A comprehensive seismotectonic study of the tectonic structures of the Siberian Platform and its folded framing was carried out in order to identify the regional regularities of the processes of destruction of the Earth’s Crust and the dynamics of the formation of focal zones of strong earthquakes. The data on the geological and geophysical structure, the newest structural plan, quantitative characteristics of the newest and modern tectonic movements were analyzed. According to the degree of activity and orientation of geodynamic processes, regional principles for the classification of neotectonic structures with the rationale for their differentiation into classes were developed. The most active segments of the Verkhoyansk marginal suture and the Baikal-Stanovoy fold system are considered, which have a dynamic impact on the style of tectonic deformations of adjacent areas of the Siberian Platform, where strategic mineral deposits of the Republic of Sakha (Yakutia) are located. It is established that the most active structures are located in zones of the dynamic influence of marginal sutures. They are contrasted against the gradient field of modern vertical tectonic movements, but they are characterized by the mosaic field of the medium and low rates of modern movements. The level of their seismic activation and the kinematic type of seismotectonic deformations are modeled by global geodynamic processes taking place at the boundaries between the Eurasian, North American and Amur lithospheric plates. The weak activated structures of the Siberian Platform, which are characterized by the highest rates of modern movements, are heterogenic genesis. The dynamics of the formation of these high-gradient deformation zones may have been influenced by glacial isostatic movements. In order to correctly assess the degree of geodynamic activity of modern structures, special consideration should be given to all the factors that control seismogeodynamic processes, including tectonic stress accumulation, and the intensity of seismic events.

Results of the investigation of the structure, magmatism, Au–Ag and Ag–Pb–Zn mineralization of the Chepchuginsky ore cluster located in the Myunkyulen mineragenic zone of the central part of the Verkhoyansk-Kolyma mineragenic province are presented. The ore cluster is localized in an extended latitudinal projection of the crystalline basement between slightly eroded massifs, manifested by gravitational minima and positive local magnetic anomalies of the zones of contact metamorphism. Structurally, the ore node is confined to the intersection of the Suntar regional fault of the Chepchugin anticline. The study of dikes showed a wide petrographic diversity of the rocks composing them (spessariters, diorite porphyry and rhyolite-porphyry). The igneous rocks of the ore field are geochemically specialized in lithophylic elements (B, Ba, Cr, Nb, Sc, Sr, V, Zr), while the content of chalcophylic (Cu, Gе, Sn, Zn, Pb) and siderophile (Ni, Co) elements is much lower. Early pyrite-arsenopyrite, middle polymetallic, and late silver-sulfosalt mineral associations were identified. The wide development and diversity of supergene minerals is typical, which suggests a significant prevalence of mineralization of galena, arsenopyrite, and sulfosalts in primary ores below the supergene zone. Differences in the mineral specialization of the Gaidar and Chepchuga sites have been identified. The Au-Ag type of mineralization with native gold in quartz veins and oxidation zones on silver-containing ores is developed at the Gaidar site. On the basis of the development of cassiterite, canfieldite, acanthite, as well as Pb, Ag, and Sb sulfosalts in the ores, it is assumed that the mineralization of the Chepchuga site is close to silver-polymetallic deposits. The metallogenic appearance of the ore cluster is associated with its position in the rear area of the marginal-continental Tithonian-Early Cretaceous Uda-Murgal and Albian-Late Cretaceous Okhotsk-Chukotka volcano-plutonic belts.

Mineral assemblages and processes occurring in olivine-pyroxenites, andesite, and dacite volcanic settings of the Kildyam Late Jurassic complex in Central Yakutia are investigated. The methods involved in the study include detailed sensing and mapping using ESRI ArcGis.Imagery Service, field observations, minerals and glass identification, recognition of vesicle composition. The results obtained in the study support the igneous vapor transport of ore elements in the andesitic system and imply preconcentration of iron, copper and ± gold and silver during lava solidification into magnetite rich lava flows. The major components of the Kildyam andesite alloys are Fe, Cu, Sn, Pb, Zn, and Ag. Alloy element maps show a covariance of Cu±(Zn, Sn, Ni, Fe), and Ag concentrations varied independently. This research confirmed that tholeitic trend of iron-rich olivine-pyroxenites evolve towards two immiscible liquids: (1) magnetite lava, and (2) melilitite matrix. Further evolution leads to the separation of native iron and the transition of lavas to the calc-alkaline trend. Petrographic and microprobe studies confirmed the liquid immiscibility in silicate melts during crystallization. Immiscible liquids are preserved as globules of one glass in another in andesites and as melted inclusions of native iron in the matrix, clinopyroxene and plagioclase phenocrysts. The vesiclehosted alloys and sulfides provide significant new data on metal transportation and precipitation from hightemperature magmatic vapors. During syneruptive vapor phase exsolution, volatile metals (Cu–Zn, Fe–Al– Cu, Ni–Fe–Cu–Sn) and Ag–Cu sulfides contribute to the formation of economic concentrations.

The article presents the results of field paleontological research within the framework of the research program “Biological aspects of mammoth fauna”, conducted in the Ust-Yana district of the Republic of Sakha (Yakutia) on the cryogenic lake Bulgunnyakhtakh in 2013. The work deals with the actual problem and the history of the study of mammoth fauna in Yakutia. During the field work at the site, more than 200 bone remains of upper Pleistocene mammal species of the mammoth fauna of northeastern Eurasia were collected: woolly mammoth -Mammuthus primigenius (Blumenbach, 1799); Pleistocene horse – Equus lenensis Russanov, 1968; woolly rhinoceros Coelododnta antiquitatis Blumenbach, 1799; primitive bison – Bison sp.; musk ox – Ovibos sp.; reindeer – Rangifer tarandus Smith, 1827; red deer – Cervus elaphus L.; elk – Alces alces L.; wolf – Canis lupus L. The paper also examines the possible causes and season of death of the mammals in this area during the Karginsky time and possible reasons of the formation of this type of sites in northern Yakutia.

The aim of the study is to clarify the origin and age of the oriented landforms and components of the Quaternary deposits of the western segment, which are widespread on the southern coast of the western segment of the Laptev Sea. The objectives of the study are: 1 – to establish the distribution of oriented landforms and their typification; 2 – to determine the composition of sediments composing oriented landforms; 3 – to establish the genesis of the identified forms and their constituent deposits; 4 – to establish the age of the identified forms and their constituent deposits; 5 – to establish the reasons for the formation of oriented forms. The main methods used in the investigation are: 1. Deciphering high­resolution satellite images of SAS Planet ­ ESPI ArcGIS Landsat package; 2. Generalization of the published materials on geomorphology and Quaternary sediments when working on the basic project of the P.I. Melnikov Permafrost Institute SB RAS «Regularities of the development of coastal and underwater permafrost in the Laptev and East Siberian Seas»; 3. Field route studies carried out by V.B. Spektor during different years in the mouth area of the Lena River, on the western coast of the Laptev Sea during the implementation of scientific programs of the P.I. Melnikov Permafrost Institute SB RAS, as well as joint research with the Institute of Geography of the Russian Academy of Sciences (headed by M.G. Grosswald) and Stockholm University (Professor Karlen Vibjorn).As a result of the studies, it was established that the territory of the coast of the Laptev and East Siberian Seas is a scabland ­ a geomorphological landscape created by a hydrospheric catastrophe. The hydrospheric catastrophe (megaflood) probably occurred as a result of the emergence of a glacial dammed lake from the shores. The lake had been formed in the Pleistocene in front of the ice shelf, which played the role of a dam. The sediments of the catastrophic flows (diluvium) include areas of overcompensated sedimentation – sandy formations on the high islands of the Lena river delta, the lower part of the Tukulannaya suite, which is widespread in the flat areas of Central Siberia, watershed cover sandy loams, loams and sands with pebbles. The areas of scabland development are the territories of the distribution of parallel troughs, oriented ridges, giant ripples, large structurally organized landforms. In the area of the Tiksi Bay, the distribution of marginal formations of the ice shelf was established: glacial deposits, exaration fields, drumlins, gouging troughs, through valleys, and glaciotectonic moraines.

For the purposes of monitoring the state of forest ecosystems, it is most effective to use the capabilities of remote sensing methods. Fragments of 27.562 km² (scale 1: 16000) of Gmelin larch (Larix gmelinii Rupr.) with various disturbances caused by fire were identified on the Landsat ETM + multispectral satellite images of the Olekminsky State Nature Reserve. Then polygons were saved at three levels of detail-4, 16.64 with scales 1: 8000, 1: 4000, 1: 2000. When decrypting, an uncontrolled classification of a fragment and polygons was carried out using the ISODATA method (Iterative Self-Organizing Data Analysis Technigue) into 2.4 classes. Distribution curves of the values of forest cover and productivity indices were constructed for the polygons of the 3rd level of detail. The nature of the distribution curves of the values of disturbed polygons differ from the normal one, while in the undisturbed ones they are close to the normal distribution of the values. Calculation of the correlation coefficient between the series of values of the indices by year showed that at all three levels of detailing the correlation coefficient of an undisturbed polygon is 2–3 times higher than that of a disturbed one. According to the results of classification into 4 classes, statistic processing was carried out with the calculation of indicators of the difference and similarity of polygons the variance of the general population and the Fisher test (F-test). The results of changes in the variance of the general population and the F-test at different levels of detail are considered.

A comparative analysis of the hibernation rhythm of two phylogenetically distant obligate winter-sleeping species, the family Erinacedae and Sciuridae, is carried out. The data from 12 individuals of long-tailed ground squirrels (Spermophilus undulatus Pallas, 1778) were analyzed. Comparative data white-breasted hedgehogs (Erinaceus roumanicus Barrett-Hamilton, 1900) were obtained from 13 individuals. The dynamics of hibernation rhythms in S. undulatus and E. roumanicus are unidirectional. The longest periods of hypothermia were observed in January-February. The winter hibernation of hedgehogs, for the total duration, is 30 % longer than that of ground squirrels. The total duration of hypothermia in hedgehogs is longer by 25 % than in ground squirrels. The average duration of the periods of hypothermia in hedgehogs is shorter by 40 % than in ground squirrels, and their number is 2,5 times larger. The duration of normothermia in hedgehogs during hibernation is 3 times higher than in ground squirrels. The average duration of normothermia during awakenings is longer by 20 % for hedgehogs than for ground squirrels. In hedgehogs, the percentage of normothermia is 12.6 % of the total hibernation time, while in long-tailed ground squirrels the percentage of normothermia is 5.9 %.

The timing of the main phenological events and some associated ecology features of the Siberian Salamander (Salamandrella keyserlingii) in several remote populations in the cold marine, extracontinental and arctic climates in northeastern Asia were analyzed. It was shown that the populations consistently differ in the duration of the season of activity: it is almost one and a half times longer (4–4.5 months) on the coast of the Sea of Okhotsk near Magadan than for the continental and the Chukotka’s population (3–3.5 months). At the same time, the start and end of reproduction, which is the key aspect of biology, their limiting dates, dynamics and total duration may coincide in coastal and continental populations (with a significant variation of each indicator depending on the weather of a particular spring). The dates and intensity of the spawned salamanders’ coming out from water bodies differ: they stay in water until August in some continental populations and on the Arctic coast, however, they come out within a month after the start of reproduction in other continental populations, as well as in the southern part of the Northeast. The timing of embryonic and larval development varies, even if the dates of spawning coincide; they differ significantly in nearby water bodies and coincide in remote populations of the region or even the range. Metamorphosis and coming out of underyearlings on land in the southernmost populations of the region begin about two weeks later than in the continental and arctic ones. The sizes of metamorphs can vary significantly both in remote areas and in nearby water bodies, or in the same water body in different years; in some cases, they are comparable to the size of underyearlings from other parts of the range. Thus, the greatest influence on the characteristics under consideration is undoubtedly exerted by the diversity of climatic and microclimatic components than by the geographical position of populations.

The data on the quantitative assessment of the diversity of vascular plants per unit area (1 km²) in the mountain systems of North-Eastern Yakutia are presented on the basis of the original standard flora procedure developed by the author. Three standard floras built in the Tas-Kystabyt Range and in the Oymyakon highlands are characterized. The diversity of vascular plants is estimated at 95 taxa/km² in the northwestern tip of the Tas-Kystabyt Range («Nelkan Pass» SF), 198 taxa/km² in the Oymyakon highlands, near the southeastern tip of the Tas-Kystabyt Range («Kuranakh-Sala» SF), and 164 taxa/km² in the Oymyakon highlands, near the eastern border of the Suntar-Hayata Range («Labyngkyr» SF). Despite the relative geographical proximity, the compared floras show a significant distinctiveness. Only 32 species and 1 variety are common to all three standard floras. Jaccard coefficient characterizing the degree of similarity of the compared floras shows the greatest similarity richer and closer to the standard floras «Kuranakh-Sala» and «Labynkyr» (0.321). The similarity of the most distant standard floras «Nelkan Pass» and «Labynkyr» is higher (0.233) than that of the standard floras «Nelkan Pass» and «Kuranakh-Sala» (0.201), due to the more upland position and the corresponding set of species in the former case.

The effect of bacterial cultures isolated from permafrost (MMP) on the salt tolerance of twenty-day-old oat seedlings of the Tyumensky Holozerny variety was studied. One strain (10-50-TS2) of the Achromobacter spanius species and three strains of the Bacillus genus: 875-TS of the Bacillus cereus species, 312-TS and 2-06-TS1 of the Bacillus megaterium species were used for the study. A vegetation experiment was carried out on saline quartz sand under laboratory conditions. The coefficient of root supply and the coefficient of symmetry of seedlings were calculated, and the amount of photosynthetic pigments in the green part of the plant was investigated. According to the results of the experiment, it is possible to evaluate the positive effect of bacterial inoculums on some measured parameters of seedlings: all four strains stimulate an increase in the number of roots, also in two variants (10-50-TS2, 2-06-TS1), the mass of roots is increased, in the variant with the use of the strain 10-50-TS2, an increase in root length was noted. The calculated coefficients of root supply and symmetry make it possible to conclude that the salt tolerance of seedlings increased in the variant with the use of the 10-50-TS2 strain. Analysis of the content of photosynthetic pigments showed that in three variants (875-TS, 312-TS, 2-06-TS1) there was an increased content of carotenoids, the content of green pigments was higher than the control one in variant 10-50-TS2. The study allowed us to conclude that the strain 10-50-TS2 (Achromobacter spanius) can be attributed to a wide group of PGPB, and it is possible to use it as a basis for creating a biological product that increases the resistance of plants growing on saline soils.

At present, the rapidly expanding development of the Arctic regions requires increased attention of researchers to the problem of climatic aging of polymer composite materials in extremely cold climate. After two years of climatic aging in extremely cold climate of Yakutsk, basalt-fiber reinforced plastic (BFRP) and glass-fiber reinforced plastic (GFRP) based on basalt fabric BT-11P-kv-12 and glass fabric Ortex 560 impregnated with a three-component binder consisting of an epoxy polymer matrix ED-22, a hardener Iso-MTGFA and accelerator Agidol 53, binder destruction was found in the surface layer: in the form of cracking to a depth of up to 1 micron in BFRP and up to 4 microns in GFRP; in the form of bare fibers and single depressions no more than 30 microns deep. Comparison of the surface morphology of the front and back sides of the plastics showed that GFRP is more exposed to solar radiation than BFRP, so that the open porosity of GFRP was 2 times higher than the open porosity of BFRP. Applicability of the moisture sorption and diffusion model consisting of Fick’s law for diffusion and constant or relaxation boundary conditions, under stationary thermal and humidity conditions was substantiated. It was shown that the diffusion coefficient of the plastics increased 5 times after climatic aging. With all this, an increase in the mechanical parameters of the plastics is observed after 2 years of climatic aging. Thus, the change in the calculated parameters characterizing the destruction of the surface layer of the plastics can serve as a quantitative estimate for diagnosing the early stage of climatic aging of plastics.

Currently, high-energy technologies for applying wear-resistant powder coatings are widely used to strengthen and restore parts of equipment in repair production. Physical-mechanical properties and the structure of coatings significantly affect their performance in friction with the metal surfaces of metal counterbodies – parts of machines and mechanisms. Therefore, to assess the wear resistance of a friction pair, it is necessary to establish the effect of the structure and properties of powder coatings on the frictional interaction with the material of the counterbody. It is necessary to identify how the features of the properties and structure of the coating will manifest themselves in the processes of wear of both contact surfaces of friction. In this work, the method of metallographic analysis and profilometry was used to study the contact surfaces during sliding friction of wear-resistant coatings with modifying additives of corundum Al₂O₃, ultrafine spinels CoAl₂O₄ and CuAl₂O₄ with counterbodies made of various materials – hard VK6 alloy, ShKh15 and St6 steel. The main mechanisms of damage to the contact surfaces of friction have been established. It is shown that wear and the formation of the profiles of the contact surfaces depends on the ratio of the wear resistance of the coating and the counterbody. To describe the friction of a powder coating with a metal counterbody during steady-state wear, a statistical model has been developed on the basis of the binomial distribution of the removed wear particles of both contact surfaces.