DOI: 10.7256/2453-8922.2021.1.34826

Abstract: The object of this research is the groundwaters and surface waters of the Sentsa River Basin. The area of explorations is situated in the Eastern Sayan hydrogeological folded region. Cold and thermal waters occur in the PR and PZ metamorphic and igneous rock. These waters are discharged through the spring series in the river valleys laid along fault zones. The main type of fieldwork was hydrogeological sampling. The analysis of the macrocomponent composition of waters was conducted in the «Geodynamics and Geochronology Center» (Institute of the Earth’s Crust SB RAS, Irkutsk), the trace element composition was determined by ICP MS on an Element-2, Finnigan MAT (Germany) at the Vinogradov Institute of Geochemistry SB RAS (Irkutsk). The scientific novelty consists in the fact that this article provides not only the characteristics of chemical composition of cold and thermal waters, but also the primary data on the distribution of microelements in the ground and surface waters of the Sentsa River Basin. Groundwater (thermal and cold) are revealed to have a bicarbonate Ca-Na composition, withal river and lake waters are generally bicarbonate Ca. Thermal waters (in the Khoyto-Gol River Basin) are largely enriched in Li, Be, B, Si, Mn, Ge, As, Br, Rb, Sr, Cs, Ba, W and depleted in Al, P, Cu, Zn, Ag relative to surface and rainwater. The REE distribution profile in groundwater and surface waters have peculiarities that are characterized by a positive europium anomaly and the prevalence of light REE over heavy ones.

DOI: 10.7256/2453-8922.2021.1.35112

Abstract: The subject of this article is exmination of the influence of the Arctic air flow on the climatic conditions of the winter period in the center of the European territory of Russia (Moscow). In recent years, the question of the relationship between regional climatic conditions and such global circulation patterns as the North Atlantic Oscillation (NAO) and the Arctic Oscillation (AK) has become increasingly important. Based on the data of long-term observations of temperature and precipitation, the relationship with the AK and NAO was considered. For the winter months of the period 2014-2018, the back trajectories of the movement of air masses were computed for each date of precipitation to identify the sources of precipitation. The amount of winter precipitation that forms the snow cover of Moscow has no connection with either the North Atlantic Oscillation or the Arctic Oscillation. The Moscow region is located at the intersection of the zones of influence of positive and negative phases of both cyclonic patterns (AK and NAO), which determine the weather in the Northern Hemisphere. For the winter months, a correlation between the surface air temperature and NAO (r = 0.72) and AK (r = 0.66) was established. Winter precipitation in the center of the European territory of Russiais mainly associated with the unloading of Atlantic air masses. Arctic air masses relatively rarely invade Moscow region and bring little precipitation (their contribution does not exceed 12% of the total winter precipitation).

DOI: 10.7256/2453-8922.2021.1.32985

Abstract: The pollen characteristics of the Zelyony Mys yedoma record cyclical changes in vegetation cover, both on a local and regional scale. There are three local pollen zones such as: Varia +Artemisia, Varia + Selaginella sibirica, and Pinus + Betula sect. Nanae. Pollen spectra reflect open landscapes of mosaic hypo-arctic tundra. Some local pollen zones in the ice wedges correspond to the local pollen zones of yedoma: Varia + Selaginella sibirica dates from 41.9-33.8 CalBP, Pinus + Betula sect. Nanae (P+B) is approximately dated to 33.5-30 CalBP. Reconstruction of the annual thawing index showed several fluctuations: two short-term periods of significant deterioration of vegetation conditions (annual thawing index was about 200-300 deg. × days, about 46, 34-33 CalBP), and two periods of improvement of vegetation conditions 45-43 and 32 CalBP (annual thawing index was about 600-750 deg. x days). Regional pollen in burrows is the same in synchronous horizons of yedoma. Noticeable amount of larch pollen (10%) in the fossil burrows in the Zelyony Mys yedoma showed that favorable conditions are created in the burrows for the preservation of larch pollen. The seeds found in minks reflect animal dietary preferences and only partlially local vegetation around minks. Reconstruction of positive temperature sums indicates the palinospectra reflect three-fold fluctuations of vegetation conditions: two short periods of substantial deterioration of vegetation conditions (the sum of positive temperatures is about 200-300 degrees x days), about 46, 34-33 thousand years (and two periods of improvement of vegetation conditions 45-43 thousand years (sum of positive temperatures about 600 degrees x days) and 32 thousand years (sum of positive temperatures about 750 degrees x days).

DOI: 10.7256/2453-8922.2021.1.33291

Abstract: The subject of the study is the analysis of the ratio of carbon (C) and nitrogen(N) and δ13C values in polygonal landscapes on the coast of Onemen Bay, near the Anadyr city. The maximum values of carbon (59.09%) and nitrogen (2.18%) in peatlands were obtained at a depth of 1.1 m in a narrow peat vein. The values of δ13C in the peatlands on the coast of Onemen Bay vary from -24.1% to -28.6%, the N content varies from 0.37% to 3.24%, the C content varies from 3.1% to 59.09%, the C/N value varies from 8.3 to 34.4.The values of δ13C and C/N values in the 1.5-m peat correspond to C3 plants, the values of δ13C and C/N values for a 2.5–m peat suggest the presence of algae along with plants C3. Fluctuations in the nitrogen and organic carbon content in the section of a 1.5-meter peatland to a depth of 0.8 m are synchronous, which suggests an autochthonous mechanism of peat accumulation, below depth of 0.8-1.2 m, there is a lightening of the carbon isotope composition, which suggests the participation of reworked organic matter in the beginning of peat accumulation. Fluctuations in the nitrogen and organic carbon content in the section of a 2.5-meter peat bog are synchronous, which suggests an autochthonous mechanism of peat accumulation.

DOI: 10.7256/2453-8922.2021.1.35361

Abstract: The subject of this research is the Late Pleistocene and Holocene ice wedges exposed near Chersky settlement, lower Kolyma River, and in the yedoma strata 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 strata 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 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.