DOI

  • Sebastian Wetterich
  • Lutz Schirrmeiste
  • Larisa Nazarova
  • Olga Palagushkina
  • Anatoly Bobrov
  • Lilit Pogosyan
  • Larisa Savelieva
  • Liudmila Syrykh
  • Heidrun Matthes
  • Michael Fritz
  • Frank Guenther
  • Thomas Opel
  • Hanno Meyer

Ground ice and sedimentary records of a pingo exposure reveal insights into Holocene permafrost, landscape and climate dynamics. Early to mid-Holocene thermokarst lake deposits contain rich floral and faunal paleoassemblages, which indicate lake shrinkage and decreasing summer temperatures (chironomid-based T-July) from 10.5 to 3.5 cal kyr BP with the warmest period between 10.5 and 8 cal kyr BP. Talik refreezing and pingo growth started about 3.5 cal kyr BP after disappearance of the lake. The isotopic composition of the pingo ice (delta O-18 - 17.1 +/- 0.6 parts per thousand, delta D -144.5 +/- 3.4 parts per thousand, slope 5.85, deuterium excess -7.7 +/- 1.5 parts per thousand) point to the initial stage of closed-system freezing captured in the record. A differing isotopic composition within the massive ice body was found (delta O-18 - 21.3 +/- 1.4 parts per thousand, delta D -165 +/- 11.5 parts per thousand, slope 8.13, deuterium excess 4.9 +/- 3.2 parts per thousand), probably related to the infill of dilation cracks by surface water with quasi-meteoric signature. Currently inactive syngenetic ice wedges formed in the thermokarst basin after lake drainage. The pingo preserves traces of permafrost response to climate variations in terms of ground-ice degradation (thermokarst) during the early and mid-Holocene, and aggradation (wedge-ice and pingo-ice growth) during the late Holocene.

Язык оригиналаАнглийский
Страницы (с-по)182-198
Число страниц17
ЖурналPermafrost and Periglacial Processes
Том29
Номер выпуска3
DOI
СостояниеОпубликовано - 1 июл 2018

    Предметные области Scopus

  • Процессы поверхности земли

ID: 36425782