Лëд и снег (Oct 2017)
History of the Scandinavian ice sheet and surrounding landscapes during Valday ice age and the Holocene
Abstract
The reconstruction of natural environments associated with the development and degradation of the Scandinavian Ice Sheet from the Mikulino Interglacial period to the Holocene is presented in this paper. A diagram showing the change of vegetation in the periglacial zone of the Ice Sheet during the last 130 ka had been constructed from the results of studying the key sections with glacial and interstadial deposits in North-Western areas of the East European plain. In addition, paleolandscape maps (glacier, vegetation, periglacial basins) were composed for Fennoscandia and adjacent areas for the following time periods: the Last Glacial Maximum (time of maximum cold or a minimum of heat provision), the Late Glacial time (optimum of the Allerød interstadial, the maximal cooling and the ice advance of the Late Dryas), and the Early Holocene (the Preboreal). The maps for the Late Glacial time show the most dramatic changes of the main components of paleolandscape associated with positions of the ice margin and the nature of the proglacial drainage. Changes in the glacial structures of the Scandinavian Ice Sheet during the growth of the warming were happening faster, mainly due to local factors (topography of the glacier bed, tectonics, and glacioisostatic and glacioeustatic movements). In the vegetation of the periglacial zone, the composition of flora throughout the late Pleistocene remained unchanged, although structures of the plant communities varied. This vegetation consisted of a mix of forest, tundra and steppe complexes adapted to the sharply continental climate conditions. Transition from the Late Dryas to the Early Holocene was found everywhere in the changes of the plant communities, that could be considered as the initial stage of formation of the present-day latitudinal zonation.
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