Diagnosis Of Clay Minerals In Selected Areas Of Sulaymaniyah Governorate Using X-Ray Diffraction (Xrd) And Their Utilization In Sustainable Development

Abstract

The study of the mineralogical composition of the clay fraction is of great importance for understanding soil genesis and pedogenesis, assessing the degree of homogeneity of soil body materials, and characterizing soil-forming processes. The study area was selected in Sulaymaniyah Governorate, northern Iraq, between longitudes 35°49′89.113″–35°49′93.795″ E and latitudes 45°47′84.917″–45°53′85.490″ N, with a total area of 17.023 km². Four areas were selected: Penjwin (471 km²), Said Sadiq (4731 km²), Sharazur (1801 km²), and Qaradagh (717 km²) for clay mineral identification. Three pedons were excavated in each area, giving a total of 12 pedons. Seven surface soil samples were also collected from each area. Sampling of soil samples was done at the study sites with precise study points being identified by use of a Global Positioning System (GPS). The purpose of this study was to establish the mineralogical composition of the soils. Physical and chemical tests were done, as well as mineralogical tests by X-ray diffraction (XRD). The results of X-ray diffraction, which were brought by the powder method to diagnose soil samples and identify the most predominant minerals, revealed that the most predominant minerals were 2:1: clay minerals and 1:1:2 clay minerals. Montmorillonite and chlorite were noted to dominate each other respectively. Chlorite prevailed in most instances over montmorillonite even though most of the soils examined were Vertisols with chestnut soils. The findings also revealed that there were two kinds of mica minerals, including dioctahedral mica (muscovite) and trioctahedral mica (biotite). Muscovite was prevailing because it was more resistant to weathering as compared to biotite. Other soils possessed quite high content of kaolinite that is not surprising because the soils are usually calcaeous and have alkaline reaction. The prevalence of kaolinite could be explained by the geological deposition in the regions.