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Hassan Al-Fugha Tayel El-Hasan Ahmad Al-Malabeh Arwa Hamaideh Ahmad El-Mezayen 《Arabian Journal of Geosciences》2013,6(10):3979-3987
The present work deals with the geologic setting and mineralogical and geochemical study of Late Precambrian magmatic rocks especially the felsic dike swarms of northeast Aqaba complex in South Jordan. The northeast Aqaba complex represents one of the most significant regions in the South Jordan basement. The basement rocks in the studied region are composed of schists, gneisses, migmatites, met gabbros, diorite, and granite. It is invaded by post-orogenic dike swarms. The post-orogenic dike swarms have been recognized as felsic dikes of dacite, rhyodacite, and rhyolite composition. They are composed of plagioclase, K-feldspar, quartz, biotite, and hornblenble with a porphyritic texture. Chemically, they are enriched in compatible elements especially in the large ion lithophile elements such as K, Rb, and Ba. The values of A/NK are more than A/CNK, indicating that dacitic dike swarms have metaluminous nature. Meanwhile, the values of A/NK are less than A/CNK in rhyodacitic and rhyolitic dike swarms of prealuminous nature. This felsic dike can be related to an intercontinental setting that was accompanied by a chemical evolution of the extensional movements and is formed by partial melting of crustal rocks, which are already known from other areas in the northeast portion of the Arabian-Nubian Shield. 相似文献
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Summary ?One of the most important features in analysing the climatology of any region is to study the precipitation and its periodicity
of different harmonics in order to study the behavior of the observed data. In this study the amplitude of frequencies, phase
angle and basic statistical parameters are calculated in order to depict spatial characteristics of precipitation over Jordan.
Precipitation records of 17 stations were chosen according to climatic regions of Jordan. The first and second harmonic analyses
explain more than 90% of the precipitation variation in Jordan effectively. The amplitudes of the first and second harmonic
were calculated in order to describe the climatic regions in the country. The maximum amplitudes were found in the northern
mountainous region. The phase angle representing the time of maximum rainfall is also used in the form of a contour chart.
It is found that Jordan has its main rainfall season in winter with maximum around January. The coefficient of variation shows
the high variability of rainfall of the country.
Received February 4, 2002; revised August 1, 2002; accepted August 6, 2002 相似文献
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The main scope of the present work is to investigate the potential of using ground calcium carbonate (GCC) from the Barre de Ghomrassene (BDG) in Southeast Tunisia in paint industry. In order to evaluate the performance of the material and the formulated paint films, representative raw specimens of main deposits of naturel GCCs in the Mediterranean basin and Middle East countries such as extra-white limestone from the Abiod Formation (Feriana region in West-Central Tunisia), A??gedi?i Formation (Ni?de Group, South Central Turkey), and Samalut Formation (Elminea, South Cairo, Egypt) were considered. Samples were ground to specific surface of about 3000 cm2/g and were subjected to detailed characterization including chemical and mineral composition, physical, and chromaticity characteristics. Results show that the GCC from the lower part of the Barre de Ghomrassene is, in most, dark and grainstone in texture, which limit its use in paint and coating application. Elsewhere, it is marked by high purity degree (generally more than 97% calcite); high lightness (more than 86.5, 95.2 in average) with relatively low chromaticity (a*?<?3.3, b*?<?9.1); low oil intake (17.4 g/100 GCC); very low electrolyte levels; good pH buffering (close to 9); accepted ranges of density and abrasion (2.65–2.7 and 10–18, respectively); good grindability; low levels of harmful components such as MgO, SiO2, Fe2O3, and acid insoluble residue (less than 0.1% each); and improved rheological properties. The BDG seems to be a suitable filler for paint when mixed with water, styrene acrylic, and common additives. The formulated paint films meet all standard requirements, in that they have very good opacity, matt visual dualgloss 20/60°, high luminescence (L*?=?96.4), suitable hardness (145 s), good adhesion (B5), and sufficient impact resistance (1.5 kg m). The performances of these films are analogous to those based on Abiod and Samalut formations (natural carbonate), but they are slightly less lighter than those based on A??gedi?i Formation (metamorphic carbonate). Hence, the studied GCC can be used to substitute them in particular for local GCCs from the Abiod Formation, which are limited and over exploited. 相似文献
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Q. Y. Tarawneh M. El Alfy 《International Journal of Environmental Science and Technology》2017,14(6):1267-1276
Saudi Arabia is a huge area with diverse climatic and topographical features. This diversity in climate is augmented by seasonal weather variations. The study discusses solar irradiance and sunshine duration in terms of seasonal weather systems. Sunshine duration and solar irradiance maps show that the East Mediterranean weather systems (such as Cyprus low) in winter affect the majority of the geographical regions in Saudi Arabia. In spring and autumn, Sudan low becomes more active than Cyprus low, especially in the west and central regions. Sunshine duration in April is 47% compared to 50% in January. Sunshine duration in the southwest region is affected by the rainy and wet summer monsoon which reduces sunshine duration to 33% in summer (July), while it is 43% in winter (January). In addition, the study uses the Angstrom equation to estimate solar irradiance. The absolute relative error between estimated and observed solar irradiance ranges between 2 and 10% in the majority of cases, with a few cases exceeding 13%. 相似文献
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A hydrological record extension model for reconstructing streamflows from tree‐ring chronologies 
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下载免费PDF全文 Characterizing drought events is an important factor in designing and operating water resource projects, but instrumental hydrologic records are generally short (<100 years). Because estimates of drought statistics can improve when longer records are available, we developed a stochastic model to extend instrumental streamflows based on tree‐ring chronologies. This Record Extension plus Noise (or REXTN) model consists of an autoregressive term to account for the temporal persistence of streamflows, predictor variables with longer records, and a noise term. The noise term was included to avoid underestimating the variability of the flows and to generate multiple extensions, which offer the possibility of quantifying the uncertainty of drought statistics such as the critical drought. For cases where having multiple extensions is not desirable, a statistically based algorithm was developed to select a single extended record. Using a simulation experiment, model REXTN was found to perform better than other existing reconstruction methods. The model was then applied to extend streamflows of the Poudre River, CO, USA, based on tree ring‐chronologies back to the year 1600, and the reconstructions were used to determine drought statistics such as duration and magnitude. When results based on the classical linear regression model were compared with those calculated by model REXTN, the latter was found to better match flow and drought statistics from the instrumental records, as well as to give a broader range of drought duration and magnitude. The REXTN model provides a useful addition to the range of tools available to hydrologists for coping with the uncertainty associated with water resource management under future climate scenarios. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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This study investigates the diversity of immigrant populations and their spatial residential patterns at the census tract level within twenty‐nine counties of the Atlanta Metropolitan Statistical Area (MSA), using 2013 American Community Survey (ACS) five‐year estimates summary data from 2008–2012. Correlations coefficient analyses with local job opportunities, education level, and English proficiency and the presence of foreign‐born populations are also discussed. We find that immigrants have different patterns of settlement depending on their place of birth and region of origin. Local job opportunities, dominant language at home, and education levels also relate to the distribution of foreign‐born populations. Further research opportunities concerning differential settlement are discussed. 相似文献
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The contents of Li, V, P2O5, and Al2O3 in marls and mudstones collected from three different formations, cropping out in northern Iraq, showed that the ratios of Li/Al2O3, V/Al2O3, and P2O5/Al2O3 in these rocks can be used to discriminate environments of deposition of these formations. Relatively high values of the above ratios characterize the deep marine Shiranish environment while lowest values characterize freshwater environment of deposition of the Injana rocks. Despite that marls of the Fatha formation were deposited in marine lagoonal environment, the ratios P2O5/Al2O3 and V/Al2O3 could not be discriminated from the freshwater Injana mudstones. The well-known phenomenon that marine surface water and down to a depth of 50 m almost lacks soluble P explain this behavior. In such water, almost all the soluble P is consumed by surface organism rendering it unavailable for adsorption by the sediments. The high salinity of the lagoonal environment prevented adsorption of soluble V on clay minerals because of its inability to compete with other species of much higher concentrations. 相似文献
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