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Vertic features in paleosol of Raygorod outcropтезисы доклада
- Авторы: Alexandra Churilina, Tatyana Romanis, Marina Lebedeva, Pavel Kust, Alexander Makeev, Alexey Rusakov, Redzhep Kurbamov, Tamara Yanina
- Сборник: Abstracts of the International conference “Loessfest2018: Diversity of loess: properties, stratigraphy, origin and regional features”. Moscow-Volgograd, September 23-29, 2018
- Редакторы: Курбанов Реджеп Нурмурадович, Янина Тамара Алексеевна
- Тезисы
- Год издания: 2018
- Место издания: Volgograd State University Volgograd
- DOI: 10.13140/RG.2.2.25716.40326
- Аннотация: We've investigated the outcrop on the right bank of Volga river (Svetloyarsky district of Volgograd region) near Raygorod village (48 ° 25'46.3 "N 44 ° 57'20.0" E). Seven levels of buried soils were identified in the outcrop coordinated to loess interbeds. We've described the paleosol of MIS5c stage, formed in a heavy silty loam at a level of 17.6 m from the present-day surface. In the soil profile were noted signs of vertic features formation such as sliding surfaces (slickensides). These slikensides are described for both different-colored layers (tawny and dark-gray), that were separated in a soil profile by a sharp boundary. In the upper tawny layer large (up to 2 cm) gypsum roses were noted. Their growth was accompanied by small slickensides formation. The lower dark-gray horizon is underlain by a sandy loam layer with a variety of ferriferous neoformations. The boundary between these layers is complicated by cryogenic wedges. Below is a thick layer of well-washed sand. Micromorphological studies of both layers showed vertical differentiation of microstructure elements. In the tawny layer specific unaltered wedge-shaped structures were crearly marked as well as strong striated b-fabric and stress cutans along the cracks. In the upper 5 cm of the dark-gray layer a large number of carbonized plant tissues scraps were noted. The signs of gleyzation are widely presented below by high heterogeneity of iron oxides impregnation of fine-dispersed material and slickensides. Since the vertisols swelling features and slickensides occurrence are inextricably linked with mineralogy, we've conducted X-ray diffractometric analysis of clay fraction (<1 μm) for both considered layers. The obtained results showed dominance of smectite (about 80%), which is typical for modern vertisols (Kovda et.al., 2017). The feature of diagnosed smectite is calcium form of cation filling. The accompanying minerals are chlorite, imperfect kaolinite and highly hydrated hydromica. There were no obvious differences between upper and lower layers in clay content and it's qualitative composition. Mineralogical and micromorphological studies confirmed the macromorphological diagnostics of vertic processes in buried soils of MIS5c interval. This work was supported by the Russian Foundation for Basic Research (Grant No. 18-04- 00638a)
- Добавил в систему: Макеев Александр Олегович