Home – Home – Jornals – Avtometriya 2006 number 5

In southern Israel and on the Sinai Peninsula, ultrapotassic quartz porphyries (UPQP) with 6.5-10 wt.% K₂O and 0.1-2.5 wt.% Na₂O were found in a bimodal dike suite that formed at the final stage of the Pan-African orogeny. The suite is made up mainly of quartz porphyry (4-5.5 wt.% K₂O); mafic rocks amount to ~5%. The UPQP form rare dikes or patches in quartz porphyry dikes. These are typical igneous rocks with microgranophyric and spherulitic matrices. There is no mineralogical evidence for the gain of K at the postmagmatic stage. Evidence for low-temperature adularization found in some ultrapotassic rhyolites from other world areas has not been revealed either. Alkali-feldspar phenocrysts in the UPQP and quartz porphyries have high contents of orthoclase (≥ 85-90%). Study of melt inclusions in quartz phenocrysts in both the UPQP and ordinary quartz porphyries showed that the phenocrysts crystallized from magmas of quartz porphyry composition that contained 2-3 wt.% H₂O, up to ~1% F, and 0.1-0.15% Cl. Scanning electron microscope studies showed that many alkali quartz porphyry dikes have a heterogeneous matrix. Rounded and oval segregations (0.3-15 mm across) with microgranophyric and spherulitic textures amount to ~50%. They are enriched in K₂O and are compositionally similar to typical UPQP. In the microcrystalline aggregates hosting these segregations Na dominates over K.
To account for the UPQP generation, a model is proposed for the disequilibrium crystallization of silicic magma during its flow along fractures in cooled country rocks. The magma was of alkali rhyolite composition and contained 5-7% phenocrysts. At the early stages of the matrix crystallization, spherulitic and microgranophyric segregations formed. They were enriched in K, which is typical of a haplogranite system at the beginning of crystallization. Since the system remained closed for major components, the portion of Na in the residual melt increased. The disequilibrium crystallization conditions inhibited a chemical interaction between early and late phases. During the

High-potassium rocks have been found among ultrabasites of the Il'chir ophiolite nappe. Stock- and sill-like bodies are composed of greenish-gray to dark-gray holocrystalline (sometimes, porphyritic) rocks. Three rock varieties are recognized: albitized monzonitoids (wt.%): SiO₂ - 53.2-53.8; Al₂O₃ - 14.6-14.9; MgO - 3.3-8.3; Na₂O - 5.0-5.9; and K₂O - 0.05-0.1; syenites (orthoclasites) (wt.%): SiO₂ - 63.0-66.1; Al₂O₃ - 17.2-18.6; Na₂O - 0.2-3.1; and K₂O - 8.2-16.7; granosyenites (wt.%): SiO₂ - 71.5-77.3; Al₂O₃ - 11.5-13.5; Na₂O - 0.1-1.72, and K₂O - 9.2-10.7. The K-richest varieties are composed of allotriomorphic grains of perthites, K-antiperthites, and, sometimes, plagioclase. Biotite, amphibole, and chlorite occur in small amounts (1-5 vol.%). The rocks are strongly altered to blastocataclasites with a feldspathic groundmass. Along with intense shearing and pseudoporphyritic texture (porphyroclasts), a distinctive feature of K-feldspar and plagioclase preserved as porphyroclasts in relics is their carbonization. Neogenic K-feldspar, albite, and dark-colored minerals lack cloud-like carbon pigmentation. Potassium-rich rocks have high contents of Ba and Rb and show a distinct Eu minimum on their REE patterns. According to Rb-Sr dating, these rocks have an age of 419 ± 30 Ma (⁸⁷Sr/⁸⁶Sr = 0.7061 ± 0.0021), which is, most likely, close to the age of the last metamorphism. Indirect data evidence that primary island-arc rocks might have formed in island-arc setting, possibly, in the foreland of island arcs.

Based on Ovchinnikov's genetic-type formula, geologo-genetic models have been constructed for Mesozoic gold deposits localized in chamber-dome and chamber-depression structures in the Transbaikalian area of the Mongolo-Okhotsk fold belt. This formula includes 12 factors that characterize ore formation processes, their depth of occurrence and geodynamic settings, the sources of ore matter and ore-forming solution, energy of ore formation processes, composition of ore-forming solution, environment and mechanism of ore deposition, zoning, interaction of ores with host rocks, and thermodynamic setting of ore deposition.

Mathematical properties of the inverse dynamic seismic problem for determining the elasticity parameters of a homogeneous layered anisotropic medium are investigated for the case of orthorhombic symmetry. Analysis of the mathematical properties of the inverse problem allows predicting which parameters can be estimated to a satisfactory accuracy. The suggested inversion algorithm is tested in numerical experiments for determining elastic parameters of a thinly stratified medium including several anisotropic layers.

We investigate the stability of oil-water layered systems at arbitrary values of physical parameters. It is essential to distinguish the known electric-hydrodynamic instability from parametric resonance. Parametric resonance in layered systems under alternating current shows the presence of two frequency bands which differ in behavior of foreign charge storage. We report numerical experiments on the nonlinear behavior of parametric resonance in layered systems subject to acoustic excitation. Periodic pulse impact on the boundary of a layered system causes an increase of several orders of magnitude in the amplitude of its elastic stress relative to the initial distribution.

The preseismic stress field on the western flank of the Sunda seismic arc before the great Sumatra-Andaman earthquake modeled from earthquake mechanism data shows a heterogeneous pattern in the area of the pending source. The first motion in the source of the coming great event occurred within the region of high deviatoric and isotropic stresses near their steepest gradients. Seismic radiation in the earthquake culminated in the zone of lowest stress extending for about 350 km along the northern edge of Sumatra Island as far as the Nicobar Islands. The revealed stress distribution in the earthquake nucleation area agrees well with laboratory experiments on rock failure in which low and medium stresses correspond to brittle failure. The suggested model of the metastable state of rocks in seismogenic regions includes the presence of different stress zones and the formation of a zone of high stress gradient in the place of the pending bigger earthquake.

Four climatholiths of the Upper Pleistocene are used in Siberia as regional stratigraphic horizons: Kazantsevo, Zyrjanka, Karginsky, and Sartan. Their geochronological basis is discussed in this paper. A conclusion is made that they are erroneously correlated in the official stratigraphic scheme. New detailed data obtained by international teams on key sections of Arctic Siberia suggest an alternative division of the Upper Pleistocene. A new version of chronostratigraphic scheme of West Siberia is proposed for discussion. The new scheme for the lower Upper Pleistocene is based on well-known key sections of the Karginsky and Zyrjanka Horizons. The main thermomer of the Upper Pleistocene is represented by the Malaya Kheta and Karginsky strata with geochronometric marks corresponding to early marine isotope stage 5. The complex of the last glaciation (Zyrjanka Horizon) is dated within a broad interval from 100 to 50 kyr BP. Two new horizons with stratotypes on the Yamal Peninsula are proposed for the second half of the Upper Pleistocene. These are the cold Var'yakha interstadial about 50-30 kyr BP and the Syoyakha cryomer 30-11 kyr BP. The new horizons are in good paleoclimatic correspondence with the Middle and Late Pleniglacial of Europe.

Platiniferous ultramafic-mafic magmatic assemblages of different types of mobile belt structures from the folded framing of the Siberian and South Chinese cratons are considered in a wide span of time, from Precambrian to Mesozoic. Attention is given to platinum mineralization linked to diverse complexes formed under different geodynamic settings: ultrabasic and basic intrusions of Precambrian greenstone belts, layered ultramafic-mafic intrusions of marginal near-platform rift-related structures, Alpine-type ultrabasic rocks of Riphean-Early Paleozoic ophiolite belts, volcanic-plutonic complexes of Paleozoic collision orogens, picrite-dolerite and alkali-basite volcanic-plutonic associations of Hercynian and Permian-Triassic systems.

We investigate cratonic terranes in northeastern Russia which have very high mineral potential but remain poorly explored or not explored at all. The suggested synthesis of the available data from an underexplored but exceptionally rich province provides evidence of high metallogenic prospects of cratonic terranes and their surroundings in northeastern Russia as well as in other regions. Especially good prospects are expected for gold mineralization, which shows continuous development from Precambrian to Cenozoic structures of northeastern Russia.

A general metallogenic analysis and metallogenic zoning of the Altai-Sayan orogenic area (ASOA) were carried out in terms of the modern plate tectonics and mantle geodynamics concepts. The Altai-Sayan folded area is an example of a polyaccretionary orogenic system that resulted from the long evolution of the Paleoasian ocean. The main metallogenic belts have been recognized, in which typical ore associations (model types of mineral deposits) and their ages and geodynamic settings of formation have been established. A total of 48 metallogenic belts including 450 mineral deposits of 70 model types were studied. These belts are related to four time spans (metallogeny epochs) corresponding to the cycles of geodynamic processes that led to the formation of the polyaccretionary orogenic area: Riphean-Vendian (1200-620 Ma); Vendian-Silurian (620-410 Ma); Devonian-Early Carboniferous (410-320 Ma); and Late Permian-Triassic (260-205 Ma). Study was also given to typical geodynamic settings in which ore-forming productive systems originated. It is shown that the metallogenic evolution of the ASOA was determined mainly by the multistage formation of active continental margins and island-arc systems in the Riphean-Vendian and Early (V-S) and Middle (D-C₁) Paleozoic.
At the postorogenic stage, the ASOA evolution was the most productive in the Triassic. The geodynamic and metallogenic events in this period were determined by the tectonothermal activity on the periphery of the Permo-Triassic Siberian superplume in the interblock zones of the orogenic collage, which led to serious shifts along the plate and block boundaries, the formation of near-fault troughs and grabens, appearance of rift structures, and development of anorogenic granitoid magmatism (manifested as alkali and subalkalic rare-metal granites) and alkali-basaltoid magmatism.
Transpression settings (oblique subduction) and plume magmatism are shown to have played a key role in the formation of mantle and mantle-crustal ore-forming systems. For the Middle Paleozoic and Mesozoic stages, new geochronological evidence has been obtained, and spatial and temporal correlations for the formation of the main types of mercury, gold, and rare-metal deposits have been made.

In the Orhon-Selenge trough (OST) (northern Mongolia), which is part of the extended Permo-Triassic Selenge volcanoplutonic belt, the formation of ore-bearing porphyry complex and large-scale stockwork Cu-Mo mineralization (Erdenetiyn-Ovoo deposit) was preceded by multiphase magmatism, which was accompanied by ore mineralization of different scales and types. The evolution of the Permo-Triassic magmatism successively resulted in ore occurrences, which form a single metallogenic series (predominance of Cu and permanent presence of Mo): native Cu (P; differentiated basalt-andesite-rhyolite series)-Cu-Ni-sulfide, Cu-skarn, and Cu-vein (P₂-T₁; basites and granitoids of the Selenge complex)-native Cu (P₂-T₁; trachyandesite-basalt series)-porphyry Cu-Mo (T; Erdenet ore-bearing porphyry complex). In this series, the intensity of fluid flow grows and the redox potential of the endogenous system shifts to that of more oxidizing conditions, which favors the transfer of ore-forming elements from depth and increases the Cu-bearing capacity of magmatogene fluids. The development of magmatism and accompanying mineralization in the OST is assumed to be related to one of the lower-mantle plumes that existed in the vast Asian area in the Permo-Triassic.

The internal structure and proportions of the main rocks of the Kuvalorog gabbro-cortlandite massif, the largest intrusion on the Kamchatka Peninsula, are considered. The intrusive rocks are shown to abound in pargasitic amphibolite and biotite. Ultrabasic orthopyroxene contains melt inclusions with porphyritic pargasite phenocrysts, which point to a high water content in the parental melt of this intrusion. In trace-element patterns of rocks and minerals the massif is similar to Ni-bearing traps of the Siberian Platform. The behavior of lanthanides in the cortlandites evidences that their parental magma was melted out of a garnet-bearing mantle source and then crystallized under high-pressure conditions. Like the productive intrusions in the Noril'sk district, the rocks and all rock-forming minerals of the Kuvalorog massif are depleted in Ni relative to chondrite C1, which indicates a high Ni-sulfide ore potential of the massif.

After the Earth had melted in the conditions of mostly reduced fluids, its chemistry included two distinct groups of light and heavy elements with high and low oxygen affinity, respectively. Light elements, with their density lower than in Fe but oxygen affinity higher than in FeO, accumulated in the essentially oxygenic sphere composed of silicates and oxides. Heavy elements with low oxygen affinity and native Fe sank to the Earth's center and formed the iron core. Thus the Earth's protomaterial partitioned to make an oxygen-free core where liquid iron stores enormous amounts of H₂, CO, CH₄, S, H₂S, and other reduced gases surrounded by an almost 3000 km thick mantle in which the constituent minerals contain 75-80% oxygen. This separation of elements at the beginning of the Earth's history predetermined the specific behavior of fluids in all deep processes, including metallogeny, for the billions of years which followed.
Self-organization of the Earth's upper layers by means of granite formation produced the crust. Having lost its granite-forming components, the mantle graded into solid depleted mantle underlain by non-depleted asthenosphere impregnated with fluids. The mineralizer capacity of asthenospheric fluid systems correlates with their T and P conditions and the related maturity of lithospheric blocks. Therefore, the deep-seated origin of mineral deposits stems from two feeding fluid super-systems, the core and the asthenosphere, each with its typical chemistry. The two sources produced the respective metallogenic provinces with the chemistry of deposits controlled by the causative mineralizer systems.

Fluid and melt inclusions in minerals from magmatic rocks and associated ores and metasomatites were studied. Based on the results obtained as well as on experimental data, possible evolution trends are considered for the phase composition of magmatogene fluids separating from granitoid and basic melts at different depths. Three types of fluids have been recognized according to their composition and phase state, which differ in metal contents: (1) homogeneous supercritical, (2) heterophase

We present a synthesis of numerical modeling data for the evolution of mantle-crust systems in oceanic and continental spreading zones from decompression melting with the associated generation of mafic magmas and fluid release in their crystallization to mineral deposition in the crust. Model parameters were chosen to match those appropriate for natural magmatic-fluid systems in slow-spreading mid-ocean ridges (MOR) and the Siberian trap province. The evolution of a melting region was modeled for two cases: (i) a hot spot beneath a mid-ocean ridge, with 7-10 km thick oceanic crust underlain by metasomatized lithosphere, and (ii) a melting region beneath anomalously thick crust. Magmatic systems beneath thick crust were found out to be more compact and symmetrical and undergo a longer evolution.
Numerical modeling for continental melting zones with regard to the lithospheric structure and the size of the juxtaposed cratons and plates allowed the following inferences: (1) the extent of the predicted lithospheric melting region slightly exceeds the length of the respective lava field, (2) the melting zone has a layered structure (therefore, melts derived from a relatively homogeneous substrate should be homogeneous and of the same type), (3) magma chambers are relatively independent, which provides a qualitative explanation for the known cyclicity of lava compositions and the spatial distribution of major-element compositions of rocks in igneous provinces.
The behavior of the compositions of fluids outgassing at the solidus boundary from the crystallizing basaltic melt were computed using the Selektor software in a flow reactor and a step source modifications. Modeling shows that a quasi-steady temperature profile of a fluid-magmatic system related to a 30-40 km deep magma source sets up for 0.5 to 1 Myr. We infer that uncondensed reduced fluids vent on the seafloor and produce graphite and Fe, Ti, and Mn ferrite deposits found in the crest of the Mid-Atlantic Ridge. The numerical results were supported by physical modeling of carbon precipitation during the interaction of synthetic gas with mafic and ultramafic minerals. Carbon-related mineralization associated with gas condensation is controlled by the relative contents of C, H, Cl, F, and S in magmatic fluids. The composition of outgassing fluids changes notably within the liquidus-solidus range in crystallizing magma. During retrograde boiling, fluid separates into a low-density fraction and a brine.
Retrograde boiling in magma chambers and auto-metasomatism of igneous rocks are similar in mid-ocean ridges and in the Siberian trap province in the case of very low wall-rock assimilation and contamination of mafic melts. Assimilation of crustal material, especially carbonates and salt-bearing rocks, coal beds, hydrocarbons, or oil water, by mafic melts produces anomalous magmatic fluids with up to 60 rel.% total hydrocarbons, including 45-50% CH4, and total H₂O, H₂S, N₂, and with H₂ two orders of magnitude higher than CO₂ and CO. These very fluids promote the formation of mineral deposits hosted by igneous rocks.

We report results of computer modeling of physicochemical ore formation processes at mercury deposits accumulated during the development of secondary-hydrothermal and mixed-fluid ore-forming systems. Exogenous chloride brines, oil waters of artesian basins, and petroleum pools are shown to serve as secondary mercury reservoirs and geochemical barriers.
Modeling of possible mechanisms of mercury transfer and deposition in the form of cinnabar (α - HgS) was performed for ore-forming solutions of different compositions. Four main thermodynamic models have been constructed using the Chiller program: (1) simple cooling (cooling only), for recent thermal springs, (2) mixing of high-chloride hydrothermal solutions with cold hydrosulfuric waters (mixing model), for telethermal deposits, (3) isoenthalpic boiling (P = f (T)), and (4) solution-rock interaction (rock titration model).

As inferred from melt inclusions in minerals of volcanogenic rocks, the ore-magmatic pyrite systems of Rudny Altai and Tuva had quite a specific history. Volcanism manifestations in these regions have both similarities and differences.
The chemical composition of melt inclusions in quartz of acid volcanic rocks from the pyrite deposits of Rudny Altai is close to the chemical composition of the rocks, and in REE content they correspond to island-arc magmas. At early stages of development of a magmatic system, acid melts formed, which had high temperature (1230-1250

A method for numerical calculating the nonuniform transmittance of one of the cavity mirrors to obtain the given output intensity distribution is proposed. The calculation was done for the axially symmetric case of field distribution in the cavity. Transmittances for obtaining a beam with a uniform intensity distribution in a circle are calculated.

Results of investigating the accuracy of reconstruction a 3D surface of a human trunk model by computer optical topography are considered in comparison with the multislice computer tomography.

An adaptive algorithm for preprocessing signals that represent short information phase-shift keyed packages against noise in the presence of Doppler effect is considered. Processing based on phase break allocation of initial signals makes it possible to avoid frequency shift equalization in problems concerned with estimating the time delay of phase-shift keyed signals in the case of multichannel distribution.

A Doppler signal processor representing a complex envelope tracking filter supplemented with a digital error correction system is described. The LDA processor characteristics in measuring the gas flow turbulent characteristics are studied.

Design features and construction principles of silicon multiplexer matrices based on production technologies are considered. Two versions of unified 128 x 128 multiplexers based on 1.2 m CMOS and 3 m CCD/CMOS technologies are presented.

Future prospects of creating bursting radar technologies within the scope of a new interdisciplinary scientific trend

Experimental data connected with the investigation of a new class of bacteria n

The morphological composition and size distribution of bacteriophages of the Angara were investigated for the first time by means of transmission electron microscopy. Eight morphological types were found; among them, 59 % are the representatives of Siphoviridae family and 11 % are the phages of Podoviridae family. According to the frequency of occurrence, the major part of bacteriophages (70 %) is comprised by the phages with tail appendix. Predomin

The goal of the investigation is comparative evaluation of the protein spectra and their changes under stress in several species of fresh-water amphipoda. Endemic species from Lake Baikal and Palearctic species differing by their adaptive ability were studied. Polymorphism of the protein spectra not only between systematically dissimilar but also between closely related species was revealed. Polymorphism of the protein spectra was observed in the differently aged stages of two Baikalina amphipod species. The effect of temperature stress on the protein spectra was estimated. It was shown that the temperature stress affects the content and synthesis of some proteins which have inter-species and age differences.

Features of the occurrence of bacteria of Caulobacter genus in Lake Baikal in various econiches and in different seasons are investigated. The number of microorganisms was observed to vary from the absence in the majority of samples from the lake pelagialy to 700 000 p./ml in the mouth of the Barguzin river. For the first time, identification of Caulobacter from Lake Baikal was carried out by means of hybridization with the fluorescent oligonucleotide probe. Different morphological species of the bacteria of Caulobacter genus were determined with the help of investigations using the light, epifluorescent, transmission and scanning electron microscopes.

The results of investigation of the dynamics of population of Paramecium caudatum infusoria fed with oil-degrading bacteria utilizing easily available organics and diesel oil are presented; changes in the population of the protozoa for different concentrations of the food resource are described. The data of morphometric measurements and the data on the changes in specific growth rate with different kinds of bacterial food are presented. Adaptive reactions of the infusoria to consumption of the bacteria cultivated under different conditions are investigated.

The problem of the features of expansion with the invasive species of water ecosystems of East Transbaikalia is considered for the example of the Bailkanian amphipod Gmelinoides fasciatus (Stebbing, 1899). Settling of G. fasciatus from the Ivano-Arakhley lakes is negatively affected by the summer mean-water intermittence of the brooks flowing out of the lakes and their freezing during the winter mean water period. In Lake Arakhley, the major effect on the spatial distribution of this species during the summer period is caused by the depth, the character of bottom sediments, near-bottom temperature, and the amount of oxygen dissolved in water. The features of the life cycle of G. fasciatus in the lake, the effect of the invader species on the population of the local amphipod species Gammarus lacustris (Sars, 1863) and macro-animal benthos were revealed.

The faun

Ecological characteristics of two species of genus Salmincola crustaceans - parasites of Baikal omul are considered. The species are characterized by strict localization in the gill cavities (S. extumescens) and in muscles in the base of fins (S. extensus). Isolation of the species occurs because S. extensus is infecting young age groups of omul, while S. extumescens - those of old age. The regularities of the distribution of crustaceans depending on the depth of the reservoir and the features of seasonal infection dynamics by S. extumescens of the Chivyrkui omul population were determined.

The effect of oil products and oil hydrocarbons on different Cladocera species was an

The goal of the investigation is to estimate the mechanisms of activation of the antioxidant system (AOS) under the oxidative action of exogenic character in Palearctic Gammarus lacustris Sars. The oxidative action was induced by exposing the amphipoda in the solutions of a humin-containing laboratory preparation. Investigations indicated that exposure of the amphipoda under question in the solutions of the preparation leads to an increase in the activity of peroxidase and glutathione-S-transferase enzymes, as well as the level of lipid peroxide oxidizer (LPO), which is an evidence of the intensification of oxidative stress. A two-stage mechanism of the reaction of antioxidant system was revealed in the amphipoda. The first stage is characterized by the high protection level and allows effective containment of the negative oxidative action. The second stage is of low efficiency; it is accompanied by an increase in the level of LPO and the activity of glutathione-S-transferase, which is an evidence of the destruction of cell membrane structures.

The effect of petroleum and oil products (petrol, diesel fuel) under the model n

The structure of the communities of elaterids was investigated in the regions affected by brass works in the areas located in different ecological and geographic sub-zones of the taiga zone. A comparison of emission sources of the same kind in forest ecosystems of different sub-zones of the taiga allowed us to analyze changes in the structural arrangement of elaterid complexes over the gradient of chemical pollution, to reveal adaptive mechanisms of elaterid complexes to high industry-related load, to observe general and specific zonal features of the reaction of click beetles to this kind of anthropogenic action. We succeeded to demonstrate that the latitudinal

The effect of thiophane, a polyfunciton

Human impact on soils of biogeocenoses, such as black soil, leached and dark-gray forest soil, is followed by a decrease in humus level and deterioration of its quality. Annual humus mineralization in full-profile soil reaches 0,7 t/ha, while estrangement of this substance due to erosion processes varies within the range 1.4-1.8 t/ha. As a result of annual wash-out of the upper part of humus horizon and increase in arable owing to underlying soil layers, the composition of humus is transformed from humate to fulvate-humate. The effect of plough-out is more clearly pronouced under the Siberian conditions than in the similar kinds of soil in the European part of the country.

The effect of the diet containing 10 % (mass) of dry finely ground parts of Serratula coronata L. plant with different content of ecdysteroids on the development of caterpillars of Egyptian cotton leafworm Spodoptera littoralis of the IV age is investigated. It is shown that in the absence of a clearly exhibited antifidant action, the growth and development of the worm were suppressed, pupation period increased, and imago prolificacy decreased substantially.

The lichen species composition of the museum-reserve "Tomskaya Pisanyza" was determined from 227 species, 82 genera and 35 families. All the species are new for the reserve, and Caloplaca brachyspora Mereschk. is a new species for Russia and Asia, Aspicilia griseopallida (Vain.) Oxner, Pyrenopsis umbilicata Vain, Verrucaria squamulosocrustacea (Savicz) Oxner are the new ones for Asia, Protoparmeliopsis macrocyclos (H. Magn.) Moberg et R. Sant. is a new species for Siberia, and Cryptothele rhodosticta (Tayl.) Henssen is a new one for West Siberia. The diameters of the largest lichen thalli Caloplaca cirrochroa (Ach.) Th. Fr. and Xanthoria elegans (Link) Th. Fr. near petroglyphs were measured in order to determine their age.

Changes in the level of nitrogen pollution of the ground water in the regions near the Ishym river with the mineral compounds of nitrogen during the years 1985-2004 is considered on the basis of the samepls from wells and holes. A connection between the pollution level and changes in the regional management conditions was revealed. High saturation of the buffer capacity of geosystems with nitrogen compounds was established.