Data analysis of a revisited exploration geochemical dataset of quartz porphyrites from SW Jordan using GIS techniques     

《Chemie der Erde / Geochemistry》2016,76(4):519-527

The spatial distribution of Cu and its pathfinder elements in quartz porphyrites along Wadi Araba was studied in order to gain an insight about the geologic framework of Cu mineralization in the area. A geochemical exploration data set of 242 samples was revisited. Multivariate statistical and geostatistical analysis were performed on the data set. The objectives of the study were to define Cu relationships with its possible pathfinder elements and to figure out whether geostatistical treatment of exploration data would help telescoping already existing Cu mineralization in Wadi Araba, SW Jordan. Factor analysis and hierarchical cluster analysis were performed on the data set. The results of which indicate that seven elements, namely, Ba, Cr, Mn, Ni, Sc, Sr and V can be considered as pathfinder elements for Cu. Significant correlations do exist between Cu and these elements. The encountered experimental semivariograms of the defined pathfinders were fit to exponential models with varying nugget effects with the exception of Mn which was fit to the spherical model. Ordinary kriging was found to be most appropriate to generate geochemical exploration maps. The applied methods succeeded in deriving valuable information and visualizing the already existing Cu mineralization in Wadi Abu Khusheiba area.  相似文献   

Geomorphological analysis of the morphometric characteristics that determine the volume of sediment yield of Wadi Al-Arja,South Jordan     

Ali Hamdi ABU SALIM 《地理学报》2014,24(3):457-474

This study addresses the morphometric variables that determine the sediment yield in Wadi Al-Arja through the analysis of the impact of different morphometric characteristics along the course of the valley on its sediment yield, as well as the analysis of spatial and formal dimensions and morphologies of the basin and its relationship to the sediment yield. The study also addresses the size of variation in the volume of sediment yield of the river tributaries that make up the water network of the valley under the differences of its morphometric and hydrological characteristics. The study found several results, most notably: The classification of Wadi Al-Arja basin according to the hypsometric integral value (72.1%) within an uneven topography, which increases the force of the erosive activity and the size of the sediment yield if the basin was exposed to moist climatic periods. The study also showed the presence of convergence in the intra-spaces between the river tributaries in the water network. This increases the volume of water flows when these tributaries meet with each other and thus increasing their erosive ability and sediment yield.The study also showed the presence of marked variation in the sediment yield of the river tributaries depending on the differences in its morphometric characteristics. The results of the step-wise regression analysis confirmed the importance of the morphometric and hydrological variables, and plant coverage in interpreting the variation in the size of the sediment yield of the river tributaries of different stream order in Wadi Al-Arja basin, where these variables interpreted 43% of the total variation, with statistical significance less than 0.05.  相似文献   

Inland saline lakes of Wadi El Natrun depression, Egypt     

Amany G. Taher 《International Journal of Salt Lake Research》1999,8(2):149-169

The morphology and geochemistry of saline lakes in the Wadi El Natrun depression were studied. All lakes had pH values of 8.5--9.5 and a salinity from 283 to 540 g/L. The main ionic components were sulphate, chloride, carbonate and sodium. Traces of magnesium were also present. The water of the lakes is of the Cl^– to SO ₄ ^2– -Cl^– type. Increased Cl^– in Wadi El Natrun brines can increase metal solubility due to the formation of soluble chloro-complexes of trace elements. The metal concentrations decrease in the order: Pb > Cu > Cd > Ni > Zn > Fe > Mn. The characteristics of Wadi El Natrun saline lakes are compared with those from other saline lakes.  相似文献   

地貌特征对约旦南部阿尔阿加河(WadiAl-Arja)流域产沙影响分析(英文)   总被引：1，自引：0，他引：1  

Ali Hamdi ABU SALIM 《地理学报(英文版)》2014,24(3):457-474

This study addresses the morphometric variables that determine the sediment yield in Wadi Al-Arja through the analysis of the impact of different morphometric characteristics along the course of the valley on its sediment yield, as well as the analysis of spatial and formal dimensions and morphologies of the basin and its relationship to the sediment yield. The study also addresses the size of variation in the volume of sediment yield of the river tributaries that make up the water network of the valley under the differences of its morphometric and hydrological characteristics. The study found several results, most notably: The classification of Wadi Al-Arja basin according to the hypsometric integral value(72.1%) within an uneven topography, which increases the force of the erosive activity and the size of the sediment yield if the basin was exposed to moist climatic periods. The study also showed the presence of convergence in the intra-spaces between the river tributaries in the water network. This increases the volume of water flows when these tributaries meet with each other and thus increasing their erosive ability and sediment yield. The study also showed the presence of marked variation in the sediment yield of the river tributaries depending on the differences in its morphometric characteristics. The results of the step-wise regression analysis confirmed the importance of the morphometric and hydrological variables, and plant coverage in interpreting the variation in the size of the sediment yield of the river tributaries of different stream order in Wadi Al-Arja basin, where these variables interpreted 43% of the total variation, with statistical significance less than 0.05.  相似文献   

Hydrochemical variation in the springs water between Jerusalem–Ramallah Mountains and Jericho Fault,Palestine     

Saed Khayat  Peter Möller  Stefan Geyer  Amer Marei  Christian Siebert  Fayez Abu Hilo 《Environmental Geology》2009,57(8):1739-1751

The spatial and temporal changes of the composition of the groundwater from the springs along the Wadi Qilt stream running from the Jerusalem–Ramallah Mountains towards the Jericho Plain is studied during the hydrological year 2006/2007. The residence time and the intensity of recharge play an important role in controlling the chemical composition of spring water which mainly depends on distance from the main recharge area. A very important factor is the oxidation of organics derived from sewage and garbage resulting in variable dissolved CO₂ and associated HCO₃ ⁻ concentration. High CO₂ yields lower pH values and thus under-saturation with respect to calcite and dolomite. Low CO₂ concentrations result in over-saturation. Only at the beginning and at the end of the rainy season calcite saturation is achieved. The degradation of dissolved organic matter is a major source for increasing water hardness. Besides dissolution of carbonates dissolved species such as nitrate, chloride, and sulfate are leached from soil and aquifer rocks together with only small amounts of Mg. Mg not only originates from carbonates but also from Mg–Cl waters are leached from aquifer rocks. Leaching of Mg–Cl brines is particularly high at the beginning of the winter season and lowest at its end. Two zones of recharge are distinguishable. Zone 1 represented by Ein Fara and Ein Qilt is fed directly through the infiltration of meteoric water and surface runoff from the mountains along the eastern mountain slopes with little groundwater residence time and high flow rate. The second zone is near the western border of Jericho at the foothills, which is mainly fed by the under-groundwater flow from the eastern slopes with low surface infiltration rate. This zone shows higher groundwater residence time and slower flow rate than zone 1. Groundwater residence time and the flow rate within the aquifer systems are controlled by the geological structure of the aquifer, the amount of active recharge to the aquifer, and the recharge mechanism. The results of this study may be useful in increasing the efficiency of freshwater exploitation in the region. Some precautions, however, should be taken in future plans of artificial recharge of the aquifers or surface-water harvesting in the Wadi. Because of evaporation and associated groundwater deterioration, the runoff water should be artificially infiltrated in zones of Wadis with high storage capacity of aquifers. Natural infiltration along the Wadis lead to evaporation losses and less quality of groundwater.  相似文献   

Pan-African high-grade metamorphism of southern Sinai,Egypt, fluid inclusion evidence     

Mohamed El Tokhi  Abdalla Musallum 《中国地球化学学报》2009,28(4):358-363

Fluid inclusions in the leucosomes of Wadi Feiran migmatites showed that CO ₂ , H₂O and (H₂O-CO₂) fluids were likely to have been present when partial melting began in these rocks. Low salinity, aqueous fluid, to a lesser extent, CO₂-rich fluids are the most abundant fluids. The present study suggests that high-density CO₂ inclusions were formed at the earliest stage, while H₂O inclusions were formed at the late stage. In an intermediate stage, low-density CO₂ and H₂O, CO₂ inclusions were formed. At the early stage of uplift and during melt crystallization, the CO₂-bearing vapour was trapped at grain boundaries. At the late stage of uplift, H₂O released at the time of crystallization of the melt was trapped as inclusions.  相似文献   

Historical aspects of soil erosion in the Mejerda catchment,Tunisia     

Sihem Jebari  Ronny Berndtsson  Fethi Lebdi  Akissa Bahri 《水文科学杂志》2013,58(5):901-912

Abstract

Agricultural use and related water erosion may lead to significant changes in the sedimentological and hydrological characteristics of watersheds, and therefore negative consequences for rural development. This research aimed to put present-day soil erosion of the important Mejerda catchment into a historical context. The catchment of Wadi Mejerda in northern Tunisia has experienced soil erosion due to weather and human impacts for thousands of years. We used historical texts and results from archaeological research that go back to 1000 BC, as well as data collected during the last century. Soil erosion from different types of agricultural landscape management was analysed together with information on the soils' production potential, the hydrographic network and flood frequency. The results showed that water erosion has increased the hydrographic network by 65 km and increased the deltaic plain by as much as 15 km²/century. However, soil productivity has decreased significantly. Moreover, due to in channel sedimentation and river choking, the number of flooding occurrences has multiplied over the last century. Finally, it is shown that water erosion follows a specific cycle of degradation throughout the watershed. These findings should be considered for better water and soil management in the context of semi-arid areas.

Editor Z.W. Kundzewicz

Citation Jebari, S., Berndtsson, R., Lebdi, F., and Bahri, A., 2012. Historical aspects of soil erosion in the Mejerda catchment. Hydrological Sciences Journal, 57 (5), 901–912.  相似文献   

Vecteur de la pollution metallique du bassin versant de l’Oued El Bey vers le Golfe de Tunis (Tunisie)     

Samia Khadhar  Ammar Mlayah  Anis Chekirben  Abdelkrim Charef  Malika Methammam  Shabou Nouha 《水文科学杂志》2013,58(8):1803-1812

Résumé

L’Oued El Bey, qui draine 60% de la charge polluante hydrique de plusieurs agglomérations urbaines du Nord-Est de la Tunisie, est un exemple représentatif du transfert des métaux lourds résultant de l’activité industrielle et urbaine. Il fournit une indication sur le devenir et la répartition des métaux lourds dans le Golfe de Tunis. Dans la fraction dissoute, Cd, Pb, Co et Hg ne sont pas détectés mais Zn varie entre 0,01 et 0,07 μg/L. Les concentrations du Mn, Zn, As, Ni, Pb, Cu et du Cd sont très élevées dans la fraction particulaire par rapport à la fraction dissoute, avec un coefficient de partage Kd de l’ordre de 10⁶, ainsi que dans les sédiments du lit de l’oued pour Pb et Zn. La pollution par les métaux la plus élevé de l’Oued El Bey a été trouvée pour Zn, Pb et Cu: les concentrations variaient respectivement entre 1698,9 et 14575, de 0 à 2153,7 et de 0 à 3431,8 μg/g. La variation spatiale des teneurs en métaux lourds confirme l’effet des eaux usées rejetées dans l’Oued El Bey. Les teneurs de ces métaux lourds dans les trois phases dissoute, particulaire (MES) et sédiments confirment que la MES constitue le vecteur de transport principal via la Sebkha Soliman vers le golfe. L’examen des rapports des différents éléments (Pb, Cu et Cd) par rapport au Zn dans les sédiments de l’oued montre une augmentation au niveau de la confluence de l’Oued El Bey et de son affluent l’Oued El Meleh, ce qui signifie que les apports sédimentaires de cet affluent contrôlent la signatutue chimique des sédiments de l’Oued El Bey.

Editeur Z.W. Kundzewicz; Editeur associé B. Touaibia

Citation Khadhar, S., Mlayah, A., Chekirben, A., Charef, A., Methammam, M., Nouha, S., et Khemais, Z., 2013. Bassin versant Oued El Bey: vecteur de transport de la pollution métallique vers le Golfe de Tunis (Tunisie). Hydrological Sciences Journal, 58 (8), 1803–1812.  相似文献   

Geochemistry and genesis of magmatic PGE-bearing Cu-Ni sulphide deposit in Wadi Bayhan,southeastern Yemen     

Moteea A.Al-Shameery  M.Alqadasi  M.Mattash 《东北亚地学研究》2011,(1)

The Wadi Bayhan mafic-ultramafic intrusions associated with magmatic PGE-bearing Cu-Ni sulphide deposit are located in the south margin of the Arabian-Nubian Shield,SW Yemen.The intrusions consist of dunite,olivine-pyroxenite,lherzolite,hornblendite,gabbro and gabbronorite.The dunite and lherzolite are the main host rock for the Cu-Ni ores.The new data of the chemical compositions of the rocks have SiO2(50%-53.6%),Al2O3(0-32%) and MgO(4%-28%),and relatively low TiO2(0-3.2%) and K2O+Na2O(0.04%-5.2%).The geoc...  相似文献   

Geology and fluid inclusion of Wadi Sharis Neoproterozoic orogenic gold deposits in northwestern Yemen     

Moteea A.Al-Shameery  SUN Fengyue 《东北亚地学研究》2011,(1)

The Wadi Sharis orogenic gold deposit in northwestern Yemen is related to the fault and shear zones vein at medium depth in the crust in the Neoproterozoic meta-sedimentary and meta-volcanosedimentary succession of greenschist to amphibolite facies metamorphism.Three distinct fluid inclusion types have been identified in the gold-bearing quartz sulphide veins of the deposit:(1) type I:vapour-liquid two-phase(VH2O-LH2O),(2) type II:three-phase CO2(VCO2-LH2O-LCO2) and(3) type III:vapour-rich(LCO2-VCO2) inclus...  相似文献