Home – Home – Jornals – Chemistry for Sustainable Development 2008 number 2

The Late Mesozoic and Cenozoic location of volcanic zones in the Central Asian intraplate volcanic province has been reconstructed. The anomalous-mantle regions related to magmatism in the province changed in shape in the Cretaceous and Cenozoic. In the early Early Cretaceous, the anomalous-mantle regions spanned from 42? to 61?N (about 2000 km in latitude), and their location might have remained unchanged throughout the Cretaceous. Magmatism in the province took place in the lithospheric regions of the Eurasian Plate with a thickness close to or smaller than that of the oceanic lithosphere. Late Mesozoic magmas originated mainly from hydrated mantle sources with isotopic compositions typical of PREMA or EM-II. In the Early Cenozoic (50 Ma) the anomalous mantle was considerably less active than in the Early Cretaceous. Magmatic melts were generated only in two mantle regions: the local South Hangay hotspot and, apparently, the fairly extensive (at least 800 km wide) mantle region north and northeast of it. The entire anomalous mantle spanned from 46? to 59?N (about 1300 km in latitude). Magmas of OIB type originated from slightly hydrated sources with isotopic compositions typical of PREMA or EM-I. In the Miocene, the mantle might have again "ejected" heated decompressed anomalous matter. The ejection led to an outburst of magmatism and expansion of the volcanic province up to 2000 km in latitude. The lithosphere in all the volcanic zones was thin, including the entire Eurasian territory over the South Hangay hotspot.

Current deformation in Pribaikalia, Western and Central Mongolia, and Tuva has been studied fr om measured horizontal GPS velocities and respective computed strain and rotation rates using 1994-2007 data of the Baikal-Mongolian GPS triangulation network.
The GPS velocity field shows two main trends: an NE trend within Jonggaria, the Mongolian Altay, and the Great Lakes Valley and an SE trend in the Hangayn and eastern Gobi Altay mountains, and in the Transbaikalian block of the Amur plate. The velocity magnitudes and vectors are consistent with an SE motion of the Amur plate at a rate of ~2 mm/year.
The derived strain pattern includes domains of crustal contraction and extension recognized fr om the magnitudes of relative strains. Shortening predominates in the Gobi and Mongolian Altay and in the Khamar-Daban Range, where it is at µ₂ = (19.2 ± 6.0)·10^-9 yr^-1 being directed northeastward. Extension domains exist in the Baikal rift and in the Busiyngol-West Hangayn area, wh ere the crust is stretching along NW axes at µ₁= (22.2 ± 3.1)·10^-9 yr^-1. The eastern Hangayn dome and the Gobi peneplain on its eastern border show low and unstable strain rates. In central and northern Mongolia (Orhon-Selenge basin), shortening and extension are at similar rates: µ₂ = (15.4 ± 5.4)·10^-9 yr^-1 and µ₁ = (18.1 ± 3.1)·10^-9 yr^-1. The strain pattern changes notably in the area of the Mogod earthquake of 1967.
Most of rotation throughout Central Asia is clockwise at a low rate of about © = 6·10^-9 deg·yr^-1. High rates of clockwise rotation are observed in the Hangayn domain (18.1 ± 5.2)·10^-9 deg·yr^-1, in the Gobi Altay (10.4 ± 7.5)·10^-9 deg·yr^-1, and in the Orhon-Selenge domain (11.9 ± 5.2)·10^-9 deg·yr^-1. Counterclockwise rotation is restricted to several domains. One is in western Tuva and northwestern Great Lakes Valley of Mongolia (© = 3.7·10^-9 deg·yr^-1). Two more counterclockwise rotation regions occur on both flanks of the Baikal rift: along the craton edge and in basins of Transbaikalia on the rift eastern border, wh ere rotation rates are as high as (13.0 ± 3.9)·10^-9 deg·yr^-1, while rotation within the Baikal basin does not exceed the measurement error. Another such domain extends from the eastern Hцvsgцl area to the Hangayn northern foothills, with the counterclockwise rotation at a highest rate of (16.3 ± 2.8)·10^-9 deg·yr^-1.

Structures of dynamic metamorphism have been traditionally studied proceeding from their similarity with faults, according to stratigraphic criteria and with reconstructions of predeformation settings. Using the example of the Kedrovyi-Butachikha shear zone in Rudny Altai, we suggest to distinguish zones with abundant dynamic metamorphic rocks (tectonites) as a special class of structures. Their diagnostic features are (i) dense fault populations, with mostly strike slip geometry of motion and intense mechanic failure and rework of the substrate; (ii) generally coordinated orientations (anisotropy) of structural elements at all hierarchic levels; and (iii) ordered patterns of laminar and turbulent flow. Complexes of tectonites in the Kedrovyi-Butachikha shear zone have been classified into dynamic clastics, tectonic schists, tectonic mixtites, and mechanic metasomatites according to their lithological and structural features. The new classification is used to image the architecture of the dynamic metamorphic zone in a map model which shows the pattern of tectonite complexes with their substrate unevenly reworked by shear-induced metamorphism.

The discussed spline approximation in spatial data modeling for geosciences implies formulation of the variational problem in terms of functional minimization and allows simultaneous inversion for several surfaces. This modeling employs the following basic elements: stabilizers to define the common properties of unknown surfaces; differential operators to describe the unknown surfaces and their relation with the known fields; data specified locally at test points; partial differential equations similar to equations of mathematical physics for the properties of the surfaces of interest; elements of regression analysis, with the regression coefficients being calculated while solving the principal modeling problem; arbitrary amounts of direct or indirect information which is incorporated additionally into the functional on the basis of approximate conditions using weight coefficients as control parameters.
The suggested generalized formulation includes the concepts of global and local equations and strict and nonstrict relationships. This formulation, realized in the GST software, may apply to many surface modeling problems to be solved using second-order partial differential equations, with multiple criteria optimization of results and with the use of different auxiliary datasets.

Much information on the regional lithospheric structure may come fr om MTS data acquired by synchronous 2D arrays and processed with regard to the nonlocal response of a laterally inhomogeneous subsurface. We suggest to invert the nonlocal MT responses applying correlation of all surface horizontal and vertical components of the geomagnetic field recorded simultaneously at all stations. The inversion algorithm has been applied to 2004-2005 European observatory data of diurnal S _q variations for first five harmonics and yielded lateral conductivity patterns for different periods. The maps show spatial correlation between conductivity maxima and lithospheric thickness minima and, specifically, highlight the contours of the Pannonian basin, wh ere lithosphere is as thin as ~50 km, from seismic data.

The oldest igneous rocks in the Paleoproterozoic (~1.88-1.85 Ga) North Baikal postcollisional volcanoplutonic belt of the Siberian craton are the basaltoids of the Malaya Kosa Formation (Akitkan Group). The youngest are the composite (dolerite-rhyolite) and doleritic dikes cutting the granitoids of the Irel' complex and the felsic volcanic rocks of the Khibelen Formation (Akitkan Group). The position of Malaya Kosa basaltoids in the Akitkan Group section and published geochronological data on the felsic volcanic rocks overlying Malaya Kosa rocks suggest that their age is ~1878 Ma. The rhyolites from the center of a composite dike were dated by the U-Pb zircon method at 1844±11 Ma, and the dolerites in the dikes are assumed to be coeval with them. Malaya Kosa basaltoids correspond to high-Mg tholeiites and calc-alkaline andesites, whereas the dolerites in the dikes correspond to high-Fe tholeiites. Geochemically, these basaltoids and dolerites are both similar and different. As compared with the dolerites, the basaltoids are poorer in TiO₂ (an average of 0.89 vs. 1.94 wt.%), Fe₂O₃* (9.54 vs. 14.71 wt.%), and P2O5 (0.25 vs. 0.41 wt.%). However, these rocks are both poor in Nb but rich in Th and LREE, ε _Nd (T) being negative. According to petrographic and geochemical data, they derived from compositionally different sources. It is assumed that the basaltoids originated from subduction-enriched lithospheric mantle, whereas the dolerites originated from refractory lithospheric mantle metasomatized by subduction fluids. The isotopic and geochemical features of mafic rocks in the North Baikal belt are well explained by their formation during crustal extension which followed subduction and collision in the region. The early stages of postcollisional extension evidenced the melting of subduction-enriched lithospheric mantle with the formation of parent melts for Malaya Kosa basaltoids. At the final stages of the formation of the North Baikal belt, during the maximum crustal extension, Fe-enriched melts rose to the surface and generated the dolerites of the dikes.

In the east of the Tuvinian trough within the Kropotkin Ridge, the formation of Devonian volcanic associations was intimately conjugate with rifting on the southwestern framing of the Siberian Platform. The associations include picrite-like basalts, trachybasalts, basaltic trachyandesites, trachyandesites, trachytes, trachyrhyodacites, trachyrhyolites, comendites, and subvolcanic dolerites. The basic and normal-basic rocks are subdivided into two groups by TiO₂ contents: high-Ti (TiO₂ ~ 2.2-4.2 wt.%) and medium-Ti (TiO₂ ~ 1.3-2.0 wt.%). Compared with the high-Ti basites, the medium-Ti ones are depleted in K, Rb, REE, Nb, Ta, Th, and U and have features of magmatic series of active continental margins. The high-Ti rocks are similar in composition to within-plate basalts. But in the isotopic compositions of Sr and Nd the above groups of basanites are similar and correspond to mantle sources forming enriched within-plate basalts of the OIB type. This combination of within-plate and continent-marginal geochemical features in the basites localized in the same structure-geologic conditions might indicate the formation of rock associations in the rift zone at the rear of active continental paleomargin during the evolution of their common plume source. Its interaction with the suprasubductional lithospheric mantle determined the geochemistry of rocks.

The distribution of gold in rocks from some igneous complexes of the central and southwestern areas of eastern Transbaikalia (Daurian, Aga, and Argun structure-formational zones) was studied by quantitative extraction-atomic-absorption analysis and mass spectrometry with inductively coupled plasma (Element-2 mass spectrometer). High gold concentrations (on average, 0.0043 ppm) are typical of the most widespread hornblende-biotite granodiorites and granites of the main phases of batholith intrusions in the Upper Paleozoic Unda complex in the east of the study area and in the Triassic-Middle Jurassic Kyra complex in the west. The rocks of the Early-Middle Jurassic (Sokhondo) and Middle-Upper Jurassic (Shakhtama, Kharalga, and Kukul'bei) complexes have much lower Au concentrations (mainly 0.0014-0.0030 ppm), with the minimum ones established in the Shakhtama complex. During the magmatic differentiation of granitoid intrusions, the concentrations of gold in the late leucogranite differentiates decreased.
The Au concentrations in the studied complexes do not depend on the composition of the host terrigenous rocks of different ages, which evidences the endogenous nature of the revealed differences in Au concentrations in the regional granitoids. Abnormally high concentrations of gold in some studied samples are observed mainly to the regional hydrothermal mineralization occurrences.
The classification R-type cluster analysis showed that all variables of the studied igneous rocks are subdivided into three groups by the degree of correlation. Gold shows a distinct tendency to the correlation with siderophile oxy- and sulfurophile groups of metals. The Q -type analysis generally confirmed the correctness of the known formational classification of the regional granitoids.

The paper discusses the important and urgent problem of enlarging the mineral resources of Russia. Volcanosedimentary complexes of greenstone belts are suggested as a new alternative source of apatite ores. The distinguishing features and minerageny of greenstone complexes in the Karelian, Aldan, and Anabar Shields have been considered. Apatite occurrences have been described in brief. The paper suggests the main lines of study and geological exploration of apatite-bearing metavolcanosedimentary complexes.

Examples of the geological and geomorphic framework of river valleys in the Tunka rift basin (Baikal rift system) and in the Irkutsk amphitheater (Siberian craton) have been used to show that horizontal and vertical motions of tectonic units in southern East Siberia are superposed with periodic movements. In the latter, the waves of slow uplift are attendant with erosional incision events, whereas during the subsidence cycles, the incised valleys become filled with mostly alluvial sediments. The latest erosional incision in the area occurred in the past 70 kyr.

We summarize the results of paleomagnetic and sedimentological studies of the Neoproterozoic rhythmic terrigenous-carbonate rock unit in the Karagas Supergroup, which were carried out in the middle reaches of the Biryusa and Uda Rivers. The paleomagnetic data are presented along with a detailed description of the studied sections and the specific sedmentological characteristics of the studied deposits. The new data refine the position of Late Precambrian paleomagnetic poles in Siberia and mark the paleogeographic and facies features of the rock unit formation. They also show that the rock unit was deposited much more rapidly than it was supposed earlier, in the environment of shallow-water sea basin on the margin of the Siberian continent. The origin and evolution of the Karagas sedimentary basin was governed by both global and regional tectonic factors. We associate the initiation of the basin with a global tectonic event, namely, the opening of ocean in southern Siberia during the break-up of Rodinia. Regional tectonic processes controlled the position of the Karagas sedimentary basin and its evolution. The position of the mean paleomagnetic pole (Plat = 3.9°, Plong = 292.3°, A₉₅ = 7.1°) confirms the corresponding interval of the Neoproterozoic trend of APW in Siberia and proves the near-equatorial position of the continent in Karagas time.

We investigate the upper mantle velocity structure through processing first arrival data fr om peaceful nuclear explosions. The reported 2D model has been obtained by ray tracing for a spherical Earth, unlike the classical plane-approximation approach with subsequent spherical symmetry corrections, which is not always applicable to a laterally heterogeneous subsurface. The upper mantle velocity highs and lows imaged to 200-220 km depths show obvious correlation with major structures of the craton basement. Namely, low-velocity zones are observed beneath basins, the largest (to 8.0-8.1 km/s) under the Vendian-Cambrian Sayan-Yenisei syneclise. A discontinuous high-velocity layer (8.6-8.7 km/s) at depths between 150 and 240 km is underlain by a zone of lower velocity (8.50-8.55 km/s) down to the 410 km discontinuity, wh ere the velocity at the top of the transition zone is 9.4-9.5 km/s.

The photosynthetic capacity of wood plants under urban conditions was evaluated on the basis of the level of reduced assimilates. Noticeable deceleration of the synthesis of carbohydrates was observed in Sorbus sibirica and Tilia cordata during vegetation, which correlated negatively with the overall technogenic load on the atmosphere in different districts of the city. It was concluded that this index of photosynthetic capacity may be used as an indicator of overall pollution of urban air, and Tilia cordata may be accepted as the indicator species.

Possibility to describe the regularities of the radial growth of wood plants and their properties using the deformation model is demonstrated. Examples of such a description for the subarctic and temperate zones in the perennial and annual climatic cycles are given.

A system of integrated multiрarametric descriрtion of landscapes of micro- and meso-hierarchic levels is developed. On the basis of field descriptions made according to this system in the Chuya steppe, a geographical database was compiled; it contains qualitative and quantitative characteristics of the land-based ecosystems of the Chuya steppe and their major components (relief, rocks, soil, vegetation). The technology for automated calculation of the ratio of abiotic to biotic components of micro-landscape on the basis of digital photographs of the reference grounds was tested. Using the triangular diagrams, the component composition of meso-landscapes was analyzed. The results may be used to decipher and interpret the data of remote probing sensing of the Earth, and also for mapping and modeling geosystems at the local and regionаl levels.

Data on the impact of ground fire events on forest ecosystems in the Eastern Pribaikalia are anаlyzed. The negative impact of ground fires on the growth and productivity of tree stands is demonstrated. The characteristics of lower vegetation layers are presented, variations of soil parameters under the impact of fire events of different intensity and remoteness are demonstrated.

Results of the investigation of the parameters of post-fire succession and seed-bearing capacity of modal tree stands, factors of ground environment (thickness of the unburnt layer of forest litter, projective cover of grass and mossy vegetation), as well as the number, vitality and age structure of self-sown Pinus sylvestris and accompanying small-leaved species in the Lower Selenga pinery of forest-steppe in the south-west of Transbaikalia are presented. The seed crops turned out to be 1,5-2 times more abundant in comparison with the geographically substituting forest types in the forest-steppe of West Siberia, while the vitality of pine undergrowth under the canopy of tree stands passed by fire was extremely low. It was demonstrated that pine reforestation is successful at fire sites in the zone of semination from the forest walls and in the fire sites with sparse growth of trees in bilberry-rhododendron pineries: 2-3 times more abundant than that in the forest-steppe of West Siberia, and insufficient at fire-sites in bearberry-lichen pineries.

The studies were conducted in different parts of the Baikal Region - Southern Prebaikalia, South-Western Transbaikalia, and Northern Prebaikalia. It was shown that the biogeographical conditions have a greater effect on alteration of the trends of chemical elements concentrations, while they exhibit smaller changes in different forest types in the same geographical region. However, the most significant factor causing misbalance of the majority of elements is the emission load. It is concluded that the investigation of the trends of elements contents in assimilating organs of trees serves as the most important link in the system anаlysis of the vital state of tree stands under natural conditions and under the action of abiotic factors.

Ecological conditions in solifluction areas that are widespread in the cryolitic zone of Central Evenkia are investigated. Essential changes of microhabitat in some solifluction "microecosystems" are recorded. They are sharply different from microhabitat in the reference stand. These new ecological conditions result in changes of plant species composition and its diversity. However, no essential differences among ecological groups with respect to hydrothermal and trophic conditions were revealed.

Reservoir construction on large rivers drastically changes the environment of flood-plain. Plant succession and rapid change of plant species start in the flooded zone. The results of investigation of succession processes in the plant cover arising in the area of flooded native ecosystems under the impact of the Sayan-Shushenskoye reservoir are presented.

The state of trees in five types of virgin spruce forest at the territory of the Pechoro-Ilych biospheric reserve was investigated. It was revealed that mature stands of bilberry and fern wood sorrel spruce forest types are characterized on the basis of the vital state of trees as the "healthy forest stand" with the damage index 0,03 to 0,50. The tree stand of polytric spruce forest with the damage index 0,7 relates to the category of "weakened tree stand". Reforestation process is expressed in all the types. The undergrowth accounting for 1,5 to 4,3 thousand sp. ha^-1 consists mainly of conifers and is healthy.

Seven groups of conjugated vascular plants were marked out in the vegetation of landscapes in the upper and middle stream of the Pechora river basin using the Brave conjugate coefficient and graph theory. It was also revealed using Ellenberg indicator values and Ipatov coefficient that the assemblies of the investigated species occupy different positions in the ecological space and are characterized by clearly exhibited coenotic role in quite definite plant communities. The pleiades  of conjugated species, the majority of which was interpreted as ecological-coenotic groups of species, may be used as the indicators of eco- and biotope conditions.

Effect of strong (75 %) and complete (100 %) artificial defoliation of Betula pendula Roth on the dynamics of soluble sugars and phenols - flavonols, catechins and tannins - in the leaves of damaged plants was investigated. Within the first 15 days after strong defoliation of birch, no changes in flavonol, catechin and tannin content were revealed in the leaves. The amount of sugars increased at first, but returned to the normal level on the 10th day after defoliation. One year after strong defoliation, the amount of catechins and tannins in the leaves of damaged trees increased, while the amount of flavonols and sugars did not exhibit any differences from the leaves of reference trees. Within two years after strong damage, increased tannin content is conserved in the leaves, while the level of catechins and sugars remains at the reference level. One year after complete (100 %) artificial defoliation, the amount of flavonols and sugars in the leaves of damaged plants did not differ from that in the reference plants, while the concentrations of catechins and tannins exceeded those in reference plants. Two years after complete damage, the leaves contained increased amount of tannins, while the level of catechins, flavоnols and sugars did not differ from the reference.

The species composition of the lichen flora of steppe communities was determined for the first time on the basis of own collections made in the State natural reserve "Khakasskiy". It consists of 134 species, 47 genera and 27 families. Biomorphological, ecological and geographical analyses were carried out.

Based on detailed analysis of the stratigraphy of a standard peaty profile laid on the large oligotrophic bog in the country between the rivers Kas and Sym, the left bank tributaries of the Yenisei river, the change of local vegetation and hydrological regime in the course of past seven thousand years was reconstructed.
Analysis of the stratigraphy of peat deposit revealed three stages of local changes of bog vegetation. Different degrees of bog moisture correspond to these stages. It was established that the regional climate had only a slight effect on the development of bog ecosystem.
The process of peat accumulation and its rate greatly varied during different periods of the Holocene. The average rate of peat accumulation in the profile was 0,88 mm/year.

A model of phylogenetic development of the vital forms of herbaceous plants is proposed on the basis of multiaspect studies of physiological and morphological indices of the complete species compositions of two herbaceous coenoses (meadow and steppe). It is stated and justified that the physiological mechanism of their development, as water supply of the environment changes, consists in optimization of water deficit and production capacities of the leaf, respective emergence of the most economical species-related sprout forms (non-rosette, semi-rosette and rosette) and finally in the establishment of a definite proportion between these forms within the composition of this or that herbaceous coenosis.

The seasonal dynаmics of water-soluble substances and water content in the meristematic tissues of vegetative buds of Picea obovata L. and Pinus sуlvestris L. are considered. Changes of the concentrations of cytoplasmic solutions of meristematic cells under their dehydration as a result of extracellular or extra-organ ice formation were determined. It was discovered that the concentration of water-soluble substances of the cytoplasm can increase by a factor of 2-2.5 with a decrease in temperature in the negative range down to -40 °С as a result of water crystallization. A connection between the cellular content of water able to get crystallized, unfreezing water and the concentration of water-soluble substances under temperature decrease from 0 to -40 °C was established.

Structural and functional features at the level of the leaf apparatus, sprout, entire organism of Syringa vulgaris under the conditions of Kemerovo city were revealed. The possibility to use these features in the diagnostics of atmospheric pollution was evaluated.
Maximal changes of the parameters under investigation for Syringa vulgaris were observed in Zavodsky, Kirovsky and Rudnichny districts that are characterized by the high degree of atmospheric air pollution.

It was established on the basis of the data of perennial observations that the annual growth of the layer of early tracheids of the trunk and the skeletal root of pine correlated with each other (r = 0,72-0,73). The size of annual rings of the organs under investigation were determined mainly by the width of the layer of early tracheids (r² = 83-92 %) and were dependent on their radial diameter by 50 % for trunk and by less than 20 % for the skeletal root. The width of the layer of early and late tracheids of the trunk and skeletal root was significantly correlating with warmth and water supply, while the radial diameter of early and later tracheids was determined mainly by the temperature conditions of the environment. The joint effect of temperature of air and soil, air humidity and precipitation on the structure of annual rings of trunk and skeletal root, excluding the width of the layer of late tracheids, was 34-58 %.

Sorption of Cu²⁺ and Zn²⁺ cations from model solutions by humic acids that were extracted from oxidized brown coals of Gusinoozyerskoye deposit has been investigated. An effect of pH value on the extraction of Cu²⁺ ions has been considered; sorption isotherms of Cu²⁺ and Zn²⁺ ions have been plotted. Maximum sorption exchange capacities of humic acids have been calculated on the basis of the Langmuir isotherm equation

Physical and chemical features of natural clays have been studied using the methods of X-ray diffraction, chemical, thermal and spectral analyses, ESR and IR spectroscopy; the nature of their medical properties being considered. The composition of macro and trace impurities in the clays has been analysed. The medical properties of the clays are determined by the presence of almost all the chemical elements necessary for normal functioning of a living organism as well as by sorption features due to a specific character of crystal structure. Using ESR technique, the forms of occurrence for some trace impurities (Mn²⁺, Fe³⁺) and for paramagnetic centers (PC) of the radiation nature have been determined. The intensity of PC response has been shown to correlate with the content of actinoid ions such as U and Th in the samples. Basing on the ESR spectral data it has been established that blue color of the clays is caused by V⁴⁺ impurity ions V⁴⁺ in the form of vanadyl VO²⁺. The content of the microelements such as vanadium, boron and chromium in blue kaoline глинах has been demonstrated to be 10-15 times higher as compared to clay samples of another coloring. An important role of complex influence of macro- and microelements (silicon-boron, vanadium-chromium, manganese, etc.) on the enzymes and hormones in various organs, as well as the presence of such combinations of chemical elements in blue clays have been noted.
Keywords: natural clays, physicochemical features, medical properties

Determination of the polycyclic aromatic hydrocarbons (PAH) accumulated in the needle of a Scotch pine (Pinus sylvestris L.) was for the first time carried out over the Baikal Natural Territory (BNT). It has been established, that in the industrial and urbanized territories of the BNT the level of PAH accumulation in needle amounts to as much as 1800 ng/g, whereas the background regions of BNT this value is less than 20-60 ng/g. The composition of PAH accumulated includes a priority series of organic pollutants from this class. The investigation of different age needle has demonstrated that the needle of the second year could be considered as an adequate bioindicator of atmospheric pollution. The levels of PAH accumulation in pine needle indicate a local character of atmospheric pollution over the southern part of BNT, as well as an insignificant contribution of regional transfer of the mentioned pollutants to the pollution of the Baikal lakeside comparable with the background level. The comparison of PAH content in the needle with the suppression degree of pine timber-stands allows one to assume these pollutants to exhibit a phytotoxic effect.

Processes of crystallization of calcium oxalate monohydrate from aqueous solutions and the effect of amino acids on these processes were investigated. It is shown that amino acids inhibit the growth of crystals of the compounds under investigation; the inhibiting action of an amino acid depends on its structure and increases with an increase in its concentration. The inhibiting effect on the crystallization of calcium oxalate monohydrate is also produced by magnesium ions in the concentration corresponding to the physiological solution (urine). It is demonstrated that the presence of hydroxyapatite crystals in solution initiates the crystallization of calcium oxalate monohydrate.

Iodine content within abiotic components and plants of Transbaikalian landscapes has been studied. A low iodine reserve of soil-forming rocks, natural waters, soils and plants has been revealed. A possibility has been studied for enriching plants with iodine by means of iodine micro-fertilizing.

The interaction of oxohydroxobismuth (III) nitrate trihydrate with the solutions of gallic acid was studied by means of X-ray phase analysis, thermogravimetry, IR spectroscopy and chemical analysis. The effect of temperature of pH of the medium on the rate of the exchange of nitrate ions for gallate ions was studied. The conditions of the formation of bismuth oxogallate trihydrate having the composition C₆H₂(OH)₃COOBiO · 3H₂O were investigated. The reasonability of the synthesis of high-purity bismuth oxogallate through the interaction of oxohydroxobismuth (III) nitrate trihydrate with the solution of gallic acid was demonstrated.

A combined method is proposed for the degradation of chlorophenols in a flow-through photoreactor using an UV XeBr* excilamp (283 nm) and the subsequent processing of the photolysis products by a destructor microorganism Bacillus cereus culture isolated from the aeration pond of the Baikal Pulp and Paper Mill. The maximum efficiency for the degradation of chlorophenols amounts to 95 %, thus the utilization of main photolysis products is achieved.
Keywords: chlorophenols, degradation, excilamp, photolysis products, microorganisms

Reactions of CH₃NH₂HCl with MBH₄ (M = Li, Na, K) proceeding during mechanical activation of the mixtures of crystal substances in a vacuum ball vibratory mill are investigated. It is established that the stage-by-stage pyrolysis of reaction products at 100 ^oC, then at 200 ^oC results in the formation of N-trimethylborazine (CH₃NBH)₃. Maximal yields of N-trimethylborazine with LiBH₄, NaBH₄ and KBH₄ are 60, 34 and 36 %, respectively. Melting points, saturated vapour pressure, density, refractive index of N-trimethylborazine are determined; the IR spectrum is reported.

Fatty acid composition of Siberian marmot fat (Marmota Sibirica, tarbagan) has been studied; the basic physicochemical parameters have been determined. 36 fatty acids have been identified, about 90 % among those being represented by palmitic, oleic, linoleic and linolenic acids. A comparative analysis of the compo-sition of tarbagan's hypodermic, abdominal and brown fat was carried out. It has been established that for the kinds of fat under investigation the composition of acids is variable, and the greatest differences in the concentration of saturated acids are inherent in brown fat. An unusually high fat unsaturation level for land species of animals observed for a Siberian marmot might cause the fat biological activity.

The effect of gas-phase ozonization on variation of chemical composition of solid combustible minerals of various genetic types and petrographic composition of brown coal maturity and products of their basic hydrolysis has been investigated. It was found that directions of oxonolytic transformations of organic matter as well as the yield and componental composition of products of alkaline extraction of coals are governed by features of their molecular organization. Reactivity of combustible minerals in relation to ozone increases with an increase in the H/C atomic ratio.

By means of mesomodeling method it has been established that the variations of рН, dissolved organic substances added and herbicide in polluted natural waters can significantly influence Cu, Pb and Cd distribution between aqueous phase and suspended substances. The changing of these parameters is reflected by the rate of withdrawing the mentioned heavy metals to bottom sediment. So, given lowered pH and concentration of dissolved organic substances as well as the presence of herbicide components in water the rates of Cu, Pb and Cd withdrawal to bottom sediment decreases. An assumption has been made that such a distribution depends on the state of heavy metals in the aqueous phase