Origin and study of geochemical properties of detrital sediments in southwestern Iran

The origin and geochemistry of the sediments that make up the Khuzestan plain as one of the key areas of southwestern Iran has always been discussed. Detailed geochemical studies of these sediments, in addition to determining their origin, can provide appropriate information about weathering, erosion, ancient tectonics and environmental pollution in the Khuzestan plain. In this research, after library studies, 276 different points for field surveys were determined with the help of satellite images. Sampling was done from designated points in spring and summer when soil moisture was minimal. The collected samples were sent to the Central Laboratory of Tehran Geological Survey for geochemical experiments after sizing by sieving device of Ahvaz Center of Geology. Findings from sediment granulometry studies show that most of the grains studied have bad to very bad sorting and contain about 70% of particles equal to and larger than silt. In addition, the findings of geochemical studies show that CaO, SiO2 and Al2O3 are the most abundant oxides in these sediments and Ti, Zr, V, Ce and La are also the most abundant by-products. The classification of the sediments based on geochemical indicators shows that these sediments are mainly in the range of Vaki and iron-bearing shales. It is noteworthy that the sediments of this plain are enriched with elements such as As, Bi, Cd, Co, Cu and U, which need to be studied more closely. The results of the study of these findings show that the deposits of the Khuzestan Plain, often in a short time with a high-energy environment. These conditions are more evident in the northern part of Khuzestan province, which is often composed of larger grain particles than the southern parts of Khuzestan province. In addition, geochemical studies performed to determine the ancient tectonics of Khuzestan plain sediments show that the primary origin of these sediments were Continental Island Arc and Active Continental Margin, which corresponds to the Zagros tectonic conditions and can indicate the primary origin of this Sediments are from Sanandaj zone of Sirjan (especially in the northern parts of Khuzestan province). Environmental studies on the collected samples show that these sediments are in a warning state due to the presence of elements such as As, Bi, Cd, Co, Cu and U.