The Kungurian stage of ammonoid development is marked by the decline and extinction of previously dominant genera, alongside the emergence of morphogenetic trends that contributed to the formation of new families and subfamilies. Western Verkhoyanie is one of the very few regions worldwide with a broad vertical and lateral distribution of Kungurian ammonoids. Long-term studies of reference sections have revealed that the biostratigraphic relationship between the previously identified Orol and Takamkyt ammonoid associations is less clear than previously assumed. New materials required a reevaluation of the stratigraphic sequence and taxonomic composition of Kungurian ammonoids in the region, with the primary goal of constructing a new biostratigraphic scale for ammonoids. To this end, the taxonomic affiliations and stratigraphic ranges of the studied cephalopods were revised. In the Kungurian deposits of Western Verkhoyanie (comprising 13 main localities), 10 ammonoid species were identified, belonging to seven genera within the families Paragastrioceratidae, Spirolegoceratidae, Mongoloceratidae, and Medlicottiidae. Paragastrioceratids predominate, representing four genera and seven species. The genus Tumaroceras constitutes the main component of the Kungurian community. Based on the analysis of the vertical distribution of ammonoids in Western Verkhoyanie, five successive complexes have been established, each representing distinct biostratigraphic units: Paratumaroceras? sp. nov. Beds, Tumaroceras yakutorum Beds, Tumaroceras kashirzevi Beds, Epijuresanites musalitini Beds, and Baraioceras stepanovi Beds. The first three biostratons correspond to the Lower Tumarian regional substage, while the latter two correspond to the Upper Tumarian regional substage. The key section of the Kungurian stage in Western Verkhoyanie, located in the upper reaches of the Dulgalakh River, is presented. A shell fragment and suture line of the holotype of the index species from the Baraioceras stepanovi Beds are illustrated. Ultimately, this research contributes to the modernization of the Regional Stratigraphic Scheme of the Permian deposits of Verkhoyanie.

Intergrowths of platinum group minerals (PGM) with gold, silver, rare metals and semimetals (Bi, Pb, Sn, Sb, Te,As)from the Anabar River basin placers (northeastern Siberian Platform) were analyzed for their chemical composition and structure. While magmatogenic Au and PGE mineralization is recognized in sulfide and oxide ores of differentiated mafic-ultramafic intrusions, these metals typically reside as isomorphic impurities or as microscopic, dispersedinclusions, making them unsuitable for forming large placer grains. Recent discoveries of complex magmatogenicdeposits reveal geochemical signatures in precious and rare metals indicative of both granitoid and mafic-ultramaficmagmatism. The long-term evolution of these ore-magmatic systems spans stages from early magmatic and transitional fluid-magmatogenic to late hydrothermal-metasomatic. Consequently, rare discoveries of large polymineralintergrowths of noble and rare metals are invaluable for constraining the physicochemical parameters of such paragenetic ore associations and for guiding the exploration for nearby sources of precious metals. We demonstrate that themicrostructures of these natural precious-metal intergrowths resemble those of synthetic and metallurgical alloys. Byanalyzing compositional variations and structural forms, we discuss potential crystallization trends of these polymineral natural alloys using Pd-Au-Cu and Pd-Au-Te phase diagrams, which constitutes the core scientific contribution ofthis work. This study indicates that the sources of complex noble-rare metal mineralization in the northeastern Siberian Platform are primarily fluid-magmatic ore systems of diverse ages, related to Phanerozoic, differentiated maficultramafic platform intrusions. Furthermore, a genetic association with ancient metamorphosed granitoids and basiccrystalline schists is supported.

In the Verkhne-Timptonkiy ore district, despite the presence of large placer deposits and more than a century-long mining history, no comparable primary gold deposits have been identified, and information on their possible types remains highly limited. The aim of this study was to investigate the mineralogical characteristics and chemical composition of pyrite from the Utanakh occurrence in order to reconstruct the conditions of ore formation and to classify the type of gold mineralization. The composition of pyrite from the Utanakh gold occurrence in the Verkhne-Timptonkiy district was examined using electron probe microanalysis (EPMA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The Utanakh occurrence is hosted in diaphtorites (biotite–muscovite and chlorite schists) of the Kholodnikan greenstone belt.Mineralization is represented by carbonate–quartz veins and lenses 0.11.5 m thick, and by adjacent metasomatites containing disseminated sulfides. Two generations of pyrite were distinguished. Pyrite-1 hosted in epidote–quartz metasomatites is close to stoichiometric composition and forms fine cubic aggregates up to 200 µm in size. Pyrite-1 is enriched in Ni, Cu, As, Pb, Te, and Zn, contains moderate amounts of Co and Se, and exhibits well-developed sectoral zoning: the cores are enriched in As and Ni, whereas the rims are enriched in Cu, Co, and Pb. Pyrite-2 occurs as anhedral grains 0.8–7.0 mm in size, with chalcopyrite and bornite crystallizing in structural defects in association with native gold. Pyrite-2 from carbonate–quartz veins differs from Py-1 by anomalously high concentrations of Co and Se, low contents of Ni, Cu, and As, and elevated Co/Ni ratios. Gold concentrations in both pyrite types are extremely low. The obtained results indicate a transition from early As–Ni-rich metamorphic fluid sources to late Co–Cu-rich magmatic-derived fluids. The established geochemical indicators are typical of orogenic gold mineralization controlled by diaphtorite zones within granulite and amphibolite complexes. The study demonstrates that pyrite chemistry is an effective tool for classifying poorly investigated gold occurrences. 

Determining the metallogenic specialization of igneous rocks in ore districts remains a pressing and often controversial challenge. Addressing this issue requires a comprehensive approach, that integrates petrographic and petrogeochemical data with geochronological studies of individual formations. Such integrated analysis, when contextualized within specific formation conditions and metallogenic assessments, provides a robust framework for interpretation. The Evotinsky massif, located within the eponymous Evotinsky placer ore region in the central Aldan-Stanovoy shield, represents one such critical formation. This study investigates its petrogenesis based on rock samples collected 
during fieldwork from 2018 to 2020, focusing on the massif’s main phases. Subsequent processing and major element analysis were performed using silicate and multielement techniques at the Department of Physicochemical Analysis Methods of the Diamond and Precious Metals Geology Institute SB RAS (Yakutsk). Trace element concentrations were determined by mass spectrometry at the САС Plasma LLC laboratory (Tomsk). Finally, geochronological U-Pb dating of zircons was conducted using SIMS (SHRIMP-II) at the Center for Isotope Research of the Karpinsky Russian Geological Research Institute (VSEGEI). The Evotinsky massif displays an antidromous structure and comprises two intrusive phases: an earlier phase of amphibole quartz syenites and a later phase of amphibole-pyroxene quartz monzonites. The rocks are classified within the high potassium calc-alkaline series, corresponding to derivatives of the shoshonite-latite series. Geochemical data indicate a mixed mantle and crustal source for the magmas. Petrochemical parameters and trace element ratios (Rb, Y, Yb, Ta) show compositions analogous to volcanic rocks from continental margins and island arcs. U-Pb zircon geochronology (SHRIMP II) constrains the emplacement of the amphibole quartz syenites to 119 ± 1 Ma and the amphibole-pyroxene quartz monzonites to 117 ± 1 Ma (Aptian, Early Cretaceous). In conclusion, the Evotinsky massif formed under back-arc extensional conditions during the final stages of the Mongol-Okhotsk Ocean closure. Furthermore, these findings demonstrate the massif’s significant potential for gold mineralization.

The origin of oil within the Vendian terrigenous deposits overlying the crystalline basement of the Nepa-Botuoba 
anteclise remains a subject of ongoing debate. This study examines the lateral and vertical distribution patterns of oil density across the anteclise to elucidate constraints on hydrocarbon source, migration pathways, and generation history. A review of the scientific literature indicates a general consensus that reservoir oil density tends to decrease with increasing depth.  For the present analysis, oil density data were obtained from the State Balance of Mineral Reserves of the Republic of Sakha (Yakutia) for fields distributed across the Nepa-Botuoba anteclise and the adjoining Predpatomsky regional trough. Comparison of 124 oil density determinations from 24 fields revealed a distinct trend of decreasing density upsection. The distribution of oil density data according to the lithological and tectonic elements of the Nepa-Botuoba anteclise established a relatively strong correlation between oil density and depth within the Nepa-Peleduy arch and a weak correlation within the Mirny ledge. A significant overall weakening of the correlation between oil density and depth was observed in carbonate deposits relative to terrigenous ones. The results indicate that the consistent decrease in oil density with shallower depth in the Nepa-Peleduy arch is caused by a filtration effect under conditions of lithological control of the deposits and the influence of the permafrost zone during production. The weak correlation in the Mirny ledge is hypothesized to result from repeated reformation of the deposits during tectonic processes, which does not exclude the presence of oils from different genetic sources. Further research is required to clarify the genesis of the oils in the Mirny ledge.

This study developed a briquetting method for fine-grained lignite and bituminous coal using recycled cardboard as a binder to address environmental and economic challenges in fuel supply. This research is particularly relevant for the Arctic zone of the Republic of Sakha (Yakutia), where coal transported under the Northern Delivery program is subjected to prolonged storage and repeated handling, leading to particle fragmentation and reduced combustion efficiency. We propose a decentralized processing solution to convert coal fines into briquettes directly at consumption sites, thereby decreasing reliance on centralized supply chains and enhancing the energy security of remote communities. For this study, feedstock consisted of lignite from the Kangalas deposit and bituminous coal from the Denisovskoye deposit. The influence of binder content on the mechanical strength and calorific value of the briquettes was investigated to establish optimal compositions and production parameters. The results indicate that incorporating 9–13 % cardboard (by dry coal mass) for lignite and 9–10 % for bituminous coal yields briquettes with a compressive strength exceeding 7.8 MPa, although a marginal reduction in heat of combustion was observed. The process operates at ambient temperature without external energy input, which is a critical advantage for Arctic implementation. Furthermore, while briquette strength decreases after water exposure, this can be mitigated by covered storage. Therefore, the proposed briquetting technology is suitable for implementation in remote settlements dependent on the Northern Delivery Program, as processing coal fines locally can reduce transport losses and reintroduce fine coal fractions into the fuel cycle. To this end, a modular, seasonally operable production unit adaptable to local coal varieties is recommended to maximize feasibility in isolated Arctic regions.

High-efficiency thermal insulation materials are widely used in permafrost engineering for the thermal protection of ice-rich structures (dams, levees, storage facilities, airfields, roads, etc.) and for controlling natural and anthropogenic cryogenic processes and hazards (e.g., icings, seasonal freeze-thaw cycles). Investigating these processes is highly relevant task for Arctic and Subarctic regions. From 1982 to 1986, a full-scale field experiment was conducted on a dyke adjacent to the Permafrost Institute in Yakutsk. The objective was to create an impermeable frozen core within its embankment and foundation using a combination of thermosyphons and high-efficiency thermal insulation (PVC-1 foam). In 2024, a PVC-1 foam sample was retrieved from the crest of the dyke to assess its residual thermophysical properties after 40 years of service. The investigation employed thermal analysis, two-probe measurements, and steady-state technique evaluations using a Netzsch HFM 436 Lambda apparatus. The results demonstrate that the material has maintained its structural integrity and insulating performance remarkably well, confirming that PVC-1 foam constitutes a reliable and durable insulating layer under the climatic conditions of Yakutia. This finding suggests that more advanced insulating materials used to maintain foundation soils in a frozen state or to form frozen dam cores can potentially achieve a very long service life (exceeding 50 years). 

This article presents the results of an experimental study on the flight characteristics of seeds from the primary
anemochorous tree species of Yakutia—larch, pine, andbirch. Experiments were conducted under controlled laboratory conditions, where seeds were released from a height of 3.6 meters in calm, windless conditions. The parachuting speeds of the seeds were measured, enabling the calculation of flight performance coefficients for seeds of Pinus sylvestris, Larix gmelinii and Larix cajanderi, and Betula pendula ssp. platyphylla Sukacz., collected at various times and locations across Central Yakutia. The study confirms that the derived formula for anemochorous conifers applies to all tree species possessing winged, flight-capable seeds. Furthermore, the seeds with the lowest flight performance among the studied species were those of larch, followed by pine and birch (flight performance coefficients of 1.01±0.03
for larch, 0.61 ± 0.01 for pine, and 0.50 ±0.01m/sforbirch). The percentage of anemochorousconifer seeds dispersing at various distances from the parent tree under different wind speeds was calculated. Based on these calculations, tables were compiled showingthe distribution of the majority of seeds and the maximum seed dispersal distances for the main tree species of Yakutia from different release heights (ranging from 10 to 30 meters) and at varying wind speeds. Therefore, the compiled data provide a basis for the objective assessment of seed dispersal ranges for nearly any forest stand. As a result, this facilitates more accurate planning of felling area dimensions and orientation according to site-specific conditions and supports the informed selection of appropriate silvicultural measures

The industrial pollution in the Norilsk industrial region and its continuous adverse impact on the local ecosystem un derscore the need to study how chemical substances enter and accumulate in living organisms. This study aimed to investigate the accumulation of heavy metals (Zn, Cu, Cd, and Pb) in the kidneys and livers of voles and shrews in habiting areas adjacent to the Nadezhdinsky Metallurgical Plant and the Copper Plant. Animals were captured at sites located an average of 9.2 km from industrial emission sources. A total of 48 kidney and liver samples were analyzed, comprising 24 samples from voles and 24 from shrews. Heavy metal concentrations were determined by atomic absorption spectrometry with plasma and electrothermal atomization using a Kvant-2mt spectrometer. The results indicated that zinc was distributed more homogeneously in the organs of both voles and shrews than the other metals, with its concentration varying 3.8 to 10.5 times less. In contrast, copper exhibited the greatest variability, particularly inrenal tissue, reflecting considerable individual variation in kidney Cu accumulation. Variability analysis further con
firmed that the toxic elements exhibited the highest coefficients of variation. Furthermore, pronounced organ-specificdifferences in metal accumulation were observed. The kidneys of both voles and insectivores contained significantly higher levels of copper, cadmium, and lead (P < 0.01–0.001) than their livers. Diet also influenced accumulation patterns, as insectivorous shrews showed elevated concentrations of Cu, Cd, and Pb in their organs relative to herbivorousvoles. Consequently, these findings provide valuable baseline data for assessing the impact of industrial pollution on small mammals and can inform future environmental monitoring in affected areas.

Small’s blueberry (Vaccinium smallii) is a berry shrub species widely distributed in northern Japan, Sakhalin Island, the Kunashir and Iturup islands, and the Sovetsko-Gavansky district of Khabarovsk Krai. This study presents the first investigation of V. smallii coenopopulations on Sakhalin Island. Research focused on native plants, selected forms exhibiting economically valuable traits, and introduced cultivars maintained at the Sakhalin Botanical Garden Department of the Botanical Garden-Institute, Far Eastern Branch of the Russian Academy of Sciences. Field studies on Sakhalin Island, complemented by stationary research at the Botanical Garden conducted since 2019, have characterized the species’ biology. V. smallii shows a preference for well-lit habitats, a late vegetation and flowering onset that reduces late frost damage, low soil and moisture requirements, disease and pest resistance, and successful acclimatization in full-light experimental plots. The fruits exhibit superior quality compared to several cultivated species, with notable variability in key traits, indicating high potential for introduction into cultivation and selection research. Analysis revealed a more than 15-fold difference in sugar content and 4,1-fold difference in vitamin C infruits between typical and selected fruit forms. Therefore, the introduction of V. smallii into cultivation is a timely and important objective. Future research on high-value selected forms under both natural and cultivated conditions, combined with parallel efforts to develop improved varieties, will advance the cultivation of V. smallii as a promising novel berry crop.

This study investigates the initial introduction of the currant-gooseberry hybrid yoshta at the Yakut Botanical Garden from 2019 to 2024. Specifically, experimental plant material comprised seedlings propagated from seeds sourced from original stock at the “Gardens of Siberia” Irkutsk. Morphological, biological, and agronomic characteristics of yoshta were evaluated under the environmental conditions of North-Eastern Russia; these descriptions include leaf, flower, 
and fruit morphology, as well as overall plant growth form. Furthermore, the timing of key phenophases was established relative to accumulated effective temperatures for the region. While the phenological rhythm of yoshta closely aligns with the early phenological rhythm of native species from Yakutia, the initiation of spring vegetation in Yakutia occurred approximately one month later than reported for yoshta grown in northwestern Russia. Moreover, the rapid seasonal rise in effective temperatures in Yakutia resulted in compressed interphase periods. Thus, although fruit ripening in Central Yakutia and the Komi Republic occurred concurrently from late July to mid-August, initial phenophases exhibited a delay of 20–30 days. Additionally, incomplete apical bud development and insufficient shoot lignification by the end of the growing season were observed, which resulted in partial winter dieback and contributing to a distinct shrub morphology characterized by upright central branches and a sprawling peripheral habit. Regarding plant performance, winter hardiness was rated at 2 points on a standardized scale, and fruit weight exhibited the greatest variability, ranging from 0.69 g to 2.1 g, with a coefficient of variation of 12–30 %. Notably, favorable traits observed under Central Yakutia conditions included a high fruit set rate (75–80 %) and resistance to major diseases and pests. These findings indicate that currant-gooseberry hybrids are promising for cultivation in challenging northern climates due to their yield potential, environmental resilience, and suitability for small-scale horticulture. 

This article describes the unified, centralized Bioresource Collection (BRC) of genetic material from modern wild 
mammalian species of Northeastern Russia. This BRC was established at the Institute of Biological Problems of the 
Cryolithozone of the Siberian Branch of the Russian Academy of Sciences by consolidating local collections into a single, systematized repository comprising primary biological materials, DNA samples, and associated databases for various species. The BRC currently contains approximately 5,000 items representing 45 wild mammal species out of the 70 species native to the region. Additionally, the collection includes samples of wolf-dog hybrids. This unified BRC serves as a comprehensive resource for molecular genetic studies aimed at genetic identification, clarification of systematic affiliations, and the construction of evolutionary frameworks.

Reinforced polymer composite materials (PCMs), incorporating diverse fiber types, are extensively utilized across multiple industrial sectors. While PCMs possess acknowledged advantages over conventional materials, empirical evidence indicates that prolonged exposure to extreme climatic conditions induces material ageing, leading to a deterioration of elastic and strength properties. A primary design criterion for PCM components intended for cold-climate applications is a low moisture absorption, a property intrinsically linked to material porosity. This study examines pore formation during the environmental ageing of flat basalt-plastic (BP) composites under extreme northern conditions and estimates threshold porosity values. The identification of these limiting values accounts for the layered structure of BP, which exhibits plane-parallel symmetry. Porosity formation during climatic degradation initiates at the external surface of the composite. In order to describe pore formation mechanisms, a statistical model for the formation of open porosity in flat BPmaterials was developed. The porosity distribution across material layers is treated as a two-dimensional cluster structure on a square lattice. Furthermore, the analysis subsequently identifies coincident elements of these two-dimensional porosity clusters across multiple BP layers (two, three, or more). The outcomes of the evaluative and statistical computations were compared against experimental data derived from studies of open porosity in multilayer BP panels. These panels underwent open-air weathering exposure in the natural climatic environment of Yakutsk. Thus, the developed statistical model for porosity formation in multilayer basalt-plastic composite materials can be applied in the design of PCMs for service inArctic and Subarctic climatic zones.

A fundamental challenge in composite materials engineering is insufficient adhesive bonding between the matrix and the filler, which significantly reduces product reliability and durability. To address this problem, chemical and physical surface modification of the filler is employed so that a strong bond can be created at the phase interface. This study examines the interaction between modified high-modulus fibers and an elastomeric matrix, specifically investigating the influence of surface treatment for basalt (BF) and carbon (CF) fabrics on the properties of elastomeric composites based on butadiene rubber. Two surface treatment methods were studied: a rubber compound solution in toluene (RCS) and Chemosil 411 adhesive. Microstructural analysis revealed that untreated samples delaminate at the BF/CF interface due to poor adhesion between the fabrics, whereas treated samples exhibit strong adhesion between the rein forcing fibers. Furthermore, the formation of a dense contact between the fibers and the elastomeric matrix was registered, which is attributed to the diffusion of rubber macromolecules during vulcanization. Mechanical testing demon strates that combined reinforcement with BF and CF increases composite strength by 4.9 times compared to the original elastomer, as this is related to effective load distribution across the fibers. While applying RCS to the fabric surface provides the highest strength, treatment with Chemosil ensures high stability in a hydraulic oil environment. Adhesion tests confirmed that Chemosil maintains the bond strength between BF and CF after hydrocarbon exposure because the adhesive layer acts as a protective barrier. However, under prolonged thermal exposure, all samples show reduced adhesive strength due to the degradation of both the polymer matrix and the adhesive layer; additionally, their hardness increases since additional cross-linking between rubber macromolecules occurs via post-vulcanization. In conclusion, the results prove that pre-treating basalt and carbon fibers with adhesives is effective for creating composites based on an elastomeric matrix and high-modulus fibers.