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The most convincing concept of the great Pleistocene glaciation in northern Eurasia was developed in the 1870s by the Swedish geologist O. Torell and the Russian geographer and geologist P. A. Kroptokin, who had discovered traces of an extensive glaciation in eastern Siberia and Finland, published in the fundamental book "Researches on the glacial period" (1876, in Russian). Our paper describes the complex history of glacial research in northern Eurasia by Russian geologists. Unlike Kropotkin, most of them reorganized the existence of several glaciations separated hy interglacial epochs. The main centers of glaciation were distinguished. The most important glaciation developed under the humid climates of northern Europe and western Siberia. In the relatively dry regions of eastern Siberia ice sheets were of more limited extent and thickness, but there, permafrost reached depths up to 1-1.5 km.

First observations on the Pleistocene and Recent glaciation of the Great Caucasus and the Armenian Highland (especially of the Elbrus and Ararat volcanoes) were made by G. Abich in 1844-1850. In the first half of the 20(th) century the Russian geologists A. P. Gerasimov, A. L. Reinhard, V. P. Rengarten and others established a history of Caucasian glaciations comparable with that developed by Penek and Bruckner, even though disagreements about the correlations subsisted. In the central part of the Great Caucasus young volcanic rocks alternate with glacial deposits. The modern chronology of the Great Caucasus glaciations developed by the author and A. V. Kozhevnikov distinguishes: 1) a Late Pliocene Elbrus Glaciation (analogue of the Danubian Glaciation of the Alps?)- 2) an Eopleistocene Chegem Glaciation (analogous to Gunz)- 3) an Early Pleistocene Eltubu Glaciation (analogous to Mindel)- 4) a Middle Pleistocene Terek Glaciation with several phases and stages (analogous to Riss)- 5) a Late Pleistocene-Early Holocene Bezingi Glaciation (analogous to Wurm and Buhl of the Alps)- 6) advance and retreat of glaciers in the 17(th) to 19(th) centuries. The Late Pliocene - Eopleistocene glaciations belonged to the semi-sheet type, Pleistocene glaciations to the trough valley type. The maximal advance of glaciers was in the Middle Pleistocene. In the eastern part of the Great Caucasus and in the Minor Caucasus glaciations are were limited due to a more arid climate and lesser elevations.