2025/05/13 by Yurij K. Vasil'chuk, Yurij K Vasil’chuk, Julia N. Chizhova +13
Earth and Planetary Sciences · Environmental Science · #Climate change and permafrost #Geology and Paleoclimatology Research #Peatlands and Wetlands Ecology
paper · pdf · doi:10.1002/ppp.2284
openalex publication_date 2025/05/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/25
ABSTRACT Lithalsas are found on mires in the discontinuous permafrost in the circumpolar area of the northern hemisphere and in mountainous regions. The age and growth mechanism of lithalsa in the continental intermountain region of the East Sayan Mountains were uncertain and debated. We represent the results of a detailed analysis of four representative lithalsas, including 14 C dating, C‐N content of buried peat lenses, and organic matter from soils, as well as results of stable isotope measurements (δ 18 O and δ 2 H) in the lithalsas' ice lenses. It was found that the studied lithalsas are not older than 600 years; the youngest mound began to form about 170 years BP. Main water sources for lithalsa ice formation were shallow lakes and the Sentsa River during spring floodings; freezing occurred mainly in open system conditions. However, the rate of freezing ice lens was not the same for the studied lithalsas, as well as the rate of their growth. Multiple freezing cycles were established for the highest lithalsa. High values of the C/N ratio in organic and peat horizons allow us to suppose the rapid freezing of organic matter during lithalsa growth. The findings confirm that non‐climatic factors, like flooding, are crucial for lithalsa dynamics.