Proceedings of Siberian Department of the Section of Earth Sciences of the Russian Academy of Natura

30-41

Authors: S.M. Radomskii, V.I. Radomskaya

The beginning development of the Malomyr gold deposit makes relevant the evaluation of the concentration of other noble metals (NM) in the ore samples from this deposit. The main purpose of the study is assessment of the concentrations of platinum metals in order to perform the complex extraction of useful components (Ru, Rh, Pd, Ag, Os, Ir, Pt, Au) from the mineral raw material.

57-68

Authors: A.K. Seminsky

The Purpose of the paper is to study the general patterns of emanations of radon dissolved in the underground waters of the Southern Baikal region, to identify the main factors affecting the emanations and to propose a method enabling the prediction of changes in radon concentration for a single water manifestation during a year based on a single sample selection. Methods. The radon content in each of the sources chosen for the study was measured 1 time every two weeks. The volume activity of radon (Q, Bq/l) was measured using a radiometer PPA-01M-03. In addition to the Q parameter, weather data on the days of sampling were recorded, as well as the data on seismic activity in the study area. Quantitative analysis was carried out using standard statistical methods (cluster, correlation and Fourier analyzes). Results. A monitoring network of eight sampling points was created. Underground waters of the investigated area are found to be non-radon (Q≤185 Bq/l). The studied water manifestations are divided into three groups according to the average radon content in water during the sampling period: 1st group – Q average ≈ 15 Bq/l, 2nd group – Q average ≈ 30 Bq/l and 3rd group – Q average ≈ 60 Bq/l. The radon content in water varies; ΔQ is 30-60% of the mean value in the test source. The Fourier analysis allowed to factorize the complex oscillations of the Q parameter into the simple harmonics: of the first order (the wavelength is about 365 days), of the second order (≈ 126 days) and of the third order (≈ 30 days). All the analyzed values are divided into three main clusters according to their degree of mutual dependence. The first is Q parameters for different sources, the second and third are various factors of emanation field formation: external (meteorological conditions) and internal (earthquakes of different energy class). The correlation analysis made it possible to specify that the parameter Q has a direct correlation with pressure, while its dependence on temperature and humidity is manifested only at the level of trends. Based on the revealed regularities a forecasting methodology for dissolved gas concentrations in groundwaters has been developed. Conclusions. The expected reason for the difference in the series of the Q parameter measurements obtained for different water manifestations are the conditions for the recharge and formation of groundwaters. Based on Fourier analysis three main types of harmonics have been identified. They are differently represented in the curves of various types, which is indicative of the complex correlation of factors. According to the results of statistical analysis, the studied parameters form three clusters. The factors affecting gas emanations can be classified into external and internal, whereas the effect of the former on radon concentration has appeared to be stronger in the monitoring period than the influence of the latter. The correlation analysis data have shown that the volume activity of radon is regularly dependent on pressure, slightly less dependent on temperature and humidity. The quantitative analysis of the application results of the proposed forecasting method of dissolved radon concentrations has shown the averaged 80% convergence of calculations.

77-85

Authors: A.A. Peshkova, A.V. Miromanov

The purpose of this work is to develop a conceptual model of a geo-informational project that will improve the integrity and self-descriptiveness of the initial geological and geophysical data when searching for oil and gas deposits, allow to avoid information duplication as well as promptly provide the user with relevant geological and geophysical information in the process of geodata base development. Method. The method of conceptual (infological) design is used to form a general representation picture of geological and geophysical data. Results. Geological and geophysical data used at the enterprise are considered. Description is given to the software environments where geological and geophysical information is processed. The main users of the geoinformational project are appointed. The main performance capabilities of the geoinformational project are identified and the conceptual model of the project is created and described. Conclusion. The created concept of system operation gives an opportunity to form an infologic model of the developed geoinformational project. The latter will allow to collect and analyze the received information, store initial geological and geophysical information and provide the access to geological and geophysical materials. The application field of geoinformation technologies is important and demanded as the use of geoinformation systems for the search for oil deposits and forecasting of oil and gas accumulation zones has shown that modern geoinformation systems fix researchers up with purpose-built tools opening new opportunities for creating forecast maps and making the entire search and forecast process more justified, and the result – more reasoned.

94-97

Authors: S.A. Sverkunov, A.G. Vakhromeev, N.N. Martynov

The Purpose of the paper is study and analysis of mining-and-geological conditions of drilling of deep wells for oil and gas in the South of the Siberian platform, the search for the solution of the existing problems associated with the elimination of drilling mud absorption and such complications as differential sticking of the drill string and casing string. Methods. Production data obtained at well-drilling in the Republic of Sakha (Yakutia) and the Irkutsk region have been collected. Their statistical researches have been conducted. Results. Having analyzed the data collected from production facilities the most effective method against differential sticking has been chosen. Conclusions. A number of fields of Eastern Siberia (including the Irkutsk region, the Republic of Sakha (Yakutia) are located in the geological conditions predisposed to the differential sticking occurrence. Differential sticking of drill and casing strings regularly arise in such geological conditions that break normal working process of well drilling and require additional costs. Moreover, the elimination of this type of sticking is extremely expensive and complicated, and even impossible sometimes. All these cause considerable economic losses in the cycle of well-drilling for oil and gas. The forecast and prevention of differential sticking will significantly facilitate the problem of development and prospecting drilling. The measures proposed by the authors will allow an unconstrained drill-string running in the conditions of abnormal low pressures in the open bore hole. They will also allow to liquidate an immediate differential sticking with minimum economic and temporary losses

38-53

Authors: M.I. Mansurov, M.H. Safari, B.G. Kalandarov, V.M. Kerimov, A.G. Mamedova

The Purpose of the paper is to analyze the zoning nature of mineralization and metasomatites in the known porphyry copper deposits of the Goshgarchai ore magmatic system (OMS) associated with the Murovdag group of intrusives. The Methods used in the study include complex structural and geological, metallogenic, geological-petrological, ore metasomatic and petrochemical parameters of metasomatites as well as the studies that take into account science-based geological prospecting works carried out earlier. There is some regularity between the petrochemical parameters of metasomatites and the contents of copper and molybdenum. Results. It has been found that the thickness of methasomatically altered rocks varies from several meters to tens and hundreds of meters (in the intersections of multi-oriented faults) within the Goshgarchai OMS. Their length ranges from 500-1000 m to 2000-3000 m. Three gradually changing each other elliptical metasomatic zones are distinguished around the ore generating intrusives of the Goshgarchai OMS. They border the intrusive massif of porphyry composition. The inner zone including the endocontact and apical parts of the porphyry intrusive is represented by strongly silicified rocks, which are almost completely transformed into secondary quartzirtes. The middle zone is determined as quartz-sericite-chlorite facies of secondary quartzirtes. The third external zone of the metasomatic column is represented by the propylite facies of secondary quartzirtes. Conclusions. Having studied ore zoning within the borders of the Goshgarchai deposit we have obtained the following series of vertical zonality of elements (bottom-up): Mo→Cu→Со→Ni→Cr→Ag→Pb→Zn. Hydrothermal metasomatic variations of enclosing rocks in the zones of different types of metasomatites generated under deposit formation have been studied and compared on the basis of petrochemical data

66-78

Authors: V.V. Boroldoeva, A.Ya. Medvedev

The purpose of the paper is to determine the crystallization order of rocks based on the study of the mineralogical and petrographic composition of the Khentei Range Cenozoic basaltoids. Methods. A microprobe X-ray spectral analysis by means of the JXA-8200 tool (JEOL Ltd., Japan) has been used in the study. Results. The research results in the determination of chemical compositions of rock-forming minerals and the sequence of minerals formation. Conclusions. Melt movement to the surface was accompanied with the capturing of mantle xenoliths. Olivine and pyroxene of the first generation were formed first, then, olivine and pyroxene of the second generation were formed, as well as oxide bearing minerals. Plagioclase, potassium feldspar, nepheline and leucite were crystallized last from the interstices. The presence of residual glass has also been noticed in the interstices

99-114

Authors: A.A. Yakovleva, G.D. Maltseva

The goal of the paper is to analyze the changes in mineral crystal lattice under acid activation. Methods. Clay from the Slyudyanka deposit is the material under investigation. The methods used in the study include x-ray phase analysis using Bruker D8 Advance diffractometer. The diffractogram is recorded using the EVA program installed on a PC in combination with the diffractometer. The quantitative composition is calculated using the Topas 3.0 program. The study also uses the methods of scanning microscopy of the oriented sample, titrimetric analysis methods (the methods of neutralization and complexometry 0; conductivity measurement (determination of solution electrical conductivity); potentiometric measurements (determination of electrokinetic potential at electrophoresis); sedimentation analysis in gravitational and centrifugal fields. Modern databases and Excel are used for thermodynamic calculations. Results. Crystallochemical analysis of mineral structure and thermodynamic assessment of process spontaneous flow conditions allowed to explain the nature of the potential curve after acid activation of the clay from the Slyudyanka deposit. The extreme nature of this dependence is associated with the changes in the field of force on the surface of particles as a result of the flow of the complex of physico-chemical interactions, the most important of which are interactions of backbone ions with the components of environment. In its turn, the changes in the interaction energy of clay particle weight calculated by the results of colloid-chemical studies allow to analyze the processes occurring in the crystal lattice of clay under acid activation. Experimental data confirm the similarity of some patterns of acid activation of clay minerals associated to the fact that the process is accompanied by the washout of ions from the crystal lattice skeleton and formation of structure defects. The defects of crystal lattice causing the disturbance of its regularity, the transition of surface silica in amorphous state provide the change in both system dispersion and porosity of clay samples. Conclusions. It is more preferable to use the acid activation for the production of mineral sorbents with developed porosity when minerals with an expanding structural cell are used as a source material.

20-34

Authors: Zh.V. Seminsky

The purpose of the article is to describe the ore belts of the Baikal-Transbaikal region identified in the course of the long-term metallogenic studies. Methods. Based on the analysis of the materials on the ore content in the region metallogenic zoning has been carried out. Two taxa have been distinguished: regional metallogenic belts and ore belts which are the links of the former. The first ones we described earlier. The minerals of the ore belts are examined in connection with the description of main tectonic elements and geological complexes composing them. We did not set the task to provide a complete description of all minerals: consideration was given to the most significant and large ore objects only. This article deals with the belts of marginal continental and collision-accretionary conditions. The second part of the article (to be published in the next issue of the journal) is going to deal with the ore belts of intraplate orogenic nature. Results. Ore belts of the Baikal-Patom marginal continental metallogenic belt are located in the marginal western part and in the north of the territory. The geodynamic situation here is determined by the spread occurrence of ancient blocks of foundation (terranes) and complexes sewing and overlapping them. The main is the Neoproterozoic metallogenic epoch which is characterized by the formation of fluorite-polymetallic, pyrite-lead-zinc, uranium and gold mineralization (Pribaikalsky, Akitkansky, Tyaya-Olokitsky, Bodaibo belts). The ore belts of the Baikal-Muya and Baikal-Vitim accretionary collision metallogenic belts are located in the central part of the region (Charo-Tokkinsky, Muya and other ore belts). Large stratiform deposits of cupriferous sandstones, banded iron formations, gold-quartz, large polymetallic and fluorite deposits, which were formed during the Proterozoic, Paleozoic and partly Mesozoic metallogenic epochs are localized within their boundaries. Conclusions. The ore belts of the marginal-continental type are represented by the systems of foundation blocks with overlapping and sewing complexes where stratiform, fluorite-polymetallic deposits, gold ore deposits, uranium mineralization in ancient volcanites are formed. The accretionary collision ore belts contain the terrains of different nature, fragments of island arcs, formations of subduction and collision geodynamic environments. Large stratiform deposits of cupriferous sandstones, lead-zinc ores, banded iron formations are widespread.

48-60

Authors: I.A. Izbrodin, G.S. Ripp, D.Ts. Ayurzhanaeva, V.F. Posokhov

The Purpose of the article is investigation of isotopic and geochemical features of Kyakhta sillimanite deposit quartzites, their genesis and possibilities to be used as a raw quartz material. Methods. Quartzites and their enclosing rocks have been examined by the complex of methods including geological, geothermal surveying methods, geochemical and isotopic (O, H) studies. Results. It is determined that quartzites located in sillimanitebearing rocks (Krutoi, Traktovy-II, Glukhaya Pad, Lesnoi sections) and in gneisses (Chernaya Sopka) have similar mineral compositions. The quartzites are enriched with titanium (0.8–2.5 wt.% TiO2) and contain high concentrations of aluminum (0.2–1.45 wt.% Al2O3). The rocks are characterized with the differentiated REE distribution range. To evaluate the sources of fluids participated in ore formation the thermocriometrical studies were conducted and isotopic abundance of oxygen and hydrogen in minerals was determined. The results of the thermocryometrical investigation of fluid inclusions indicate the predominance of aqueus carbon dioxides in all types of quartzites with the insignificant role of aqueus acids of Ca, Mg chloride fluids. The isotopic composition of oxygen (δ18O % v-SMOW) in quartz (-0.3...-3.5), sillimanite (-1.1), muscovite (-3.2... -3.7), hematite (-4.2...-4.6), rutile (-6.4…-7.6) and hydrogen (δD % v-SMOW) in muscovite (-160.0....-175.3) demonstrates the participation of fluids with the contribution of meteoric waters in the formation of quartzites. According to the isotopic thermometers quartzites were formed at the temperatures of 720–600°C. Conclusions. Some parts of quartzites correspond to raw materials for the production of silica products. The presence of rutile does not hinder concentration by traditional methods of quartz beneficiation. The rutile concentrate can be used as a raw material for titanium production

70-81

Authors: Yu.N. Didenkov, Z.V. Proskuryakova

The Purpose of the article is to study the role of rifting in the formation of Baikal region natural waters. Methods. The main research methods used in the study are structural hydrogeological analysis and simulation computer thermodynamic modeling using the “Selector” software complex. Results. A formation scheme of structural and hydro-geological conditions of the Baikal region has been developed as well as a conceptual scheme and formation models of natural waters. Zoning has been performed and identified hydrogeological structures have been described. The results of physico-chemical modeling of endogenous hydrocarbon fluid evolution when lifting to the surface and discharging into Lake Baikal have been shown. Conclusions. The structural-hydrogeological analysis and thermodynamic modeling allowed to establish the possibility of the existence of an endogenous renewable source of fresh water formed as a result of degassing at the present stage of Baikal rifting development. This fact determines both the hydrosphere freshness of the region under investigation and the preservation of the unique composition of waters of the rift lakes of Baikal and Khubsugul.

90-98

Authors: E.V. Averkina, E.V. Shakirova, Yu.V. Fokin

Introduction. The drilling practice of inclined directed wells in Eastern Siberia involves different materials and reagents with defoaming and foam suppressing properties. However, different substances work selectively in different media where it is supposed to suppress foam. The efficiency of an anti-foaming agent is evaluated by the comparison results of its action with other anti-foaming agents when processing a drilling mud of a certain composition. We have conducted comparative researches aimed at the determination of the most efficient foam suppression and foam prevention performed by anti-foaming agents on a drilling mud used in the construction of producing wells on the Yarakta oil-gas condensate field. Methods. Two methods are applied in this research: evaluation of foam suppression efficiency by the method of drilling mud density variation and determination of foam prevention efficiency. Results. It has been revealed that all tested anti-foaming agents have different compatibility with initial drilling mud. It has been concluded that BauDF Antifoam and Reapen 1408 reagents have the best lubricating ability. It has been determined that the most optimum anti-foaming agent for the drilling mud of this composition is Atren Antifoam C of 1% concentration which has one of the best indicators of both foam suppression and foam prevention. Conclusions. Application of Atren Antifoam C in 1% concentration as a part of the drilling mud will allow to prevent its foaming while being prepared and prevent the adverse impact of foam on drilling equipment.

107-117

Authors: M.P. Belykh, A.Yu. Chikin, S.V. Petrov, N.L. Belkova

Purpose. The processes of biopassive detoxication are of special interest for the solution of environmental issues of detoxification of gold heap leach cyanide-bearing wastes whose detoxification period is unlimited. These processes are based on spontaneous degradation of cyanides under the influence of natural factors including the action of autochthonous bacterial community. The purpose of the work is to develop a biopassive detoxification technology of heap leach stockpiled wastes. Methods. A long-term experiment on ore mass storage under the conditions of heap leach ore pile zoning has been carried out in order to model the process of passive detoxification of gold heap leach stockpiled wastes. The content of toxic compounds in the ore mass has been determined using a chemical analysis based on standard procedures. Results. It is found that biochemical processes dominate over simple chemical oxidation during passive detoxification of the gold heap leach ore pile. Approximating biodegradation equations have been calculated for the major toxic compounds (thiocyanates and cyanides including copper and nickel cyanide complexes).The technology of biopassive detoxification of heap leach stockpiled wastes has been developed at an industrial heap leach site of the Sakha Republic (Yakutia) deposit. Water balance of the heap leach installation and detoxification time for the major mass of the ore pile have been calculated. Process circuit and process flow diagram of the proposed technology have been developed. Conclusions. The introduced technology eliminates the costs for reagent detoxification and is based on high economic and environmental efficiency as compared to conventional chemical technology. Introduction of additional modernizations of the irrigation circuit as well as removal and transportation of snow will be carried out at low capital and operational costs. The expected economic potential of the technology of bipassive detoxification of gold heap leach site will be 151429.7 thousand roubles