Home – Home – Jornals – Contemporary Problems of Ecology 2008 number 2

Sedimentological and geochemical studies of a Triassic volcanosedimentary section of the Tura Group on the southern margin of the Koltogory-Urengoi Rift have shown a wide occurrence of fine- and very fine-clastic turbidites with admixtures of glauconite and basic and acid pyroclastic material. According to petrographic and geochemical data, the section sandstones are mainly graywackes and partly litharenites, and the mudstones are montmorillonite clayey rocks with admixtures of chlorite, hydromica, and kaolinite. The sourcelands of the peneplaned plateau abound in basic volcanics, which suggests (by analogy with the Triassic strata of the Siberian Platform) a wider occurrence of flood basalts in the past. Most of these basalts were, most likely, eroded, which resulted in a predominance of rift basalts on the pre-Jurassic weathering surface. Along with tephra and volcanoclastics, the clastic rocks are dominated by products of chemical weathering developed after basic volcanics. Marine deposits revealed in the Koltogory-Urengoi Rift section suggest the inflow of sea waters from the northern (in the modern frame of reference) ocean basin localized north of the modern Severnaya Zemlya Archipelago. The sedimentation basin of the rift was a narrow but extended bay of the Red Sea type, where the formation of marine deposits was accompanied by the eruption of basalts in the area of Nikol'skaya BH-1 lasting up to the late Middle Triassic.

nsoluble carbonaceous substance (ICS) at the Sukhoi Log gold deposit has been studied following the scheme: source shales - concentrates - residual substance of rocks. Examination by electron microscopy, transmission electron microscopy with electron microdiffraction, thermography, and mass spectrometry revealed several morphogenetic ICS varieties: dot-drop-like, honeycomb, single graphite crystals, and spherical graphite crystals.
Study of source shales and concentrates has shown their similar carbon isotope compositions (δ¹³C _av = 18.03-17.54 ‰). Residual carbonaceous substance is characterized by a heavy carbon isotope composition (δ¹³C _av = 10 ‰). Its enrichment with heavy carbon isotope, as compared with the source rocks, calls for special geochemical studies. The ICS heterogeneity in the Sukhoi Log shales points to variations in the physicochemical settings of ore formation at the deposit.

Cenozoic combustion metamorphic (CM) complexes produced by fossil natural coal fires are widespread at range-basin junctions worldwide. Large-scale fires accompany the initial orogenic phases as fresh coal-bearing strata become drawn into the aeration zone as a result of crustal deformation. In combustion metamorphism, the protolith melts to different degrees either into ferrous basic paralava or in glassy clinker. The melt rocks have a phase composition favorable for ⁴⁰Ar/³⁹Ar dating of ignition coeval with the onset of each episode in Late Cenozoic orogenic events. We suggest an algorithm providing correct ⁴⁰Ar/³⁹Ar age determination of CM rocks followed by well-grounded geological interpretation and test the new approach on melt rocks from the Kuznetsk Coal Basin.
Paralava samples were dated by ⁴⁰Ar/³⁹Ar incremental heating and the isotope ratios were corrected for Ca-, Cl-, and K-derived Ar isotopic interferences. The interpretation of age-spectrum results was checked against internal and external criteria. The former were plateau and isochrone ages and the latter included the so-called

Distribution of hydrogen and carbon isotopes (D/H and ¹³C/¹²C) in the microbial systems CH₄-H₂O and CH₄-CO₂ was studied in different world's regions. According to the distribution of these isotopes in the above systems, two types of microbial methane are recognized in the Earth's crust: (1) resulting from CO₂ reduction and (2) produced through acetate fermentation. In the case of methane 1, the biologic distribution of hydrogen and carbon isotopes in the above systems corresponds to the thermodynamic isotope exchange equilibrium at a given temperature of the methane genesis medium. In the case of methane 2, the same systems show mainly a nonequilibrium distribution of these isotopes. We have revealed a linear relationship between the isotopic compositions of CH₄, H₂O, and CO₂: δD - CH₄ = α _D ^b δD - H₂ O + b and δ¹³ C - CH₄ = α _C ^b δ¹³ C - CO₂ + d, where α _D ^b

In 1996 the Volgian Stage was divided into the Jurassic and Cretaceous units, removed from the Geological Time Scale, and substituted by the Tithonian Stage according to the guidelines of the Interdepartmental Stratigraphic Committee of the Russian Federation (ISC RF). Consequently, the Upper Volgian Substage including three zones (five subzones) was placed into the Berriasian Stage (the Cretaceous) proceeding from ammonite fauna, and the Cretaceous lower boundary was defined by the base of the Kachpurites fulgens Zone. Some stratigraphers, however, contested that decision and suggested to restore the former status of the Volgian Stage. Their idea has been validated by magnetostratigraphic studies carried out in 2003 in Jurassic-Cretaceous boundary strata in the Nordvik Peninsula (the Laptev Sea), which bear the most complete record of Boreal deposition and biostratigraphy. The new data prove that the Volgian Stage, in its nearly full stratigraphic volume, rather belongs to the Jurassic period.

We report new radiocarbon ages, pollen stratigraphy, and botanical composition of an organic sediment sequence from mountains along the northwestern side of Lake Baikal. The calendar age of the peat is ca. 9.5 kyr BP. The pollen spectra between 9.5 and 8.5 kyr ago show vegetation consisting mostly of open larch and spruce-larch forests with minor birch. The interval from 7.5 to 6.8 kyr BP is marked by broad fir spread confirmed also by the peat botanical composition. The climate inferred for the period of fir dominance combines mild winters, cool summers, thick snow cover, and abundant moisture, apparently due to more intense North Atlantic air transport. Fir percentages decrease dramatically after 6.8 kyr BP, when pines begin to spread in the Baikal watershed. The peat record bears imprint of North Atlantic cooling events identified as intervals of ice-rafted detritus deposition and low surface water temperatures. The new data allow a better insight into the regional climate and landscapes, and the reliable age model provides regional and inter-regional correlations of global change events.

The problem of an elastic stress field in a rotating medium is formulated and solved analytically within the limits of the classical theory of elasticity with a symmetrical stress tensor. This is a rotation elastic field of action at a distance. There are two specific types of elastic waves with a moment in rotating media: solitons and excitons, or rotation waves. The soliton solutions to the wave equation represent waves of global earthquake migration (slow tectonic waves) which are no faster than ~1 cm/s, i.e., approach the migration velocity of large and great earthquakes (M > 7.5). The exciton solutions correspond to waves of local migration of foreshocks and aftershocks in earthquake sources (fast tectonic waves) and have their maximum velocity comparable to faulting rate and/or to S-wave velocities.

We have designed a frequency-domain electromagnetic induction sensor for imaging the distribution of electrical conductivity of soils in civil engineering applications. The device implements the ultimate technical feasibility of measuring harmonic signals on the ground surface. Digital recording and narrow bandpass filtering of synchronous detection allows a sufficient measurement accuracy for ~1 μV signals and suppression of power-line noise of more than 100 dB. We suggest practical methods for investigating the characteristics of the sensor and estimating its measurement accuracy.

An algorithm for digital filtering based on the Capon approach for frequency-shift keyed signal demodulation is proposed. The filter coefficients correspond to an information-optimal solution to the problem of minimizing the output linear filter dispersion. It is shown that the method is efficient in the conditions of additive noises and inexact knowledge of the central signal frequency spectrum. The algorithm can be implemented on a programmable logic in real time.

The nonparametric pattern recognition algorithms are investigated under incomplete data in the training sample. Requirements on the incomplete data filling methods are formulated by analyzing conditions of their asymptotic convergence.

A method for determining an object orientation by a set of positions of its points located on faces of a 3D model or on surfaces is considered. An orthogonal position line algorithm is designed for measuring orientation angles and normalizing an object for subsequent control actions. Determining the orientation of a 3D object represented by a set of points on a cone surface is illustrated.

A rotation, translation, and scaling invariant Fourier transform of a 3D image function is proposed. The transform is based on expanding into a series of spherical functions.

The developed method for computer designing physically accurate pictures of irregular objects having optically coupled surfaces with diffuse, mirror, and diffusely-mirror reflections is based on solving generalized equations of theoretical photometry. The method is approved by results of mathematical simulation. Applicability of the method for designing pictures of a wider class of objects with diffusely-guided surface reflection is shown.

A noninvasive method for investigating the deformity of dentofacial bone tissues is proposed. The method is based on speckle field correlation analysis. The optimal conditions for the method are found. It is shown that the threshold sensitivity of the method may reach 10 m m.

A system of transformations of the initial process with nonstationary season variations is considered. The process is described by an autoregressive multiplicative model and an integrated moving average for further forecasting. The transformations are completed by reducing the initial process to a stationary form to realize model identification and forecast the process.

Implementation of an automatic process control system for the Severomuiskii tunnel is presented. Its subsystems are considered, which can be used for design of other similar control systems.

Changes in the indicative characteristics demonstrating the accumulation of heavy metals in tundra shrubs under the conditions of aerotechnogenic pollution of the Yamal Peninsula were investigated. Calculations depicting the theoretical solubility of complex-forming metals depending on pH of the medium in the system containing

Trends of changes of forests and phytomass resources over the territory of Georgia since the early stage of the existence of human society are considered. The landscape approach is used in the investigation. Map an

Features of the distribution of the life forms of indigenous flora fraction (1888 species) over the botanical-geographic regions of the District are considered. This allows one to characterize the ecological-coenotic and adaptation features of the plant cover of these regions.

A number of distributions describing a small sample is analyzed. Estimation of the horizontal structure of coenoses is made on the basis of small coenotic formations. i.e. biogroups at a level of a growing individual. The characteristics of biogroups are the number of

Photosynthesis and respiratory rates are the standard indicators for plant state assessment. The photosynthetic activity is often measured by metering CO2 decrease. The INNO-Concept GmbH Company (Germany) has produced

Features of plant cover formation over the territories disturbed by coal mining in different n

The content and distribution of Mn in soil-forming rocks, natural waters, soils, and plants of steppe, meadow and agricultural cenoses of Transbaikalia region are examined. The content of Mn in soil-forming rocks, soils and natural waters is 1,3

The paper presents an outline and analysis of the structure of the adventive flora of the North-Eastern Prisayan

Results of passage route assessments of birds over the territory of the Sary-Chelek biospheric reserve during the years 1982

Data on the action of animals on the vegetation cover of the Commander Islands are reported. Vegetation at the regions of arctic fox dens and seabird colonies is characterized; this vegetation is formed as a result of the transformation of the initial one. Often similar plant groups are formed. The features of the zoogenic vegetation of different origin at the Commander Islands are discussed; its comparison with the zoogenic vegetation in other regions of the Arctic and Subarctic are discussed.

The possibility to use self-propagating high-temperature synthesis (SHS) for obtaining stable icosahedral quasi-crystals in the system 65 at. % Al + 20 at. % Cu + 15 at. % Fe was established as a result of X-ray and electron microscopy investigations, both for a mixture of the initial metal powder mixture and after their mechanical activation for a short time. Icosahedral quasi-crystals formed during SHS are shaped as pentagonal dodecahedrons 2

Results of the extraction of humic acids (HA) from the oxidized brown coal of the Gusinoye Ozero deposit with the help of the solutions of sodium, potassium and ammonium hydroxides are presented.
A comparison of the yields of HA for different ratios of an alkaline solution to coal and duration of ultrasonic treatment (sonication) of alkaline humate-containing extracts or without ultrasonic treatment (settling) is carried out. The amounts of acidic functional groups (phenol and carboxyl) in HA and in the initial oxidized coal are determined.

A comparative investigation of the nature of substances adsorbed on the surface of continental atmospheric aerosol particles sampled in the industrial and background regions of the Novosibirsk District and Yamal-Nenets Region, as well as the marine atmospheric aerosol sampled in the region of the White Sea is carried out by means of secondary ion mass spectrometry.

Using WATEQ4F computer code, chemical speciations of coexistence of heavy metals in superficial waters of the Novosibirsk reservoir have been calculated. Although the code allows one to calculate only complexes of metals with inorganic ligands, conclusions of a general character have been drawn on the bioavailability and potential ecological danger of particular chemical speciations of metals in a specific water body. Based on the large evidence of long-term monitoring studies, enrichment of living matter, particularly the plankton, by certain metals has been revealed, the metals being available in the water of the Novosibirsk reservoir in the most mobile and consequently the most available forms, namely, free non-complex ions and hydroxo and carbonate complexes. Peculiar features of microelemental composition of the plankton of the Novosibirsk reservoir as compared to that of the bottom silt are its enrichment by P, Br, Cd, Ca, Zn, Cu, and by Pb to a lesser degree. By and large, the revealed low values of enrichment factors (10

Solid solutions on the basis of strontium cerate that was doped with yttrium or gadolinium (SrCe0.95Y0.05O3 

Petroleum samples from two holes of the Verkhne-Salatskoye deposit (the holes Nos. 118 and 122) have been studied. It has been found that they differ essentially both in their content of pitchy and aromatic components and in the composition of paraffin-naphthene hydrocarbons, which defines the features of their deposit formation. Accordingly, the process of sludge formation for a petroleum sample from the hole No. 122 that is characterized by a higher than usual content of pitchy components starts at a temperature of 50 oC. The process of deposit formation for a petroleum sample from the hole No. 118 occurs at 70 oC.
A decrease in the temperature of a petroleum flow leads to the predominantly dendritic type crystallization of paraffin hydrocarbons and to an increase in the structural amorphism of the petroleum deposit.

Sorption of selenium (IV) ions from the solutions of sodium selenite on natural zeolite-containing tuff from the Kholinskoye deposit (Transbaikalia) and on the tuff form modified with protein hydrolysate is investigated. Optimal conditions for tuff modification with protein hydrolysate are chosen. The zone of the safe action of selenium-containing tuff is determined using the test culture Tetrachimena pyriformis.

Methods of UV and IR spectroscopy,

A potentiality has been disclosed to obtain new types of natural/synthetic polymers with the use of the radical grafting method on the basis of humic acids (HA) that have been extracted from wastage of coal mining. Conditions for obtaining graft copolymers of HA with vinyl monomers are described. An assumption has been made about the inhibiting effect of radical centres in aromatic system of HA on processes of the inoculation of vinyl monomers to them. It has been demonstrated that modification of HA and coal matter by polymers makes it possible to enrich their functional composition with new oxygen-containing functional groups. It has been found that cation-exchange capacity of the received coal and humic copolymers increases with an increased number of acid groups in their composition and with the ionisation degree in a series from coal to its copolymers and from HA to their modified forms. The sorption exchange capacity of the new derivates that has been investigated in relation to ions of sodium, copper, and nickel is 1.1

The data on the synthesis routes and the possibilities to modify the structure of linear alkaloids of natural origin

Reaction of catalytic hydrogenation of natural compounds (limonene, a-pinene, b-pinene, camphene, 3-carene) on

The interaction of oxohydroxo bismuth (III) nitrate trihydrate with ammonium bromide solutions is investigated by means of X-ray phase analysis, thermogravimetry, electron microscopy, IR spectroscopy and chemical analysis. The reasonableness of obtaining high-purity bismuth (III) oxobromide of the composition BiOBr from metal bismuth after its preliminary oxidation with the oxygen of the air is demonstrated. Thus formed bismuth oxide is dissolved in nitric acid (1 : 1); bismuth is purified from the accompanying metals by means of its precipitation in the form of oxohydroxo bismuth (III) nitrate trihydrate and treatment of the resulting precipitate with NH4Br or HBr solutions at a temperature of (60

The bibliometric analysis of the scientific publications of Academician V. A. Koptyug during the years 1953

The largest over several recent years All-Russian Conference with international participation