Mineral and chemical composition of the ravine alluvium at the Kamyshin city area (Volgograd region)

Abstract

Introduction: valleys under the erosive relief conditions makes transit and accumulation functions formed under the natural and technogenic factors. Researching the alluvial formation at the urbanized areas has practical discipline for analysing the flow of the substances. Purpose: researching the material composition of the ravine alluvium at the Kamyshin city area (Volgograd region).

Methodology: in 2022 have been collected 22 samples of the alluvial formations, including 20 samples along the ravines and 2 samples at the mouths of the small rivers. The analysis of the mineral composition has been made on a x-ray difractometr D8 ENDEAVOR; the analysis of the chemical composition has been made on a X-ray equipment «Spectroscan MAKS-GVM», microscopic researching of samples has been made on a microscope MBS-10.

Results and discussion: in the composition of the ravine alluvium the 3 main situations of the accumulation are reflected. Without deep erosion and soils accumulation in the thalweg which arrived from the lateral tributary valley and also with surface wash, the proportion of quartz decreases to 50–60 % (SiO₂ 40–60 %); the composition of the hydromica, the kaolinite and feldspar are increased. Increasing loss of ignition and Al₂O₃ in the petrochemical composition. When there are no deep crossing and accumulation soil from the lateral tributary valley and form the surface wash in the thalweg next process carry: increasing the composition of the hydro mica, the kaolinite and feldspar, increasing loss of the ignition and content of Al₂O₃ in the petrochemical composition. When there is no bogging up of the mouth ravine, the biogenic accumulation of the chemical elements plays the main role in the decreasing the proportion of quartz (>50 %) and SiO₂ (<40 %), increasing of the cola-spar, chlorate and hydro mica; the loss of the ignition is at maximum value. Increased content of several micro elements is connected with technogenic addition and specificity of the sources of this addition. In the composition of the technogenic material contains particles of the slag, broken bricks, coal smut, ash, metallic microspherol, synthetic fiber, plastic, glass.

Conclusion: The composition of the ravine alluvium in the cities is the result of the erosive and accumulative processes at the water collection area which reflect geological and geomorphological circumstances and technogenic flows of the substances of different sources. Analysis of the ravine alluvium has practical discipline for the geoecological zoning of the city area, the control of the contains of water that has been brought to the receiving basin and making the nature preserving decisions.