The current study was conducted to find out the effect of the sediment source (sedimentary of Iraqi-Iranian borderline and Tigris River) on the content and distribution of feldspar minerals and their effect on the optical properties of these minerals in some soils of Wasit and Maysan province. Eight pedons were chosen to represent the study area, five of them represented sediments coming from the borderline, which included pedons of (Badra, Taj Al-Din, Al-Shihabi, Jassan, and Galat), while two of them represent the sediments of the Tigris River (Essaouira, Al-Dabouni). Finally, the pedon of Ali Al-Gharbi represented the mixing area of sediments of all the torrents coming from borderline and the sediments of the Tigris River. The diagnostic tests showed the presence of two types of feldspar minerals in these soils, which are Potassium feldspar (Orthoclase and Microcline), and ranges between (0-11.5%), (0-7.11%), respectively. The second type included the plagioclase minerals represented by (Albite and Anorthite) with percentages (3-21.7%) and (0-8.7%) respectively. Moreover, the results showed that the distribution of the Potassium feldspar mineral percentages was opposite to the horizontal distribution of the plagioclase minerals and for all the study soils. The Plagioclase feldspar minerals increased from the borderline towards the Iraqi lands for the soil pedons affected by the torrents coming from the borderline, while their percentages increased in the soil pedons affected by the Tigris River sediments in the south, the optical features indicated the presence of two types of Potassium feldspar minerals, which included orthoclase and microcline minerals. It was also diagnosed that there are two types of plagioclase minerals, which were altered due to the conditions of transport and sedimentation and the distance from which the particles were transported, which were distinguished by their scratched, eroded and faceted deficient. The second type, which was called the fresh, was characterized by its perfect edges and was not affected by the conditions of transport and sedimentation. © 2020 Plant Archives. All rights reserved.
