O. Koltun, V. Koltun
In the Earth sciences (e.g. soil sciences, geochemistry, geology, paleogeography, geomorphology) the analysis of ironand calcite-pedofeatures or iron and carbonate content in soils and rocks is the usual source of information about environmental conditions of their sedimentation and different types of changes. But it doesn't apply to the Liesegang rings. The Liesegang rings are not well-known phenomenon if we talk about loose sediments, including loess and paleosols. These mainly round structures present a specific type of spreading in sediment layers the iron- and calcite-bearing pedofeatures. In 1970s and 1980s for unofficial use were made some geotechnical tests of Upper Pleistocene loess and paleosols monoliths from Khmelnytskyi plateau area, and first of all they had shown a difference in results of subsidence evaluation (in this case as compaction caused by first-time wetting of moisture-deficient clay or silty soils) between the ordinary samples and sample with iron-bearing Liesegang rings. According to recent research of samples from boreholes and pit excavation, iron-bearing rings occur in Upper Pleistocene loess and paleosols, calcite-bearing rings occur in Middle Pleistocene paleosols. In both cases they have rare representation, diameter up to 10 cm. There are not only geological and geotechnical engineering reasons for bigger scientific interest in the Liesegang rings, but also paleogeographic, for example, to answer the question, when and why these structures appeared if groundwater table lies more than 12 m deeper, and opposite to modern fertile soils, oversaturation seemly is not here a cause of forming of iron-bearing pedofeatures. This study is primarily an attempt to engage colleagues in research of Liesegang rings phenomenon in loose sediments, especially in the loess-paleosol sequence, as well as the invitation to discussion.