Kungurian ammonoids had high taxonomic diversity, but were distinguished by an extremely high level of endemism and sharp geographic differentiation. Therefore, outside the regions containing the most important conodont taxa, the Artinskian-Kungurian boundary based on ammonoids must be established through indirect evidence due to the lack of common species with potential global stratotypes of the lower boundary of the Kungurian. A long-term study of the reference sections of the Echian and Tumarian regional stages and their ammonoids made it possible to change the understanding of the bio- and lithostratigraphy of the Artinskian-Kungurian boundary deposits of the Kuranakh structural-facies zone of Western Verkhoyanie. Clarification of the upper boundary of the Khabakh Formation in the stratotype section led to the fact that the ammonoids previously belonging to this formation began to be considered in the lower part of the Orol formation. They characterize the Paratumaroceras? sp. nov. biostratigraphic beds of the lower part of the Tumarian Regional Stage. At the current level of knowledge, the ammonoid substantiation of the Artinskian–Kungurian boundary in Verkhoyanie is difficult due to the existing hiatus corresponding to the Khabakh formation and its age analogues. However, the appearance at the base of the Tumarian Regional Stage of the first paragastrioceratids with a ventral sinus in transverse sculpture (Paratumaroceras? sp. nov.) suggests that the boundary in question is located near the base of the indicated regional stage or even combined with it. For further clearer identification of the Kungurian lower boundary in Verkhoyanie, new studies of the Echian–Tumarian boundary deposits in typical sections, independent of paleontology, are necessary. Such research should primarily include isotope-stratigraphic subdivision and high-precision U-Pb dating.

Mineralogical and geochemical investigations of the underexplored gold ore deposits within the Murunsky node, specifically the Seredinskoye and Andreevskoye ore fields, were conducted utilizing mineralogical and microprobe analytical techniques. The study identified several minerals, including bismuth minerals such as wittichenite and aikinite; cadmium mineral greenockite; cobalt minerals cobaltite and carrollite; arsenic minerals arsenosulvanite and tennantite; antimony minerals antimonite and tetrahedrite; tellurium minerals hessite and Te-canfieldite; mercury mineral cinnabar; thallium minerals raguinite and copper-rich talcusite; and tin minerals kesterite and jeanbandyite. Additionally, potassium sulfide djerfisherite with an unusual silver admixture was discovered. The findings underscore the remarkable and largely untapped potential of the Murunsky massif, particularly concerning its ore mineralization. A notable characteristic of the identified minerals is their non-stoichiometric composition, which includes the presence of impurities and isomorphic substitution of elements, attributed to the disequilibrium conditions under which they formed. The discoveries of raguinite and jeanbandyite represent the first occurrences of these minerals in Russia.

The investigation of the Syuldyukar kimberlite field, located within the Yakut diamond-bearing province, involved approximately 4,000 X-ray fluorescence (XFA) analyses and 150 inductively coupled plasma atomic emission spectroscopy (ICP AES) analyses on the host sedimentary rocks of the Upper Cambrian Holomolokha formation in proximity to the kimberlite bodies. The results indicated a disruption in the correlation ratios when compared to background concentrations, while subclark levels of vanadium (V), scandium (Sc), chromium (Cr), nickel (Ni), and other elements remained consistent. The elements were divided into three categories: typomorphic elements for kimberlites (Cr, Ni, Co), elements associated with carbonatites (barium (Ba), strontium (Sr), neodymium (Nd), zirconium (Zr)), and elements characteristic of basalts (V, Sc, zinc (Zn)). High positive correlation coefficients were established for the specified elements in the background concentrations. However, ICP analyses indicated significant decreases in the correlation between elements from different groups in the near-kimberlite space at the Syuldyukar site. X-ray diffraction (XRD) studies showed that in the compression areas, the correlation ratios of various elements were inconsistent when compared to the stretching areas. The analysis of the XRF and ICP data reveled that the average elemental concentrations in the background and near-tube space were nearly identical, except for some unusual hurricane values, with variations showing only slight changes. The positive correlation of several elements likely reflects background geological processes, including sedimentation in a marine basin and subsequent transformations such as hypergenesis, diagenesis, and catagenesis. The significant decrease in correlation coefficients, even with background concentrations remaining stable, is likely due to the redistribution of elements in the fluid resulting from phreatomagmatic explosions linked to the intrusion of kimberlites. Aqueous chloride fluids were observed to most actively redistribute elements in areas experiencing local tectonic compression. The identified changes in the correlation ratios of background elemental concentrations in sedimentary rocks containing kimberlite could act as a new indicator for locating hidden diamond-bearing kimberlites.

We studied metabasites from metamorphic complexes located in the northern part of the Lyapin anticlinorium of the Subpolar Urals and the Kharbey anticlinorium in the Polar Urals of the Central Ural Uplift, which are part of the Arctic zone. For the first time, ferrosaponite containing copper, nickel, and rare earth metals has been identified in these metabasites. The morphological and typochemical characteristics of ferrosaponite were examined using electron microscopy. In the Polar Urals, ferrosaponite is found in the almandine eclogite of the Marunkeu eclogite-amphibolite gneiss. The mineral is associated with garnet, quartz, pyroxene, muscovite, amphibole, and sulfides. The general formula for the mineral from almandine eclogite: (Ca_0,06–0,27K_0,01–0,06Се_0,01)_{∑0,13–0,31}(Fe²⁺ _1,67–2,21Mg_0,51–0,84 Cu_0,01–0,09Ni_{0,03–0,11)∑2,25–3,08}[(Si_2,84–3,08Al_0,92–1,16)_∑4,00O10](OH)₂ ×3,55–3,83H₂O. In the Subpolar Urals, this mineral was examined in a sample of garnet-amphibole-biotite-plagioclase-quartz shale, where it occurs in association with other minerals: amphibole, plagioclase, quartz, epidote, biotite, zircon, albite, titanite, apatite, and sulfides. The general formula of the mineral: (Ca_0,14–0,22K_0,01–0,02Се_0,01)_{∑0,15–0,23}(Fe²⁺ _1,24–2,22Mg_0,76–0,97)_{∑2,17–3,15} [(Si_2,86–2,96Al_1,04–1,14)_∑4,00O₁₀](OH)₂ ×3,41–4,47H₂O. It is assumed that ferrosaponite forms through a hydrothermal-metamorphic process during the late fluid stage of rock transformation. Feldspars and biotite serve as sources of potassium and aluminum, while hornblende, pyroxenes, and epidote are the primary suppliers of magnesium and iron. In the chemical composition, alongside the main components of the mineral—potassium, calcium, magnesium, aluminum, silicon, and iron—copper, nickel, and rare earth metals were also detected. Under the influence of fluids, copper and nickel may have been derived from replaced sulfides, while cerium could have been introduced from allanite, apatite, and other minerals containing rare earth elements. Continued study of the mineragenic features of metamorphic rocks in the Arctic regions of the Urals is essential for a comprehensive assessment of their resource potential, as well as promising sources and concentrators of rare metals.

The presence of substantial accumulations of bitumen is critically significant as they serve as direct indicators of oilbearing regions. However, in the context of environmental studies, their existence complicates the assessment of technogenic soil contamination by oil and petroleum products. The objective of this research was to identify informative geochemical parameters that would facilitate the differentiation between natural surface seepages and technogenic hydrocarbon fields resulting from commercial oil spills. This study examined natural surface oil seepages in the Amga River Basin and technogenic oil contamination near the Amga Oil Depot. Employing classical bituminology, Fourier transform infrared spectroscopy, gas chromatography, and mass spectrometry, a comparative analysis of their compositional characteristics was conducted. Notably, significant differences in geochemical parameters, such as the concentrations of hydrocarbons, resins, asphaltenes, and oxygen-containing compounds, were observed when comparing oil pollution to natural surface seepages for the first time. Furthermore, it was demonstrated that genetic parameters for diagnosing soil contamination by oil, based on biomarker composition, could include the presence of 12- and 13-methylalkanes in the hydrocarbon profile of the pollutant. These compounds are recognized as distinctive biological markers of Cambrian and Early Paleozoic oils from the Nepsko-Botuobinsk oil and gas region. Conversely, these biomarkers were absent in the natural surface oil seepages of Amga. The findings of this research may prove valuable in environmental studies, particularly in monitoring efforts aimed at identifying technogenic oil contamination in soils that are not associated with natural oil seeps.

The assessment of carbon stocks in the litter and soil of highly productive forests on the Prilenskoe Plateau was conducted using widely accepted methods of general biology, landscape science and geocryology. The research focused on larch-birch and pine-larch forests situated on continuous permafrost, as well as on long-term fallow lands. Notably, the fallow land, in contrast to the forested areas, exhibited a significant loss of organic carbon from the soil, amounting to up to 83 % within a 30 cm depth due to the exploitation of forest resources. The total organic carbon (TOC) reserves in the forest litter ranged from 17 to 35 kg/m². In the larch-birch forb-lingonberry forest, the TOC reserves in the soil were measured at 19.57 kg/m² for the 0–30 cm layer, 26.79 kg/m² at 1 m depth, and 34.98 kg/m² at 2 m depth. Conversely, in the pine-larch lingonberry forest, these values decreased to 9.28 kg/m², 15.41 kg/m², and 18.91 kg/m², respectively, while in the fallow land, the measurements were 3.37 kg/m², 6.35 kg/m², and 8.91 kg/m². The total inorganic carbon (TIC) reserves in the active layer of the larch-birch forest were found to be 3.46 kg/m², in the pine-larch lingonberry forest 5.81 kg/m², and in the fallow land 4.35 kg/m². The forests of South-Eastern Yakutia represent an essential component of the global carbon reservoir; however, they may lose their nutrient accumulation function under anthropogenic pressures. This study serves as the preliminary phase of a long-term research initiative aimed at systematizing carbon pools in representative permafrost landscapes of Yakutia and elucidating the patterns of carbon variation across diverse natural and climatic zones

The research conducted has yielded, for the first time, a quantitative evaluation of the NDWI (Normalized Difference Water Index) for the purpose of identifying areas of natural and technogenic aufeis within Southern Yakutia. In contrast to the widely used NDSI (Normalized Difference Snow Index) in aufeis investigations, the NDWI offers the advantage of delineating aufeis contours without being influenced by the presence or absence of snow cover. Calculations pertaining to the aufeis areas in the “Gorbyllakh” and “Durai” sections of the Federal Highway “Lena” during the winters of 2020–2021 and 2021–2022 indicate a notable increase in these areas, attributed to heightened precipitation levels anticipated in the subsequent summer period. However, limitations of this approach include the interference of cloud cover in satellite imagery, which can obscure the study area, as well as the potential for ambiguous interpretations of shaded regions within the aufeis meadow, where the NDWI may suggest the presence of surface water.

The article discusses the findings from monitoring sites of accumulated environmental damage (AED) along the East Murman coastline. The area surveyed includes the mouth of the Kharlovka River estuary, which is near the Seven Islands Archipelago within the Kandalaksha State Nature Reserve. During a thorough engineering and environmental assessment of the region, an inventory of AED sites was conducted, along with an evaluation of the amount of accumulated waste and an analysis of pollutant levels in the soil. The survey revealed six unauthorized waste disposal sites, primarily consisting of fuel and lubricant containers and scrap metal. Soil testing at two locations within the Barents Sea’s water protection zone indicated significant contamination with oil products, while the levels of metals (Zn, Cd, Pb, Cu) were found to be acceptable. The analysis of soil conditions revealed that degradation within the Kharlovka River estuary began during the operation of a fuel and lubricants storage facility in the area. At the time of the assessment, over a third of the surveyed area lacked a fertile soil layer, and the remaining soil and vegetation were sparse. The degree of contamination by oil products requires the implementation of highly efficient soil remediation methods.

The balance of pro-antioxidants within the cells of common fir (Abies alba) and mugwort (Artemisia vulgaris) seedlings cultivated across eight distinct climatogeographical regions of Russia and Kharkov (Ukraine) was investigated. The intensity of lipid peroxidation processes was recorded as a pro-oxidant response, and the antioxidant response was measured by assessing the total content of low-molecular-weight antioxidants and the activity of superoxide dismutase. An assessment of the pro-antioxidant balance within the cellular structures of seedlings, originating from seeds of plants grown in diverse climatogeographical environments, was performed. This evaluation included the analysis of seedling survival rates, the degree of lipid peroxidation, and the activity of the antioxidant system, utilizing the coefficient method for measurement. The results suggest that the regions from which plant seeds were collected can be classified into three distinct zones according to the values of the extremity coefficient. A significant positive correlation was identified between the activity of superoxide dismutase in the cells of the examined seedlings and the levels of solar insolation in the regions where the seeds were collected. Adaptation changes in wild plants to temperature, humidity, and light conditions lead to the activation of antioxidant systems. The seedlings of plants whose seeds were formed in environments characterized by high insolation and low precipitation (such as Yakutsk, Ulan-Ude, and Srednekolymsk) exhibited a low total antioxidant content, accompanied by a compensatory increase in superoxide dismutase activity. Our research indicates that the survival rates of seedlings of common fir and mugwort are contingent upon the pro-antioxidant balance that has developed in response to the climatic conditions experienced by the plants. This relationship is characterized by species specificity, nonlinear dynamics, and is predominantly affected by the volume of precipitation received during the active growing season of the maternal plants.

This study investigates the genetic predisposition to anxiety and its impact on adaptation to the extreme conditions of the North-East region of Russia, particularly concerning the Yakut population. Special attention was given to the polymorphism of the serotonin receptor gene HTR2A (rs6311) and its association with levels of situational anxiety (SA) and personal anxiety (PA). The study involved 261 Yakuts (n = 261) who are permanently residing in Yakutia, do not exhibit any psychoneurological symptoms, and provided voluntary informed consent. Anxiety level was assessed using the Spielberger-Khanin scale. Genotyping was performed using PCR and RFLP, followed by detection through electrophoresis in an agarose gel. The findings indicate that the sample was characterized by a predominance of individuals with moderate levels of SA (60.9 %) and PA (57.5 %). However, in the group of women, individuals exhibited a high level of PA (53.8 %). The highest percentage of agreement in anxiety levels (69.7 %) was observed among individuals with moderate SA and PA. Given that the serotonergic system is involved in regulating behavior, emotions, and various physiological functions, and plays a crucial role in mitigating the negative behavioral consequences of stressors, a study on the polymorphism of the serotonin receptor gene HTR2A (rs6311) was conducted. The analysis of the distribution characteristics of the genotypes and alleles associated with the polymorphism of the serotonin receptor gene HTR2A (rs6311) in the Yakut population revealed a significant predominance of carriers with the homozygous genotype GG (60.2 %), and the G allele (0.782). Futhermore, when examining the distribution of allelic variants of the studied polymorphism based on the level and type of anxiety, it was observed that the AG and GG genotypes were more prevalent among individuals with high PA and low SA. These results confirm the significance of genetic factors in adaptation to the extreme conditions of the North.

This research examined the influence of interspecific interactions among shrew species on their territorial distribution and trophic conditions within larch and poplar-chosenia forests along the upper Kolyma River. The study specifically analyzed the biotopic characteristics associated with the relative abundance and energy reserve content, including fat tissue mass and glycogen levels in the liver, of Sorex caecutiens and S. isodon. Fieldwork was conducted in the Seymchan- Buyunda depression during July and August in 2003 and 2010. A total of 1,588 individuals from both species were captured using pitfall traps. The assessment of energy reserve content in S. caecutiens (n = 736) and S. isodon (n = 113) was carried out between 2006 and 2010. The abundance of S. caecutiens in the examined habitats exhibited consistent trends and a strong correlation (R_S = 0.95, p < 0.01). Conversely, S. isodon displayed asynchronous fluctuations in abundance across various habitats, likely attributable to competition with Laxmann’s shrew, which tends to displace S. isodon from its preferred larch forest during periods of elevated population density. The interannual variations in energy reserve content for both shrew species were remarkably similar, with no significant differences observed between habitats. The nature of these variations suggested insufficient feeding conditions for the animals during years of high overall abundance, with the dominant species, S. caecutiens, contributing most significantly to this phenomenon in both habitats of the upper Kolyma. The results indicate that interspecific relationships play a crucial role in shaping both territorial distribution and food availability for these shrew species.

The article examines the criteria for classifying regions in the Far North as part of the Arctic Zone within the Russian Federation. It evaluates a range of factors, including natural and climatic conditions, socio-economic aspects, and the medical and biological characteristics of the territories. Additionally, the article presents the outcomes of zoning the northern territories of the Russian Federation based on the natural and climatic conditions that impact human life. This analysis resulted in the identification of three criteria for determining the inclusion of territories in the Arctic Zone of the Russian Federation: the vegetation component of landscapes in its zonal distribution; the CAFF boundary, which proposed by the Arctic Council’s Arctic Flora and Fauna Conservation Working Group; and the level of ultraviolet deficiency, which reflects the direct impact of latitude on the natural environment and human health. These criteria are characterized by their clarity and ease of interpretation, and do not require the development or endorsement of supplementary methodological guidelines. They are easily grasped by both regional leaders and residents regarding the inclusion or exclusion of areas from the Arctic Zone of the Russian Federation. Consequently, these criteria can be effectively integrated into federal legislation as directly applicable norms.

In 2006, 2011, 2013, and 2020, four groups of young wood bison, each made up of 30 individuals from Canada, were introduced to Yakutia. The bison began to reproduce at ages 2 to 3 in 2008. Their mating behavior was first noted in 2007 when they were 2 to 3 years old, and calving took place in the spring of 2008 when they were 3 to 4 years old. Between 2008 and 2023, 16 generations of calves were born from both Canadian and Yakutia-born bison. The percentage of females that gave birth varied each year, ranging from 46.2% to 92.3%, with an average of 69.3 ± 5.4%. In 2017 and 2018, some bison were released in the middle section of the Sinyaya River. By 2023, the total population of bison in the nurseries “Ust-Buotama,” “Tympynai,” and in free-ranging groups reached 348 individuals. We discuss the characteristics of pastures, plant nutrition, feeding, reproduction, reintroduction to the wild, and the distribution of bison in Yakutia and surrounding areas. Bison have adapted well to the region’s climate, which features long winters, short summers, and extremely low winter temperatures. Central Yakutia offers a broad ecological niche for bison, with shallow valley lands that have meadow and shrub vegetation. This environment supports the potential for successfully restoring the historical habitat of the Bison genus in Yakutia and nearby regions. To avoid inbreeding and preserve genetic diversity, it is crucial to regularly release animals into the wild and occasionally introduce new individuals from various parks in Canada.

The article summarizes research on the thermal cycles, structure, and properties of welded joints made from low-alloy and low-carbon steels during arc welding in sub-zero temperatures. This review aims to analyze previous research to create solid recommendations for welding steel bridge structures during winter conditions. The results of a comparison of experimental measurements of thermal cycles of welding samples with different sizes made at room and subzero ambient air temperatures (down to minus 50 °C) are considered. It is shown that in small plates with dimensions of 200 × 250 × 10 mm, due to more intense heat reflection from the edges of the specimen, the thermal cycles of welding at different temperatures do not differ significantly. In more massive samples (sized 450 × 250 × 10 mm), an increase in the cooling rate of the overheated welded joint area is observed compared to room temperature welding. The impact of hydrogen on the development of cold cracks in low-alloy steels during welding at temperatures below freezing is examined. Metallographic analysis has revealed that the structural changes that occur during the welding of various steel grades are notably different and are influenced by the steel’s chemical composition as well as the thermal cycle parameters of the welding process. Dilatometric studies indicate that variations in the levels of alloying elements within different grades significantly influence the kinetics of austenite transformation. Therefore, to identify the best welding techniques for subzero temperatures, it is essential to consider not just how heat disperses in these conditions, but also the kinetics of phase changes and their effects on the structure and properties of the products resulting from austenite decomposition.

The design of energy-efficient heating techniques is emerging as a crucial scientific and technical challenge, driven by the growing focus on the advancement of the northern regions of the country, particularly the Arctic. Research in Arctic materials science, which incorporates cutting-edge techniques from various interdisciplinary fields like nanotechnology and electrotechnology, could become a key area of study for the development of these northern regions. The development of an electric heating composite material that utilizes an organosilicon elastomer as the polymer matrix and metallized multilayer carbon nanotubes (MWCNTs) serving as a conductive filler with enhanced resistance to icing enables an efficient electrothermal anti-icing system The paper presents the results of the study of an electric heater based on the wiring of an elastic composite with the effect of temperature self-regulation. For modification of the silicon-organic compound, metallized MWCNTs were used, which increased the sensitivity of heating elements to ice formation. When the ambient temperature decreases, the polymer composite has different values of electrophysical parameters, which create the effect of acceptable electrical heating concerning the ambient temperature. The research results have significant practical value, as the heating elements can have different compositions and can be operated at low temperatures. Heating elements can effectively adjust the heating mode to the ambient temperature conditions, saving electrical energy. The heating time required for the ice to melt is 210 seconds, and the dynamics of the current consumption value correlate with the ambient temperature, reflecting the effect of temperature self-regulation.