Abstract: This article is dedicates to the assessment of the contribution of Professor Vasilchuk to the development of isotopic geocryology, as well as testing the reliability of paleogeocryological reconstructions based on the study of isotopic composition of polygonal ice wedges. His discovery of direct dependence of isotopic composition of the sprouts of modern ice wedges on the temperature characteristics of the winter season of 1989 marked the beginning of a promising research of the Holocene and Late Pleistocene syngenetic ice wedges as a reliable paleoclimatic archive. He was first to obtain the characteristics of the winter period for the late Pleistocene and Holocene, as well as create the maps for distributing paleotemperatures for the key periods of Late Pleistocene. The data on the isotopic composition of ice wedges acquired by other scholars later fit into the distribution of paleotemperature within the cryolithozone reconstructed by Professor Vasilchuk. For establishing the degree of reliability of paleotemperature reconstructions, the authors tested the ratio proposed by Y. K. Vasilchuk and regression equations from the works of Konyakhin, Mayer, and Oblogov. The acquired results demonstrate that the values of winter-average and January-average temperatures in reconstruction by Vasilchuk’s ratio always fall within the reliability interval in the entire modern temperature range. Testing the current temperature using regression equations often determine a considerable deviation (often within 3-4°C) from the actual values of winter-average and January-average temperatures.

Keywords: model of heterocyclic growing of ice wedge, isotope paleogeocryology, testing regression equations, paleotemperature, oxygen isotope, Holocene, Late Pleistocene, Ice wedge, Yedoma radiocarbon dating strategy, Late Pleistocene cryochron

Abstract: The subject of this research is the cryogenic formations found in gas emission funnels in the north of Western Siberia. The object of this research is cryogenic processes that prepare the explosion, which forms a gas emission funnel. The study of cryogenic structures that shape the walls of gas emission funnels is based on the structural-genetic analysis, which reveals the peculiarities of the initial cryogenic structure of frozen rock, as well as the cryogenic textures modified as a result of dynamic metamorphism. The authors examine such aspects of the topic as the general orientation of plastic and explosive deformations under the influence of high pressure. Analysis is conducted on the role of intra-ground gas filtration in transformation of the initial cryogenic structure. Special attention is given to the patterns of emergence and development of the local geodynamic system that ultimately substantiates the formation of gas emission funnel. The novelty of this research consists in the establishment of paragenetic relations between the processes of gas filtration and deformations of gas-saturated ice surface material (from viscoplastic motion to brittle fracture). The main conclusions are as follows: such external influences as increase in the temperature or pressure change thermodynamic conditions, which lead to multi-phase structural transformation of the initial cryogenic structure of the cryolithic zone; a series of plastic and explosive deformations instigates the intense heat and mass transfer, redistributing the substance in the liquid, solid and gaseous state; in frozen rocks, ice is the most deformable component, thus, most information on the processes preceding the formation of gas funnels can be acquired by studying the morphology of cryogenic formations observed in the walls of the funnels, as well as in the unthawed fragments of frozen rocks thrown to the surface. The authors’ special contribution lies in examination of the complete lifecycle of the development of selected geosystems, from the initial stage –  formation of conditions for decomposition of the gas hydrates, to the final stage – explosion and emission of ice surface material.

Keywords: ice ground saturated geosystems, fluid geodynamics, gas fluids, gas filtration,, dissociation of gas hydrates, heat flux, plastic deformations, permafrost,, stage of development, paragenetic relationships

Abstract: The subject of this research is the composition of micro- and macro- rare earth elements in the Late Pleistocene syngenetic ice wedges of the Seyakha yedoma, explored in the outcrop of the Gulf of Ob in the east of Yamal Peninsula (70°9'27.88 "N, 72° 34'8.31" E), north of the Western Siberia. The All-Russian Scientific-research Institution of Mineral Resources after named N.M. Fedorovsky examined the composition of chemical elements in the ice wedges using the methods of atomic-emission spectrometry and mass spectrometry with inductively linked plasma (spectrometers Elan-6100, Optima-4300DV, Perkin-Elmer, Polyvac E-1000, Rank Hilger). The following conclusions were made: 1) Ice wedges of the Seyakha yedoma are rich in macro - and microelements was recorded, which exceeds such in ice wedges of Yakutia by 8-10 times. The high composition of microelements indicates the role of aerosol and soil particles in the formation of chemical composition of ice. The differences between the ice of Yamal and Northeastern Yakutia also testify that the chemical composition reflects the involvement of marine aerosols in ice formation. 2) Rare-earth elements accumulate in the ice of Seyakha yedoma. The composition of all rare-earth elements exceeds the Clarke number in river waters by 69 (Tm ) – 382 (Y) times. 3) Variability of microelement composition within the ice wedge is insignificant, which implies that the water of the polluted with dust and aerosols spring-summer snow is filtered through the entire snow layer and is partially cleaned prior to getting into the ice-break in the ground under the snow.

Keywords: northwest Siberia, Yamal Peninsula, Seyakha, trace elements, yedoma, permafrost, Late Pleistocene, Ice wedge, Russia, Ob Bay coast

Abstract: The subject of this research is the syngenetic ice wedges stripped in the Batagaika crater (67°34 '49" N, 134°46 ' 19 " E), located 10 km southeast of the Batagay settlement. The assessment of macroelement composition of ice was conducted using “Stayer” ion chromatograph (Russia), the chloride ion detection limit is 0.02 mg/l. The article examines the ionic and macroelement composition of ice in suspended and dissolved forms in the Late Pleistocene syngenetic ice wedge of the Batagay yedoma. A comprehensive geochemical research of the Batagaika crater is carried out for the first time. The author explores the upper and lower ice wedges of different age. The main conclusions are as follows: 1) mineralization of Late Pleistocene ice wedge of the Batagay yedoma ranges from 66.56 to 424.8 mg/l, from ultra-fresh to slightly salted; by ionic composition, the ice is bicarbonate-calcium and corresponds to the snow formed under the influence of continental air masses; 2)  the share of Ca contained in the dissolved form does not exceed 20-30%’ as far as other elements, the share of Mg, K, Na, Al, Fe, Mn in the suspended form is over  90%; 3) by mineralization, the Pleistocene ice of Batagay yedoma coincides with the previously studied Pleistocene ice wedges of Yakutia and the Interior Alaska.

Keywords: Siberia, Yakutia, Batagay megaslump, chemical composition, yedoma, permafrost, Late Pleistocene, Ice wedge, upper Yana valley, thermal erosion

Abstract: This article examines the sections of the high floodplain of the Seyakha River (Zelenaya) and sections of Holocene peat layers with ice wedges on the third terrace. Palynospectra from sediments and ice wedges of the high floodplain are characterized by a rhythmic fluctuations typical to floodplain facies. The presence of spruce pollen is related to resedimentation, since spruce pollen is detected in the samples with the composition of verifiably resedimented palynomorphs around 10% or higher. The change in composition of the pollen of Siberian pine, scots pine, and birch tree is associated with a change in wind drift, since fluctuations in the composition of the pollen of these taxonomic units do not correlate with fluctuations in resedimented palynomorphs. Therefore, the three periods of increased wind drift and possible increase in pollen productivity can be determined based on mid-period contrast changes in the structure of palynospectra. At the same time, the local peak of cereals is replaced three times by the maximum pollen of dwarf birch and alder. The absence of larch trunks can be substantiated by fires, the traces of which are observed in the section, as well as that larch at the northern limit of its habitat has crumbly wood tissue, which is being rapidly destroyed. Tree limb, needles, and cones usually remain, while the wood tissue is absent. It is assumed that ice wedges formed here 8.5-6 thousand years ago during a single cycle of the change in wind direction and speed , when prevalence of birch tree pollen with some alder pollen at a relatively low pollen concentration was replaced by the dominance of gramineae pollen, and then, dwarf birch pollen in the spring pollen rain. Palynospectra of these ice wedges indicates an increase in the sum of positive temperatures from 8.3 to 6 thousand years.

Keywords: northwest Siberia, Yamal Peninsula, peatbog, floodplain, permafrost, spores, pollen, Ice wedge, Russia, Ob Bay coast