In the central part of the regional Adycha-Taryn fault (ATF) zone, separating the Adycha-Elginsky and Nersky anticlinoria (Verkhoyansk-Kolyma folded area), three stages of tectonic deformation in the Upper Triassic rocks have been established. In the first stage, thrusts and folds of the northwest strike formed. Deformations of the second stage are represented by folds with steep hinges and associated sinistral strike-slip faults. The third stage of deformation marked by the formation of dextral strike-slip faults is also presumed. It is established for the first time that the intensity of tectonic deformations varies both along and across the ATF. The intensity of deformations decreases from northwest to southeast on the southwest flank of the ATF zone. On its NE flank, the deformation intensity gradually increases in the same direction. The orientation of paleostress axes responsible for the formation of tectonic structures in the study area was determined for the first time. Folds and thrusts of the first deformation stage were formed under NE-directed subhorizontal compression. The formation of sinistral strike-slip faults and associated folds of the second stage was related to subhorizontal compression in sublatitudinal direction. Subsequent dextral strikeslip faults resulted from NW-directed subhorizontal compression and NEoriented subhorizontal extension.

A description of sulfide nodules from the block of dolerites, found on the terrace of the Bolshaya Kuonamka river on the eastern side of the Anabar shield (north-east of the Siberian platform) is given. Dolerites are represented by medium-grained rocks with ophitic texture, consist mainly of plagioclase, augite, and Ti-magnetite; potassium feldspar, amphibole, pigeonite, apatite, chlorite, zeolite, quartz, calcite, and ilmenite are less common. In terms of chemical composition and structure, these dolerites are similar to the Precambrian subalkaline dolerites. Sulfides in the studied dolerites occur in the form of separate rounded segregations up to 8 mm in size, consisting mainly of pyrrhotite and chalcopyrite. Small (from several microns to 0.5 mm) drop-shaped precipitates of pyrrhotite and chalcopyrite are often found. Such forms of sulfide mineral segregations indicate that large nodules are formed during merging of small primary sulfide droplets immiscible with silicate magma. Siegenite (Co,Ni,Fe)₃S₄, gersdorffite NiAsS with a high Fe content up to 6 %, Co up to 12 % and Sb up to 3 %, galena, sphalerite, and others are less common in sulfide segregations. Sulfide minerals are often gravitating to the accumulations of Ti-magnetite and apatite, forming close sulfide-apatite-titanomagnetite segregations. The presence of liquation sulfide segregations in igneous rocks is one of the important criteria of the saturation of magmatic melts with sulfides, indicating their potential ore content. Platinoid-copper-nickel sulfide deposits of the Norilsk region are characterized by similar forms of segregations and sulfide mineral associations. Vein-disseminated coppernickel mineralization in taxite gabbro-dolerites of the Budyurkhaiskaya dike along the Kengede river is known, which allows us to suggest the possible presence of Precambrian basite rocks with Cu-Ni sulfide mineralization on the Anabar shield.

The present paper discusses the results of a systematic study of mica microcrystals of the phlogopite-kinoshitalite group found in the main body of the Yakut kimberlite province, by the example of mid-Palaeozoic pipes of the Khompu-May kimberlite field in Central Yakutia. Сhemical composition and zone distribution of minerals are reported, a comparison is provided with mica, peridotite mantle xenoliths from the kimberlite pipes of Africa, single kimberlite bodies of Canada, Africa, USA, China, and Yakutian kimberlite province, carbonatite massifs of Brazil, and melilitites of Russia. The following mica types were identified: phlogopite, barium-bearing phlogopite, barian phlogopite, and potassium kinoshitalite. All these types can be found within one grain, defining its zone distribution. The late-stage magmatic character of the mica under investigation was specified, with its composition being caused by barium-rich fluids. Investigation of zoning in flakes allowed us to describe the behavior of BaO in kimberlite formation of the pipes. Similarities and differences in the composition of mica from the Khompu-May kimberlite pipes and kimberlite bodies studied earlier, carbonatites, mantle xenoliths, and melilitites indicate that the mineral is specific for different magmatic systems with barium-rich fluids. Thus, mica composition can be used for comparative studies of kimberlites and other alkaline ultrabasic rocks.

This work is devoted to the study of the content, composition and character of the distribution of adamantane hydrocarbons. The objects of investigation were naphthides of different genetic types from the deposits in Western Yakutia: oils and condensates from the Vendian-Cambrian sediments, which were generated by planktonic algal organic matter of marine facies (I genotype), and the Mesozoic oils and condensates, which were generated by continental terragenous organic matter (II genotype). The individual hydrocarbon composition of the fractions was determined by chromatography-mass spectrometry on the Agilent 6890 set, which had an interface with the high-effective mass-selective detector Agilent 5973N. The characteristic distribution pattern of adamantane and its methyl derivatives was obtained by scanning for fragmentary m/z ions 135, 136, 149, 163, 177, 188. As a result of the conducted research, the presence of adamantane hydrocarbons of the composition from C₁₀H₁₆ to C₁₄H₂₄ was established for the studied samples of naphthides. It was shown that adamantane hydrocarbons within each genetic type were characterized by a similar composition and distribution. At the same time, certain differences were detected in the distribution of naphthides of different genesis. The naphthides of I genotype (generated by planktonic algal organic matter of marine facies) differed from the naphthides of II genotype (generated by terragenous organic matter of continental facies) by lower content of adamantine and its methyland dimethylpropionic derivatives, a high content of triand tetramethylguanidine, lower values of C₁₁/C₁₃ and C₁₂/C₁₃ ratios, and the values of ethyuladamantane index. The obtained data on the composition of adamantane hydrocarbons can be used as additional geochemical criteria for determination of the genesis of naphthides.

Due to global climate change, large industrial companies face the challenges of reducing greenhouse gas emissions and implementing climate projects that contribute to the absorption and disposal of carbon dioxide (CCS). The developments of the ALROSA Group in the implementation of tasks to achieve carbon neutrality, ESG projects, climate risk management mechanisms, and projects that reduce greenhouse gas emissions in 2016–2020 are considered in detail. The company's participation in the implementation of a large-scale project to create a highly productive ecosystem in the Arctic «Pleistocene Park», as well as the beginning of the development of a unique worldwide CCS project for the absorption of carbon dioxide from the atmospheric air by kimberlite ore during its extraction and processing, was considered.

Distribution of 15 warm season indicators, extensively studied in ecology over the North-East of Asia was studied based on the data from 97 weather stations (w/s) during the years from 1931 to 1960. The continental part of the North-East of Asia and the Okhotsk sea are indistinguishable by May temperature (–0,5…2,5°С) and the dates of snowloss (14.05–25.05). Variation of other 9 indicators in the same regions coincided to different extents. The ranges of temperature sums above 0 ° and 5 °С and the dates of temperature transition over 0 °С in spring coincided to a higher extent (by 70–75 %) than other parameters. The common parts of the named ranges are 1130–1330 °С, 1066–1290 °С, and 9–18.05, respectively. The mean July temperatures and the dates of temperature transition over 10 °С characterize the continental areas as warmer than coastal ones, while the number of days with temperatures higher than 0 °C and the duration of snowless periods characterize the continental areas as colder ones. Almost the entire mountainforest belt of the North-East of Asia, which is dominated by open larch forest and dwarf pine communities, may be considered as a uniform temperature hyperzone during the warm season. The landscape monotony is explained by the weak gradients of heat supply and by the outstanding ecological resistance of the dominants of vegetation cover.

The phytocenotic characteristic of the steppe communities with the participation of the springblooming species Alyssum lenense in the middle reaches of the Lena River valley is considered. The objects of the study were 11 communities, described at 4 locations at different distances from Yakutsk in 2019. Тhe species similarity of the communities (Sørensen coefficient K_s) was determined by the formula K_s = 2c / (a+b) · 100. The study area is characterized by a sharply continental climate, which manifests itself in low winter, high summer temperatures and high aridity (average annual rainfall is 192 mm). The Alyssum lenense species is a component of feather stipas, agropyrons, festucas, pulsatillas, artemisiacommutatas, artemisiafrigidas, developed on the southern slopes of the Lena River valley, as well as the grassy layer of the sparse dry pinus forests and their edges, common in the river valley. Communities with the Alyssum lenense participation are of low diversity and include 9 to 19 species. The species diversity of the studied communities is predominantly represented by species of the steppe complex; species with oriental genetic ties predominate. In the biomorph spectrum, rooted plants and turfy cereals, characteristic of dry habitats, are most steadily represented. In the communities with the participation of Alyssum lenense, species listed in the Red Book of the Republic of Sakha (Yakutia) grow – endangered species Gagea pauciflora, reducing the number of populations – Ephedra monosperma. Allium prostratum, A. ramosum, Krascheninnikovia lenensis, and the narrow-local endemic of middle reaches of the Lena River valley – Astragalus lenensis.

A prospective cohort study of the influence of a long navigation period on the metabolomic blood plasma profile of shift workers (river workers) in the Far North was carried out. On the basis of voluntary written informed consent, 53 water transport workers of the Republic of Sakha (Yakutia), who arrived from other regions of Russia and the CIS, took part in the study. The survey was carried out before (spring) and after (autumn) the voyage. The identification and determination of the concentrations of metabolites in blood plasma samples was carried out by means of gas chromatography with mass spectrometry (GC-MS). Analysis of blood plasma metabolomic profile data was performed using the MetaboAnalyst platform (V5.0). The results of studies of the metabolomic profile of blood plasma in river workers revealed significant differences in both the qualitative and quantitative composition of metabolites before the beginning of navigation (spring) and after its end (autumn). In autumn, after long-term navigation, the proportion of river workers with a breakdown in adaptation increases by a factor of 1.81, which indicates a significant decrease in adaptation reserves during navigation. The level of 5-hydroxyproline in the blood of this group of river workers increases. The increased content of ribonic acid in blood serum in spring is the evidence of the high adaptive potential of a person, the ability of the body to work out a long shift in the northern river fleet without depleting the adaptive reserve, that is, without prejudice to health. The results obtained make it possible to propose a metabolomic test, first of all, the content of ribonic acid in blood plasma, as a test for the selection of shift workers for work in the Arctic and Subarctic.

The composition of the winter diet of Martes zibellina sable was studied on the basis of its stomach contents (n = 390). . The content of bile acids, primarily glycocholic and cholic acids, was associted with the composition of the diet in wintertime for both local and acclimatized sables in different climatic zones of Yakutia. A high proportion of prey feed in comparison to plant feed resulted in the high total content of bile acids, and vice versa, in the bile of Martes zibellina. This pattern should be taken into consideration when organizing biotechnological processing of sable bile in order to obtain bioactive additives for cosmetic and medical purposes. Sex differences and climatic conditions of habitat did not have a significant impact on the content of cholesterol and bile acids in the bile of sables in the wintertime.

Since the end of the 19th century, it was believed that the genus Picea in the flora of the Magadan Region was represented only by the Siberian spruce (P. obovata), growing in its natural state at a limited territory in the Yama River basin and adjacent areas. As a result of introduction works, carried out in 1960-1970s, the composition of the spruce species of the region was supplemented by European (P. abies), Siberian (P. obovata from the western areas of the species range), and Ayan (P. ajanensis) spruces. At present, the Ayan spruce is represented in artificial plantings by a separate group of six trees in the village of Snezhnaya Dolina, located 20 km north of Magadan. All the trees are in good living condition. In 2019, strobiles were formed on the two tallest of them for the first time, which indicates the successful acclimatization of the species in the region. Researchers’ opinions on the prior existence of the Ayan spruce here were contradictory, because the only spruce tree that grew in the Magadan area and was cut down in December 1940, was considered by some people as Ayan spruce, and by others as Siberian one. The analysis of available literature sources and archive materials of the Magadan Local History Museum showed that even before the middle of the 20th century a single tree of the Ayan spruce grew in Magadan environs. Therefore, modern plantings of this species of spruce in the Magadan Region should be considered as reintroduction.

Currently, when developing new functional polymeric materials, especially for arctic purposes, it is not sufficient to provide an increase in strength, elasticity, wear resistance of these materials, but it is necessary to create polymeric materials taking into account operation requirements. One of the important requirements is the stability of properties during operation under climatic factors. This paper presents the results of comparative studies of the physical and mechanical properties of ultra-high molecular weight polyethylene and modified polymer composite materials (PCM) before and after exposition on the climatic field testing ground in Yakutsk. Studies of changes in the physical and mechanical parameters of the exposed samples were carried out after 1, 3, 6, 9, 12, 18, 24 months. Studies of changes in samples structure by IR spectroscopy were also carried out. It has been established that under the conditions of sharply continental climate of Yakutia, ultra-high molecular weight polyethylene and a composite containing 5 wt.% of Belum carbon fibers (CF) are subject to aging by the fourth month of exposure. In this regard, ultra-high molecular weight polyethylene was modified not only with carbon fibers, but also with a stabilizer of the СO-4 brand produced by the NIOCH SB RAS. This stabilizer prevents the propagation of destructive-oxidative processes in the composite material. It is found that PCM based on UHMWPE, containing 0.5 wt.% of a stabilizer, retains its deformation and strength properties at the level of an unexposed sample for 270 days. Thus, on the basis of the studies carried out, it has been established that additional modification of the UHMWPE-CF composite with a stabilizer of the CO-4 grade leads to a slowdown in the oxidative-destructive processes in the composite during exposure. Due to this, physical and mechanical indicators under the influence of unfavorable climatic factors remain unchanged for a long time. This fact allows us to predict high performance of developed materials under the conditions of sharply continental climate of Yakutia.