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The article discusses salt-affected soils in the south of Eastern Siberia around Lake Baikal. These soils occur in intermontane depressions and foreland basins. The difference in the genesis and chemistry of soil salinization in the western (Cis-Baikal), central (Baikal), and eastern (Trans-Baikal) parts is associated with specific regional features of the geology, hydrogeology, and relief. The deep closed Cenozoic basins of the rift zone in the central (Baikal) region contribute to the advancement of steppe landscapes and saline soils to the north up to 56.4°N (Muisk depression). The presence of gypsum-bearing saline Cambrian rocks in the western (Cis-Baikal) region leads to the formation of predominantly neutral saline soils with a high gypsum content and a predominance of magnesium among toxic cations of soluble salts. The extent of sodasaline soils increases from the west to the east. Soda salinization is virtually absent in the Cis-Baikal region; soda-sulfate salinization predominates in the Baikal region and western part of the Trans-Baikal region. Sulfate–soda and soda salinization predominates in the eastern part of the Trans-Baikal region. [ABSTRACT FROM AUTHOR]

The scale of geological events sets the system of spatial-time coordinates underlying modern natural science concepts. This determines the relevance of projects aimed at creating a network of field training polygons, providing geological practices and geological education of the population, the development of cognitive geological tourism. Localization of polygons determines the complexity of the geological structure of the territory, the presence of outcrops of igneous and sedimentary rocks of different ages, tectonic activity, including modern and ancient seismic dislocations, the ability to observe the results of physical and chemical weathering, the activity of other exogenous processes, glacial, cryogenic, fluvial, aeolian morphosculture. The content of the educational project «Geology of the articulation zone of the Baltic Shield and the Russian Platform» was developed on the basis of a field study of geological objects, taking into account the results of the latest geological research and long-term experience of the authors on the organization of field training practices in North-West Russia (Leningrad Oblast and neighboring regions). The project covers the articulation line of the southern part of the Baltic Shield and the northwestern part of the Russian Plate (the northwestern wing of the Moscow Syneclise (inclination), where outcrops of Archean rocks of the Late Paleozoic are observed on the surface. The research methodology included a comprehensive survey of geological objects and the determination of the possibility of using them as educational and tourist-recreational geological resources. The influence of tectonic structures and geological bodies (rocks, formations) on the landscape differentiation of the territory and the visual perception of the landscape is considered. Based on a comprehensive assessment, the regional network of geological objects of natural and man-made origin supporting the implementation of geological education and enlightenment programs includes groups of objects that form linear structures of submeridional and sublatitudinal stretches, representing the system of traditional routes: along the Popovka valley, to the Sablinsky caves, to Duderhof heights, to the waterfalls of the Tosno river, to the island of Gogland in the Gulf of Finland (igneous and metamorphic rocks of the acidic and basic composition Islands, disjunctive tectonics, seismic dislocations); coast of the Gulf of Finland near the village Vistino (strip clay outcrops, active abrasion-landslide cliff), Baltic-Ladoga cliff with limestone outcrops and karst; a quarry for the extraction of phosphorites from the Kingisepp deposit; Kurlevsky mine for mining loose sediments of lake-marsh reservoirs consisting of calcium carbonate; the exposure of the middle Devonian red sandstones and the karst-suffusion cave in the village of Rozhdestveno. [ABSTRACT FROM AUTHOR]