Geochemical Study of the Sediments in Main Valleys East of Mosul city, Iraq

Abstract

Abstract The geochemical alterations in the sediments along streams enable predicting processes transpiring on the Earth's surface, such as weathering, transportation, cation exchange, and more. Moreover, the sediments serve as an environmental indicator and facilitate a clearer comprehension of the geological conditions. In addition to being the primary repository for heavy metals (H.M.s), sediments can also act as a source of pollution associated with these elements. The study area is located on the eastern side of Mosul, northern Iraq. The valleys of Al-Rashediya, Al-Kharrazi, Al-Khosar Al-Danffilli, and Al-Shor descend from elevated regions towards the Tigris River. The sediments in these valleys encompass various constituents, including clay minerals, organic matter, iron oxides, carbonates, and H.M.s, as part of these components or adsorbed onto them. Thirty-six sediment samples were collected from these valleys and subjected to chemical analysis using the X-ray fluorescence technique to determine their chemical composition. Several statistical procedures were employed to examine the distribution of H.M.s in the sediments, including correlation coefficient and factor analysis. The factor analysis yielded four principal components, accounting for 80.86% of the total variance. The first, third, and fourth components elucidate the influence of weathering and transportation on different parent rocks, whereas the second component represents the impact of human activities. The impact of industrial, civil, and agricultural activities on these valleys was assessed using pollution indices such as the geoaccumulation index (Igeo) and the enrichment factor (E.F.).