Petrology of Cr-rich Podiform Chromitites of Bulqiza, Eastern Ophiolitic Belt, Albania

<正>The ultramafic massif of Bulqiza,which belongs to the eastern ophiolitic belt of Albania,is a major source of metallurgical chromitite ore.The massif consists of a thick(4 km)sequence,composed from the base upward of tectonized harzburgite with minor dunite,a transitional zone of dunite,and a magmatic sequence of wehrlite,     

Predicting forest structural parameters using the image texture derived from WorldView-2 multispectral imagery in a dryland forest,Israel

Estimation of forest structural parameters by field-based data collection methods is both expensive and time consuming. Satellite remote sensing is a low-cost alternative in modeling and mapping structural parameters in large forest areas. The current study investigates the potential of using WordView-2 multispectral satellite imagery for predicting forest structural parameters in a dryland plantation forest in Israel. The relationships between image texture features and the several structural parameters such as Number of Trees (NT), Basal Area (BA), Stem Volume (SV), Clark-Evans Index (CEI), Diameter Differentiation Index (DDI), Contagion Index (CI), Gini Coefficient (GC), and Standard Deviation of Diameters at Breast Heights (SDDBH) were examined using correlation analyses. These variables were obtained from 30 m × 30 m square-shaped plots. The Standard Deviation of Gray Levels (SDGL) as a first order texture feature and the second order texture variables based on Gray Level Co-occurrence Matrix (GLCM) were calculated for the pixels that corresponds to field plots. The results of the correlation analysis indicate that the forest structural parameters are significantly correlated with the image texture features. The highest correlation coefficients were calculated for the relationships between the SDDBH and the contrast of red band (r = 0.75, p < 0.01), the BA and the entropy of blue band (r = 0.73, p < 0.01), and the GC and the contrast of blue band (r = 0.71, p < 0.01). Each forest structural parameter was modeled as a function of texture measures derived from the satellite image using stepwise multi linear regression analyses. The determination coefficient (R²) and root mean square error (RMSE) values of the best fitting models, respectively, are 0.38 and 109.56 ha⁻¹ for the NT; 0.54 and 1.79 m² ha⁻¹ for the BA; 0.42 and 27.18 m³ ha⁻¹ for the SV; 0.23 and 0.16 for the CEI; 0.32 and 0.05 for the DDI; 0.25 and 0.06 for the CI; 0.50 and 0.05 for the GC; and 0.67 and 0.70 for the SDDBH. The leave-one-out cross-validation technique was applied for validation of the best-fitted models (R² > 0.50). In conclusion, cross-validated statistics confirmed that the structural parameters including the BA, SDDBH, and GC can be predicted and mapped with a reasonable accuracy using the texture features extracted from the spectral bands of WorldView-2 image.     

A combined methodology of multiplet and composite focal mechanism techniques for identifying seismologically active zones in Syria

This contribution is an attempt to enlarge the current knowledge about the focal mechanisms as well as the seismotectonic settings in Syria. The seismologically active zones have been identified by applying an appropriate methodology to the events recorded during the period 1995–2003 by the Syrian National Seismological Network (SNSN). The recorded events in Syria were classified as weak during the research period. It was extremely important to propose and apply an appropriate methodology to identify the focal mechanisms generating this seismic activity. The proposed methodology consists of applying a combination of two techniques: the multiplet and the composite focal mechanisms. The combination of many events in one composite focal mechanism was realized by a multiplet technique using the spectral coherence of the events as a measure of similarity. The application of the proposed methodology allows a data set of composite fault plane solutions to be obtained. Most of the composite fault plane solutions had strike-slip mechanisms which are in agreement with the configuration of seismogenic belts in Syria.     

Antibiotic resistant bacteria as bio-indicator of polluted effluent in the green turtles, Chelonia mydas in Oman

Antibiotic resistant bacteria were studied as bio-indicators of marine polluted effluents during egg-laying in green turtles. A non-invasive procedure for sampling oviductal fluid was used to test for exposure of turtles to pollution in Ras Al-Hadd, Oman, which is one of the most important nesting beaches in the world. Each sample was obtained by inserting a 15 cm sterile swab gently into the cloacal vent as the sphincter muscle is relaxed and the cloacal lining is unfolded to the outside. Forty turtles were sampled. A hundred and thirty-two species of bacteria from 7 genera were isolated. The dominant isolate was Citrobacter. Among the isolates 60.6% were multiple resistant to 15 tested antibiotics. The dominant resistance to antibiotics was ampicillin followed by streptomycin and sulphamethoxazole. Sampling oviductal fluid for resistant bacteria to antibiotics is valuable way to assess exposure to polluted effluents during feeding and migratory in turtles. Polluted effluents using bacteria as bio-indicator may influence reproductive potential in this endangered species.     

Geochemistry of lamprophyre dykes,Wadi Sikait area,South Eastern Desert,Egypt

The Wadi Sikait area lies at about 95 km southwest of Marsa Alam City along the Red Sea Coast, Eastern Desert, Egypt. It is occupied by Precambrian rocks of ophiolitic mélange, metamorphosed sandstones (MSS), gab-bros and monzogranites which were later intruded by lamprophyre dykes and quartz veins. The lamprophyre dykes were extruded in NW-SE and NE-SW trends cutting monzogranites and metamor-phosed sandstones. The lamprophyres are porphyritic and composed of clinopyroxene, olivine and amphibole phenocrysts enclosed in a fine-grained groundmass of clinopyroxene, amphibole, opaque and lithium mica. The al-teration products are represented by amphibole (tremolite-actinolite and hornblende), carbonate, epidote, chlorite, iddingsite, clay minerals, limonite and serpentine. The Sikait lamprophyre dykes can be classified as alkaline lamprophyres characterized by silica contents rang-ing from 41.65 wt% to 50.88 wt% and Na2O>K2O. They are enriched in LILE, LREE and HFSE, but strongly de-pleted in compatible elements such as Cr and Ni relative to the primitive mantle. Sikait lamprophyres have moderate Zr/Hf (35.6-52.8) and Nb/Ta (20.5-22.5) ratios. Most of these features are attributed to the origin of these dykes from the metasomatized mantle affected by subduction-related fluid. These lamprophyres are compositionally similar to Salu lamprophyres in eastern China. The Sikait lamprophyre samples have high LREE (320×10-6-419×10-6) relative to HREE (20×10-6-33×10-6) with ratios (LREE/HREE=11.6-18.7) and no negative Eu anomaly (Eu/Eu*=0.9-1.04). The relative presence of posi-tive Ce anomaly (Ce/Ce*=1.04) in lamprophyre samples suggests the oxidizing condition under which the REEs were precipitated due to the common occurrence of fluorite and apatite.     

http://www.sciencedirect.com/science/article/pii/S167498711100048X

Metavolcanic rocks hosting base metal sulphide mineralization, and belonging to the Kid Metamorphic Complex, are exposed in the Samra-Tarr area, Southern Sinai. The rocks consist of slightly metamorphosed varicolored porphyritic lavas of rhyolite-to-andesite composition, and their equivalent pyroclastics. Geochemically, these metavolcanics are classified as high-K calc-alkaline, metaluminous andesites, trachyandesites, dacites, and rhyolites. The geochemical characteristics of these metavolcanics strongly point to their derivation from continental crust in an active continental margin. The sulphide mineralization in these metavolcanics occurs in two major ore zones, and is represented by four distinct styles of mineralization. The mineralization occurs either as low-grade disseminations or as small massive pockets. The associated hydrothermal alterations include carbonatization, silicification, sericitization and argillic alterations. The base metal sulphide mineralization is epigenetic and was formed by hydrothermal solutions associated with subduction-related volcanic activity.     

Comparison of biostimulation and bioaugmentation for remediation of soil contaminated with spent motor oil

Aerobic fixed bed bioreactors were used to study and compare biostimulation and bioaugmentation for remediation of soil contaminated with spent motor oil. Bioaugmentation using consortium of bacteria and biostimulation using inorganic fertilizer and potassium dihydrogen orthophosphate were investigated. The bioremediation indicators used were the oil and grease content removals, total heterotrophic bacteria counts and carbon dioxide respiration rates. Results showed that biodegradations were very effective with 50, 66 and 75 % oil and grease content removal efficiencies for control, bioaugmentation and biostimulation respectively after ten weeks. Carbon dioxide respiration followed similar pattern as the oil and grease content removals. Biostimulation option has the highest carbon dioxide generation (6 249 mg/kg) and the control with the least (4 276 mg/kg). Therefore, the biostimulation option can be used to develop a realistic treatment technology for soils contaminated with spent motor oil.     

Geotechnical investigation of sewage wastewater disposal sites and use of GIS land use maps to assess environmental hazards: Sohag, upper Egypt

Land application is the only currently available technique for sewage wastewater disposal along the Nile Valley in Upper Egypt. Wastewater disposal projects have been established in the lowland desert zone extending between the cultivated floodplain and the Eocene Limestone plateau. The plan is to use the treated wastewater in irrigating woody farmlands. Some wastewater disposal sites are already operating, and several others will be established in the near future. The proposed wastewater disposal sites are located in a sensitive desert zone that is extremely narrow and situated very close to vital resources including the cultivated floodplain, reclaimed lands, residential areas, and surface water resources. In addition, the subsurface sediments of this zone (Pleistocene sand–gravel succession) constitute a significant part of the Quaternary aquifer of the valley. The objective of this study is to characterize and investigate the wastewater disposal sites and assess their probable environmental hazards. The study showed that the available lands are insufficient to accommodate the projected quantities of wastewater. At the currently operating sites, excess raw wastewater is accumulating on the ground surface forming large uncontrolled ponds. Such wastewater ponds represent a potential environmental hazard and might cause disastrous health effects, where chemical and bacteriological pollution of soil, crops and water resources may occur.     

The use of magnetic and geo-electrical data to delineate the subsurface structures and groundwater potentiality in Southeastern Sinai, Egypt

The study area is located in the southern part of Sinai Peninsula. This study was done to delineate the subsurface structure of the basement rocks affecting the groundwater potentiality in the study area and to perform the lateral and vertical variations in the subsurface lithologic properties. To achieve these, a high-resolution total intensity magnetic map and geo-electrical survey were acquired. Two-dimensional power spectrum, analytical signal, and Euler deconvolution techniques are applied on magnetic data. The geo-electric data interpretations concluded that, the study area can be classified into five units of sediments arranged as: (1) the top surficial layer of dry sand and gravels; (2) the second layer of silty sand layer with thickness ranging from 5 to 35 m; (3) the third layer of dry sand with thickness ranging from 5 to 130 m; (4) the fourth layer composed of saturated sand which was considered as the water-bearing zone of the investigated interval, its thickness ranges between 50m and more than 200 m; (5) the fifth layer is interpreted as basement rocks. The depth to the basement surface has an average value of 156 m at the eastern side and 758 m at the western side of the study area. This area is characterized by a graben structure bounded by major faults striking in the NW–SE direction and is considered one of the most promising regions for water resources in Sinai.     

Effects of phosphate mining activity on groundwater quality at Wadi Queh, Red Sea, Egypt

The groundwater in Wadi Queh exists in two main hydrogeological units; fractured Precambrian basement and sedimentary rocks with high contribution for groundwater recharge. To study the impacts of phosphate mining activities on the groundwater quality in the area, three groundwater samples that represent all water wells in the area were collected and analysed for major ions and some heavy metals. In addition, three bulk samples representing the phosphatic sediments collected from upstream and downstream of the drainage basin were collected and analysed to understand the source of groundwater contamination. The total concentrations of dissolved solids suggest that the groundwater in the area grades from fresh to brackish water (961–1,580 mg/l), and is characterized by sodium–calcium–sulphate–chloride and sodium–magnesium–sulphate–chloride chemical types. The results showed high concentrations of the heavy metals in well nos. 1 and 2 in downstream parts compared to well no. 3 in upstream part reflecting their influence by the mining activities.