Mineralogy and physicochemical properties of Iraqi surface soil and dust particlesin Ilam province

Dust phenomenon is one of the important climatic and environmental hazards in arid and semi-arid regions of the world. The aim of this study is to determine the mineralogical and physicochemical properties of some soil samples in Iraq and dust particles in Ilam province in order to find out the origin of dust. Dust samples were collected from Ilam, Mehran and Dehloran cities. In addition, some surface soil samples were collected from different parts of Iraq as the source of dust. Physico-chemical and mineralogical analysis of dust and soil samples was fulfilled. The results revealed that the highest percentage of particles forming Iraqi dust and dust in Ilam province are sand and silt and clay was the least. Electrical conductivity in all samples was more than 4 dS/m in both samples meaning as saline classes and pH of the samples was similar in dust of Ilam and Iraqi soils, and showed the neutral to alkaline range. The lime content of all samples was more than 25%. Different regions had low organic carbon percentage, the highest rate was in the Iraqi margin (1.18%), and the lowest was in Najaf (0.16%). The SAR of most Iraqi soils was more than 13 and showed severe alkalinity in dust particles, SAR is also relatively high. Mineralogical results showed that dominant minerals in Iraqi soils and dust of Ilam province are calcite, gypsum, quartz and palygorskite. The results of XRD studies in clay samples of Iraqi soil and Ilam province dust indicated the presence of minerals such as kaolinite, chlorite, ilite and smectite. Overally, the results of physical, chemical, and mineralogical analysis indicated that desert regions in Iraq are the sources of dust production in Ilam, and that dust storms can lead to salinity and alkalinity of the surface soil in Ilam province.