Impact of Sedimentary Conditions and Relative Distribution of Sand Sedimentary Minerals in Iraqi Soils

Abstract

This study investigated the relative distribution of sand-separating minerals and the effect of sedimentary and climatic conditions on their distribution in some soils from northern and southern Iraq. The samples were collected from four Iraqi governorates: Erbil (included the soils from areas of Shaqlawa, Soran, and Juman), Sulaymaniyah (included the soils from Dokan, Sayed Sadeq, and Halabja), Maysan (included the soils of Al-Kahla, Ali Al-Sharqi, Awasha, Kumit, Ali Al-Gharbi, and Al-Tayyib), and Wasit Governorate (included the soils of Zurbatiya, Badra, Jassan, Al-Muwafiqiyah, Al-Numaniyah, and Zubaidiyah). The results indicated that the percentages of light sand minerals were higher than the percentages of heavy sand minerals in all the soils of the study sites. It is attributed to the nature of the mineral composition and the intensity of the weathering factor’s influence on the sedimentation sites or during transportation. The results also indicated the dominance of the quartz group, followed by the group of carbonate rock pieces and the group of feldspar minerals in terms of dominance within the light part of sand minerals in all soil samples in southern Iraq (Wasit and Maysan). The rock-cut minerals group was dominant, followed by the quartz and feldspar minerals group in all soil samples in northern Iraq (Erbil and Sulaymaniyah). The other light minerals of the group were found in varying proportions and distribution in all soil samples, which included (mudstone, lime, evaporites, igneous and metamorphic rocks, clay-coated grains, and other minerals). The results showed that the percentages of the opaque minerals were higher in all soil samples than the group of non-opaque minerals, which included minerals (zircon, tourmaline, rutile, strolite, epidote, and kyanite) with irregularity and a significant difference in the proportions as the large percentages indicate that they bear transportation over long distances and their resistance to weathering processes. These ratios were more evident in the northern regions of Erbil and Sulaymaniyah, which indicate the intensity of weathering processes (wet climate) compared to the soils of Wasit and Maysan in southern Iraq. The low percentages appeared in the soil samples due to the short transportation distance and the diversity of the source rocks.