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Интеллектуальная Система Тематического Исследования НАукометрических данных |
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Paleocrygenic stages of extreme pedogenesis in the geological history of the Earthтезисы доклада
- Автор: Alexander Makeev
- Сборник: Abstracts book 5th EUROSOIL International Congress
- Тезисы
- Год издания: 2016
- Место издания: Istambul, Turkey
- Аннотация: Cryogenic soils (Cryosols and long season frozen soils) are formed in extreme environments, when pedogenesis is limited to a very short period with positive temperatures, and soil horizonation is influenced by cryogenic processes. The study of paleosols leads to the development of a new research area – paleocryogenic studies. Cold biospheres constitute about 4% of the geologic history of the Earth. Nevertheless plate tectonics and shifting of the poles result in extension of paleocryogenic soils in the geological record of all thermal belts of the Earth, including tropical. During cold biospheres the glaciers could occupy up to one third of the Earth terrain with periglacial zones even wider. Frost features in paleosols could be correlated with modern features and for this reason paleocryogenic soils are one of the most reliable indicators of cold environments. Frost features in soils helps to reconstruct the former land surface (especially when soil profile is truncated), position of permafrost table and the depth of seasonal freezing. So paleocryogenic soils are important for stratigraphy. Frost features in soils appear at all morphological levels - at the level of the soil cover, on the macro-, meso, and micro- and sub-micro levels. Frost impact also influences chemical features of paleosols. Frost features may be syngenetic to pedogenesis. However quite often in paleosols a complex relationship is recorded between temperate pedogenic and frost features that may precede each other. So that frost features could affect temperate soils and temperate pedogenesis could be superimposed on frost features appeared in the preceding cold period. Paleocryogenic soils are currently recorded starting from Paleo-proterozoic. They are extensively spread in the Quaternary glacial and periglacial sediments and could often influence surface soils of the Upper Pleistocene glacial and periglacial areas. Keywords: extreme pedogenesis, paleosols, paleocryogenic soils, geological history, frost features
- Добавил в систему: Макеев Александр Олегович