δ18O values in recent ice veinlets and mean January air temperature in the Kolyma Lowland region

Oxygen isotope measurements of most of the ice wedges studied were carried out using a G-50 device in the isotope geology laboratory at the Institute of Geology, Tallinn, Estonia (Prof. R. Vaykmäe) and in the isotope hydrology laboratory at the Institute of Water Problems of Russian Academy of Science (Dr. A. Esikov). Control measurements were carried out in both laboratories. The ice wedges sampled during field work in 2018 were analyzed in the stable isotope laboratory of the Geography Faculty at Lomonosov Moscow State University (Prof. Y. Vasil'chuk and Dr N. Budantseva) using a Finnigan Delta-V Plus mass spectrometer, applying equilibration techniques. International water standards (SMOW, GRESP, and SLAP) were used for calibration. Analytical precision was ±0.4‰ for δ18O and ±1‰ for δ2 H. All values are presented in δ-notation in per mille (‰) relative to the Vienna Standard Mean Ocean Water (VSMOW). Deuterium excess (dexc) is calculated as dexc = δ2 H-8δ18O.38 14C ages of bulk samples were obtained at the Institute of Geology RAS (lab. code GIN) and at the Institute for the History of Material Culture, St. Petersburg (lab. code Le). Radiocarbon ages were calibrated using OxСal 4.3 based on the IntCal13 data set and given as yrs cal BP.39,40

Isotopic composition of hydrogen (δD), oxygen (δ¹⁸О) and Deuterium excess in veinlets of the syngenetic ice wedges in the Russian permafrost zone

The authors obtained new results on isotope data for recent growing ice wedges on the coast of the Chukotka Peninsula and summarized data from publications of the last 15-20 years. Field sampling was carried out in ice veinlets, usually lying under the grooves of interpolygonal ice wedge massifs. Identified variations of stable isotopes and values of deuterium excess in recent growing ice wedges, with age of about 100 years, penetrating into growing ice wedges at Russian permafrost zone, allow to consider the additional cryogenic fractionation during ice veinlets growth in frost cracks. The study confirmed the predominantly atmospheric origin of moisture, filling frost cracks. Limited cryogenic fractionation usually accompanies the freezing of melted snow after it fills the frost crack

Stable isotope (δ18О, δ2H and dexc) minimum, mean and maximum values, standard deviations, slopes and intercepts for ice-wedges

Oxygen isotope measurements of most of the ice wedges studied were carried out using a G-50 device in the isotope geology laboratory at the Institute of Geology, Tallinn, Estonia (Prof. R. Vaykmäe) and in the isotope hydrology laboratory at the Institute of Water Problems of Russian Academy of Science (Dr. A. Esikov). Control measurements were carried out in both laboratories. The ice wedges sampled during field work in 2018 were analyzed in the stable isotope laboratory of the Geography Faculty at Lomonosov Moscow State University (Prof. Y. Vasil'chuk and Dr N. Budantseva) using a Finnigan Delta-V Plus mass spectrometer, applying equilibration techniques. International water standards (SMOW, GRESP, and SLAP) were used for calibration. Analytical precision was ±0.4‰ for δ18O and ±1‰ for δ2 H. All values are presented in δ-notation in per mille (‰) relative to the Vienna Standard Mean Ocean Water (VSMOW). Deuterium excess (dexc) is calculated as dexc = δ2 H-8δ18O.38 14C ages of bulk samples were obtained at the Institute of Geology RAS (lab. code GIN) and at the Institute for the History of Material Culture, St. Petersburg (lab. code Le). Radiocarbon ages were calibrated using OxСal 4.3 based on the IntCal13 data set and given as yrs cal BP.39,40

Winter air temperature in Holocene reconstructed from the ice wedges stable water isotopes near Anadyr town

The object of research is syncryogenic Holocene strata on the coast of the Onemen Bay, 2 km from the town of Anadyr. In July 2017, the outcrop of the first marine terrace uncovered by strong storms was examined. The stratigraphy of the outcrop was represented mainly by sandy loam (5-7 m thick) covered by peat (1-1.5 m) and underlain by sand. Numerous ice wedges were opened in the upper part of this outcrop. Along with that another outcropping of transect of a lakemarsh basin represented by a peat bog of 2-2.5 m thick underlain by sandy loam was also investigated. Ice wedges occur below the polygonal trenches. The present-day narrow ice wedges were found in the upper part of the peat bog. Two representative fragments of both the above outcrops were thoroughly examined. Radiocarbon dating had shown that accumulation of peat on surface of the first marine terrace started in early Holocene (about 8 ka BP). Accumulation of peatland within the lake-marsh basin was also dated to the beginning of the Holocene (about 9 ka BP). In the middle of the Holocene, it was most likely interrupted as a result of thermokarst processes and bogging of the surface. Formation of peatlands in Chukotka during the Holocene is known to be accompanied by active growth of the ice wedges inside them, so the age of the wedges studied by us was estimated as the beginning of the Holocene. The analysis of stable oxygen and hydrogen isotopes in the Holocene and the modern ice wedges had allowed establishing mainly the atmospheric type of moisture feeding of the wedges (due to melted snow) and lack of noticeable isotope fractionation during the ice formation. It has been found that δ¹⁸О and δ²Н values in the Holocene ice wedges were lower than in the modern wedges and snow by an average 2-3 and 7-12 ‰, respectively. Paleotemperature reconstructions performed on the basis of isotopeoxygen data showed that the air temperature of the coldest winter month in the first half of the Holocene in the Onemen Bay area was lower than the present-day ones by an average 2-3 °C, which is in a good agreement with the trend of rising winter temperatures throughout the Chukotka Peninsula, as well as in other areas of Eastern Siberia and Alaska

Mineralization and chemical composition of water-soluble salts in ice wedges, segregated texture-forming ice and ground ice in northern Siberia

Geochemical composition of Holocene syngenetic ice wedges of southern and central parts of the Yamal Peninsula (within the thick peat bogs in the Shchuchya River valley, the Seyakha settlement, the floodplain of the Lakkatoso River, and the vicinity of the Cape Kamenny settlement) was determined. The authors have analyzed the content of trace elements and heavy metals.Holocene ice wedges are ultra-fresh and fresh, their mineralization varies from 20 to 200 mg/l, hydrocarbonates and calcium dominate in the ion composition. Participation of chlorides in the ice wedges on terraces indicates the influence of marine aerosols, the same for the ice wedges on the floodplain means the direct participation water of Ob Bay in their formation. The increasing of iron ions in some fragments of ice wedges, comparable to their content in segregated ice in the peat bog, may indicate a periodic participation of swamp waters in the formation of ice wedges

δ18О in ice wedges (δ18Оiw) and reconstructed mean January air temperature (ТmJ) in Kolyma Lowland region for three key Holocene stages

Oxygen isotope measurements of most of the ice wedges studied were carried out using a G-50 device in the isotope geology laboratory at the Institute of Geology, Tallinn, Estonia (Prof. R. Vaykmäe) and in the isotope hydrology laboratory at the Institute of Water Problems of Russian Academy of Science (Dr. A. Esikov). Control measurements were carried out in both laboratories. The ice wedges sampled during field work in 2018 were analyzed in the stable isotope laboratory of the Geography Faculty at Lomonosov Moscow State University (Prof. Y. Vasil'chuk and Dr N. Budantseva) using a Finnigan Delta-V Plus mass spectrometer, applying equilibration techniques. International water standards (SMOW, GRESP, and SLAP) were used for calibration. Analytical precision was ±0.4‰ for δ18O and ±1‰ for δ2 H. All values are presented in δ-notation in per mille (‰) relative to the Vienna Standard Mean Ocean Water (VSMOW). Deuterium excess (dexc) is calculated as dexc = δ2 H-8δ18O.38 14C ages of bulk samples were obtained at the Institute of Geology RAS (lab. code GIN) and at the Institute for the History of Material Culture, St. Petersburg (lab. code Le). Radiocarbon ages were calibrated using OxСal 4.3 based on the IntCal13 data set and given as yrs cal BP.39,4

Changes in the oxygen isotopic composition (δ¹⁸O) of modern ice wedges in the Kolyma lowland with the distance from the coas

Variations of oxygen isotopes in the modern veinlets of the syngenetic ice wedges in the lower Kolyma River have been studied in relation to distance to the coast. Similar publications containing the δ¹⁸О data of the lower Kolyma area are used and data was compiled from Solomatin, 2013 and Konyakhin et al., 1996 with addition from Vaikmäe & Vasil'chuk, 1991, and Vasil'chuk, 1992

Ion concentration of Holocene and Late Pleistocene ice wedges in the yedoma of Stanchikovsky Yar and near the Chersky settlement, Northern Yakutia

The subject of the study are Late Pleistocene and Holocene ice wedges exposed near Chersky settlement, lower Kolyma River, and in the yedoma of the Stanchikovsky Yar on the Maly Anyuy River. In the yedoma of the Stanchikovsky Yar, multi-tiered syngenetic ice wedges were exposed at different levels - from 10 to 35 m above river level. Ice wedge in the lower tier was sampled in detail. In the yedoma near Chersky relatively small fragments of ice wedges up to 1.5 m wide and up to 2 m high were exposed. 1.5-2 km from Chersky settlement within the lacusrtine-paludal depression Holocene ice wedges were exposed. Ice wedges in these three sections was sampled to clarify the geochemical conditions of their formation. It is shown that concentration of Na+, K+, Mg2+, Cl- and SO42- in Holocene and Late Pleistocene ice wedges is very low and mean values do not exceed 5 mg/L. The highest values were obtained for Ca2+, which corresponds to the predominance of this ion in the modern snow of Yakutia and indicates that ice wedges were formed mainly from melted snow. Rather high values of NO3-, reaching 14-27 mg/L, are quite likely due to the swampy environment within polygonal landscapes, where organic matter of both plant and animal origin is decomposed. For comparison, in the water of the Kolyma and Maly Anyu rivers, concentration of nitrates is quite low and does not exceed 0.3 mg/L