Men'shikov V.I.,RAS Vinogradov Institute of Geochemistry |
Vlasova V.N.,RAS Vinogradov Institute of Geochemistry |
Lozhkin V.I.,RAS Vinogradov Institute of Geochemistry |
Sokol'nikova Iu.V.,RAS Vinogradov Institute of Geochemistry
Analitika i Kontrol | Year: 2016
The analytical technique to determine platinum-group elements (PGEs) Ru, Rh, Pd, Ir, Pt and Re in the geological samples within 0.1 ng/g - 10 μg/g range and Os on ng/g level in the ultramafic rocks by inductively coupled plasma mass-spectrometry with external calibration and without chemical removal of main interferences of Zr and Hf was proposed. The samples were prepared after their burning by acid decomposition in the open vessels, melting the insoluble residue with NH4F and with a subsequent cation exchange separation of PGEs from matrix elements by KU-2-8 resin (Russia). The measurements have been carried out using the high resolution mass-spectrometer Element 2 (Germany). The accuracy of the technique on μg/g level has been verified with reference materials: pyrrhotite ore RP-1 (Russia) and sulfide copper-nickel ore Zh-3 (Russia). In addition, the accuracy of the trace level (ng/g) has been verified by comparison of the results obtained in this study with those reported in the literature for international sample of comparison OPY-1, developed by the International Association of Geoanalysts (IAG). The procedural blanks are 0.000n ng/ ml for Os, 0.00n ng/ml for Ru, Rh, Re, Ir and 0.0n ng/ml for Pt and Pd. The detection limits were estimated by taking into account the blanks and their standard deviations (sample mass 1 g, volume 50 ml) and were 0.02 ng/g for Os, 0.07 ng/g for Re, 0.09 ng/g for Rh and Ir, 0.13 ng/g for Ru, 1.0 ng/g for Pt and 1.4 ng/g for Pd respectively. The content of Re was determined in the reference materials RP-1 and Zh-3, and in the sample of comparison OPY-1.
Parshin A.V.,RAS Vinogradov Institute of Geochemistry |
Auzina L.I.,National Research Irkutsk State Technical University
7th EAGE Saint Petersburg International Conference and Exhibition: Understanding the Harmony of the Earth's Resources Through Integration of Geosciences | Year: 2016
Eastern Siberia is one of the prospective hydrocarbon areas. Existing and new fields need water to ensure the economic and technological needs. In the little-studied regions of Eastern Siberia locating wells based on direct hydrogeological features not bring the desired result.The aim is to improve the efficiency of geological exploration in the field of groundwater in complex geological and hydrogeological conditions of oil and gas fields in Eastern Siberia. To maximize the effectiveness of consolidating information and improving the accuracy of forecasting method applied expert estimations and modern GIS technology. The technology is based primarily on archival and remote of the data that allows forecast at the stage of design work. On the basis of the GIS project calculated qualitatively new spatial information, aquatic and morphostructural. Factor analysis allowed to identify from all of the geodata - compact set of indicators related to the abundance of water. For this set proposes scientifically based methods of indicators scaling and mapping. Given a method for the calculation and mapping the new complex index of watery, integrating individual features. Applied open GIS technology, significantly increasing the costeffectiveness of geological exploration. The proposed approach has shown its legitimacy on some fields Chonskoy group.
Auzina L.I.,National Research Irkutsk State Technical University |
Parshin A.V.,RAS Vinogradov Institute of Geochemistry
IOP Conference Series: Earth and Environmental Science | Year: 2016
The article describes the basic methodological elements of system-integrated approach to estimating water abundance in the upper hydrodynamic zone of Eastern Siberia territory to optimize water exploration. The technique is based on materials available at the pre-survey stages of exploration. When processing the information, the integrated geoinformation analysis has been used. © Published under licence by IOP Publishing Ltd.
Skuzovatov S.Y.,RAS Vinogradov Institute of Geochemistry |
Wang K.-L.,Academia Sinica, Taiwan |
Shatsky V.S.,Novosibirsk State University |
Buslov M.M.,Novosibirsk State University
Precambrian Research | Year: 2016
The Baikal-Muya Foldbelt is one of the oldest and the most enigmatic terrain among the Central Asian Orogenic Belt. During the Early (1.0-0.8 Ga) and Late (0.8-0.6 Ga) Neoproterozoic orogenic cycles a notable amount of juvenile crust has been formed in subduction-collision settings along with the reworking of the existing Early Precambrian continental crust. The latter is perfectly presented within the North Muya metamorphic block (Anamakit-Muya zone) including the oldest high-pressure subduction-related rocks in the Central Asia. In order to evaluate the process of the juvenile crust formation in the Precambrian continental unit, whole-rock trace elements along with zircon U-Pb ages and Hf-isotopic composition were analyzed in granites of unknown age that intrude the Precambrian volcanic-sedimentary rocks of the Parama series in the southern North Muya Block. Combined geochemical and zircons isotopic studies indicate the formation of granites with the main pulse at ~810 Ma due to partial melting of a juvenile mafic crust accompanied by reworking of the older crustal material from the continental arc basement. The composition of the granites was controlled by processes of intracrustal differentiation together with a probable contamination by older crustal substrate. Geochemistry and age of the studied granites are comparable to the granites of the Muya complex observed in the volcano-plutonic Kelyana-Irokinda zone. It is assumed that the Muya block and the Kelyana-Irokinda zone (terrane) had possibly been parts of the large continental-arc system beyond the Siberia margins. © 2016 Elsevier B.V..
Kulik D.A.,Paul Scherrer Institute |
Wagner T.,ETH Zurich |
Dmytrieva S.V.,Institute of Environmental Geochemistry |
Kosakowski G.,Paul Scherrer Institute |
And 4 more authors.
Computational Geosciences | Year: 2013
Reactive mass transport (RMT) simulation is a powerful numerical tool to advance our understanding of complex geochemical processes and their feedbacks in relevant subsurface systems. Thermodynamic equilibrium defines the baseline for solubility, chemical kinetics, and RMT in general. Efficient RMT simulations can be based on the operator-splitting approach, where the solver of chemical equilibria is called by the mass transport part for each control volume whose composition, temperature, or pressure has changed. Modeling of complex natural systems requires consideration of multiphase-multicomponent geochemical models that include nonideal solutions (aqueous electrolytes, fluids, gases, solid solutions, and melts). Direct Gibbs energy minimization (GEM) methods have numerous advantages for the realistic geochemical modeling of such fluid-rock systems. Substantial improvements and extensions to the revised GEM interior point method algorithm based on Karpov's convex programming approach are described, as implemented in the GEMS3K C/C++ code, which is also the numerical kernel of GEM-Selektor v.3 package (http://gems.web.psi.ch). GEMS3K is presented in the context of the essential criteria of chemical plausibility, robustness of results, mass balance accuracy, numerical stability, speed, and portability to high-performance computing systems. The stand-alone GEMS3K code can treat very complex chemical systems with many nonideal solution phases accurately. It is fast, delivering chemically plausible and accurate results with the same or better mass balance precision as that of conventional speciation codes. GEMS3K is already used in several coupled RMT codes (e.g., OpenGeoSys-GEMS) capable of high-performance computing. © 2012 Springer Science+Business Media B.V.
Shatsky V.S.,Novosibirsk State University |
Malkovets V.G.,Okayama University |
Belousova E.A.,Macquarie University |
Skuzovatov S.,RAS Vinogradov Institute of Geochemistry
Precambrian Research | Year: 2015
U-Pb dating and Hf-isotope analysis of zircons and whole-rock Nd-isotope analyses were carried out on country rocks of the eclogite-gneiss complex of the North Muya dome in the Anamakit-Muya zone of the Baikal Muya accretionary fold belt. Zircons from garnet-biotite gneisses (Qtz+Kfsp+Pl+Bt+Grt) and garnet-biotite-muscovite schist (Pl+Kfsp+Bt+Mu+Grt+Qtz) were dated using the LA-ICP-MS technique. Based on U-Pb isotope data and CL images zircon grains were divided into three groups: detrital, magmatic and metamorphic zircons. Metamorphic zircons display no zoning or the cloudy zoning. The grains morphology together with the well-developed oscillatory zoning clearly identifies the igneous origin of magmatic zircons. The metamorphic zircons (ages 576-680Ma) have Th/U ratios varying from 0.271 to 0.004, whereas the ratio in magmatic zircons ranges from 0.779 to 0.11. Magmatic zircons from granite-gneisses of the North Muya dome exhibit a relatively narrow spread in the crystallization age with the major peak at ca 764Ma. Younger ages are interpreted as due to the partial resetting of U-Pb system during the subsequent metamorphic evolution. Detrital zircons from two-mica schist sample Mu-93-10 give ages of 1.88-2.66Ga. The oldest detrital zircon from this sample plots near concordia and has a 207Pb/206Pb age of 3.2Ga. Zircons from this sample are characterized by the widest scatter of eHf(t) values (from +13.9 to -15.3) and TCDM model ages (0.82-3.86Ga). Zircons from other samples have a much narrower ranges of eHf(t) (+11.6 to -0.7) and TCDM (0.85-1.52Ga). The involvement of older crustal material is also evident from the whole-rock Nd isotopic compositions. The gneisses and schists exhibit a range of Nd isotopic compositions with eNd(t) values ranging from -3.5 to +3.6 and tNd(DM) from 1.64 to 1.09Ga. The integration of the Hf-isotope data with the age spectra provides with the first evidence for the existence of Mesoarchean crust in the Baykal-Muya sector of the Central Asian Orogenic Belt. © 2015 Elsevier B.V.
Chudnenko K.V.,RAS Vinogradov Institute of Geochemistry |
Palyanova G.A.,Novosibirsk State University
Applied Geochemistry | Year: 2016
It is difficult to interpret the significance of some types of gold alloys without thermodynamic data describing the Au-Ag-Cu-Hg systems. Literature data on the content of copper and mercury in native gold and silver and that of silver and gold in native copper and mercury from gold deposits of different genesis were collected and analyzed. Activity coefficients of the solid solutions in Au-Ag-Cu-Hg quaternary system were estimated. The corresponding calculation module prepared for a "Selektor-C" software package allows calculation of the composition of quaternary solid solutions depending on the change in T,P,X-parameters. Ore formation scenarios were modeled for two objects: i) "hydrothermal" - on the example of formation of quaternary solid solutions in hydrothermal conditions at the Aitik Au-Ag-Cu porphyry deposit (Sweden); ii) "hydrothermal-hypergene" - on the example of formation of Au-Cu intermetallics at the Wheaton Creek placer deposit (Canada). The approach described in our work can be used as an additional tool for the analysis of the genesis of gold deposits and estimation of formation conditions of natural solid solutions of noble metals that are in many cases the main carriers of ore components. © 2015 Elsevier Ltd.
Mysovsky A.S.,RAS Vinogradov Institute of Geochemistry
International Journal of Quantum Chemistry | Year: 2012
We report a new mathematical result: it is possible to construct a spectral representation of the two particles Coulomb potential in the form of |r - r'| -1 = ∑ λ λg λ* (r) g λ(r'). We call this formula λ-decomposition. Two special nontrivial cases of λ-decomposition are reported together with the numerical analysis of the convergence for one of them. It is shown how λ-decomposition allows to construct a new fast algorithm for Hartree-Fock exchange operator calculation, in which the calculation of electron repulsion integrals (ERIs) is completely avoided. The connection between the new method and the resolution of identity and Cholesky decomposition based approaches has been established. Finally, the accuracy of ERIs evaluation within the new approach has been studied numerically. The results demonstrate that it is possible to achieve the accuracy of 10 -10 for the ERIs in wide range of their orbital exponents with relatively small number of terms in λ-decomposition. © 2011 Wiley Periodicals, Inc.
Chubarov V.,RAS Vinogradov Institute of Geochemistry |
Amosova A.,RAS Vinogradov Institute of Geochemistry |
Finkelshtein A.,RAS Vinogradov Institute of Geochemistry
X-Ray Spectrometry | Year: 2016
This paper describes the X-ray fluorescence technique for estimation of the ratio between sulfide and total sulfur in sulfide ores using the influence of sulfur chemical state on positions and intensities of lines (SKα1,2, SKβ1,3) and satellites (SKβ′, SKα3,4) of the sulfur X-ray emission spectra measured by the wavelength-dispersive X-ray fluorescence spectrometer. The samples to be analyzed were prepared as pressed powder pellets on boric acid substrate. The SKα1,2 line chemical shift is the most appropriate parameter for sulfur chemical state estimation because spectral lines in this field are intensive and are almost not affected by spectral overlap of lead spectrum lines. The ratios of line intensities SKβ′/SKβ1,3, SKα3,4/SKα1,2 and SKβ1,3/SKα1,2 were also used as analytical parameters. Forty-one samples of sulfide ores collected in the Russian Far East and Southern Ural deposits have been analyzed. The results of estimation of sulfur chemical state by gravimetric and proposed X-ray fluorescence techniques agree fairly well. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
Kravtsova R.G.,RAS Vinogradov Institute of Geochemistry |
Makshakov A.S.,RAS Vinogradov Institute of Geochemistry |
Pavlova L.A.,RAS Vinogradov Institute of Geochemistry
Russian Geology and Geophysics | Year: 2015
New data on the mineral composition and the first data on the geochemical composition of ores of the Rogovik gold-silver deposit (Omsukchan ore district, northeastern Russia) have been obtained. Study of the regularities of the spatial distribution of ore mineralization shows that the deposit ores formed in two stages. Epithermal Au-Ag ores of typical poor mineral and elemental compositions were generated at the early volcanic stage. The major minerals are low-fineness native gold, electrum, acanthite, silver sulfosalts, kustelite, and pyrite. The typomorphic elemental composition of ores is as follows: Au, Ag, Sb, As, Se, and Hg. The content of S is low, mostly <. 1%. Silver ores of more complex mineral and elemental compositions were produced under the impact of granitoid intrusion at the late volcanoplutonic stage. The major minerals are high-Hg kustelite and native silver, silver sulfosalts and selenides, fahlore, pyrite, chalcopyrite, galena, and sphalerite. The typomorphic elemental composition of ores is as follows: Ag, As, Sb, Se, Hg, Pb, Zn, Cu, and B. The content of S is much higher than 1%. The ores also have elevated contents of Mo, Ge, F, and LREE (La, Ce, and Nd). At the volcanoplutonic stage, polychronous Au-Ag ores formed at the sites of the coexistence of silver and epithermal gold-silver mineralization. Their specific feature is a multicomponent composition and a strong variability in chemical composition (both qualitative and quantitative). Along with the above minerals, the ores contain high-Hg gold, hessite, argyrodite, canfieldite, orthite, fluorapatite, and arsenopyrite. At the sites with strongly rejuvenated rocks, the ores are strongly enriched in Au, Ag, Hg, Cu, Pb, Zn, Ge, Se, La, Ce, Nd, S, and F and also contain Te and Bi. The hypothesis is put forward that the late silver ores belong to the Ag-complex-metal association widespread in the Omsukchan ore district. A close relationship between the ores of different types and their zonal spatial distribution have been established. In the central part of the Rogovik deposit, epithermal Au-Ag ores are widespread in the upper horizons, Ag ores are localized in the middle horizons, and rejuvenated polyassociation Au-Ag ores occur at the sites (mostly deep-seated) with ore-bearing structures of different ages. © 2015.