ABSTRACT
The present study investigated the mineralogical composition of the deposited dust from Khamasin wind on the agricultural soils at Assiut city through April 2008 and 2009. Five sites were chosen between the fringes of eastern and western deserts throughout the Nile valley. Wood boxes [dimensions of 1xlm] were put in the selected sites and precipitated dust was collected from each box after the finish of Khamasin storms in the two years. The quantity, pH and EC were determined for the collected Khamasin dust. The mineral particles of these dusts were examined by the scanning electron microscope [SEM] and the X-ray analysis. The obtained results revealed some variation in the dust quantity of Khamasin wind in the year of 2008 and 2009. The quantity of the collected bulk samples of the Khamasin dust varied from site to another in both 2008 and 2009 years. The highest amounts in both years are recorded in the sites of the eastern side of the Nile valley that faraway from the western desert where the Khamasin wind come. The mean values of dust EC and pH were low and similar in both years of 2008 and 2009. The Scanning electron microscope photomicrographs showed that the grain sizes of Khamasin dust in the sites located in the interference zone of Nile valley with the eastern desert were finer than those in site located in the western side of the Nile river. Generally, relatively large angular to subangular grains, larger amount of very Fine grains with more oblate particle and spherical particles with differences in size as well as particles with irregular shapes in Khamasin dust of 2008 and 2009 years. Semi-quantitative measurements of the identified minerals in the Khamasin dust of 2008 year have shown the order of quartz >k-feldspar>calcite> magnetite >epidote> anhydrite > garnet > augite> tourmaline > zircon > ilmenite > plagioclase > goethite > actinolite > hematite. However, the minerals in the Khamasin dust of 2009 year could be ordered as quartz >k-feldspar>calcite>epidote> magnetite > tourmaline > anhydrite > augite > plagioclase >Imenite>rutile> hematite > garnet >actinolite. There was no general trend for distribution of these minerals throughout the studied sites. From a qualitative point of view, most of the sites have the same mineralogical composition. Comparison of the mineralogical compositions of mineral dusts at the five sites, revealed certain quantitative differences