Cold periods of the Pleistocene in eastern Siberia (based on the geological profile of Mamontova Gora)

Abstract

Article in French.

ORIGINAL TITLE: Périodes froides du pléistocène de la Sibérie orientale (sur l'exemple du profil géologique de Mamontova Gora) 

This article presents the results of a multifaceted palaeogeographic analysis of the geological profile of Mamontova Gora, which is located in the lower Aldan Valley in eastern Siberia. The study covered Neogene and Quaternary sediments within several terrace levels (20–50 metres) and cover sediments. Mineralogical analysis of heavy fractions, clay minerals and pollen were employed to reconstruct Pleistocene climate and vegetation conditions. The results suggest that there were at least two distinct cold periods during which forests were replaced by tundra-steppe, interspersed with warmer interglacial periods characterised by the growth of coniferous and deciduous forests. Changes in the mineral composition of the sediments correlate with climatic changes, as confirmed by mineral stability indicators and pollen spectrum composition. The presence of permafrost and periglacial environmental conditions played a special role in preserving the sediments.