Earth’s Cryosphere, 2024, Vol. XXVIII, No. 5, p. 3-11.
REGIONAL AND HISTORICAL GEOCRYOLOGY
NEW DATA ON THE GEOCHRONOLOGY OF QUATERNARY SEDIMENTS AND STABLE OXYGEN AND HYDROGEN ISOTOPES IN GROUND ICE OF THE MAMONTOVA GORA
N.V. Torgovkin1,*, D.E. Sivtsev1,2, A.A. Gavrilova3, I.A. Platonov2, A.I. Kizyakov2, L. Schirrmeister4, T. Opel4, S. Wetterich5, S.F.M. Breitenbach6, H. Meyer4
1 Melnikov Permafrost Institute, Siberian Branch of the Russian Academy of Sciences, Merzlotnaya St. 36, Yakutsk, 677010 Russia
2 Lomonosov Moscow State University, Faculty of Geography, Leninskie Gory 1, Moscow, 119991 Russia
3 Institute of Precambrian Geology and Geochronology, Russian Academy of Sciences, Makarova St. 2, St. Petersburg, 199034 Russia
4 Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, 14473 Potsdam, Germany
5 Institute of Geography, Dresden University of Technology, 01069 Dresden, Germany
6 Department of Earth and Environmental Sciences, Northumbria University, Newcastle-Upon-Tyne, NE1 8ST, United Kingdom
*Corresponding author; e-mail: n.torgovkin@yandex.ru
The results of studies of the ice complex, lacustrine, and lacustrine-alluvial sediments from the Mamontova Gora section performed in 2022–2023 are analyzed. Optically stimulated luminescence dating indicates that the formation of the lacustrine–alluvial sands of the Elga Group ended 250–242 ka ago, at the end of cold MIS 8, while the overlying lacustrine silts accumulated until 138–126 ka ago corresponding to the late cold MIS 6 – early warm MIS 5e. The average isotopic composition of the Yedoma Ice Complex (MIS 3) syngenetic wedge ice is –(31 ± 2)‰ for d18O, –(239 ± 15)‰ for dD, and (8 ± 2)‰ for dexc. For the first time, we quantify the isotopic composition of the Yedoma Ice Complex pore ice with the average values of –(26 ± 2)‰ for d18O, –(201 ± 17)‰ for dD, and (10 ± 4)‰ for dexc. The formation of lacustrine and lacustrine–alluvial sequences during MIS 7 and MIS 5e was fostered by warmer and likely longer thaw periods and associated permafrost thaw. The degree of warming remains to be estimated for this region.
Keywords: ice complex, lacustrine–alluvial sediments, OSL dating, ground ice, stable oxygen and hydrogen isotopes, paleoclimate, Middle and Late Pleistocene.
Recommended citation: Torgovkin N.V., Sivtsev D.E., Gavrilova A.A., Platonov I.A., Kizyakov A.I., Schirrmeister L., Opel T., Wetterich S., Breitenbach S.F.M., Meyer H., 2024. New data on the geochronology of Quaternary sediments and stable oxygen and hydrogen isotopes in ground ice of the Mamontova Gora. Earth’s Cryosphere XXVIII (5), 3–11.
Received May 6, 2024
Revised July 4, 2024
Accepted August 25, 2024
Translated by M.A. Korkka