bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal regime of the earth’s lithosphere and the mantle:
geothermal studies at IPE RAS
Authors: Gliko A. O. , Parphenuk I. O.
Published: May 2019

The paper is devoted to a historical retrospective of the development of geothermal research in the former Soviet Union. The detailed history of the Laboratory of geothermics at the Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS) from the mid-1950s to the mid-1980s when a full range of geothermal studies were conducted by the laboratory is presented. The main results with the special focus on the world-level achievements made by IPE RAS in this field are outlined. The second part of the paper addresses the key recent results including the theoretical studies of heat and mass transfer and numerical modeling of mantle convection.
Gravitational differentiation in the regimes from stokes settling to Rayleigh–Raylor flows
Authors: Trubitsyn V. P.
Published: May 2019

The Earth’s core was formed under gravitational differentiation in the course of the separation of iron and silicates. Most of the iron has gone into the core as early as when the Earth was growing. However, iron continued to precipitate even during the subsequent partial solidification which developed from the bottom upwards. At the different stages and in the different layers of the mantle, iron was deposited in different regimes. In this paper, the mechanisms of the deposition of a cloud of heavy interacting particles (or drops) in a viscous fluid are considered. A new approach suitable for analytical and numerical tracing the changes in the structure of the flows in a two-component suspension under continuous transition from the Stokessettling (for the case of a cloud of large particles) to the Rayleigh–Taylor flows and heavy diapirs (for the case of a cloud of small particles) is suggested. It is numerically and analytically shown that the both regimes are the different limiting cases of the sedimentation convection in suspensions.
Grigory Aleksandrovich Gamburtsev: a person and a scientist
Authors: Gamburtsev A. G.
Published: May 2019

The paper is devoted to the outstanding scientist, academician Grigory Aleksandrovich Gamburtsev, a pioneer in creating seismic methods for mineral prospecting and exploration in the USSR, a founder of the scientific schools and research directions, a theorist and experimentalist.
Analysis of long-term observations of the groundwater level In an aseismic region
Authors: Lyubushin A. A. , Kazantseva O. S. , Manukin A. B.
Published: May 2019

The results of the analysis of continuous precise time series of atmospheric pressure and groundwater level fluctuations in a well drilled to a depth of 400 m in the territory of Moscow are presented. The observations are remarkable in terms of their duration of more than 22 years (from February 2, 1993 to April 4, 2015) and by the sampling interval of 10 min. These long observations are suitable for exploring the stationarity of the properties of hydrogeological time series in a seismically quiet region, which is important from the methodological standpoint for interpreting the similar observations in seismically active regions aimed at earthquake prediction. Factor and cluster analysis applied to the sequence of multivariate vectors ofthe statistical properties of groundwater level time series in the successive 10-day windows after adaptive compensation for atmospheric pressure effects distinguish five different statistically significant states of the time series with the transitions between them. An attempt to geophysically interpret the revealed states is made. Two significant periods – 46 and 275 days – are established by spectral analysis of the sequence of the transitions times between the clusters.
On 100 000-year rhythmicity in geodynamics and paleoclimate
Authors: Bezverkhnii V. A.
Published: May 2019

The 100 000-year rhythmicity in paleoclimate variations in the Quaternary can be associated with the respective oscillations in insolation and seafloor volcanism forced by Solar-Moon gravitation (SMG). This conclusion is based on the wavelet analysis of long time series of the variations in the eccentricity of the Earth’s orbit, different paleoclimatic characteristics, and the existing spectral estimates of variations in SMG and seafloor volcanism.
Experimental methods for studying the wetting properties of oil reservoirs: a review
Authors: Ivanova A. A. , Mitiurev N. A. , Shilobreeva S. N. , Cheremisin A. N.
Published: May 2019

The theoretical principles of the laboratory methods for studying the wettability of unconventional oil formation rocks are discussed and examples of their practical implementation are presented. The comparative analysis of the advantages and disadvantages of each method is presented. It is shown that despite the recent progress in the development of methods for determining the wettability of rocks, they still need to be improved. Examples of their possible improvements are discussed.
Surface wave tomography of the arctic from seismic Rayleigh and Love wave group velocity dispersion data
Authors: Seredkina L. V.
Published: May 2019

The results of studying the deep structure of the Earth’s crust and upper mantle of the Arctic from surface wave data are presented. For this purpose, based on the frequency-time analysis procedure, a representative dataset of group velocity dispersion curves of seismic Rayleigh and Love waves (1555 and 1265 paths, respectively) in the period range from 10 to 250 s is obtained. With the use of a two-dimensional tomography technique for a spherical surface, group velocity distributions are calculated at separate periods. Overall, 18 maps for each type of surface waves are constructed and the horizontal resolution of the mapping is estimated. For four tectonically different regions of the Arctic, the dispersion curves calculated from the tomography results are inverted for the velocity sections of the SV- and SH-waves. Based on the obtained distributions, the main large-scale features are analyzed in the deep structure of the Earth’s crust and upper mantle of the Arctic, and the revealed velocity irregularities are correlated to various geological structures. The results of the study are of considerable interest for further constructing the three-dimensional model of the shear wave velocity distributions and for studying the anisotropic properties of the upper mantle of the Arctic, as well as for building the geodynamical models of the region.
Аccounting for autocorrelation in a linear regression problem on an example of analysis of atmospheric column NO2 content
Authors: Gruzdev A. N.
Published: May 2019

A method is proposed for taking into account a serial correlation (an autocorrelation) of data in a linear regression problem, which allows accounting for the autocorrelation on long scales. A residual series is presented as an autoregressive process of an order, k, that can be much larger than 1, and the autocorrelation function of the processes is calculated by solving the system of the Yule–Walker equations. Given the autocorrelation function, the autocorrelation matrix is constructed which enters the formulas for estimates of regression coefficients and their errors. The efficiency of the method is demonstrated on the base of the multiple regression analysis of data of 26-year measurements of the column NO2 contents at the Zvenigorod Research Station of the Institute of Atmospheric Physics. Estimates of regression coefficients and their errors depend on the autoregression order k. At first the error increases with increasing k. Then it approaches its maximum and thereafter begins to decrease. In the case of NO2 at the Zvenigorod Station the error more than doubled in its maximum compared to the beginning value. The decrease in the error after approaching the maximum stops if k approaches the value such that the autoregressive process of this order allows accounting for important features of the autocorrelation function of the residual series. Estimates have been obtained of seasonally dependent linear trends and effects on NO2 of nature factors such that the 11-year solar cycle, the quasi-biennial oscillation, the North Atlantic Oscillation and other.
About salt fractionation in the process of terrigenous aerosol generation
Authors: Savenko A. V. , Savenko V. S.
Published: May 2019

The content of water-soluble salts in samples of surface soils from arid regions and separated from them fraction <0.1 mm was analyzed. Existence of salt fractionation in the aleurite was shown. The fractionation coefficients, defined as the ratio of ions concentrations in the water extracts from fraction <0.1 mm and soil as a whole, are arranged in the successions: Na > K > Mg > Ca and SO4 > HCO3 > Cl. It was found that the fractionation of salts depends on their solubility: than solubility below, that enrichment of soils fine fraction is more.
A study of the diagenesis of organic matter of peat using Rock Eval pyrolysis
Authors: Melenevskу V. N. , Klimin M. A. , Tolstokorov S. V.
Published: May 2019

We used Rock Eval pyrolysis to examine a peat collection in the Gursky field (located in the Lower Priamurye) during the early stages of diagenesis. This study focused on the top 350 cm of peat, and it also studied the producers of the organic matter. A pyrogram of peat consists of the superposition of three peaks that represent hydrocarbons that desorb at low temperatures (<300°C), intermediate temperatures (300°C–400°C), and high temperatures (>400°C). These peaks represent the lipid, labile, and kerogen components, respectively. We found that diagenetic transformation of organic material was followed by a gradual reduction in lipid and labile components and a simultaneous increase in the kerogen component. This effect is most intense in the top portion of the studied section
Trace elements sorption by bentonite in the presence of bacteria
Authors: Perelomov L. V. , Sizova O. I. , Atroshchenko Yu. M.
Published: May 2019

Sorption of lead and copper by calcium bentonite, living and destroyed cells of gram-positive bacteria Bacillus subtilis, as well as in systems including the clay mineral and one of the biotic components in the concentration range of the elements from 25 to 250 μM was studied. The effect of acidity on the biosorption of trace elements was shown. The maximum biosorption of lead and copper was observed at pH 6 and reached 0.72 and 0.52 mM/g of dry matter, respectively. At pH 6 the maximum biosorption by the destroyed cells was also observed — 0.81 mM/g of lead and 0.71 mM/g of copper. Accumulation of trace elements by living and destroyed cells significantly exceeded their sorption by calcium bentonite. In the ternary systems, including bentonite and bacterial cells or bentonite and cell debris, there was an increase in the sorption of lead and copper compared to bentonite alone. At the same time, the sorption of trace elements by a mixture of bentonite and cell fragments was lower than the additively calculated sorption by the individual components for both lead and copper at all concentrations studied. A similar pattern was observed for the system of living cells and bentonite for copper and living cells and bentonite for lead at low metal concentrations.
Regularities of groundwater quality formation at the abandoned copper mines of Levikha ore field (Middle Urals, Russia)
Authors: Rybnikova L. S. , Rybnikov P. A.
Published: May 2019

In the Urals region in recent decades, dozens of copper mines, which are the most dangerous in terms of environmental impact, have been closed and ﬂooded. In many of them, acid mine waters continue to form, the concentrations of most components in which exceed the permissible values by several orders of magnitude. The formation of the chemical composition of acidic groundwater has a pronounced unsteady character: a sharp increase in the content of all components in the water after ﬂooding and a gradual decline for many years. On Levikha copper mine (Sverdlovsk region) after ﬁlling the depression con in 2007, a site of concentrated discharge of groundwater was formed (technogenic reservoir-a failure in the zone of collapse and displacement). The concentrations of many components 10 years after the completion of ﬂooding are higher than during the development. The analysis of regularities of non-stationary character of hydrogeochemical processes is made on the basis of the data of detailed monitoring and extended deﬁnitions of groundwater quality indicators. The main source of acidic water with increased mineralization is the collapse zone, within which the process of drainage for several decades formed technogenic sulfuric acid weathering crust enriched with secondary minerals. According to the data of numerical geoﬁltration modeling, in the hydrodynamic balance the lateral ﬂow coming from the surrounding areas is 60%, its value is manifested in the dilution of the solution, which is formed in the collapse zone. The time of movement of this ﬂow in the area of collapse is 6–8 years, extremely high values of almost all indicators in the man-made reservoir are observed during this period. According to the inverse physical-chemical modeling (program code Visual MINTEQ ver. 3.0 / 3.1 was used) the composition of rocks, as a result of dissolution-deposition of which underground waters in the area of the ﬂooded mine can be formed, is determined. The duration of the process of formation of acidic groundwater is estimated at tens of years.
Transformation of the montmorillonite structure and its adsorption properties due to the thermochemical treatment
Authors: Krupskaya V. V. , Zakusin S. V. , Tyupina E. A. , Dorzhieva O. V. , Chernov M. S. , Bychkova Ya. V.
Published: May 2019

Complex studies revealed changes in the composition, structure, and properties of bentonite clays from the Taganskoye (Kazakhstan) and Dashkovskoe (Moscow region) deposits due to the thermochemical treatment. The leaching of cations from the interlayer and octahedral positions, protonation of the interlayer and OH-groups, leads to modification of the interlayer and 2:1 layer composition, which in turn contributes to significant changes in properties:-a decrease in the cation exchange capacity due to a decrease in the layer charge and increase in the specific surface due to destruction and partial amorphization. Bentonites from the Dashkovskoye deposit demonstrated higher resistance to thermochemical treatment than the bentonites from the Taganskoye deposit due to the protecting effect of the organic matter. Results of the work showed that even after quite intensive thermochemical treatment (13M HNO3, 90 °C, 5 hours), bentonite clays retain a significant part of the adsorption capacity.
Iron and sulfur isotope factors for pyrite from experimental gamma-resonant studies and heat capacity
Authors: Polyakov V. B. , Osadchii E. G. , Voronin M. V. , Osadchii V. O. , Sipavina L. V. , Chareev D. A. , Tyurin A. V. , Gurevich V. M. , Gavrichev K. S.
Published: May 2019

Pyrite Moessbauer spectra (FeS2) is measured in the temperature range from 90 to 295 K. The temperature dependence of the isomer shift is described by the Debye model with Moessbauer temperature θM=551.4 K. Using these results, we calculated the kinetic energy of thermal vibrations of the iron sublattice of pyrite and the iron β-factor for pyrite:

103lnβ57Fe/54Fe=(1.2665±0.0391)x–(0.4584±0.0283) × 10-2x2+(0.2581±0.0239) × 10-4x3; x=106/T 2 (K-2) The Moessbauer-derived iron β-factor for pyrite agrees well with results of ab initio calculations, 57Fe nuclear inelastic γ-resonant scattering synchrotron experiments and direct isotope exchange experiments between pyrite and Fe2+ dissolved in water.

Heat capacity of pyrite is measured at temperatures from 79 to 300 K. Its temperature dependence are described using the Thirring expansion. Based on this expansion, the kinetic energy of thermal vibrations of total crystalline lattice of pyrite is calculated. The kinetic energy of the thermal vibrations of the sulfur sublattice in pyrite is found by subtracting the iron sublattice kinetic energy from the total kinetic energy of pyrite crystalline lattice. Temperature dependence of 34S/32S β-factor for pyrite calculated from the kinetic energy of the sulfur sublattice is following:

103lnβ34Fe/32Fe=(1.7532±0.0623) x–(1.0470±0.0752) × 10-2 x2+(1.0424±0.1126) × 10-4 x3; x=106/T 2 (K-2)

This 34S/32S β-factor values exhibit a good agreement with of ab initio calculations and isotope-exchange experimental results in the pyrite-sphalerite-galenite system.
Mean contents of volatile components, major and trace elements in magmatic melts from main geodynamic settings of the earth. II. Silicic melts
Authors: Naumov V. B. , Dorofeeva V. A. , Girnis A. V. , Yarmolyuk V. V.
Published: May 2019

As a continuation of our previous study, we estimated the mean contents of volatile, major, and trace components in silicic (>66 wt % SiO2) magmatic melts from main terrestrial geodynamic settings on the basis of our database, which includes (as of middle 2017) more than 1 500 000 determination of 75 elements in melt inclusions and quench glasses from rocks. Among the geodynamic settings are those related to subduction processes (III, island-arc zones originated on oceanic crust and IV, magmatic zones of active continental margins, where continental crust is involved in magma formation) and intracontinent rift and continental hot-spot regions (V). For each geodynamic setting, we calculated the mean contents of elements with confidence limits separately for melt inclusions and groundmass glasses and for the entire data set. Systematic differences were found between the mean compositions of melt inclusions and groundmass glasses from these geodynamic settings. Primitive mantle normalized spider diagrams were constructed for all geodynamic settings. Some ratios of elements and volatile components (H2O/Ce, K2O/Cl, La/Yb, Nb/U, Ba/Rb, Ce/ Pb, etc.) in silicic and mafic melts were compared. Variations in the ratios of various elements to Th, which is one of the most incompatible elements in silicic and mafic melts, were discussed.
Methane and sulfide sulfur in the bottom sediments of lake Baikal
Authors: Gar’kusha D. N. , Fedorov Yu. A. , Andreev Yu. A. , Tambieva N. S. , Mikhailenko O. A.
Published: May 2019

The paper analyzes data on the distribution of methane and sulfide sulfur concentrations in the upper layer of the bottom sediments in different areas of Lake Baikal obtained during expeditions in 2014 and 2015. During the study, concentrations of methane and sulfide sulfur in lake sediments varied from <0.01 to 3.69 μg/g dry sediment (mean 0.34 μg/g) and from 0.002 to 0.830 mg/g dry sediment (mean 0.042 mg/g), respectively. The maximum concentrations of methane were typical of the Northern region, where the waters of the Upper Angara, Kichera rivers flow, and separate stations of profile along the estuary zone of the Selenga River, as well as stations located in the zone of underwater wastewater discharge of Baikalsk and the Baikal pulp and paper mill closed in 2013. A comparison of the distribution of methane and sulfide sulfur concentrations indicates an intense sulfate reduction at the stations with the highest methane concentrations, which suggests the conjugate processes of their generation. Variations of methane and sulfide sulfur concentrations in the studied upper layers of Lake Baikal sediments are caused by the differences in the anthropogenic impact and also by the variability of sedimentation conditions that determine the grain size composition and the content of organic matter, and, as a consequence, the intensity of methanogenesis and sulfate reduction.
Radioecological situation in the area of monazite placer in South Yakutia
Authors: Sobakin P. I. , Gerasimov Ya. R. , Perk A. A.
Published: May 2019

The results of radioecological investigation of the territory of Vasilyevka monazite placer in South Yakutia are given. The processes of deposit development causing radioactive pollution of the territory are described. They induce high exposure rates of gamma-radiation on ground surface and higher concentration of thorium in soil and plants. Identified areas of natural concentrations of thorium in the alluvial sediments, creating the anomalously high values of dose rate of gamma radiation on the surface and is exceeding 9–23 times of the normal natural radiation background. The extent of wind dispersion of thorium from pollution source was estimated along its vertical distribution in a soil profile of podbours.
Estimation of the content and composition of trapped melt in dunite
Authors: Bazylev B. A. , Ledneva G. V. , Bychkova Ya. V. , Kononkova N. N. , Kuz’mina T. G. , Romashova T. V.
Published: May 2019

A method was developed for the quantitative estimation of the content of trapped melt in various dunite types and the composition of this melt on the basis of the major- and trace-element characteristics of the dunites and compositions of their chrome spinels. Our approach is advantageous over the method based on clinopyroxene geochemistry and clinopyroxene–melt partition coefficients for the contents of the light REE and more incompatible elements in melt, comparable with it for the middle REE, and possibly less accurate for the heavy REE and Sr. The estimated mean contents of trapped melt in dunites from ophiolite and concentrically zoned complexes are 1.0–1.5 wt %, which is probably typical of various dunite types, including cumulate dunites from layered complexes. These values are an order of magnitude higher than previous estimates. The correspondence between the compositions of calculated trapped melts in dunites and real natural melts indicates that the estimated contents of trapped melt in dunites are realistic, and the mineral–melt partition coefficients that were used in our calculations are valid for the complexes considered in this paper. In general, the proposed method is suitable for serpentinized dunites, including dunitic serpentinites.
Sapphirine-bearing granulites of the anabar shield
Authors: Nozhkin A. D. , Likhanov I. I. , Savko K. A. , Krylov А. А. , Serov P. A.
Published: May 2019

The results of a detailed study of the mineral and chemical composition, geothermobarometry, and U-Pb isotope dating of zircon of high-aluminous sapphirine-bearing crystals of shales associated with biotite-garnet-sillimanite gneisses, hypersthene-two feldspar and high-potassium hypersthene orthogneisses, Ti-rich and subalkaline metabasites belonging to the Kilegirian Formation of the Daldyn series of the Anabar shield. Unlike the known granulites of the Daldin and Upper Ananbar series, the rocks of this association are enriched in K, Rb, Ba, Th, light REEs, differing in elevated (La/Yb)n. The results of thermobarometry yielded the P–Tparameters of formation and evolution of sapphirine-bearing granulites in the Anabar shield with peak values of UHT metamorphism in the range of T= 920–1000°C at P= 9–11 kbar. Isotope-geochronological data indicate a polymetamorphic evolution of these rocks. Detrital zircon cores in the center of crystals yielded ages of 3.36, 2.75, 2.6, and 2.5 Ga. Later, superimposed metamorphic transformations of the detrital zircon formed rims dated to 2.4, 2.3, 2.2, and 1.8 Ga. The timing of formation of aluminous metasedimentary and associated metamagmatic rocks can be estimated in the interval from 2.5 to 2.4 billion years. A potential provenance source of the detrital zircons could be hypersthene plagiogneisses and metabasites of the Daldyn series with a premetamorphic age no less than 3.3 Ga, and products of their metamorphism of about 2.7 Ga old, and possibly not yet detected in the region Na-K granites with an age of about 2.6–2.5 billion years, known on other shields and enriched with radioactive (K, Th, U) and rare elements. An additional source of clastic material in the formation of aluminous sediments could be the associated two feldspar magmatic rocks of rhyolite composition, having the same model age with them.
Geochemical features, sources and geodynamic
settings of accumulation of the cambrian sedimentary rocks of the Mel’gin trough (Bureya continental massif)
Authors: Ovchinnikov R. O. , Sorokin A. A. , Kovach V. P. , Kotov A. B.
Published: May 2019

The first data about geochemical features of the Cambrian sedimentary rocks of the Mel’gin trough of the Bureya continental Massif, as well as ages of detrital zircons of them are obtained. It is established, that among the detrital zircons from the sandstones of the Chergilen and Allin formations of the Mel’gin trough zircons with Late Riphean (peaks on relative probability plots – 0.78, 0.82, 0.94, 1.04 Ga) and Early Riphean (peaks on relative probability plots – 1.38, 1.45, 1.64 Ga) ages predominate. The single grains have a Middle Riphean, Early Proterozoic and Late Archean ages. We can suppose, that the sources of Late Riphean detrital zircons from sandstones of the Chergilen and Allin formations are igneous rocks of gabbro-granitoids (940–933 Ma) and granite- leucogranites (804–789 Ma) association, identified in the Bureya continental Massif. We can`t assume, what kind of rocks were the source for Middle Riphean and older detrital zircons from the Cambrian sedimentary rocks of the Bureya continental Massif, because in this massif still do not identified complexes older Late Riphean age. The most probable geodynamic conditions of accumulation of the Cambrian deposits of the Mel’gin trough is the conditions of active continental margin, which is corresponding to of Early Cambrian granitoids magmatism.
Stable carbon and nitrogen isotopes in woody plants and herbs near the large copper smelting plant
Authors: Veselkin D. V. , Chashchina O. E. , Kuyantseva N. B. , Mumber A. G.
Published: May 2019

Variations of stable carbon (13С and 12С) and nitrogen (15N and 14N) isotopic composition are analyzed in forest plants subjected to the emissions of large copper smelting plant. The studies were carried out in pine forests at ten test plots near the Karabash copper smelting plant and in the Ilmen State Reserve at South Urals. The 13С/12С and 15N/14N isotopic ratios were analyzed in leaves of plants of different functional groups (with ecto-, ericoid, or arbuscular mycorrhiza; with nitrogen-fixing symbiosis, and non-mycorrhizal). The 13С/12С ratio did not change under technogenic pollution. The low isotopic 15N/14N ratio was established in ectomycorrhizal trees, while the high ratio was found in herbs with arbuscular mycorrhiza, nitrogenfixing symbiosis, and non-mycorrhizal groups. As compared to nonpolluted habitats, the 15N content in leaves near the copper smelting plant increases by 2.7‰ in the ectomycorrhizal trees and by 3.4‰ in undershrubs with ericoid mycorrhiza, and by 2.2‰ in herbs with arbuscular mycorrhiza. This indicates a significant change in conditions of mineral feeding of plants under heavy metal pollution of natural ecosystems.
Conditions of ore formation of the Aunikskoye F-Be deposit (Western Transbaikal)
Authors: Damdinova L. B. , Damdinov B. B. , Rampilov M. O. , Kanakin S. V.
Published: May 2019

This study examines the compositions of the ore and the ore formation solutions, conditions of formation, and sources of Be mineralization using the Aunikskoye F-Be deposit, which is an integral part of the Western Transbaikal beryllium-bearing provinces, as a representative example. Further, the main factors responsible for the formation of beryllium mineralization were evaluated. The ore deposits are presented by the feldsparic–fluorspar–phenacite–bertrandite metasomatites formed in the carboniferous limestones during their metasomatic alternation with hydrothermal solutions by introducing F, Be, and other associated elements. The formation of early phenacite–fluorspar association occurred in high-fluorite СО2-containing solutions of elevated alkalinity with a salinity of ~10.5%–12% wt eq. NaCl in a temperature range of ~ 370–260 °С at pressures ranging from 1873 to 1248 bar. More recent fluorite and bertrandite deposits were formed by solutions with a salinity of 6.4%–7.7% wt eq. NaCl in a temperature range of ~156 °C–110 °C and a pressure range of 639–427 bar. The examination of the isotopic signature of the ore association minerals confirmed the apocarbonate nature of the main ore deposit and allowed the determination of the magmatogene nature of the ore-forming paleothermal springs, which are the source of subalkaline leucogranites. The primary factors that influenced the formation of the F-Be ore included the reduction of the F activity in solutions because of the binding of Ca and F in fluorite as well as because of the decrease in temperature during the ore deposition process. The elevated alkalinity of the ore-formation solutions resulted in the low solubility of the Be complexes, which caused a relatively low Be content in the ore and a relatively small amount of mineralization in the deposit.
Primorskoye epithermal Ag-Au deposit (Northeast of Russia): geologic aspects, mineralogic and geochemical features, and ore formation conditions
Authors: Savva N. E. , Volkov A. V. , Sidorov A. A. , Kolova E. E. , Murashov K. Yu.
Published: May 2019

As a potentially large Ag-Au epithermal deposit, Primorskoye comprises the following three areas: Kholodny, Spiridonych, and Teply. This deposit is located in the Omsukchan district of the Magadan Region, where similar deposits, including Dukat, Lunnoye, Goltsovoye, Arylakh, Tidit, and Perevalnoye, have developed. The deposit can be attributed to the Kalalagian volcano-tectonic depression and is localized in a flat-lying rock mass in the Late Cretaceous ignimbrites and rhyolites having thicknesses of greater than 700 m, which is cut through by numerous dykes of medium and major composition. According to the drilling data, the solid mass of leucocratic granites is located in deposits at a depth of 400–500 m with outcrops in the northeastern part of the ore field. The presence of Bi-containing galena and matildite, the availability of mid and high temperature facies of metasomatites (epidote and actinolite), and the specific physical and chemical conditions during the formation of the epithermal Ag-Au ores indicate the intrusive position above and the role of granitoids as generators of high temperature magmatic fluids, which introduced Bi and heated the rocks enclosing the mineralization. The geochemical features of the ores are well correlated with their mineral compositions. The high concentrations of Mn and Ag, elevated concentration of Au, low concentrations of Cu, Pb, Zn, Sb, As, Bi, and Te, low sum of REE, and negative Eu- and positive Се-anomalies were observed. The high values of the Te/Se, Sr/Ba, Y/Ho, and U/Th indicators in the ores are associated with the deposit location in the zone of granitoid massif effect. Further, the physical and chemical parameters of ore formation in the Teply area are unusual and are characterized by high temperatures, low concentrations of salts, and fluid density, which are indicative of the typical “dry steam” conditions. The obtained results allow the Primorskoye epithermal deposit to be attributed to the intermediate class. The information present in the article is practically valuable for the regional forecast and metallogenic developments as well as for searching and assessing the epithermal Ag-Au deposits.
Mineral types of gold deposits and regularities of their distribution in south-eastern part of the East Sayan
Authors: Damdinov B. B.
Published: May 2019

Based on the mineral composition, gold deposits of the south-eastern part of the East Sayan were typed. The most informative classification criterion for typing is the composition of the gold producing ore mineral associations which are specific to each of the selected types. Whereas using other criteria different structural, composition or genetic characteristics of deposits will necessarily overlap. Eight mineral types of deposits, characterizing the main gold-bearing ore mineral associations were identified: gold-polysulfide, gold-quartz, gold-telluride, gold-tetradymite, gold-stibnite, gold-bismuth-sulfosalt, gold-pyrrhotite and gold-fahlore types. Regional metallogenic divisions such as structural metallogenic zones, differ somewhat in the characteristics of mineralization. Thus, within the Bokson-Garganskaya metallogenic zone, gold-quartz, gold-polysulfide and gold-pyrrhotite types dominate, although gold-telluride and gold-bismuth-sulfosalt types are common in the western part of this zone. In the Ilchir zone, gold-fahlore type deposits are developed. Khamsarinskaya zone is characterized by gold-tetradimite and gold-antimonite deposits existence. It has been established that the mineral types of deposits formation depend on the enclosing rock complexes composition. Thus, gold-quartz, gold-polysulfide and gold-pyrrhotite types are formed in association with the ophiolites and rocks of the Archean crystalline basement. At the deposits associated with granitoid massifs, minerals of metalloids, such as bismuth-bearing sulfosalts, stibnite, tetradimite and tellurides, take a leading role in ores. In the carbonate strata, a gold-fahlore type is formed. The proposed classification allows typing all known gold deposits in the south-eastern part of the East Sayan and can be applied to adjacent regions.
Hydrocarbons in the basement of the South China Sea (Vietnam) shelf and structural-tectonic model of their formation
Authors: Kerimov V. Yu. , Leonov M. G. , Osipov A. V. , Mustaev R. N. , Khai Vu Nam
Published: May 2019

Research of genesis of hydrocarbon accumulations located within pre-Cenozoic basement of the South China Sea shelf (Vietnam) presented. Formation of hydrocarbon deposits is confined to the protrusive massifs of granites that have undergone structural and tectonic processing at the stage of prototectonics and postmagmatic tectonics. The totality of post-structure-forming processes led to a change in the viscosity properties of rocks, to their tectonic and material heterogeneity and stratification and, as a consequence, to vertical and lateral redistribution in space with the formation of granite protrusions. The mechanisms of formation of voids and oil and gas traps within the protrusions are considered. Based on the similarity of the geochemical characteristics and biomarker parameters of the oils and organic matter in the Oligocene-Miocene sediments and in the basement rocks, a conclusion has been made about the organic nature of the oils in the basement of the shelf of the South China Sea (Vietnam). Possible mechanisms of migration and accumulation of hydrocarbons in basement rocks are considered. It is confirmed that the formation of hydrocarbon deposits occurred due to lateral and downward migration of hydrocarbons through the contact area from the Oligocene-Miocene source rocks into crystalline massifs — into voids and increased fracture zone in the protrusions.
A tectonic remnant of the mesoarchean oceanic lithosphere in the Belomorian Province, Fennoscandian Shield
Authors: Slabunov A. I. , Shchipansky A. A. , Stepanov V. S. , Babarina I. I.
Published: May 2019

The results of the detailed geological mapping, coupled with the isotope-geochemical study of a metamorphosed mafic-ultramafic complex known as the Central Belomorian Belt located in the Belomorian province of the Fennoscandian Shield, are reported.

The protholith of the complex is ~ 2.9—3.1 Ga old. It has been subjected to two 2.87 and 1.87 Ga structural-metamorphic reworking. This complex is one of the oldest in the Belomorian Province.

We present several lines of evidence showing that these lithologies constitute a tectonic remnant of the Mesoarchean oceanic lithosphere, rather than any other mafic-ulramafic complex from the other geodynamic settings. The Central-Belomorian high grade mafic-ultramafics reveal a clear geochemical coherency, which implies their genetic relationships. Their mafic protholiths stem from the partial melting of a mantle peridotite protholith. The petrologic modelling has shown that primary melts were formed in the garnet lherzolite field at a pressure of 3.5–3.8 GPa at ambient mantle potential temperatures of 1520–1550 °С which led to an emergence of ~ 25–30 thick oceanic crust. The available geochemical data suggest that the complex was formed at the initial stage of subduction. It marks the start of early continental crust-forming processes in the Belomorian Province.
Late Vendian kotlinian crisis on the East European Platform: lithogeochemical indicators of depositional environment
Authors: Maslov A. V. , Grazhdankin D. V. , Podkovyrov V. N.
Published: May 2019

Sharp changes in the biodiversity of fossil organisms in the Upper Vendian of the East European Platform are considered as the manifestation of global crisis immediately prior to the “Cambrian Explosion.” However, they could be caused by local environmental perturbations. Variations of some lithogeochemical indicators of depositional environment (indicators of paleoclimate, exhalation activity, redox settings, and paleobioproductivity) were analyzed in order to establish the possible influence of sedimentary systems on evolutionary processes in the Late Vendian and at the boundary with the Cambrian. The applied algorithm of lithogeochemical studies revealed no significant perturbations in physical properties of the environment on a scale of sedimentary basins. The obtained data suggest that local factors did not affect the evolution of Ediacaran biota on the East European Platform and confirm the global nature of transitions between the Redkinian, Belomorian, and Kotlinian biotas.
Terrigenous sedimentation on the submarine Shirshov Ridge (Bering Sea) during the last deglaciation
Authors: Murdmaa I. O. , Dorokhova E. V. , Ovsepyan E. A. , Dara O. M. , Nürnberg D.
Published: May 2019

The submarine Shirshov Ridge is an independent system of terrigenous sedimentation, which is geomorphologically isolated from bottom terrigenous influx into the deep-water basin of the Bering Sea. Using the ridge as example, we studied background hemipelagic sedimentation of the finely dispersed terrigenous suspended material from water column and deposition of the coarser grained ice-rafted material in the western part of the deep-water basin. The grain-size and mineral composition of postglacial sediments of the Shirshov Ridge was studied in cores SO201-2-85KL and SO201-2-77KL taken from local basins in the central and southern parts of the ridge, respectively. Statistic treatment of uninterrupted grain-size distributions (GD) of terrigenous component of the postglacial sediments by end-member (EM) modelling revealed that the grain-size distributions of terrigenous sediments from two cores are determined by the mixing of three EMs. EM-1 and EM-2 reflect the hemipelagic sedimentation with and without bottom currents influence respectively, while EM-3 with mode at fine-grained sand characterizes GD of the ice-rafted material. Reconstructed mechanisms of terrigenous influx on the Shirshov Ridge involve advection of the suspended matter with surface and intermediate water masses and ice-rafting. The relative role of both mechanisms of the terrigenous sedimentation under the influence of varying bottom current velocities for intervals of Last Glacial Maximum, early deglaciation, Heinrich event 1, Bølling–Allerød, Younger Dryas, and Early Holocene is estimated. It is ascertained that the grain-size distribution of terrigenous component is defined by climate variations, sea ice coverage, sea ice drift pathways, conditions of fast ice melting, and mobility of bottom waters. High concentrations of drifting ice or seasonal sea ice cover likely existed above the southern part of the ridge during the second half of the Heinrich 1 event. The low mobility of bottom waters facilitated only the subice hemipelagic sedimentation of fine fractions from the background reserve of suspended material. A sharp reduction of ice-rafted flux was reconstructed for the Bølling–Allerød warming interval. Bottom currents affected sedimentation in the central part of the ridge during the entire deglaciation (in addition to the second half of the Heinrich 1 event), and in the southern part during the Bølling–Allerød, Younger Dryas, and Early Holocene.
Spatial-temporal dynamics of a local population of Black Sea Bottlenose dolphins (tursiops truncatus ponticus barabash, 1940): visual and acoustic methods of description
Authors: Logominova I. V. , Agafonov A. V. , V. Gorbunov R.
Published: May 2019

This work is devoted to research of the Sudak – Novy Svet (Crimea) local population of Black Sea Bottlenose dolphins. Observations and acoustic records were carried out all the year round in 2014 and 2015. Along with visual identification of individuals, for the first time in our country the method of «acoustic identification» was applied (according to the made catalog of «signature whistles»). «Signature whistles» are defined as tonal signals having a frequency contour, unique for each animal, and dominating in its repertoire. In such aspect «signature whistle» can be considered as a peculiar «acoustic marker» of this individual. In the analysis of all volume of the registered whistles of dolphins (about 30 thousands of signals) 206 dominating types (i.e. «signature whistles») have been defined. On the basis of comparison of visual and acoustic data the structure of groups, making the studied population, has been described; the seasonal picture of visit of the water area by various groups has been presented as well as «transit» and «resident» groups have been allocated.
Estimation of primary production in the northwestern part of the Sea of Japan by ship- and satellite-based observations
Authors: Zvalinsky V. I. , Lobanova P. V. , Tishchenko P. Ya. , Lobanov V. B.
Published: May 2019

In this paper, we analyzed data of POI FAB RAS cruise (No. 33) held on «Akademik M.A. Lavrentyev» vessel in the northwestern part of the Japan Sea in May 2004 and compared them with satellite derived data from Climate Change Initiative Ocean Colour (CCI-OC) and Ocean productivity databases. The following in situ data were used for the analysis: CTD-data, assimilation number, nutrients (P, N, Si) and chlorophyll a (Chl). Ship assessments of Chl in the first optical layer were in average 0.5±0.58 mg/m3, while satellite Chl were nearly twice more – 0.95±0.36 mg/m3. Ship assessments of primary production (PP) were 1870±900 mg C/m2day that is 1.5 times larger than satellite derived data - 1226±432. Vertical profiles of nutrients, temperature and Chl showed that main mass of Chl was concentrated in a layer from 20 to 45 m, where the main production is formed. According to values of assimilation number, main production formed in a layer of 0-55 m in the south of the region and 0-30 m in the north. Weak correlation between ship and satellite PP values found in this paper may be explained by low accuracy of satellite derived estimation.
On advective model of the ventilated thermocline
Authors: Mirabel A. P. , Vakulenko N. V.
Published: May 2019

A model of an advective thermocline is proposed for the case of continuously stratified Sverdrup circulation with a ventilated layer caused by the divergence of flows in the Ekman layer: an immiscible layer with homogenized vorticity and a layer of abyssal liquid, which applies to anticyclonic gyre waters. The results of calculations for the Atlantic Ocean (region 15-52°N, 00-63°E) made with this model are presented. With an abyssal density of 28.0, the values of the surface density and density of the unventilated layer grow to the north from 24.2 to 27.0 and from 27.8 to 27.9, respectively, with an almost zonal distribution, i.e. ventilation zones have latitudinal circles. From calculations of the depths of wind circulation, it follows that the ventilating layer is as deep as 900 m in the north-western region and raises to 250 m in the southern and eastern parts of the basin. The same tendency is traced for the depth of the gyre, but here there is an increase in depth from 500 to 1500 m. The active dynamics in the ventilating layer and the shadow area on the eastern border are noted. The structure of the thermocline is demonstrated with a typical zonal section, characterizing a much larger isopycnic increment for ventilated layers than in non-ventilated layers.
The structure and distribution of autumnal zooplankton in the South-Eastern part of the Baltic sea in 2015
Authors: Polunina Ju. Ju. , Lange E. K. , Krechik V. A.
Published: May 2019

Were found peculiarities of the structure and distribution in the autumn plankton of the South -Eastern part of the Baltic sea (SEB) in October 2015 taking into account hydrological and hydrochemical data. There were no changes registered as to the taxonomic composition of phyto- and zooplankton, including no increase in the number of the stenothermic and stenohaline species, as well as no significant differences in the hydrological parameters in comparison with the long-term analogous data. Thus, there was no influence of the winter Major Baltic Inflow in December 2014 on the plankton SEB next autumn. The level of phytoplankton vegetation in the upper homogeneous layer (125±39 thous. cells/l, 664±143 mg/m3) was higher compared to the long-term data. The abundance and biomass of zooplankton (5.1-16.8 thous. ind/m3 and 49-143 mg/m3) were within the typical value for autumn in the studied area. Peculiarity of zooplankton spatial distribution were related to trophic resources and the thermohaline structure of the water column.
Yeso scallop population under climatic and anthropogenic changes of environment in Amursky bay of the Sea of Japan
Authors: Silina A. V.
Published: May 2019

At the study area of industrial and domestic sewages into Amursky Bay at the coasts of Vladivostok city, three main stages in a development of the scallop Mizuhopecten yessoensis population and community of endo- and epibionts of its shell were revealed for 1981–2016. During the first stage lasting until the beginning of 90th, the scallop growth rates and lifetime had decreased, but scallop mortality and degree of the shell bioerosion performed by endolithic polychaeta Polydora brevipalpa had increased. It was a period of an intensification of anthropogenic pollution of Amursky Bay. Further, at the middle of 90th, at a transitional period, the decline in the scallop growth rates had stopped. It was a period of a reduction of the pollution of the water and bottom sediments related to the decrease of sewages due to degradation of industry. During the second stage lasting until the middle of 2000th, the scallop growth rates had increased, but the degree of bioerosion and abundance of epibionts of the scallop shells had decreased. It was a period of the gradual natural depuration of the Bay. Later, during the third stage, which goes on to present day, the scallop growth rates declined again due to an increase of the water euthrophication resulting in the decline of the water oxygen saturation. This was most pronounced for periodic rises of the water temperature caused by quasi-biennial and 7–8-year periodicities of temperature fluctuations. Poaching became one of the negative anthropogenic factors entailing the substantial decline of the scallop population density.
Spatial-temporal changes of macrophytobenthos in the Laspi bay (Crimea, Black sea)
Authors: Pankeeva T. V. , Mironova N. V.
Published: May 2019

For the first time, a comparative analysis of spatial-temporal changes in macrophytobenthos based on a landscape approach was performed in the Laspi Bay for the period from 1983 to 2008. Landscape maps of the Laspi Bay was created, the distribution of the bottom natural complexes with the key Black Sea phytocoenoses was shown. It was found that the plant components of the bottom natural complexes in the Laspi Bay had undergone significant restructuring and degradation during 25 years due to the impact of natural factors and anthropogenic activities in the coastal zone.