Академическое издательство «Гео»

Cryochrons and themochrons, cryogenic area, cryogenic stratum, aggradation and degradation of cryogenic stratum, wedge ices and casts



KRIOSFERA ZEMLI, 2006, Vol. X, № 2, p. 3-26

Modern conceptions of the evolution of cryogenic area of West
and East Siberia in Pleistocene and Golocene ( Report 2)

S.M. Fotiev

Earth Cryosphere Institute SB RAS, 625000, Tyumen, P/O box 1230, Russia, kriozem@online.ru

The major part of the present Russian cryogenic area is occupied by two adjacent geocryological regions - West and East Siberia. Their total extent is about 4500 km from the eastern piedmonts of the Urals (longitude 60° east) in the west to the western piedmonts of the Verkhoyanskii ridge (longitude 135° east) in the east. In latitudinal direction they extend from the edge of the modern shelf in the seas of the Arctic Ocean (latitude 80-84° north) to the piedmonts of the Altai and Sayany (latitude 50-56° north), i. e. for 4000-4500 km. During 5 million years the conditions of the evolution of cryogenic process have changed substantially in accordance with the variations of the latitude- and altitude-zonal conditions of heat exchange under the active impact of the regional factors, the main of which are the glacial cover (in East Siberia) and the sea transgression (in West Siberia). The analysis of the conditions of evolution of the cryogenic process during the last 5 million years has been fulfilled for the first time. The results of the investigations are based on the paleogeocryological interpretation of the unique climatic chronicles found by the large group of scientists after the careful study of the Lake Baikal bottom sediments. The joint examination of the evolution of the cryogenic area in the two adjacent regions allows one both to reveal regional peculiarities of each of them and to understand the reason of significant differences in modern geocryological conditions.

Cryochrons and themochrons, cryogenic area, cryogenic stratum, aggradation and degradation of cryogenic stratum, wedge ices and casts
главная

www.izdatgeo.ru