Home – Home – Jornals – "Philosophy of Education" 2013 number 4

Paleogeographic reconstruction of the West Siberian basin during the Jurassic is based on a variety of criteria used to evaluate the depositional environments (paleontological, sedimentological, geochemical, etc.). Extensive geochemical data on the hydrocarbon biomarkers in bitumen from organic matter are first used to constrain the depositional setting of this large region over a span of about 45 Myr. The study provides a detailed description of paleogeographic maps compiled for the main epochs of the Jurassic period with the reconstruction of paleorelief and differentiation of potential external and internal sources of terrigenous material. The paleogeographic reconstructions of the basin are considered with implications for the formation of regional seals and reservoir units. A special emphasis is given to interpretation of organic matter type and depositional setting of the major oil and gas source rocks. The study infers a paleogeographic control on the stratigraphic and areal distribution of hydrocarbon accumulations in the basin.

The obtained new data on conodonts, brachiopods, ammonoids, and ostracodes from the Stolb Island section indicate the predominantly Early Famennian (triangularis–lower rhomboidea Zones) age of sedimentation. The Upper Kellwasser global biotic event, which marks the Frasnian–Famennian boundary, has been distinguished for Arctic Siberia for the first time. It was found that carbonate-terrigenous sequences accumulated in basinal sedimentary environments. Fine-clastic material was supplied to the sediments from different sources. A flow of dolomite debris is associated with the most distant source — areas of evaporite sedimentation. The presence of calcareous fragments is due to destruction of skeletal material (close provenance areas). Siliciclastics, which make up a considerable part of the sediments, were produced by partial rewashing and eolian differentiation of felsic pyroclastics. The existence of organic-rich horizons and beds of well-washed and well-sorted clastic sequences suggests that the Upper Devonian sediments have a high general petroleum potential.

Studies of the paleontology and stratigraphy of the Triassic strata from the Lena-Olenek interfluve area and Kotelny Island have important implications for improving the accuracy of interregional and global correlations, refining the Boreal standard and international stratigraphic scale for the Triassic System. The importance of this study is also underlined by the necessity of refining the stratigraphic basis for regional geological exploration in Artic zone that now became the focus for building the country’s strategic resource base. Analysis of recent paleontological and stratigraphic data from key Triassic sections in the Laptev Sea coastal region provides new age constraints for the Triassic strata based on different faunal groups. The Triassic stratigraphic scheme for the region has been refined using new data on the paleontology, thickness variations, and boundaries of local stratigraphic subdivisions.

Recent integrated studies of Mesozoic key sections of the Anabar area (northern Central Siberia, Laptev Sea coast) and the reinterpretation of previous data based on a modern stratigraphic model permit considerable improvement of the bioand lithostratigraphic division and facies zoning of the Jurassic and Cretaceous sediments in the region. Analysis of abundant paleontological data permitted the development or considerable improvement of zonal scales on ammonites, belemnites, bivalves, foraminifers, ostracodes, dinocysts, and terrestrial palynomorphs from several Jurassic and Cretaceous intervals. All zonal scales are calibrated against one another and against regional ammonite scale. The analysis of the lateral sistribution of fossils in different regions of the Northern hemisphere permits the recognition of reference levels for interregional correlation and the suggestion of parallel zonal scales within the Boreal Zone standard for the Jurassic and Cretaceous. A combination of these scales forms an integrated biostratigraphic basis for a detailed division of Boreal-type sediments regardless of the place of their formation and comparison with the international stratigraphic standard as far as the possible use of a set of correlation reference levels.

The particularities of the current tectonic structure of the Russian part of the Arctic region are discussed with the division into the Barents–Kara and Laptev–Chukchi continental margins. We demonstrate new geological data for the key structures of the Arctic, which are analyzed with regard for new geophysical data (gravitational and magnetic), including first seismic tomography models for the Arctic. Special attention is given to the New Siberian Islands block, which includes the De Long Islands, where field work took place in 2011. Based on the analysis of the tectonic structure of key units, of new geological and geophysical information and our paleomagnetic data for these units, we considered a series of paleogeodynamic reconstructions for the arctic structures from Late Precambrian to Late Paleozoic. This paper develops the ideas of L.P. Zonenshain and L.M. Natapov over the Precambrian Arctida paleocontinent. We consider its evolution during the Late Precambrian and the entire Paleozoic and conclude that the blocks that parted in the Late Precambrian (Svalbard, Kara, New Siberian, etc.) formed a Late Paleozoic subcontinent, Arctida II, which again “sutured” the continental masses of Laurentia, Siberia, and Baltica, this time, within Pangea.

Based on the analysis of various geophysical data, namely, free-air gravity anomalies, magnetic anomalies, upper mantle seismic tomography images, and topography/bathymetry maps, we single out the major structural elements in the Circum Arctic and present the reconstruction of their locations during the past 200 Myr. The configuration of the magnetic-field patterns allows revealing an isometric block, which covers the Alfa-Mendeleev Ridges and surrounding areas. This block of presumably continental origin is the remnant part of the Arctida Plate, which was the major tectonic element in the Arctic region in Mesozoic time. We believe that the subduction along the Anyui suture in the period from 200 to 120 Ma caused rotation of the Arctida Plate, which, in turn, led to the simultaneous closure of the South Anyui Ocean and opening of the Canadian Basin. The rotation of this plate is responsible for extension processes in West Siberia and the northward displacement of Novaya Zemlya relative to the Ural–Taimyr orogenic belt. The cratonic-type North American, Greenland, and European Plates were united before 130 Ma. At the later stages, first Greenland was detached from North America, which resulted in the Baffin Sea, and then Greenland was separated from the European Plate, which led to the opening of the northern segment of the Atlantic Ocean. The Cenozoic stage of opening of the Eurasian Basin and North Atlantic Ocean is unambiguously reconstructed based on linear magnetic anomalies. The counter-clockwise rotation of North America by an angle of ~15º with respect to Eurasia and the right lateral displacement to 200—250 km ensure an almost perfect fit of the contours of the deep-water basin in the North Atlantic and Arctic Oceans.

The patterns and history of Mesozoic-Cenozoic plume magmatism in the Arctic are considered in relation with suprasubductional volcanism and geodynamic events. The Mesozoic-Cenozoic magmatic history of the area includes seven stages, distinguished by correlation of ages and compositions of volcanics associated with mid-ocean rifting, plumes, and subduction; three of seven stages correspond to global events at 230-200 Ma, 130-120 Ma, and 40-30 Ma. The reported study supports the inferred inverse correlation between plate velocities and amount of subduction-related volcanism. The gained knowledge is used for paleotectonic reconstructions.

The Late Paleozoic and Mesozoic history of petroleum and coal basins in the Arctic and adjacent areas is investigated and compared with the history of plume magmatism in the same areas. The sedimentation rates in all discussed cases are proven to be the fastest (more than 100 m per 1 Myr) during rifting events. Other peaks of rapid deposition may be associated with collisional mountain growth and/or climate change.

Numerical models are developed to predict the generation, accumulation, and escape of hydrocarbons at the time of sediment accumulation (basin modeling) in the West Siberian geosyneclise during the Jurassic, Cretaceous, and Cenozoic. A theoretical framework for such computer models is presented with a special emphasis on modeling of gas generation during early catagenesis. The study provides a description of the algorithm used for interpretation of simulation results and considers the stages of formation of a shale cap rock during lithogenesis. Peak oil generation began in the Aptian and continued for about 80 Myr till Eocene–Miocene time; gas generation in the late catagenetic window took place from Valanginian to Maastrichtian. Numerical simulations show that the major oil-prone source rocks in the South Kara kitchen area were, in the decreasing order of potential, the Bazhenovo (Yanov Stan), Kiterbyut, and Malyshevka Formations. The Upper Jurassic regional rock unit generated over 60% of liquid hydrocarbons and heterocyclic compounds (oils). The major gas-prone source rocks in the area were, in the decreasing order of potential, the Kiterbyut, Malyshevka, Alym, and Bazhenovo (Yanov Stan) Formations. The Lower and Middle Jurassic regional rock units generated about 65% of hydrocarbon gases. Results are presented to quantify the amount of hydrocarbons dissipated due to either the absence or poor effectiveness of confining seals and to explore the role of Cenozoic tectonic processes in the formation of petroleum accumulations in the basin.

Chromato-mass-spectrometric studies made it possible to identify a wide spectrum of hydrocarbon biomarkers in crude oils from Cenomanian pools of northern West Siberia (Russkoe, Pangodinskoe, Van-Eganskoe, Severo-Komsomol’skoe). The distribution pattern of the main hydrocarbon components ( n -alkanes, acyclic isoprenanes, steranes, terpanes) shows that most of the oils underwent intense microbial oxidation. We have established high concentrations of 25-norhopanes typical of high-degree degradation; demethylated hopanes are also revealed in “alkane” crude oils. Among low-molecular chemofossils, biand tricyclic monoand sesquiterpanes have been recognized, whose precursors are usually biomolecules synthesized by plants. Unsaturated precursors of monoand sesquiterpanes might have been the starting material for thermocatalytical synthesis of framework adamantanoid structures, whose high concentrations have been found in alkane-free crude oils.

We present results of geochemical studies of organic matter of the Jurassic–Cretaceous deposits in the west of the Yenisei–Khatanga regional trough. The studies were carried out on a representative set of well cores by a complex of modern organic-geochemistry methods (determination of organic-carbon content in rocks, pyrolysis, estimation of the carbon isotope composition in the kerogen of rocks, extraction, liquid and gas–liquid chromatography, and chromato-mass spectrometry). Based on the distribution of biomarkers in the studied bitumens and pyrolysis of rocks, two groups of the samples were recognized: with terrigenous (type III) and marine (type II) organic matter. The terrigenous bitumens are characterized by a low hydrogen index (HI) and a predominance of hydrocarbons C29 among steranes and C19 and C20 among tricyclanes. The marine bitumens, revealed in stratigraphic analogs of the Bazhenovo Formation and in the Malyshevka, Nizhnyaya Kheta, and Shuratovka Formations, show an even distribution of sterane homologues and a predominance of medium-molecular tricyclanes. The Pr/Ph and C35/C34 ratios and the presence of diahopanes testify to the burial of organic matter in suboxidizing sea coast environments. In the Yanov Stan (J3–K1), Gol’chikha (J2–K1), and, to a lesser extent, Malyshevka (J2), Nizhnyaya Kheta, and Shuratovka (K1) Formations, we have recognized widespread stratigraphic levels with marine organic matter of rocks. Its contents and degree of maturity permit these rocks to be considered oil-generating.

Much work at A.A. Trofimuk Institute of Petroleum Geology and Geophysics (Novosibirsk) has been done to synthesize geological and geophysical data from the Siberian Arctic and Arctic shelf. Namely, seismic-geological modeling and petroleum potential assessment have been performed for the Neoproterozoic–Phanerozoic section of the Anabar–Lena province in the northern Sakha Republic (Yakutia). The results include seismic-geological division, a set of structural maps, and structural, paleotectonic, and facies analysis. The study shows that Riphean, Vendian, Cambrian, and Permian sequences are of interest in terms of petroleum potential; oil and gas may accumulate in traps of different types.

Formation of the passive continental margin of the Laptev Sea (Laptev Plate), which was part of the Siberian Platform till the Late Cretaceous, was related to the Late Mesozoic–Cenozoic rifting of the Arctic geodepression. The regime of the passive continental margin still continues. The maximum thickness of the deposits of this age seems to exceed 6 km in the northeastern part of the shelf. The hydrocarbon resources of the Late Precambrian–Cenozoic deposits forming the Laptev Plate cover are evaluated. Based on the concept of the similar evolution of the Laptev Plate and Vilyui syneclise, the geochemical characteristics of dispersed organic matter of the coeval deposits of the Vilyui syneclise are used.

Information about the effect of wetting regime on the composition of the flora of the Verkhoyansk Ridge (Yakutia) is presented. The regularities of changes in ecomorph structure in connection with latitudinal zoning and vertical belt sequence of the mountain system under consideration are analyzed.

Results of the investigation of postfire succession dynamics in light-coniferous – small-leaved forests in the Prienisey part of the Eastern Sayan on the landscape-ecological basis are presented. A generalizing scheme of the directions and rates of succession interchanges taking into account the pyrogenic factor was built and analyzed.

Data of the experimental investigation of postfire digression of the subtaiga – forest-steppe pine forests in the South-Western Pribaikalia are analyzed. It was established that the surface fire of forest floor – humus type are the major destructive factor in the dynamics of pine forests. The action of the surface fire is accompanied by tree dryout, while the vitality of the trees that survived in fire depends on the severity of fire damage. Characterization of the lower plant storeys and its dynamics under the effect of middle-intensity fire events are presented. A negative effect of surface fire on the changes of the stand, qualitative fractional composition of organogenic soil horizons and their chemical composition was demonstrated.

The phytocenotic role of separate Gmelin larch trees that survived on burns after fire was shown for the conditions of cryolitozone of Middle Siberia. Depending on the vital state of the trees, the boundaries of their effect on the recovery of species composition of the lower storeys of phytocenoses and the formation of a new generation of tree stand were determined.

Ecological structure of flora burnt depends on climatic conditions and geographic location. The secondary post-fire succession in lowland pine forests occurs rather rapidly, and after ten years the burns are at the stage of the formation of communities of patient plants. Pyrophyte plants become important in the formation of vegetation in burns. Formation of zonal vegetation types does not occur in ten years. A reduction of periods between fires leads to the fact that plant communities in flat pine forests are under constant influence of the pyrogenic factor.

Pyrogenic changes of microelement content in soil and plants of the pine forests of West Transbaikalia (Republic of Buryatia) were studied. It was established that surface fires under the studied conditions cause changes of soil properties, insignificant increase in the concentrations of Mn, Zn, Cu, Pb in the upper layers of soil (0–40 cm) and Mn, Zn, Pb in plants. It was revealed that the ratio Fe : Mn in soil gets narrower. Investigations show that the pyrogenic change of vegetation and soil properties, in particular elemental composition, is observed during several years after the fire.

The data on the variability of the structure of plant communities formed under the conditions of the steppe extrazonality of the Barguzin basin (North-Western Pribaikalye) are represented. Geobotanic and soil profiles for one of the most significant study areas were made. The structure of contact communities of the light-coniferous taiga and extrazonal steppe was revealed. The edaphic conditions and location of plant communities reflected the direction of vegetation cover developing in this part of Pribaikalia.

Soil samples from natural forests and adjacent farmland were analyzed to investigate the dynamics of soil organic matter of red soil in Southern, China. Based on the δ¹³C values and the content of soil organic matter, the data indicated that the turnover of soil organic matter under the virgin forest was slower than that under cultivation. Soil organic matter is fresh in coarse sand and oldest in fine silt and clay. Also, the soil light fraction contained the younger organic matter than soil heavy fraction and bulk soil. Deforestation has accelerated the decomposition rate of soil organic matter and reduced the proportion of active components in SOM and thus soil fertility.

Soil seed bank is an important component of ecosystem resilience and represents a stock of regeneration potential in many plant assemblages. Soil seed banks can be used to predict the composition of new plant recruitment. Species overcome periods of unfavorable weather conditions by building up a large seed bank. With this strategy, the species diversity is preserved and information on their dynamics and structure is retained. The research on soil seed bank has received wide interest because of its important role in plantation renovation and restoration, biological diversity preservation, vegetation succession and diffusion processes and other aspects. This paper reviews the relationship between soil seed bank and disturbance, geographic factor, vegetation and seed size and is aimed at providing some useful reference for future research.

The hygroscopic properties of forest floor in coniferous (Larix sibirica Ledeb., Pinus sylvestris L.) and deciduous (Populus tremula L., Betula fruticosa Pall.) plantations were studied using the isotherms of water vapor sorption and methods of thermal analysis (TG, DSC). Sub-horizons OL and OF in larch and pine plantations had the larger monolayer adsorption capacity. The forest floor in larch plantation was characterized by the highest hydrophilicity. Results of DSC indicated that hygroscopic water had higher binding with the substance of sub-horizon OL in coniferous and sub-horizon OH in deciduous plantations. The forest floor in coniferous plantations was characterized by higher store of hygroscopic water than in deciduous ones.

Investigation of the enzymatic activity of modern and lower gorizont of soils of the islands and the near-bench floodplain of the Lobanovskaya branch at the right bank of the Selenga delta is described. Ecological conditions determining its differences at the regions under study are conditions. Evaluation of the activity of enzymes in the soils of the right bank part of the delta in comparison with the regions of the left-bank part differing in the landscape ecological parameters is presented.

Results of laboratory modeling of the remediation of waste product containing oil products (652 g/kg) and natural radionuclides (²²⁶Ra, ²³²Th и ⁴⁰K) by means of landfarming, biostimulation and bioaugmentation are presented. It is established that landfarming and biostimulation provide a decrease in oil product content and in the phytotoxicity of the waste product; landfarming is a more rapid process.

Phytomonitoring of atmospheric pollution was performed using Scotch pine as a highly sensitive bioindicator. Pine needle samples were collected in reference sites along the 320 km Sayansk-Irkutsk-Listvyanka transect passing through the major industrial centers of Baikal region and stretching to the shores of Lake Baikal. The concentrations of inorganic pollutants such as sulfur, fluorides, heavy metals etc. in needles were determined. The highest level of atmospheric pollution was detected at the territories of the Angarskiy, Irkutskiy, Usolskiy, Shelekhovskiy industrial centers, lower pollution is observed within the Sayan and Cheremkhovo industrial centers. The data show that the majority of pollutants reach the Baikal shore.

The anatomic-morphological indicators of the needles of Picea obovata Ledeb. under the effect of emissions from the industrial zone of Kemerovo were investigated. Some changes of the negative nature were detected: a reduction of length, area and the surface of pine needles, the thickness of the inner lining and epidermis, an increase in the asymmetry of the central conducting beam, a reduction of the number of pitch channels. Some changes of the adaptive nature were also detected: an increase in the thickness of epidermis and endodermis, an increase in the area of pitch channels and the central cylinder. The significant correlation of the complex index of atmospheric pollution with the anatomic-morphological characteristics of pine needles was revealed. This confirms the fact of the substantive effect of emissions from the industrial zone of Kemerovo on the anatomical structure of pine needles of Picea obovata Ledeb.

Evaluation of urban soil for Kirov as example was carried out by means of chemical analysis and biotesting. Total content and the concentrations of mobile forms of heavy metals (Zn, Cu, Cd, Ni, Fe, Pb), pH of water and salt extracts, humus content were determined in different regions of the Kirov city. On the basis of the total index of tecnogenic pollution (Z_c), urban soil is characterized by the low level of pollution. Test objects of different trophic groups were used for biotesting: Daphnia magna Straus , Paramecium caudatum, Escherichia coli. Results of the comparative analysis of the sensitivity of different biotesting methods are presented.

The six litter types, such as heavily decomposed, middle decomposed, rhizome-like (coarse decomposed), turfy, peaty and turf, were determined on the gradient of large grass-dead soil cover-sphagnum in the bog birch forest. Specificity of their biochemical transformation depends on the amount of gumic acid accumulation, mainly of the first fraction (GA-1), at the background of relatively uniform rate of the formation of fulvic acids. The intensity of GA-1 formation is closely positively connected with the biological activity of substratum, judging from the C/N ratio. However, unclear distinctions between these indices of forestry-morphological litter types limit their diagnostic reliability. Grouped biochemical litter categories – mild (heavilyand middle decomposed), transitional (rhizome-like, turfy, peaty) and coarse (mossy) are significantly discriminated by the C/N ratio – 20, 30, 40, as well as by the content of GA-1 – 14, 10, 6 %, respectively.

Incidence and intensity of bark stripping of trees by ungulates was investigated at no bamboo (Fargesia nitida (Mitford) Keng f. ex Yi) (B–) site and understory bamboo dominant (B+) site of a subalpine Abies faxoniana forest, southwest China. The percentage of damaged trees in B– site was higher than in B+ site. Bark stripping obviously occurred more frequently on Abies faxonian а Rehder & E. H. Wilson compared to other tree species. Appearance of stripped bark and dead stems of the trees in different size-classes of A. faxoniana strongly depended on the density of dwarf bamboo at the site, and also on the size and bark structure of the trees, with highest damage rates occurring on the smaller DBH classes (10–40 cm) in B– site. The bark stripping intensity of A. faxonian а decreased significantly with higher density and coverage of F. nitida around damaged trees. Therefore, there is an indirect negative effect of the distribution of dwarf bamboo, F. nitida , on bark stripping of tree species. We suggest the indirect effects of dwarf bamboo species should be taken into account while considering the succession and regeneration of natural forests.

The article describes experimental destruction of kimberlite ore and impact crushers and bases the use of the combined impact crusher DKD-300 at one of the crushing stages within the dry concentration scheme at the Zarnitsa kimberlite pipe projectre.

The authors have designed a stand with a pendulum drop hammer to model the hammer head–impact tool–rock mass interaction. The rock mass is simulated with an adjustable gas–liquid dampener, metal plate and marble block. The comparison analysis includes measured impact pulses in the hammer head and the impact tool, and the influence of the hammer head velocity recovery factors on interaction of the hammer head and impact tool with the dampener and rock block.

The article describes the design of the unique monitoring system for technical state of transportation vehicles and production machines used in mining and construction. The introduction of the system will cut down expenditures due to sudden machine failure, and will increase efficiency and capacity of machines.

The article presents experimental research of the influence exerted by electrochemical polarization on electrode potential, phase composition of surface formations, adsorption of collector and floatability of basic sulfides of gold-bearing ore. It is shown that phase composition of surface formations under different polarization modes affects adsorption of collectors and floatability of minerals.

Based on the nonmechanical energy deposition tests aimed at intensification of destruction and processing of rebellious minerals, it is found that mineral treatment by accelerated electron flow enhances technological performance of mineral processes and is cost-effective: metal extraction grows by 27% and processing performance is enhanced 2.2 times.

In terms of galena, the authors specify construction principles for kinetic “ion” modeling of surface layer composition on grains of sulfide minerals of nonferrous heavy metals during flotation. The physical sense of the models consists in connection of parameters of ions within liquid phase of flotation slurry with relative fractions of mineral grain surface. Commercial tests proved the theoretical concept on formation of sorptive layer of sulfhydryl collectors on the surface of sulfide mineral grains under flotation conditions.

It is possible to forecast efficiency of mechanical activation of loparite concentrate to make it subsequent nitric-acid leaching fast using the X-ray crystal analysis data. It is found that the type of accumulated energy influences the energy of activation and reactivity of loparite. The authors suggest an expression to estimate extraction of rare earth elements in nitric-acid solution versus energy of structural changes caused in loparite by mechanical activation and leaching.

The article focuses on the current situation and problems of the mineral and raw materials base in Russian Federation.

In the article, there is analyzed one of the “innovations” within the framework of the educational reform: the actual elimination of teaching the educational discipline of “politology” in the Russian higher educational institutions, in spite of the extremely low political culture of the population. There is argued the discrepancy between the real governing in the country and the democratic constitutional principles, which may have extremely negative consequences in our information age.