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Lithalsas in the Sentsa River Valley, Eastern Sayan Mountains, Southern Russia
Author(s) -
Vasil'chuk Yurij K.,
Alexeev Sergey V.,
Arzhannikov Sergey G.,
Alexeeva Ludmila P.,
Budantseva Nadine A.,
Chizhova Julia N.,
Arzhannikova Anastasia V.,
Vasil'chuk Alla C.
Publication year - 2015
Publication title -
permafrost and periglacial processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.867
H-Index - 76
eISSN - 1099-1530
pISSN - 1045-6740
DOI - 10.1002/ppp.1876
Subject(s) - permafrost , massif , geology , meteoric water , isotopes of oxygen , groundwater recharge , stage (stratigraphy) , geomorphology , reticulate , frost (temperature) , hydrology (agriculture) , geochemistry , groundwater , paleontology , aquifer , oceanography , geotechnical engineering
Perennial frost mounds identified as lithalsas occur in the Sentsa River valley of the Eastern Sayan Mountains, Russia. We report the first detailed study of permafrost in this region, based on analysis of the cryostructure and distribution of stable isotopes of oxygen and hydrogen, and ion concentrations from the ice‐rich cores of two lithalsas 3–7 m high. Their main cryostructures are reticulate and lenticular, with visible ice contents exceeding 50–60%. The vertical and lateral distribution of δ 18 О and δD values show a step‐by‐step mechanism of lithalsa growth: in the first stage a large lithalsa formed, and in the second stage a small lithalsa formed. The more negative isotope values of ice in the large lithalsa ice probably resulted from gradual release of isotopically depleted water from the central to peripheral part of the massif during ice segregation in water‐saturated fine‐grained lake sediments. Minor variations of isotope values suggest intensive recharge of lake‐fen and meteoric water supply during freezing and lithalsa growth. Copyright © 2015 John Wiley & Sons, Ltd.