Petrochemical characteristics of the series of silicate rocks, alkali utrabasic rocks and syenites with carbonatites of the Tomtor massif are given, and the change in their compositions is analyzed using experimentally studied triple diagrams of phase states. In the process of such analysis on different cross sections of “the extended basalt tetrahedron” Ne-Fo-SiO2-La, covering both quartznormative (tholeiitic), and nephelinenormative (alkali) basalts, possible trends of evolution of the Tomtor ore-magmatic system are interpreted. Existence of such polychromous complicated ore-magmatic ring complexes as Tomtor massif indicates occurrence of intraplate deep large magma-generating hearths in lithosphere mantle. Extraordinary complex precious–rare-metal ore content, wide variety of igneous rocks from ultrabasic to middle magmatites, enriched with volatile and ore components, are signs of non-depleting primary melts. Such easily fusible hearths, conserved in lithosphere mantle of residual melts of kimberlite, alkali-basaltoid, lamproite, carbonatite compositions, under the subsequent favorable geodynamic settings, are subject to rapid flotation, undergoing decompression melting and forming concentric-zonal platform complexes of alkali ultrabasic rocks with carbonatites. The Phanerozoic alkali-ultrabasic complexes of the rocks are predominantly confined to the periphery of the Siberian platform, and its related to location of their potential hearths during formation of large igneous provinces as a result of breakup of the Rodinia supercontinent with a divergence North-Asian (Siberian) and North-American (Laurentia) cratons, which began in the Neoproterozoic.

A new method of computer analysis of the symmetry of the real shape of diamond crystals of dodecahedral habit is tested. Produced the first objective data on the distorted form of crystals from mineral deposits of the Yakutian diamondiferous province: placer Kholomolokh, Anabar diamondiferous district, Pyropovy Ruchey placer Daldyno-Alakit diamondiferous district. The principal possibility of analyzing the symmetry of the real shape of rounded diamond dodecahedroids with the help of reliable instrumental measurements of crystals is shown. Compared with dodecahedrons kimberlite origin from the deposits of Pyropovy Ruchey, dodecahedron placer Kholomolokh (representing placers of the northeastern Siberian platform) have a significant degree of curvature of the convex faces of dodecahedron, which requires amendments to results of measurement of distances between parallel faces. The discrepancy of the measurement results between the curved faces of dodecahedral crystals of kimberlite origin is within the measurement error of the device and does not require correction. The crystals from the deposits of Pyropovy Ruchey were 7, and placer Kholomolokh 13 morphological types of distortion of the rhombic dodecahedron. Common morphological types of distorted rhombododecahedron are varieties №2 [0363], №5 [0444], №7 [0444], №8 [0462] with matching face sets. The external symmetry of crystals mostly corresponds to the lower categories of point symmetry groups. For the first time, the external pseudotrigonal symmetry of group 32 was observed in diamond dodecahedroids. This symmetry found in crystals from placers Kholomolokh.

Typomorphous features of placer gold in the basins of the Anabar and the Bolshaya Kuon- amka were investigated for the purpose of determining its indicator signs for the prediction of potential primary sources. It is shown that the main sources of gold are auriferous reservoir rocks of Neogene- Quaternary age. The indicator typomorphic features of this kind of gold are small size (–0,5 mm), scaly and platelet shape, coarse shagreen surface with the prints of mineral indentation, and high fineness (900– 999 ‰). The most informative feature is its strongly altered internal structure showing evidence of granula- tion and recrystallization. Autochthonous gold of ore habit is also found. Characteristic features of this type of gold are a very small size (–0,2 mm), angular-cloddy forms of individual particles, rough porous surface, widely ranging fineness (535 to 999 ‰), heterogeneous chemical composition, and a complex, multi-phase internal structure. This indicates the presence of neighboring primary sources. Hydrothermal-metasomatic formations with disseminated gold-sulfide mineralization, discovered at the sites of tectonic jointing of carbonate rocks developed in fault zones could be such sources. Considering epigenetic mineral associa- tions, quartz-potassium feldspar and quartz hydrothermal-metasomatic formations are identified. Ore min- eralization of disseminated type is represented (in decreasing order) by pyrite, gold, chalcopyrite, galena, sphalerite and silver. Gold is found in native form, and in association with pyrite (quartz metasomatites) and potassium feldspar (potash feldspar metasomatites). So, near-fault hydrothermal-metasomatic forma- tions with gold-sulfide impregnated mineralization were discovered for the first time at the territory under investigation. As a result of the studies, indicator typomorphous signs of the fine gold of proximal migration for these assumed indigenous sources were revealed.

The paper presents the results of thermochronological studies conducted in the front of the northern part of the Verkhoyansk fold-and-thrust belt and the Priverkhoyansk foredeep with the aim toestablish the age of paleo-uplifts and their possible relation to tectonic events. The results of fission track analysis of apatite grains extracted from 12 samples of Permian-Eocene sandstones point confidently to the occurrence of a thermotectonic event at 77–57 Ma (Campanian-Paleocene), which was accompanied by high denudation rates. It is supposed that this was the time of the final formative stage of the Kharaulakh anticlinorium front. Deposits of the Kengdey graben are dominated by apatite grains with track ages of about 73.6±3.5 Ma, which are close to this thermochronologic event. Accumulation of these strata was likely accompanied by the erosion of the uplifting foldbelt. It is assumed that some more thermotectonic events occurred in the area under study at 110–55, 95–90, 50–25, and 45–40 Ma.

The origin and tectonic pattern of terranes of the Verkhoyansk fold-and-thrust belt are still not clearly understood. The studies of the terranes are mostly based on a variety of assumptions which, in turn, give rise to new ones. This causes a number of questions, some of which are discussed in the present paper. One of the solutions to this problem is that the Verkhoyansk-Kolyma Mesozoides system (VKMS) was formed in the Middle Jurassic–Early Cretaceous as a result of a collision of the Siberian continent with the Earth’s crust blocks or minor oceans, marginal seas, back-arc basins, microcontinents, and island arcs, which were located within the pericratonal convergent zone or in the rear part of the convergent boundary framing the shore of the North Asian continent. A characteristic feature of the VKMS terranes is that they are collisional terranes forming orogenic systems with an isometric mosaic pattern, which differ from linear orogenic systems composed of accretionary terranes.

Авторами предложена оригинальная методика реконструкции палеоклиматических параметров на основе изучения особенностей современного пространственного распространения отдельных видов растений и их связи с климатическими градиентами. В ходе исследований были построены климатограммы по средним температурам января и июля, а также по среднегодовому количеству осадков, соответствующие современным ареалам анализируемых видов растений. Для реконструкции палеоклиматов задействованы виды растений, отсутствующие в современной флоре рассмотренных регионов. Для реконструкции климата позднего плейстоцена Якутии проводится построение климатограмм, при помощи пространственного анализа с использованием ГИС-пакета ArgGIS 10.1 (ESRI, Inc.) с подключением модуля Spatial Analyst. Пространственный анализ основывался на определении амплитуд климатических показателей для каждого вида путем экстракции данных из климатических растров шаблоном современных ареалов, полученных из анализа литературы и флористических баз данных. Получены данные, что среднегодовые температуры июля в каргинский термохрон на севере Якутии были почти на 8 °С выше современных. Значительно выше по сравнению с современными сумма годовых осадков.

The population of Redowskia sophiifolia was found and marked by us for the first time in the basin of the Sinyaya River in 2000. Redowskia sophiifolia is the local endemic of the Middle Lena, listed in the Red Books of the Republic of Sakha (Yakutia) [1] and the Russian Federation [2]. Later in 2012, a more thorough study of rock vegetation was carried out at the rock outlets of the Sinyaya River. During these field works, the habitat of this rare species was specified, its abundance and age structure were revealed, other ecological and biological parameters were studied, and habitats were described. The work was carried out during the flowering period of the species, since at this time the plant is clearly visible on inaccessible sheer cliffs. It was revealed that the largest number of generative individuals of Redowskia sophiifolia was re­ corded on rocks No. 20 and 19 in the vicinity of the Ulakhan Chagyn stream. On average, 50 to 100 flower­ ing plants per one rock massif were revealed. The population of Redowskia in the Sinyaya River is inde­ pendent, capable of self-maintenance by seeds, and occupies a stronger position than the population of the species on the Lena Pillars. Thus, it is assumed that the Sinyaya Pillars are the center of the area of Re­ dowskia sophiifolia.

This article reflects the results of scientific research on the recreational potential of Mount Kisilyakh of the Yansky Plateau. The material was information collected at key sites throughout the ElgetskKisilyakh hiking trail. The landscape, floristic and geobotanical diversity was studied, the degree of aesthetics of landscapes, the resistance of natural complexes to anthropogenic influences were assessed, permissible recreational loads were determined, the stages of digression (disturbance zones) were determined, protected plant species and plant communities were identified. As studies have shown, Mount Kisilyakh has unique conditions for organizing various types of ecotourism. The development of tourism activities and related infrastructure should occur here with priority consideration for environmental restrictions. For medium-moist lingonberry larch (Larix cajanderi – Vaccinium vitis-idaea) sparse wood plumes of the Kisilyakh Mountain, the current recreational load of an average of 500 people per season can be recognized as the maximum permissible. In all types of tours, organized tourist groups of a small size are recommended no more than 10 tourists and 2 accompanying. To ensure the preservation of natural landscapes, objects in a natural state and the development of tourism in the territory of Kisilyach, specific recommendations have been developed on organizing, improving, zoning the ecotropy, protecting and monitoring adjacent ecosystems.

The types of meadows, species composition, above­ground phytomass, and feeding character­ istics of wood bison in the natural pasture at the territory of the Tympynai Valley were studied on 14–20, 2012. The most productive meadows are the grass­reed­sedge­grass and the grass­bluegrass­sedge mead­ ows confined to more humid places of the Tympynai Valley (more than 47 c/ha). Forbs, grass and sedge meadows that are confined to the driest high areas have the lowest yield of 24.5 c/ha. The aboveground mass of plants in the studied meadows varies within the range 20­33 c/ha. According to the botanical com­ position, the herbs stand of these meadows consists of the following ratios: grass – 28.3 %, sedge – 52.3 %, legumes – 1.6 %, forbs – 2 %, rags – 15.8 %. In our opinion, the species composition of plants and produc­ tivity of the aboveground phytomass of the vegetation of theTympynai Valey is more than suitable for year­ round free or semi­free keeping of wood bison.

The issue of creating various land cover maps from satellite imagery is very important. The results of the synthesis of geobotanical and cartographic materials obtained in the south-west of Yakutia during the period from 2005 to the present time are presented. The vegetation cover of the area under investigation is formed under the conditions of better heat supply with a greater amount of precipitation and a decreased continental climate. The forests in the region are characterized by a high mosaic of vegetation types associated with various manifestations of the landscape. To correctly combine the types of forest vegetation identified as a result of field studies and compare them with the results of satellite imagery analysis, single criteria have been identified that reflect the common origin, composition and location of the new sections. For a better digital classification of forest areas, a ready-made digital terrain and the use of their derivatives were required: slope maps, exposure. The relief conditions have a decisive influence on the development of forest communities, determining their appearance and typological position. It was determined that neither a visual definition nor the use of specialized vegetative indices makes it possible to determine forest vegetation with high accuracy up to forest types. The maximum unit for deciphering forest vegetation from satellite images is the group of types and formations of forests, which makes the correct selection of generalized plant complexes on cartographic products relevant.

The effectiveness of the antiradical and antioxidant effects of extracts of Phlojodicarpus sibiricus Steph. ex Spreng., Rhodiola rosea L., Rhodiola borealis Boriss and Lemna minor were study. The antioxidant activity of root extracts was investigated depending on the concentration of the extractant (40 and 70 % water-ethanol mixtures). The anti-radical activity of all extracts against DPPH and ABTS+ radicals was 90–99 %, regardless of the organs used and the concentration of extractants. The most effective in the models of superoxide-radical scavenging were extracts of the roots of R. borealis, R. rosea, as well as extracts of the aerial organs of R. rosea and callus P. sibiricus. All studied extracts of P. sibiricus and R. rosea had a high level of inhibition of NO-radicals. The extracts of R. rosea of the Yakut population exceeded the commercial preparation of R. rosea and extracts of R. borealis by the scavenging of NO radicals. In models of induced LPO, a high efficiency of inhibiting free radical oxidation was observed in 40 % of root extracts of R. rosea (54–59 %) and R. borealis, P. sibiricus (34–36 %). By comparing the antiradical and antioxidant activity of the extracts, depending on the concentration of the extractant, the greatest efficiency of radical scavenging with 40 % water-ethanol extracts was established. The possibility of considering the extracts of the studied plants as promising means of reducing the free radical load caused by oxidative stress is shown. It was noted that the antioxidant activity of extracts from the roots and aerial parts of rosea, P. sibiricus and its callus was comparable with commercial preparations of the roots of R. rosea and ginseng, and also exceeded them in relation to the inhibition of certain types of free radicals.

In the paper information on additions and changes in the list of protected species of Lepidoptera for the 3d edition of the Red Data Book of the of Sakha (Yakutia) Republic are provided. Based on studies of lepidopterofauna over the past two decades it is recommended to include 36 rare species of Lepidoptera from 25 genus and 11 families in the new edition of the Red Book of Yakutia. From them 12 species for the first time are offered: Hepialus humuli (Linnaeus, 1758), Scardia boletella (Fabricius, 1794), Endromis versicolora (Linnaeus, 1758), Actias artemis (Bremer & Gray, 1852), Ahlbergia frivaldskyi (Lederer, 1853), Pseudophilothes jacuticus Korshunov & Viidalepp, 1980, Phengaris telejus (Bergsträsser, 1779), Neptis sappho (Pallas, 1771), Lasiommata petropolitana (Fabricius, 1787), Erebia ajanensis Ménétriés, 1857, Erebia neriene (Boeber, 1809), Oeneis urda (Eversmann, 1847). As threatened are classified 16 species, for which conservation measures are recommended. In the category I of the Red Data Book it was proposed to introduce 2 species (Pseudophilothes jacuticus Korshunov & Viidalepp, 1980, Oeneis ammosovi (Dubatolov et Korshunov, 1988)), in the category II – 3 species (Parnassius arcticus (Eisner, 1968), Parnassius apollo (Linnaeus, 1758), Erebia callias tsherskiensis (Dubatolov, 1992)) and in the category III – 11 species (Scardia boletella (Fabricius, 1794), Endromis versicolora (Linnaeus, 1758), Sphinx ligustri (Linnaeus, 1758), Actias artemis (Bremer & Grey, 1852), Arctia olschwangi (Dubatolov, 1990), Borearctia menetriesii (Eversmann, 1846), Holoarctia puengeleri sibirica Dubatolov, 2007, Pararctia subnebulosa tundrana (Tschistjakov, 1990), Colias nastes jacutica Kurentzov, 1970, Ahlbergia frivaldskyi (Lederer, 1853), Oeneis urda (Eversmann, 1847). Other 20 species are recommended to be included in the List of species needing special attention to the condition of their populations in the environment (Appendix). The status of these species also raises concerns, but additional research and monitoring are required to clarify the need for protection measures.

The thermal process during electrofusion welding of polyethylene pipes for gas pipelines by connecting couplings with embedded heater is theoretically investigated on the basis of mathematical modeling. The influence of ambient temperature on the dynamics of the temperature field in the electrofusion welding of polyethylene pipes is investigated. The mathematical model of the thermal welding process considers geometric dimensions, thermophysical properties of welded pipes and coupling material, ambient temperature, latent heat of polyethylene phase transition, voltage applied to embedded heater. Results of numerical calculation of thermal welding process at various ambient temperatures are presented. Methodology has been developed for determining the parameters of electrofusion welding of polyethylene pipes, ensuring the flow of thermal process at low ambient temperatures according to the laws inherent in welding at permissible temperatures. It is shown that in order to ensure acceptable dynamics of the temperature field at air temperatures below standard, it is necessary to preheat the coupling and sections of pipes before welding. Preheating is carried out by standard embedded heater. The use of thermal insulation layer is proposed in order to reduce cooling rate of the welded coupling. Recommended technological parameters of electrofusion welding are given for pipes PE 80 GAZ SDR 11 63×5.8 at air temperatures below standard.

The supramolecular structure of a welded joint of polypropylene pipes, made into a bell at positive and negative ambient temperatures, is investigated. The hypothesis put forward by the authors is confirmed that, regardless of the ambient temperature when welding polypropylene, the structure of the seam under the surface layer of the welded joint becomes spherical like that of the main polymer material. When welding polymeric materials at low ambient temperatures, the effect of conductive heat removal on the formation of the supramolecular structure of the heat-affected zone of the welded joint is especially pronounced due to the low coefficient of thermal conductivity. The structure of welded joints of polypropylene pipes was studied using a scanning electron microscope. It was shown that the nature and size of supermolecular formations in the structure of welded joints made in the open air at a temperature of –30 °C according to the welding technology developed and patented in the Institute of oil and gas problems SB RAS are identical with the structure obtained at positive ambient temperatures. It is shown that in the heat affected zone of the welded joint of polypropylene pipes, welded even at about 0 °C, regions with a destructured supermolecular structure found. The directions of further research are given.

The article substantiates the need for climate testing of polymeric materials, since environmental factors are crucial in predicting the service life, reliability and durability of products. It is shown that one of the most aggressive factors causing premature failure of products made of polymer materials is UV radiation, under the influence of which irreversible chemical changes begin to occur in the material. To prevent the occurrence of radical chain reactions, special functional additives are used, the so-called stabilizers. To conduct complex climate studies, composite materials based on polyethylene of grade 273-83 with the addition of stabilizing additives СО3, СО4 and Stafen were selected as objects of study. These stabilizers were developed at the Novosibirsk Institute of Organic Chemistry of the Siberian Branch of Russian Academy of Science. The composition of the composites was chosen based on the study of the mechanical properties of composites of various compositions. Comprehensive climate studies have shown that one of the most sensitive characteristics to the effects of natural climatic factors is elongation at break. Exposure of composites for 9–12 months leads to embrittlement of the studied materials and loss of their performance, which is structurally reflected in the transformation of the supramolecular structure with the formation of larger and more heterogeneous formations. It was found that stabilizers СО3 and СО4 are most effective for protecting unpainted polyethylene products from UV radiation. Utilizing of CO3 and CO4 stabilizers allows to extend the life of the material under continuous exposure to natural climatic factors of the region for 3 or more months. Increasing the concentration of stabilizing additives can provide an additional increase in reliability and durability.