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Vestnik of North-Eastern Federal University Series "Earth Sciences"

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No 3 (2023)
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GEOLOGY, PROSPECTING AND EXPLORATION OF SOLID MINERALS, MINERALOGY

5-14 377
Abstract

   Within Eastern Yakutia, certain prospects for oil and gas potential are associated with a number of negative structural elements of the Mesocainozoic age. Given the presence of a powerful sedimentary cover and a relatively calm tectonic situation, the Indigiro-Zyryansky trough is considered the most promising territory for oil and gas. According to the results of deep drilling conducted in the late 1980s and early 1990s, the presence of sufficiently powerful Cenozoic age strata was established. After joint processing of the drilling data with the seismic survey materials, the thickness of Cenozoic sediments in the trough is estimated at 2 – 2.5 km. The expediency of rethinking the materials of geochemical testing together with the data obtained during deep drilling is noted. According to the peculiarities of the composition of gases obtained during deep drilling and testing of wells in the section of the Indigiro-Zyryansky deflection, there are two types of natural gas. The first type is associated with Paleogene deposits and, judging by its composition, has a microbial genesis (wells No. 272-01 and 272-02). The second type of gas obtained from Upper Jurassic deposits appears to be catagenetic and heavier in composition (well No. 272-05). An analytical review of the results of direct geochemical testing is made, which also confirms the presence of at least two different types of gases. At the same time, the gas characterized as deep has clear features similar to the gases of collapsing oil accumulations. It is assumed that near-surface gases enriched with nitrogen and carbon dioxide may be associated with carbonaceous deposits of the Upper Jurassic and Lower Cretaceous. It is recommended to conduct areal geochemical testing using artificial sorbents for aromatic hydrocarbons.

15-23 312
Abstract

   The first results on the geological structure of the deep horizons of a diamond deposit – the Mir kimberlite pipe are presented. According to the results of exploration of deep horizons, new data on the geological structure of the deposit was obtained. The morphology of the pipe with depth has a definite tendency to increase the volume of the ore body in comparison with the results of previous explorations. The material composition of kimberlites and their productivity to a depth of more than 1,500 m vary slightly. In general, the results of the exploration allowed us to obtain a significant increase in the reserves of kimberlite ore and diamonds with a total volume of over 40 million carats.

24-28 281
Abstract

   Based on the materials previously carried out by various types of geochemical surveys (water-gas, hydrochemical, litho-gas-geochemical, snow, atmochemical, bituminological sampling), an analysis of the oil and gas potential prospects of the eastern part of the Siberian platform within the Sakha Republic (Yakutia) established a direct relationship between the anomalies and the proven oil and gas potential of the studied territories. The indicators of geochemical field anomalies are an order of magnitude higher within territories with proven oil and gas potential (Nepa-Botuobinskaya anteclise) than in the territories where they are absent, including oil and gas fields that have been discovered to date (Syugdzherskaya structural low). A striking example is the geochemical research carried out within the Chayanda oil and gas condensate field, where the confirmation of deposits by drilling, using geochemical data, increased by 30 %, which indicates the validity of the use of geochemical analysis methods in the search for oil and gas. Based on the analysis of the data presented, when predicting and searching for hydrocarbon accumulations, the most rational approach is to carry out mandatory advanced zoning of large territories according to the level of geochemical background.

29-34 240
Abstract

   Recently, there has been an urgent need to accelerate exploration for oil and gas in Eastern Siberia, including the Sakha Republic (Yakutia). The need is due to the reversal of the country’s energy industry in the eastern direction due to the illegal sanctions of a number of Western countries. For territories with complex transport logistics and difficult climatic conditions, one of the main factors of the success of geological exploration is the availability of sufficient time to fulfill the planned plans. Using the example of the regional law “On ethnological expertise in places of traditional residence and traditional economic activity of indigenous small-numbered peoples of the North of the Sakha Republic (Yakutia)”, the risks of non-fulfillment of license obligations by subsoil users are shown. Seismic exploration works are considered as the main tools for regional justification, areal prospecting and preparation of objects of exploratory drilling for oil and gas. It is noted that in areas with weak seismic exploration studies, the exploratory stage of geological exploration has the characteristics and scope of the regional stage of work. The main criterion for the regional understudy of promising oil and gas territories is proposed to accept a low density of seismic observations. For promising territories with seismic exploration studies with a profile density of less than 0.2 km/km2, it is proposed to make a relaxation in the form of exemption from passing an ethnological examination in places of traditional residence and traditional economic activity of indigenous small-numbered peoples of the North in the Sakha Republic (Yakutia) regardless of whether they are carried out on a state assignment or at the expense of the subsoil users’ own funds.

PHYSICAL GEOGRAPHY AND BIOGEOGRAPHY, SOIL GEOGRAPHY, AND LANDSCAPE GEOCHEMISTRY

35-41 205
Abstract

   The problem of variability of the Milankovich scale and cyclic oscillations in the troposphere circulation mode depending on the geographical latitude of the area is investigated. Parallels in the dynamics of multi-thousand-year and intra-century climate cycles in different latitudinal zones and possible causes of this phenomenon are considered. New data on the influence of axial rotation and the shape of the Earth on the structure of rhythm-forming processes are presented. It is established that the zone with a high frequency of pulsations of climatic phases is confined to low latitudes with the highest energy potential. The dependence of the velocity of air currents on the length of geographical parallels is shown. Thus, during the formation of air currents near the equator – the longest parallel of the planet (Hadley circulation cell), their velocity, which is set by the axial rotation of the Earth, is higher than the speed of sound and twice as high as similar flows originating in the temperate latitudes (Ferell cell). Paleogeographic evidence confirming Milankovich’s calculations about the different duration of the solar cycle period in the low, temperate and polar latitudes is presented. Thus, the dating of the terraces of the island of Barbados in the Caribbean Sea (low latitudes) showed that the period of the Milankovich cycle here is close to 20 thousand years. While in the zone of temperate latitudes, the period of the same cycle, judging by the dating of the stadial moraines of the former glacial covers, is 41 thousand years, i. e. twice as long. Maximum – up to 100 thousand years – set for polar latitudes in the study of the ice sheets of Antarctica and Greenland. Different degrees of meteorological impacts on ecosystems and the level of natural hazards within different latitudinal corridors have been revealed. The most dynamic and dangerous are the low latitudes with their hurricanes, typhoons, floods and storms with high frequency. This should be taken into account when developing a strategy for the economic development of high-risk territories and preventive measures for the protection of engineering orientation.

42-52 218
Abstract

   The peculiarities of modern climate warming and the influence of global atmospheric circulation on it are considered from the position of solar-terrestrial relations. The role of the main atmospheric currents between the equator and both poles of the Earth is so great that for four decades it has caused unprecedentedly strong forest fires and other natural disasters which affected not only Siberia and Southern Europe (Spain, Portugal, France, Italy, Greece and others) but also the USA, Canada and Australia. Another phenomenon of the modern climate is a paradoxically high winter warming in the zone of the Siberian anticyclone. Due to intensification of meridian  circulation since the last quarter of the 20th century, the increase in mean annual temperature at the cold pole of the Northern Hemisphere in Yakutia has twice exceeded indicators of other regions and dictates the course of warming of all Northern Asia and North America. The warming wave from the center of the Yakutian core has even reached the southern periphery of the anticyclone in the Northern Tien Shan. The practical side of the study concerns the actively developing oil and gas complex of Yakutia. In nearest future Yakutia will not leave the zone of dangerous forest fires. Along with the costs of extinguishing fires, additional expenses will be required here to deal with post-fire cryogenic transformations of the highly porous base soils. Atmospheric meridian circulation is too large-scale phenomenon to avoid it at the regional level. It amplifies the dynamics of all natural processes in both hemispheres of the Earth and is modulated only by the Sun’s activity in the course of its 11-year and hundred-year cycles.

53-64 347
Abstract

   The article deals with the issues of physical and geographical features of the territory of Mount Vottovaara (which is the highest point of the West Karelian Upland) and its geological history. It is compared with one of the most famous attractions in the UK – Stonehenge Jam. Hypotheses of the origin and formation of this area are presented. The mountain keeps a large number of secrets, the main and most interesting among which are up to 1,600 individual stones located on its top – components of an ancient cult complex. They can be fully considered seids, many of which resemble unusual stone buildings, and according to a number of researchers who played a cult role and belonged to the culture of the ancient Sami. One of the hypotheses of the origin of the Votovaara seids connects them with the manifestation of glacial exaration processes during the periods of ancient glaciations. Another explains the presence of numerous traces of paleoseismic dislocations by a strong catastrophic palaeo-earthquake that occurred at the end of the Preboreal – the beginning of the Boreal period due to the degradation of the Late Valdai (Ostashkovsky) glaciation and the тrapid removal of glacial load. There is also a hypothesis, partly related to the ancient mythology of a Worldwide Flood, or a catastrophic flood of universal scale. According to one version, it could have happened due to the fall of a large meteorite in the area of the Philippine Sea. The tangential impact of the meteorite led to a shift of the solid earth’s crust along the surface of the liquid mantle, and the shock wave passing through the earth’s crust (compression wave) formed a ridge on the territory of modern Karelia, which includes Vottovaara. Finally, there is a version of the formation of the massif as a result of a powerful volcanic eruption that occurred several million years ago.

ECONOMIC, SOCIAL, POLITICAL AND RECREATIONAL GEOGRAPHY

65-72 333
Abstract

   The 20th century urbanization development processes led to the transition from local urban forms to area formations or agglomerations. They became the prime engine of social and economic development. This is also true for Russia: throughout its history, cities have been the centres of its spatial organization. The transition to market economy has actualized the problems of agglomerations research in Russia: they are the basis for the formation of regional and national competitiveness. At this time, a number of agglomerations has been studied in bits and pieces or scarcely researched. One of such agglomerations is the city of Yakutsk, forming the largest agglomeration in the north-east of the country. The study of agglomeration development of Yakutsk is relevant for a number of reasons: as the center of the largest region, it is inextricably linked with it in its development, forming both opportunities and problems, and at the same time it is located in difficult natural and climatic conditions on the territory of perennially frozen rocks. This article is dedicated to history of the agglomeration formation, its specific and essential features. The theoretical and methodological background of the urban agglomeration formation and functioning as a specific spatial structure including the main factors of growth and development of agglomeration firstly were considered. The article noted that a range of issues about the Yakutsk agglomeration have not yet been studied despite their expressed relevance: the agglomeration structuring, allocation of different functional zones; processes of formation and development of the city structure; positive and negative sides of the urban agglomeration development; the issue of boundary delineation and selection of methods for this operation.



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ISSN 2587-8751 (Online)