locate behavioral disturbances in the intersubjective rather than intrapsychic realm. On the one hand, individual blame is diffused as responsibility for the illness and its cure is placed in the social, not personal (or biological) realm. On the other, behavioral disorders that threaten the social fabric of society are particularly stigmatized and often met with social rejection.

  20. Comparisons of diazotrophic communities in native and agricultural desert ecosystems reveal plants as important drivers in diversity.

    PubMed

    Köberl, Martina; Erlacher, Armin; Ramadan, Elshahat M; El-Arabi, Tarek F; Müller, Henry; Bragina, Anastasia; Berg, Gabriele

    2016-02-01

    Diazotrophs provide the only biological source of fixed atmospheric nitrogen in the biosphere. Although they are the key player for plant-available nitrogen, less is known about their diversity and potential importance in arid ecosystems. We investigated the nitrogenase gene diversity in native and agricultural desert soil as well as within root-associated microbiota of medicinal plants grown in Egypt through the combination of nifH-specific qPCR, fingerprints, amplicon pyrosequencing and fluorescence in situ hybridization-confocal laser scanning microscopy. Although the diazotrophic microbiota were characterized by generally high abundances and diversity, statistically significant differences were found between both soils, the different microhabitats, and between the investigated plants (Matricaria chamomilla L., Calendula officinalis L. and Solanum distichum Schumach. and Thonn.). We observed a considerable community shift from desert to agriculturally used soil that demonstrated a higher abundance and diversity in the agro-ecosystem. The endorhiza was characterized by lower abundances and only a subset of species when compared to the rhizosphere. While the microbiomes of the Asteraceae were similar and dominated by potential root-nodulating rhizobia acquired primarily from soil, the perennial S. distichum generally formed associations with free-living nitrogen fixers. These results underline the importance of diazotrophs in desert ecosystems and additionally identify plants as important drivers in functional gene pool diversity.

  1. Comparisons of diazotrophic communities in native and agricultural desert ecosystems reveal plants as important drivers in diversity

    PubMed Central

    Köberl, Martina; Erlacher, Armin; Ramadan, Elshahat M.; El-Arabi, Tarek F.; Müller, Henry; Bragina, Anastasia; Berg, Gabriele

    2015-01-01

    Diazotrophs provide the only biological source of fixed atmospheric nitrogen in the biosphere. Although they are the key player for plant-available nitrogen, less is known about their diversity and potential importance in arid ecosystems. We investigated the nitrogenase gene diversity in native and agricultural desert soil as well as within root-associated microbiota of medicinal plants grown in Egypt through the combination of nifH-specific qPCR, fingerprints, amplicon pyrosequencing and fluorescence in situ hybridization–confocal laser scanning microscopy. Although the diazotrophic microbiota were characterized by generally high abundances and diversity, statistically significant differences were found between both soils, the different microhabitats, and between the investigated plants (Matricaria chamomilla L., Calendula officinalis L. and Solanum distichum Schumach. and Thonn.). We observed a considerable community shift from desert to agriculturally used soil that demonstrated a higher abundance and diversity in the agro-ecosystem. The endorhiza was characterized by lower abundances and only a subset of species when compared to the rhizosphere. While the microbiomes of the Asteraceae were similar and dominated by potential root-nodulating rhizobia acquired primarily from soil, the perennial S. distichum generally formed associations with free-living nitrogen fixers. These results underline the importance of diazotrophs in desert ecosystems and additionally identify plants as important drivers in functional gene pool diversity. PMID:26705571

  2. 75 FR 57761 - Desert Southwest Power, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-22

    ... Energy Regulatory Commission Desert Southwest Power, LLC; Notice of Filing September 14, 2010. Take notice that on September 10, 2010, Desert Southwest Power, LLC (Desert Southwest) filed responses to the... Commission's July 28, 2010 letter regarding Desert Southwest's petition for declaratory order...

  3. Stratification and mobility in contemporary Egypt.

    PubMed

    Nagi, Saad Z; Nagi, Omar

    2011-01-01

    The objectives in this statement are to characterize and explain the patterns of change in stratification and mobility in Egypt, over the last half century, by placing them within conceptual, explanatory, and historical contexts. First, literature relevant to the primary concepts of "class" and "status", is reviewed. Second, four institutions whose influence is fundamental in shaping these patterns are identified to form an explanatory context: family, polity, economy, and education. And third, an historical account is presented to demonstrate the interplay of these institutions and their consequences for stratification and mobility. For this, four periods are identified that are marked by change in the dominance of institutions and their corresponding influence on stratification and mobility. In addition to data available in relevant literature, this analysis utilizes primary data generated through a national probability household survey.

  4. The practice of dentistry in ancient Egypt.

    PubMed

    Forshaw, R J

    2009-05-09

    This paper addresses the questions of whether a dental profession existed in ancient Egypt and if it did then considers whether these practitioners were operative dental surgeons as we know them today or whether they were pharmacists. Evidence from hieroglyphic inscriptions, from the dentitions of the surviving mummified and skeletal remains, and from ancient documents and artefacts are examined. The conclusion would suggest that operative dental treatment if it did exist at all was extremely limited. The dental treatment that appears to have been provided was mainly restricted to pharmaceutical preparations that were either applied to the gingival and mucosal tissues or used as mouthwashes, and these at best may only have provided some short term relief. It seems apparent that many ancient Egyptians suffered from widespread and painful dental disease, which the available treatments can have done relatively little to alleviate.

  5. Vascular medicine and surgery in ancient Egypt.

    PubMed

    Barr, Justin

    2014-07-01

    Lauded alike by ancient civilizations and modern society, pharaonic Egyptian medicine remains an object of fascination today. This article discusses its surprisingly sophisticated understanding of a cardiovascular system. The term "cardiovascular system," however, carries assumptions and meanings to a modern audience, especially readers of this journal, which simply do not apply when considering ancient conceptions of the heart and vessels. For lack of better language, this article will use "cardiovascular" and similar terms while recognizing the anachronistic inaccuracy. After briefly summarizing ancient Egyptian medicine generally, it will review the anatomy, pathology, and treatment of the vasculature. The practice of mummification in ancient Egypt provides a unique opportunity for paleopathology, and the conclusion will explore evidence of arterial disease from a modern scientific perspective.

  6. Environmental impact of pesticides in Egypt.

    PubMed

    Mansour, Sameeh A

    2008-01-01

    The first use of petroleum-derived pesticides in Egyptian agriculture was initiated in 1950. Early applications consisted of distributing insecticidal dusts containing DDT/BHC/S onto cotton fields. This practice was followed by use of toxaphene until 1961. Carbamates, organophosphates, and synthetic pyrethroids were subsequently used, mainly for applications to cotton. In addition to the use of about 1 million metric tons (t) of pesticides in the agricultural sector over a 50-yr period, specific health and environmental problems are documented in this review. Major problems represented and discussed in this review are human poisoning, incidental toxicity to farm animals, insect pest resistance, destruction of beneficial parasites and predators, contamination of food by pesticide residues, and pollution of environmental ecosystems. Several reports reveal that chlorinated hydrocarbon pesticide residues are still detectable in several environmental compartments; however, these residues are in decline. Since 1990, there is a growing movement toward reduced consumption of traditional pesticides and a tendency to expand use of biopesticides, including "Bt," and plant incorporated protectants (PIPs). On the other hand, DDT and lindane were used for indoor and hygienic purposes as early as 1952. Presently, indoor use of pesticides for pest control is widespread in Egypt. Accurate information concerning the types and amounts of Egyptian household pesticide use, or numbers of poisoning or contamination incidents, is unavailable. Generally, use of indoor pesticides is inadequately managed. The results of a survey of Egyptian farmers' attitudes toward pesticides and their behavior in using them garnered new insights as to how pesticides should be better controlled and regulated in Egypt.

  7. The determinants of labor migration in Egypt.

    PubMed

    Greenwood, M J

    1969-08-01

    The factors which affect individual decisions with regard to geographic movement in Egypt are examined and the magnitude in which each factor exerts its influence on aggregate geographic labor supply adjustments is estimated. The spatial unit used in the study is the administrative region, of which there are 25. No effort is made to esimate the impact which migration has had on the origin or destination region. The migrant will presumably choose that destination which, given his information, the migrant thinks will be best. The model which is employed attempts to explain gross interregional migration without the explicit introduction of an individual decision function. Rather, migration is related to certain aggregate proxy variables. Among the independent variables employed in the analysis are (origin and destination) income, education, urbanization, and population. The other explanatory variable used is the distance between region i and region j. The migration measure employed refers to cumulative male migration which occurred prior to 1960; the independent variables are defined for a given point in time (1960). The independent variables explain a reasonably large percentage of the variance in migration between regions in Egypt. All variables were significant at the 5% level or better. The findings indicate that distance acts as an important impediment to migration. Migration is away from low wage and toward high wage regions, which may have contributed to a narrowing of regional wage differentials. Migrants are attracted to regions which have large populations and to regions which have a large percentage of urban to total population. A tendency exists for migrants to come from regions with large populations. There is also some tendency for migrants to come from regions which have a relatively large urban population. Migrants do not appear to come from regions with high educational levels.

  8. Geodiversity assessment of the Sinai Peninsula, Egypt

    NASA Astrophysics Data System (ADS)

    Torab, Magdy; Farghaly, Enas

    2015-04-01

    The Sinai Peninsula is a triangular plateau lies in NE corner of Egypt, its head in the south at Ras Mohammed and its other sides between the Gulf of Aqaba and Gulf of Suez and the triangle base on the Mediterranean Sea. Sinai Peninsula is the most attractive region from the geological, geomorphological and environmental stand points of view because it displays a variety of simple and complex structural and landforms, (Abu Al-Izz,1971). In general, Sinai Peninsula reflects all geologic column of Egypt. Geomorphologically, Sinai Peninsula comprises many geomorphologic units such as mountains blocks, cliffs, isolated hills, wadies, hogbacks, questas, sand ridges, muddy and marshy lands, lakes and shorelines. This paper aims to define and measure geodiversity assessment index of the Sinai Peninsula as the quantitative variety of geological, topographical, geomorphological, hydrological and soil features. Some geodiversity indices maps for the above features produced for Sinai Peninsula were based on the methodology presented by (Pereira et al, 2012), it depends upon calculate of some geodiversity elements for overlay grid of the study area, which divided topographic, geological maps of the Sinai Peninsula with scale 1:500000 and satellite image (landsat 8, 27th October 2014, 12 bands, 30m). It divided into 743 squares (10x10 km), and some partial geodiversity indices such as geological, topographical, geomorphological, hydrological and soil indices were calculated by counting the number of each element inside each square, then the overall geodiversity index map produced by calculate the total number of all indices inside each square, the geodiversity index map were classified into some gradual categories by using isolines: very low, low, medium, high and very high.

  9. Infiltration Through Desert Pavements, Mojave Desert, CA, USA

    NASA Astrophysics Data System (ADS)

    Young, M. H.; McDonald, E. V.; Caldwell, T. C.; Benner, S. G.

    2003-04-01

    Desert pavements consist of a surface layer of closely packed gravel that overlies thin, gravel-poor vesicular A (Av) soil horizon. Pavements are prominent features in arid and semi-arid environments and can be found on a variety of landforms of significantly diverse ages ranging from Holocene to Tertiary. Well-developed Av profiles form distinct and highly structured prismatic peds. These fine-grained, structured soils can exhibit drastically reduced infiltration rates, rendering some localized areas nearly impermeable and greatly impacting soil development, plant and biota diversity, and groundwater recharge. We sought to study how desert pavement development can impact the hydraulic conductivity characteristics in localized areas (order of 10s of cm). Field sites were chosen at the Mojave Natural Preserve, near Kelso Dunes, CA, USA, which has been the location of considerable prior research by the second author. The sites vary by parent material, clay and silt content, surface age, and variable degree of surface clast cover. Transects were chosen that traversed pavement surfaces of variable development (well developed to poorly developed). Hydraulic conductivity was determined with a tension infiltrometer conducted at different tensions and initial water contents (to better estimate the potential for preferential flow). Sites with dry initial conditions were first analyzed at zero tensions to promote inter-ped flow. After allowing soil peds to hydrate and expand, the tests were run again at a range of soil tensions to promote matrix flow. Differences in saturated conductivities (measured and fitted) were attributed to preferential flow around desiccated peds. Soil texture and structure were measured and described, respectively, allowing for the correlation of conductivity functions to soil surface age and physical characteristics.

  10. Thermal and water relations of desert beetles

    NASA Astrophysics Data System (ADS)

    Cloudsley-Thompson, J.

    2001-11-01

    The physical problems that living organisms have to contend with in hot deserts are primarily extremes of temperature, low humidity, shortage or absence of free water, and the environmental factors that accentuate these - such as strong winds, sand-storms, lack of shade, rocky and impenetrable soils. Climatic factors are particularly important to smaller animals such as arthropods on account of their relatively enormous surface to volume ratios. Nevertheless, beetles (especially Tenebrionidae and, to a lesser extent, Chrysomelidae) are among the most successful animals of the desert, and are often the only ones to be seen abroad during the day. Similar physical problems are experienced by insects in all terrestrial biomes, but they are much enhanced in the desert. Although climatic extremes are often avoided by burrowing habits coupled with circadian and seasonal activity rhythms, as well as reproductive phenology, several species of desert beetle are nevertheless able to withstand thermal extremes that would rapidly cause the death of most other arthropods including insects. The reactions of desert beetles to heat are largely behavioural whilst their responses to water shortage are primarily physiological. The effects of coloration are not discussed. In addition to markedly low rates of transpiration, desert beetles can also withstand a considerable reduction in the water content of their tissues. The study of desert beetles is important because it illustrates many of the solutions evolved by arthropods to the problems engendered, in an extreme form, by life in all terrestrial environments.

  11. Thermal and water relations of desert beetles.

    PubMed

    Cloudsley-Thompson, J L

    2001-11-01

    The physical problems that living organisms have to contend with in hot deserts are primarily extremes of temperature, low humidity, shortage or absence of free water, and the environmental factors that accentuate these--such as strong winds, sand-storms, lack of shade, rocky and impenetrable soils. Climatic factors are particularly important to smaller animals such as arthropods on account of their relatively enormous surface to volume ratios. Nevertheless, beetles (especially Tenebrionidae and, to a lesser extent, Chrysomelidae) are among the most successful animals of the desert, and are often the only ones to be seen abroad during the day. Similar physical problems are experienced by insects in all terrestrial biomes, but they are much enhanced in the desert. Although climatic extremes are often avoided by burrowing habits coupled with circadian and seasonal activity rhythms, as well as reproductive phenology, several species of desert beetle are nevertheless able to withstand thermal extremes that would rapidly cause the death of most other arthropods including insects. The reactions of desert beetles to heat are largely behavioural whilst their responses to water shortage are primarily physiological. The effects of coloration are not discussed. In addition to markedly low rates of transpiration, desert beetles can also withstand a considerable reduction in the water content of their tissues. The study of desert beetles is important because it illustrates many of the solutions evolved by arthropods to the problems engendered, in an extreme form, by life in all terrestrial environments.

  12. Libyan Desert Glass: New field and Fourier transform infrared data

    NASA Astrophysics Data System (ADS)

    Fröhlich, F.; Poupeau, G.; Badou, A.; Le Bourdonnec, F. X.; Sacquin, Y.; Dubernet, S.; Bardintzeff, J. M.; Véran, M.; Smith, D. C.; Diemer, E.

    2013-12-01

    Results are presented of new geological observations and laboratory analyses on Libyan Desert Glass (LDG), a unique kind of impact glass found in Egypt, probably 28.5-29.4 million years in age. A new LDG occurrence has been discovered some 50 km southward of the main LDG occurrences in the Great Sand Sea. From Fourier transform infrared (FTIR) analysis, the molecular structure of LDG is refined and significant differences are shown between LDG specimens and other pure silica glasses (fulgurite, industrial fused quartz, and amorphous biogenic silica) that are related to differences in their structures. The slight variations observed here for the mean Si-O-Si angle between the different glasses are attributed to their thermal histories. With regard to the other glasses analyzed, the LDG infrared spectral parameters point to a higher ratio of discontinuities and defects in the tetrahedral (SiO4) network. The quantitative mineralogical constitutions of sandstones and quartzites from the LDG geological setting were analyzed by FTIR. Cretaceous sandstones have a specific composition (about 90 wt% quartz, 10% dickite), clearly different from the Paleozoic ones (about 90 wt% quartz, but ≥7% kaolinite). It is shown that the reddish silts bearing the LDG are constituted mainly of microquartz enriched with dickite, whose particle size distribution is characteristic of fluvio-lacustrine deposits, probably Oligocene to Miocene in age. The target rocks, most probably quartz sand, resulted from the weathering (loss of the cementing microquartz) of the Cretaceous sandstones from the Gilf Khebir Plateau with deposition in a high-energy environment.

  13. The Geology of the Ka'u Desert, Hawaii as a Mars Analog

    NASA Astrophysics Data System (ADS)

    Craddock, R. A.; Irwin, R. P.; Williams, R.; Swanson, D.; Howard, A. D.; Quantin, C.; Kuzmin, R.; Zimbelman, J. R.

    2005-12-01

    The Ka'u Desert is located on the western flank of Kilauea volcano on the Big Island of Hawaii. It is a desert because it receives little annual rainfall (about 150 mm/yr) but also because it is subjected to constant outgassing from Kilauea, which creates a harsh, acidic environment. Near the summit of Kilauea the Ka'u Desert is characterized by the Keanakako'i tephra deposit, which is several meters deep thinning out to a discontinuous deposit 1.5 km (1 mile) towards the center of the desert. The deposit itself has been incised by a number of gullies that are flat-floored and terminate in a series of amphitheater-shaped plunge pools. Most of the interior desert contains undulating weathered lava flows, extensive deposits of sand, and several more recent lava flows and volcanic edifices. The southern portion of the desert is bounded by the Hilina Pali fault scarp, which is 500 m (1,500 ft) above the nearby Pacific Ocean and contains a complex series of outwash plains, alluvial fans, and debris flows. We will present a summary of the geology of the Ka'u Desert. Contrary to published interpretations, we will present evidence that the Keanakako'i was not emplaced by two separate catastrophic eruption events but rather by two distinct eruption episodes that included multiple eruption events often interrupted by long hiatuses. Despite the morphology of the gullies contained on the Keanakako'i we will present evidence that the gullies were formed exclusively by surface runoff and not groundwater sapping, including quantitative estimates about the large amounts of discharge that occur during extreme storms. We will also present analyses of the sand deposits and determine the likely provenance of these materials. For the first time, we will also describe alluvial fans and mass wasting features on Hilina Pali and show evidence that they are part of poorly integrated channel system that originates in the Keanakako'i tephra. The Ka'u Desert represents a good Mars analog

  14. Opportunities for woody crop production using treated wastewater in Egypt. II. Irrigation strategies.

    PubMed

    Evett, Steven R; Zalesny, Ronald S; Kandil, Nabil F; Stanturf, John A; Soriano, Chris

    2011-01-01

    An Egyptian national program targets annual reuse of 2.4 billion m3 of treated wastewater (TWW) to irrigate 84,000 ha of manmade forests in areas close to treatment plants and in the desert. To evaluate the feasibility of such afforestation efforts, we describe information about TWW irrigation strategies based on (1) water use of different tree species, (2) weather conditions in different climate zones of Egypt, (3) soil types and available irrigation systems, and (4) the requirement to avoid deep percolation losses that could lead to groundwater contamination. We conclude that drip irrigation systems are preferred, that they should in most cases use multiple emitters per tree in order to increase wetted area and decrease depth of water penetration, that deep rooting should be encouraged, and that in most situations irrigation system automation is desirable to achieve several small irrigations per day in order to avoid deep percolation losses. We describe directed research necessary to fill knowledge gaps about depth of rooting of different species in sandy Egyptian soils and environments, tree crop coefficients needed for rational irrigation scheduling, and depth of water penetration under different irrigation system designs. A companion paper addresses recommendations for afforestation strategies (see Zalesny et al. 2011, this issue).

  15. Factors affecting knowledge of the symptoms of schistosomiasis in two rural areas near Ismailia, Egypt.

    PubMed

    Mehanna, S; Winch, P J; Rizkalla, N H; el-Sayed, H F; Abaza, S M

    1997-11-01

    The primary method of control of schistosomiasis in Egypt is through passive chemotherapy, in which people who suspect they have the disease are encouraged to go to their local health unit to be tested and treated. If people are unable to recognize the symptoms of schistosomiasis, this strategy may fail. This paper presents data on local knowledge of the symptoms of schistosomiasis from two areas recently reclaimed from the desert near Ismailia. Using data from free-listing and triadic comparisons, it is shown that schistosomiasis is primarily seen as a urinary disease. Factor analysis performed on a series of 12 questions on the symptoms of schistosomiasis included in a survey demonstrated that responses group into three patterns, the first stressing constitutional symptoms such as weakness, the second stressing abdominal symptoms and the third blood in the urine, burning on urination and blood in the stool. The paper discusses the implications of these findings for efforts to promote regular treatment with praziquantel of people living in or near the Nile Delta who are at risk for intestinal schistosomiasis.

  16. 76 FR 50493 - Notice of Availability of the Record of Decision for the Desert Sunlight Holdings, LLC, Desert...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-15

    ... Bureau of Land Management Notice of Availability of the Record of Decision for the Desert Sunlight Holdings, LLC, Desert Sunlight Solar Farm (DSSF) and California Desert Conservation Area Plan Amendment... Amendment to the California Desert Conservation Area (CDCA) Plan, the applicable Resource Management...

  17. Diversity and Community Composition of Vertebrates in Desert River Habitats.

    PubMed

    Free, C L; Baxter, G S; Dickman, C R; Lisle, A; Leung, L K-P

    2015-01-01

    Animal species are seldom distributed evenly at either local or larger spatial scales, and instead tend to aggregate in sites that meet their resource requirements and maximise fitness. This tendency is likely to be especially marked in arid regions where species could be expected to concentrate at resource-rich oases. In this study, we first test the hypothesis that productive riparian sites in arid Australia support higher vertebrate diversity than other desert habitats, and then elucidate the habitats selected by different species. We addressed the first aim by examining the diversity and composition of vertebrate assemblages inhabiting the Field River and adjacent sand dunes in the Simpson Desert, western Queensland, over a period of two and a half years. The second aim was addressed by examining species composition in riparian and sand dune habitats in dry and wet years. Vertebrate species richness was estimated to be highest (54 species) in the riverine habitats and lowest on the surrounding dune habitats (45 species). The riverine habitats had different species pools compared to the dune habitats. Several species, including the agamid Gowidon longirostris and tree frog Litoria rubella, inhabited the riverine habitats exclusively, while others such as the skinks Ctenotus ariadnae and C. dux were captured only in the dune habitats. The results suggest that, on a local scale, diversity is higher along riparian corridors and that riparian woodland is important for tree-dependent species. Further, the distribution of some species, such as Mus musculus, may be governed by environmental variables (e.g. soil moisture) associated with riparian corridors that are not available in the surrounding desert environment. We conclude that inland river systems may be often of high conservation value, and that management should be initiated where possible to alleviate threats to their continued functioning.

  18. Diversity and Community Composition of Vertebrates in Desert River Habitats

    PubMed Central

    Free, C. L.; Baxter, G. S.; Dickman, C. R.; Lisle, A.; Leung, L. K.-P.

    2015-01-01

    Animal species are seldom distributed evenly at either local or larger spatial scales, and instead tend to aggregate in sites that meet their resource requirements and maximise fitness. This tendency is likely to be especially marked in arid regions where species could be expected to concentrate at resource-rich oases. In this study, we first test the hypothesis that productive riparian sites in arid Australia support higher vertebrate diversity than other desert habitats, and then elucidate the habitats selected by different species. We addressed the first aim by examining the diversity and composition of vertebrate assemblages inhabiting the Field River and adjacent sand dunes in the Simpson Desert, western Queensland, over a period of two and a half years. The second aim was addressed by examining species composition in riparian and sand dune habitats in dry and wet years. Vertebrate species richness was estimated to be highest (54 species) in the riverine habitats and lowest on the surrounding dune habitats (45 species). The riverine habitats had different species pools compared to the dune habitats. Several species, including the agamid Gowidon longirostris and tree frog Litoria rubella, inhabited the riverine habitats exclusively, while others such as the skinks Ctenotus ariadnae and C. dux were captured only in the dune habitats. The results suggest that, on a local scale, diversity is higher along riparian corridors and that riparian woodland is important for tree-dependent species. Further, the distribution of some species, such as Mus musculus, may be governed by environmental variables (e.g. soil moisture) associated with riparian corridors that are not available in the surrounding desert environment. We conclude that inland river systems may be often of high conservation value, and that management should be initiated where possible to alleviate threats to their continued functioning. PMID:26637127

  19. Effects of desert wildfires on desert tortoise (Gopherus agassizii) and other small vertebrates

    USGS Publications Warehouse

    Esque, T.C.; Schwalbe, C.R.; DeFalco, L.A.; Duncan, R.B.; Hughes, T.J.

    2003-01-01

    We report the results of standardized surveys to determine the effects of wildfires on desert tortoises (Gopherus agassizii) and their habitats in the northeastern Mojave Desert and northeastern Sonoran Desert. Portions of 6 burned areas (118 to 1,750 ha) were examined for signs of mortality of vertebrates. Direct effects of fire in desert habitats included animal mortality and loss of vegetation cover. A range of 0 to 7 tortoises was encountered during surveys, and live tortoises were found on all transects. In addition to desert tortoises, only small (<1 kg) mammals and reptiles (11 taxa) were found dead on the study areas. We hypothesize that indirect effects of fire on desert habitats might result in changes in the composition of diets and loss of vegetation cover, resulting in an increase in predation and loss of protection from temperature extremes. These changes in habitat also might cause changes in vertebrate communities in burned areas.

  20. Microphytic crusts: 'topsoil' of the desert

    USGS Publications Warehouse

    Belnap, Jayne

    1990-01-01

    Deserts throughout the world are the home of microphytic, or cryptogamic, crusts. These crusts are dominated by cyanobacteria, previously called blue-green algae, and also include lichens, mosses, green algae, microfungi and bacteria. They are critical components of desert ecosystems, significantly modifying the surfaces on which they occur. In the cold deserts of the Colorado Plateau (including parts of Utah, Arizona, Colorado, and New Mexico), these crusts are extraordinarily well-developed, and may represent 70-80% of the living ground cover.

  1. Desert Dust and Monsoon Rain

    NASA Technical Reports Server (NTRS)

    Lau, William K. M.; Kim, Kyu-Myong

    2014-01-01

    For centuries, inhabitants of the Indian subcontinent have know that heavy dust events brought on by strong winds occur frequently in the pre-monsoon season, before the onset of heavy rain. Yet scientists have never seriously considered the possibility that natural dust can affect monsoon rainfall. Up to now, most studies of the impacts of aerosols on Indian monsoon rainfall have focused on anthropogenic aerosols in the context of climate change. However, a few recent studies have show that aerosols from antropogenic and natural sources over the Indian subcontinent may affect the transition from break to active monsoon phases on short timescales of days to weeks. Writing in Nature Geoscience, Vinoj and colleagues describe how they have shown that desert dust aerosols over the Arabian Sea and West Asia can strenghten the summer monsoon over the Indial subcontinent in a matter of days.

  2. Desert Dust Satellite Retrieval Intercomparison

    NASA Technical Reports Server (NTRS)

    Carboni, E.; Thomas, G. E.; Sayer, A. M.; Siddans, R.; Poulsen, C. A.; Grainger, R. G.; Ahn, C.; Antoine, D.; Bevan, S.; Braak, R.; Brindley, H.; DeSouza-Mchado, S.; Deuze, J. L.; Diner, D.; Ducos, F.; Grey, W.; Hsu, C.; Kalashnikova, O. V.; Kahn, R.; North, P. R. J.; Salustro, C.; Smith, A.; Tanre, D.; Torres, O.; Veihelmann, B.

    2012-01-01

    This work provides a comparison of satellite retrievals of Saharan desert dust aerosol optical depth (AOD) during a strong dust event through March 2006. In this event, a large dust plume was transported over desert, vegetated, and ocean surfaces. The aim is to identify and understand the differences between current algorithms, and hence improve future retrieval algorithms. The satellite instruments considered are AATSR, AIRS, MERIS, MISR, MODIS, OMI, POLDER, and SEVIRI. An interesting aspect is that the different algorithms make use of different instrument characteristics to obtain retrievals over bright surfaces. These include multi-angle approaches (MISR, AATSR), polarisation measurements (POLDER), single-view approaches using solar wavelengths (OMI, MODIS), and the thermal infrared spectral region (SEVIRI, AIRS). Differences between instruments, together with the comparison of different retrieval algorithms applied to measurements from the same instrument, provide a unique insight into the performance and characteristics of the various techniques employed. As well as the intercomparison between different satellite products, the AODs have also been compared to co-located AERONET data. Despite the fact that the agreement between satellite and AERONET AODs is reasonably good for all of the datasets, there are significant differences between them when compared to each other, especially over land. These differences are partially due to differences in the algorithms, such as as20 sumptions about aerosol model and surface properties. However, in this comparison of spatially and temporally averaged data, at least as significant as these differences are sampling issues related to the actual footprint of each instrument on the heterogeneous aerosol field, cloud identification and the quality control flags of each dataset.

  3. Desert potholes: Ephemeral aquatic microsystems

    USGS Publications Warehouse

    Chan, M.A.; Moser, K.; Davis, J.M.; Southam, G.; Hughes, K.; Graham, T.

    2005-01-01

    An enigma of the Colorado Plateau high desert is the "pothole", which ranges from shallow ephemeral puddles to deeply carved pools. The existence of prokaryotic to eukaryotic organisms within these pools is largely controlled by the presence of collected rainwater. Multivariate statistical analysis of physical and chemical limnologic data variables measured from potholes indicates spatial and temporal variations, particularly in water depth, manganese, iron, nitrate and sulfate concentrations and salinity. Variation in water depth and salinity are likely related to the amount of time since the last precipitation, whereas the other variables may be related to redox potential. The spatial and temporal variations in water chemistry affect the distribution of organisms, which must adapt to daily and seasonal extremes of fluctuating temperature (0-60 ??C), pH changes of as much as 5 units over 12 days, and desiccation. For example, many species become dormant when potholes dry, in order to endure intense heat, UV radiation, desiccation and freezing, only to flourish again upon rehydration. But the pothole organisms also have a profound impact on the potholes. Through photosynthesis and respiration, pothole organisms affect redox potential, and indirectly alter the water chemistry. Laboratory examination of dried biofilm from the potholes revealed that within 2 weeks of hydration, the surface of the desiccated, black biofilm became green from cyanobacterial growth, which supported significant growth in heterotrophic bacterial populations. This complex biofilm is persumably responsible for dissolving the cement between the sandstone grains, allowing the potholes to enlarge, and for sealing the potholes, enabling them to retain water longer than the surrounding sandstone. Despite the remarkable ability of life in potholes to persist, desert potholes may be extremely sensitive to anthropogenic effects. The unique limnology and ecology of Utah potholes holds great scientific

  4. Water use, productivity and interactions among desert plants. Final report

    SciTech Connect

    Ehleringer, J.R.

    1996-09-01

    On the Colorado Plateau, precipitation comes either from winter storms generated in the Gulf of Alaska or from summer convection storms generated by the Arizona monsoon system. Understanding the current seasonal and regional patterns of precipitation inputs into an ecosystem has ramifications at several levels: on carbon and mineral cycling at the ecosystem level, on biodiversity at the community level, and on productivity and adaptation at the population and species levels. The interior deserts of Arizona, Nevada, and Utah represent the driest regions of western North America, resulting from a combination of rainshadow effects and either the southern limits of winter moisture input or the northern limits of summer moisture input or both. Shifts in strengths of storm-generating conditions in the Pacific and in the Gulf influence both the magnitude and seasonality of soil moisture availability and therefore constrain periods of primary productivity activity in these aridland ecosystems. One major consequence predicted by global climate change scenarios is a change in monsoonal (summer) precipitation; it will increase in some areas and decrease in others. A second is increased soil temperatures and increased interior drought associated with ocean-land temperature disequilibrium. This project focused on the influence of variations in summer moisture input on structure-function relationships within a cold desert ecosystem on the Colorado Plateau. The primary field sites were located at Stud Horse Point, Utah, located on the Utah-Arizona boundary in the Glen Canyon National Recreation Area and at the Arizona monsoon boundary region.