Late Cenozoic Permafrost History of the Russian Arctic

The history of permafrost over the last 2.5 million years has been traced back for both the sea shelf and the adjacent land of the Russian Arctic. Paleogeocryological maps have been constructed for four extreme climatic stages: (a) for the cool stage of the Middle Pleistocene, (b) for the warm stage of the Late Pleistocene beginning, (c) for the cool stage of the Late Pleistocene end, and (d) for the Holocene climatic optimum. The distribution pattern, temperature, and thickness of various types of permafrost (subaerial, subglacial and submarine) have been mapped. On the basis of a ground massive ice genetic analysis the different geological development as well as the different transgressive and regressive regime of the western and eastern sectors of Russian Arctic have been revealed. The possibility of permafrost formation with sheet ice directly in the marine conditions has been revealed. The Arctic Basin level fluctuations are almost unrelated to glacioeustatic processes, but are caused by regional tectonics. The glacial cover limited distribution in the Russian North and its absence on the Russian Arctic and Subarctic plains have been marked out.