T.G. Shumilova1, S.I. Isaenko1, V.N. Bocharov2, V.V. Ulyashev1, S.A. Svetov3, D.A. Mandrygina4, A.A. Zubov1, N.S. Kovalchuck1, N.I. Maksimenko1, V.P. Lutoev1, V.K. Kis5 1Institute of Geology of the Komi Scientific Center, Ural Branch of the Russian Academy of Sciences, Syktyvkar, Russia 2Saint Petersburg State University, Saint Petersburg, Russia 3Institute of Geology of the Karelian Research Centre, Russian Academy of Sciences, Petrozavodsk, Russia 4Zavaritsky Institute of Geology and Geochemistry, Ural Branch of the Russian Academy of Sciences, Yekaterinburg, Russia 5HUN-REN Centre for Energy Research, Budapest, Hungary
Keywords: Karite, diamond, astrobleme, impact metamorphism, fossil
This paper provides a detailed characterization of karite, which is represented by diamond-bearing fossils from the Kara astrobleme that formed from organic matter, specifically from fragments of ungelified wood. A comprehensive range of methods was used for this analysis, including the study of structural features at the atomic resolution level, material composition, and spectroscopic characteristics. The diagnostic features of these fossils are examined, and the mechanisms of their formation and ontogeny are analyzed. A detailed study of the ontogenetic specificity of the diamond fossils, combined with data on their structural and material characteristics, revealed fundamental differences between the mechanisms of their formation and those of typical paramorphs and pseudomorphs. Consequently, these diamond fossils are classified as pseudo-paramorphs. Given the specific conditions required for the formation of the described diamond aggregates and other carbon phases derived from organic remains by impact, it is proposed that a new variety of fossils be distinguished: impact fossils. Finally, the potential use of impact diamond fossils for geological and genetic reconstructions is assessed.
B.B. Kochnev1,2, N.I. Vetrova2, A.I. Proshenkin2 1Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia 2V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Late Precambrian, geochemistry of carbonate deposits, carbon isotope chemostratigraphy, detrital-zircon geochronology, depositional environments, Mana trough, East Sayan
We studied the chemical and isotope (C and O) composition of carbonate deposits and the age distribution of detrital zircon grains from the late Precambrian deposits of the Mana trough at the Sayan segment of the Central Asian Mobile Belt (CAMB). Limestones of the volcanosedimentary Kuvai Group (Mana and Bakhta formations) of oceanic genesis display high positive δ13C values, up to +8.9‰, which, along with other data, constrain their age to the Late Riphean (оr the late Tonian). The Angaloi Horizon strata have near-zero or slightly positive δ13C values, and the minimum detrital-zircon age is ca. 580 Ma, i.e., they can be assigned to the Late Vendian (or the late Ediacaran). In the upper part of the Anastas’ino Horizon, two pronounced positive δ13C excursions contrasting to near-zero values have been established; they mark the base of the Tommotian Stage (Cambrian). The age spectra of detrital zircons from the Angaloi Horizon and the lower bed of the Anastas’ino Horizon demonstrate two Neoproterozoic populations with peaks at 710 and 630 Ma. Zircons of these ages might have formed in volcanic and granitoid complexes at the Sayan segment of the CAMB. The presence of Paleoproterozoic zircon grains in the studied deposits suggests that the accretion of the sedimentary basin of the Mana trough to the Siberian Craton was completed in the early Cambrian. These conclusions are supported by geochemical indicators of the depositional environments of carbonates and by geodynamic reconstructions for the adjacent areas.
V.S. Zykin1,2, V.S. Zykina1, R.N. Kurbanov3,4, A.O. Volvakh1, N.E. Volvakh1, E.L. Malikova1 1V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia 2Novosibirsk State University, Novosibirsk, Russia 3Institute of Geography, Russian Academy of Sciences, Moscow, Russia 4Lomonosov Moscow State University, Moscow, Russia
Keywords: Quaternary, Griva Sequence, Griva relief, aeolian deposits, geochronology, paleosols, optically stimulated luminescence
This article examines the structure, composition, and textural features of the Griva Sequence in the Volchya Griva section and the paragenetically associated relief. Additional data supporting the aeolian origin of the Griva Sequence and the Griva relief are presented. Optically stimulated luminescence and infrared stimulated luminescence dating of the Volchya Griva section indicate that the Griva Sequence formed during the last glaciation and fully corresponds to Marine Isotope Stage (MIS) 2. The findings confirm that aeolian relief formation and the intensification of aeolian processes occurred during cold glacial periods of the Late Pleistocene, when southwesterly winds prevailed. The textural and structural characteristics of the Griva Sequence are similar to those of Upper Pleistocene niveo-aeolian sands that formed in cold, periglacial, arid regions of the world and are distributed along the southern margin of the last glacial ice sheets from Northwestern Europe to Western Siberia and Alaska. The formation of a deflationary truncation and a system of mega-yardangs in the northern part of the Lake Chany basin indicates a significant intensification of aeolian processes at the transition between the deposition of the lower and upper members of the Griva Sequence. The orientation of the Griva relief, which coincides with the prevailing direction of modern winds, suggests that wind directions during the cold and warm epochs of the Quaternary in southern Western Siberia were similar. The complete stratigraphy of the Volchya Griva section, its correspondence to the last glaciation and MIS 2, the presence of the largest Eurasian mammoth faunal locality, its distinct lithological characteristics, and the relatively high degree of its study allow this section to be considered one of the reference sections for the Upper Pleistocene of Siberia. It should be regarded as the stratotype of the widely distributed Griva Sequence in this area, which is proposed as a separate Baraba horizon (formation) for the south of Western Siberia, comprising the Eltsovka and Bagan loesses and the Suma soil that separates them.
V.V. Babich
V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Climate, paleoreconstruction, global warming, anthropogenic factor, greenhouse effect, empirical modeling
Climate has a profound effect on human life and plays a significant role in its history. There are numerous examples of serious social upheavals of local and regional proportions over the last few millennia associated with climate change. Therefore, current global warming and its causes are one of the most pressing and controversial issues in both the scientific and public communities. In this paper, we have assessed the possible contribution of the anthropogenic factor in the formation of climate in different regions of the world during the industrial period (since 1850) by analyzing data on past conditions of the climate system over a sufficiently long time interval. Using harmonic analysis, we have constructed empirical models of climate change over time for these regions and, by extrapolating them to the industrial period, have obtained “natural” scenarios of temperature variations that take into account only the impact of the natural environment and exclude the anthropogenic factor. In all studied regions, instrumentally recorded temperature values significantly exceed the “model” ones. On average, according to “natural” scenarios, the global air temperature should have increased by ~0.02 °C during the industrial period; however, it actually increased by ~0.94 °C. The deviation has been evident since around 1920, gradually increasing subsequently. These facts may indicate the manifestation of an anthropogenic factor that makes a certain contribution to current global warming.
S.A. Primakov, K.V. Sukhorukova
Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Lateral logging sounding, numerical modeling, numerical inversion, 2D axisymmetric geoelectric model, oil-and-gas-bearing reservoir, resistivity, northern fields of Western Siberia
We present the results of numerical modeling and inversion of lateral logging sounding (LLS, or BKZ in Russian) data to determine the geoelectric parameters for oil-and-gas-bearing reservoirs of the northern fields in Western Siberia. The research provides the analysis of synthetic LLS signals calculated for a typical model of the Achimovo Formation of the Yamburg field, which is characterized by small reservoir thickness. We have considered the influence of changes in parameters such as the formation resistivity, the thickness of the invasion zone, and the depth shift on the LLS signals. We have assessed the accuracy of reservoir parameter reconstruction using 2D numerical inversion, have determined areas of equivalence, and have proposed recommendations for minimizing errors. The results show that the greatest sensitivity of LLS signals corresponds to changes in the resistivity of a formation and the thickness of the invasion zone, with the error in determining the formation resistivity being up to 12%.
R.A. Valiullin, M.S. Gayazov, F.F. Davletshin
Ufa University of Science and Technology, Ufa, Russia
Keywords: Active thermometry, temperature, horizontal well, fluid flow rate, experiment, natural thermal convection
This paper presents the development and experimental validation of an active thermometry method for quantitatively assessing the fluid flow rate in horizontal wells. Two approaches are investigated in experiments on a physical well model under single-phase flow conditions: the calorimetric method, based on the integral superheat of a homogenized flow, and the convective method, which relies on the relationship between the heated pipe wall temperature and the flow rate. The Richardson number (Ri) is identified as the key criterion governing the heat transfer mechanism. For Ri > 1 (low flow rate), thermogravitational effects dominate, leading to significant thermal stratification of the flow. Under such conditions, the calorimetric method proves more reliable and enables flow rate determination with high accuracy (a deviation of ≤ 10%). The limitations of the convective method are also identified. In this study, the interpretation of the convective method considers only the forced convection component (Dittus-Boelter model). This method is valid only for Ri < 0.1 (high flow rates). This work provides a methodological foundation for further development of the method, with key directions including the refinement of the convective model to account for free (natural) convection and the adaptation of both approaches to multiphase flow conditions.
O.A. Gulevich, L.B. Volkomirskaya
Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences, Moscow, Russia
Keywords: GPR, amplitude-frequency analysis, deep GPR, electromagnetic CDP, amplitude-frequency characteristics, AFC
This study analyzes the amplitude-frequency characteristics (AFC) of deep ground penetrating radar (GPR) data gathered using variable offsets within the permafrost of the Nadym District, Yamalo-Nenets Autonomous Okrug. The initial frequency response of the raw data, which underwent only basic pre-processing, is presented, evaluating the effects of transmitter-receiver separation (100-750 m) as well as the spatial and depth-based placement of the analysis zone. This approach reveals the spectral evolution of electromagnetic signals within the geological environment during the late stages of the process. Results indicate that as the distance from the source increases, the signal undergoes standard attenuation, alongside three primary spectral effects: a downward frequency shift of the peak amplitude, a narrowing of the spectral bandwidth, and a significant rise in low-frequency components, the latter being primarily attributed to zero-line drift. Adopting spectral analysis techniques from seismic exploration for deep GPR data is a promising way to refine data processing and improve subsurface interpretation.
A.M. Soldatenko1, M.S. Sudakova2,3 1Institute of Geography of the Russian Academy of Sciences, Moscow, Russia 2Lomonosov Moscow State University, Moscow, Russia 3Earth Cryosphere Institute, Tyumen Scientific Center, Siberian Branch of the Russian Academy of Sciences, Tyumen, Russia
Keywords: Neural network, diffraction hyperbolas, machine learning, ground-penetrating radar, polythermal glacier
This article discusses the development of a methodology for creating a semi-synthetic dataset to train a neural network for the detection and segmentation of hyperbolic diffractions in ground-penetrating radar (GPR) data. The proposed method offers a solution by generating annotated data where target synthetic objects are placed onto real background sections that are confirmed to be free of the target objects. This approach enables model fine-tuning without direct manual labeling for any specific survey type. The final algorithm was successfully validated on GPR data from the Austre Grønfjordbreen glacier. This solution will significantly simplify the analysis of the internal structure of polythermal glaciers and allow us to assess their hydrothermal structure.
Spectral decomposition is a widely used method of qualitative seismic interpretation, a key limitation of which lies in the subjective selection of frequency components for visualization. Existing approaches based on the analysis of the global Fourier amplitude spectrum do not account for the temporal localization of the signal’s spectral content. We introduce a new method for automatic frequency selection based on approximating local spectra obtained via the short-time Fourier transform (STFT) as a linear combination of three Morlet wavelet spectra. This approach enables the extraction of time-dependent frequency trajectories that capture the evolution of the signal’s spectral content, rather than relying on a fixed frequency triplet over the entire interval. We have solved the optimization problem using the differential evolution algorithm and have tested the method on field data from the West Siberian oil-and-gas province. Quantitative evaluation using Shannon and Rényi entropy metrics, as well as a colorfulness metric, has shown increased visual separability and color contrast in RGB composites. The proposed method reduces the subjectivity of interpretation and ensures reproducible results.
A.A. Tamrazyan, R.K. Gasparyan, A.H. Avdalyan, M.V. Ohanyan
Nazarov Institute of Geophysics and Engineering Seismology of the National Academy of Sciences of the Republic of Armenia, Gyumri, Armenia
Keywords: Magnetic survey, anomalous magnetic field, ultrabasic rocks, hydrothermal alteration, tectonic faults, Lori Region
The results of magnetic survey investigations conducted in the floodplain areas of the Yellow and Black rivers in the Lori Region of Armenia (northern part of the Republic of Armenia) are presented. Based on field observations, digital and graphical maps of the anomalous magnetic field (∆Ta) and its three-dimensional model were constructed. Analysis of the anomalous magnetic field structure made it possible to identify a number of positive and negative anomalous zones associated with geological formations differing in magnetic properties. It has been shown that the positive anomalies are caused by the presence of ultrabasic rocks (peridotites, pyroxenites) exposed along the left bank of the Yellow River and the right bank of the Black River. An extensive negative anomaly zone has been identified and interpreted as a reflection of a tectonic fault zone and the adjacent thick area of hydrothermally altered rocks. Comparison with the data on the physical properties of rocks confirmed the high contrast of magnetic characteristics between the ultrabasic and ore-hosting rocks.
M.I. Epov1, N.N. Mikhailov2,3,4, О.Е. Аксютин5, V.N. Sokotuschenko2, O.M. Ermilov2,6 1Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia 2Gubkin Russian State University of Oil and Gas, Moscow, Russia 3Institute of Oil and Gas Problems, Russian Academy of Sciences, Moscow, Russia 4M.V. Lomonosov Moscow State University,Moscow, Russia 5PJSC “Gazprom”, Saint Petersburg, Russia 6LLC “Gazprom Dobycha Nadym”,Nadym, Russia
A new concept for multivariate modeling of filtration in anthropogenically altered near-borehole zones (NBZs) is presented. It integrates mechanical colmatation, filtration deformation of skeleton, thermobaric expansion of rock-forming minerals, and capillary entrapment of fluids. A generalized multiplicative permeability model has been developed:
allowing for the description of the radial and pressure distributions of filtration parameters. Based on an analysis of a system of continuity equations and Darcy’s law with variable coefficients, integral relationships for calculating the skin factor and well flow rate are derived. It is established that failure to account for the combined effects of these mechanisms leads to systematic relative errors (up to 40–50 %) in productivity forecasts in zones of maximum anthropogenic impact. A differentiated approach to selecting inflow stimulation methods is proposed based on identifying the dominant mechanism of NBZ damage.
A.F. Khokhryakov1,2, I.D. Novoselov1, D.V. Nechaev1, Yu.N. Palyanov1,2 1V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences,
Novosibirsk, Russia 2Novosibirsk State University, Russia
Experimental studies were conducted to model diamond resorption during oxidative mantle metasomatism at a pressure of 6.3 GPa, a temperature of 1000-1300 °C, and fO2
corresponding to WM (wustite-magnetite) and HM (hematite-magnetite) buffers. Diamond crystals were placed in forsterite and diopside aggregates with the addition of water in amounts ranging from 1 wt.% to 4 wt.%. As a result, diamond oxidation reactions were realized in the forsterite-diamond-H2O and diopside-diamond-H2O systems in a solid-phase matrix, in accordance with the EMOD (enstatite-magnesite/olivine-diamond) and DCDD (dolomite-coesite/diopside-diamond) equilibria. Changes in the morphology of resorbed diamonds and the composition of newly formed phases depending on the water content in the systems were studied. It has been established that at relatively low water contents (up to 2 wt.%) in the system, diamond dissolution/resorption occurs predominantly through negative trigons and trigonal layers. As a result, the diamond forms obtained during resorption are similar to so-called laminar dodecahedrons or octahedral habit crystals with a polycentric face structure, which are traditionally considered typical diamond growth forms. At higher water concentrations (4 wt.%), diamond resorption occurs with the formation of ditrigonal and shield-shaped layers on the {111} faces, which are typomorphic for diamond dissolution processes in hydrous melts and fluids. Typical rounded diamond crystals have not been observed in the forsterite-diamond-H2O system due to uneven surface resorption.
O.M. Turkina1, A.D. Nozhkin1, T.V. Donskaya2, U.S. Efremova2 1Sobolev Institute of Geology and Mineralogy, SB RAS, Novosibirsk, Russia 2Institute of the Earth's Crust, SB RAS, Irkutsk, Russia
Keywords: metasedimentary rocks, Neroi Group, detrital zircon, Neoproterozoic, Gutara-Tumanshet Trough, Siberian platform
A Paleoproterozoic age was inferred for metasedimentary rocks of the Neroi Group in the Gutara-Tumanshet Trough, allowing their correlation with metasedimentary deposits of Urik-Iya and Elash grabens in the southwestern Siberian Craton. This paper presents the first zircon age data for garnet-biotite gneisses, garnet-two-mica schists, and quartzites of the Alkhadyr and Tumanshet formations of the Neroi Group. Age spectra of detrital zircons demonstrate dominant Neoproterozoic (1100-600 Ma) and subordinate Paleoproterozoic and Archean data. The upper sedimentation boundary is determined by the age of the Malkhan granite and gabbroids of the Tartai massif, which intruded into the Neroi Group deposits at 740-712 Ma. The lower boundary of sedimentation is marked by the youngest zircon grains, aged 745-765 Ma, and exhibiting oscillatory zoning characteristic of magmatic zircon, which constrains the deposition of the Neroi Group to the Cryogenian. Growth of unzoned zircons with an age of ca. 600 Ma and extremely low Th/U (<0.1) in the rocks of Alkhadyr formation was resulted from Vendian metamorphism, widely manifested in the folded belts of the southern framing of the Siberian Craton. The age of detrital zircons, combined with the model Nd ages of gneisses and schists (2.7-1.9 Ga), indicate that the source province contains Early Precambrian magmatic/metamorphic complexes and dominant Neoproterozoic magmatic associations, formed by remelting of older, Paleoproterozoic crust. These conditions are satisfied by the Early Precambrian rock complexes of the Sharyzhalgai, Birusa and Angara-Kan blocks of the southwestern Siberian Craton and the Neoproterozoic granitoids of the Trans-Angara part of the Yenisei Ridge, respectively. It is assumed that formation of Gutara-Tumanshet Trough in the late Neoproterozoic occurred on the Early Precambrian basement in an intracontinental setting.
R.V. Kuzhuget1, N.N. Ankusheva2, A.Sh. Shavekina3, Yu.A. Kalinin3, A.A. Redina3 1 Tuvinian Institute for Exploration of Natural Resources, Siberian Branch of the Russian Academy of Sciences, Kyzyl, Russia 2 South Urals Federal Research Center of Mineralogy and Geoecology, Ural Branch of the Russian Academy of Sciences, Miass, Russia 3 V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Gold-telluride ore mineralization, epithermal mineralization, quartz, fluid inclusions, stable isotopes, Tuva.
For the Ovur-Ongesh gold-telluride mineralization, 2 ore stages were determined. In ore stage I, gold, electrum, Au-Ag tellurides (petzite Ag3AuTe2, mutmannite AgAuTe2, sylvanite AgAuTe2, kostovite AuСuTe2), uytenbogaardtite Ag3AuS2
were formed; in ore stage II – gold, electrum, calaverite, petzite, hessite, petrovskaite AuAg(S,Se)2, fichesserite Ag3AuSe2
with naumannite Ag2Se and acanthite Ag2S. Fluid inclusions data in quartz (microthermometry, Raman spectroscopy) showed that minerals of ore stage I were formed at P ~0.95–1.3 kbar from Na-K chloride fluid with salinity from 6.9 to 33.1 wt % NaCl eq. at temperatures of 372–327 °C, ore stage II – from NaCl fluid with a salinity from 6.6 up to 8.6 wt % NaCl eq. at 257–227 °C. The δ18ОH2O values of ore stage I fluid vary from +8.1 up to +6.9 ‰ (T=330 °C), ore stage II – from +4.5 up to +3.5 ‰ (T=245 °C) that suggested the fluid has magmatic origin during the early ore-forming stages, and, at later stages, the fluid was mixed with meteoric water. The wide range of fluid salinity from 33.1 up to 6.9 wt % NaCl eq. may be due to dilution of high saline magmatic fluid with by heated meteoric water. The δ³⁴S(H₂S) values of the fluid – ranging from -6.3 to -2.7 ‰ for the I ore stage and from -6.3 to +5.5 ‰ for the II one indicate that, in addition to magmatic fluid, hydrothermal fluid of a different origin participated in mineral formation. The results from mineralogical, fluid inclusion, and isotopic studies demonstrated the similarities between the Ovur-Ongesh ore occurrence and the gold-telluride mineral type associated with volcano-plutonic complexes.
This study assesses the capabilities and prospects for reinterpreting legacy electrical well logging data acquired in gas-bearing Cretaceous reservoirs of Arctic fields in Western Siberia. The limited suite of electrical logging measurements acquired in older wells in northern fields, together with the specifics of the geoelectric conditions, makes it necessary to rely primarily on lateral logging sounding (BKZ) data. In intervals with pronounced vertical heterogeneity, these data are difficult to interpret because of the unfocused response of the gradient arrays. However, previously disregarded features of the acquired data can now be accounted for, substantially improving the reliability of interpretation results. One approach that implements this concept is multilayer inversion. Multilayer inversion was applied to analyze well logging data from more than fifty wells in the Yamal-Gydan, Nadym-Pur-Taz and Yenisei-Khatanga regions. Detailed geoelectric models were constructed for the Pokur, Tanopcha, and Shuratov formations. The results show that multilayer inversion can substantially enhance the informativeness of legacy electrical logging data, enabling determination of the electrical resistivity of reservoir beds that cannot be reliably evaluated using layer-by-layer approaches. Under the geoelectric conditions considered, improving the accuracy and resolution of resistivity estimates may lead to a substantial refinement of hydrocarbon reserves. The results demonstrate the potential of electrical log processing approaches that account for the influence of heterogeneous shoulder beds when reinterpreting well logging data. The most promising targets for reinterpretation are intervals characterized by complex geoelectric conditions, where the results of layer-by-layer interpretation are most prone to error.
The paper presents the results of a comprehensive lithological, bio-, and chemostratigraphic study of the Ust'yarega Formation stratotype (Lower Frasnian), located on the northeastern flank of the Ukhta Anticline (South Timan). Based on lithofacies analysis, depositional environments are reconstructed and a relative sea-level curve is established. The ~42 m thick formation exhibits a distinct two-part subdivision. The lower subformation (~19 m), composed of fine-grained siliciclastic sediments, accumulated in middle- to outer-ramp settings during the filling stage of the Timan Graben. The upper subformation (~23 m), represented by argillaceous-carbonate sediments, transgressively overlies the underlying deposits along a regional unconformity surface. Its depositional settings corresponded to a deep shelf and a gentle slope of a residual basin located over the northeastern flank of the paleograben. The signatures of global eustatic events identified in the studied section are characterized by carbon (δ13C) and oxygen (δ18O) isotope data. The Genundewa Event is distinguished by stable positive δ13C values against the background of negative shifts in the underlying and overlying deposits. The subsequent Early–Middle Frasnian Carbon Isotope Excursion (EMF CIE) is recorded by three shifts: the Pre-Timan Event is marked by the first (positive) excursion, the Timan Event proper by the second (negative) excursion, and the Middlesex Event by the third (positive) excursion. The Tr Isotope Event represents the positive δ13C anomaly preceding the EMF CIE. The upper subformation is biostratigraphically constrained by FZ 2 – FZ 4 conodont zones and correlated with the Sargaevian Regional Substage. The chronostratigraphic interval corresponding to the lower subformation is found to be missing from the current regional stratigraphic chart. To fill this gap, it is proposed to introduce a separate regional unit – the Ust'yarega Regional Substage, which will provide a continuous stratigraphic succession of regional horizon stratotypes in South Timan.
The composition and conditions of formation of the absorbed cation complex (ACC) of montmorillonite, which was formed on the thermal field of the modern geothermal system of the Kambal Volcanic Range, located in the south of Kamchatka, are considered. The 9-m-thick layer of hydrothermal clays is composed mainly of montmorillonite and has a vertical zonation due to the upward flow of alkaline metal-bearing thermal waters and the influence of meteoric waters. Vertical zonation is also observed in the composition of PCC, which is caused by both the form of the metals in the pore solutions and the presence of an evaporative barrier. Montmorillonite absorbs a wide range of elements from the pore solutions, and Al, Fe, Zn, Cu, Rb, Cs, Li, and other elements are fixed in the composition of ACC. The absorption of these elements by montmorillonite through cation exchange is due to their form in the solution. In the carbonate leaching zone, aluminum was not absorbed by montmorillonite because it was in the form of an anionic complex, but as it moved towards the sulfuric acid leaching zone and transitioned to a cationic hydrated form, aluminum began to be absorbed by montmorillonite. The iron content in the ACC for the carbon dioxide leaching zone is about 30-100 g/t, but when it comes to the sulfuric acid leaching zone, the iron content increases by almost an order of magnitude, reaching values over 1300 g/t. Both aluminum and iron clearly mark the vertical zoning in the composition of the ACC montmorillonite. The calcium content is increased in the carbon dioxide leaching zone, where carbonate mineralization is developed, and the anion composition is dominated by the hydrocarbonate ion. Ore elements, such as zinc and copper, are present in the carbon dioxide leaching zone at levels of up to 1 g/t, but their content in the sulfuric acid leaching zone increases to 76 and 20 g/t, respectively. The group of alkali metals, which are poor complexing agents, is concentrated mainly in the upper part of the section, closer to the surface, and in the evaporative barrier. The lithium content in the lower part of the clay layer is 0.3 g/t, while it reaches 1 g/t in the upper part of the section. Rubidium and cesium are also concentrated in the upper part of the clay layer, where their contents reach 1.3 g/t and 17 g/t, respectively. In the lower part of the section, the content of rubidium and caesium generally varies slightly, averaging 0.5 and 3 g/t, respectively. As the acidity increases, more metals are converted to cationic forms and absorbed by montmorillonite, while rare alkaline elements are concentrated within the evaporative barrier.
Z.N. Proshkina, M.G. Valitov, N.S. Lee
V.I. Il'ichev Pacific Oceanological Institute, Far Eastern Branch Russian Academy of Sciences, Vladivostok, Russia
Keywords: structural and density modeling, deep structure, gravity field, Tatarsky trog, north-western part of Hokkaido
The paper presents the results of structural and density modeling using the 26-MP8 profile, which stretches in a meridional direction and intersects the structures of the northern Sikhote-Alin, coastal complexes of the East Sikhote-Alin volcano-plutonic belt, the South Tatar Basin, and the northwestern part of the Japan-Sakhalin Borderland with access to the island of Hokkaido. Modeling revealed inhomogeneities in the basement, as well as a complex rearrangement of the earth's crust on the traverse of the La Perouse Strait, where strong fragmentation in the middle crust and a deep fault were revealed, probably forming the boundary between the structures of the South Tatar basin and the northwestern part of the borderland. The foundation of the borderland is complicated by numerous faults and increased densities in individual blocks that coincide with or are associated with volcanic centers. A section of crustal contraction has been identified in the area of the northeastern closure of the Central Basin of the Sea of Japan and the thinning of the continental crust north of Cape Surkum.
The scarcity of palaeoecological reconstructions hinders the understanding of the patterns of environmental history in the Pre-Baikal region, as well as possible ways of human interaction with it, especially in the steppe areas of this vast region. Meanwhile, the ecosystems of such areas are very sensitive to global climate change, which emphasizes the importance of studying their climatic and ecological history. The aim of the research presented is to fill in part the knowledge gaps regarding the climate and vegetation of the Baikal region. We present the first results of the study of the physicochemical properties and palynomorph assemblages from the bottom sediments of Lake Ordynskoye, located in the intrazonal steppes of the Kuda River valley in the Pre-Baikal region. The chronology is based on a radiocarbon date for the base of the lake sediment section, supplemented by measurements of 137Cs and 210Pb isotope activity. The reconstructions suggest an alternation of humid and arid climate intervals on a scale from several decades to centuries in the interval from 2800 to 280 years BP (before present). The interaction of the North Atlantic Oscillation (NAO), the Siberian High (SH), and the regional climate likely played a significant role in the alternation of these wet-dry intervals. The profound changes in the vegetation of the Lake Ordynskoye basin and its limnosystem over the last approximately 280 years are attributed to the combined impact of regional climate and anthropogenic activities. The presented reconstruction of vegetation and climate in the Late Holocene is the first for the southern part of the Pre-Baikal region. It has shown that the coast of Lake Ordynskoye and the steppe areas in the Kuda River valley can be considered a unique location for studying paleocological variations in the Pre-Baikal region, their interconnections with regional cultural changes in the Iron Age and beyond.
The article presents the results of lithofacial analysis of terrigenous deposits of the Parfenovsky productive horizon of the Vendian (Ediacaran) of the Angara-Lena field (south of the Siberian Platform). The aim of the work is to construct a sedimentation model based on detailed study of core material, petrographic and granulometric data, as well as sequence-stratigraphic interpretation. As a result of the research, 10 lithofacies and 7 lithofacial associations were identified. It was established that the formation of the productive horizon occurred within a deltaic–estuarine system with active influence of tidal processes. Sequence-stratigraphic analysis allowed the identification of two third-order sequences and tracing the evolution of the sedimentary basin, including stages of forced and normal regression, transgression, and highstand of sea level. It is shown that sandstones of the channel facies of the upper delta plain and distributary channels of the lower delta plain, which are widely developed in the southern part of the studied area, possess the best reservoir properties. The obtained results refine the existing understanding of the structure of the Parfenovsky horizon and can be used to predict reservoir development zones during geological exploration and field development.
V.S. Shatsky1,2,3, A.L. Ragozin1, V.V. Kalinina1,I.N. Kupriyanov1, 1 V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Science, Novosibirsk, Russia
2 Novosibirsk State University, Novosibirsk, Russia
3 A.P. Vinogradov Institute of Geochemistry, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia
Keywords: inclusions in diamonds, carbonate melt, diamond formation, mantle
The article presents the results of studying unusual polyphase inclusions in alluvial diamonds from the northeastern part of the Siberian Craton. Polyphase inclusions in alluvial diamonds usually exhibit cracks surrounded by haloes of carbonate microinclusions formed during decrepitation of the inclusions. These haloes indicate that during exhumation, decrepitation of the inclusions occurred, with part of their contents released into the forming cracks. This means that the contents of the polyphase inclusions were melt at the time of entrapment, which gives us grounds to interpret them as inclusions of carbonate melts. Two diamonds contain mineral inclusions of eclogitic (rutile, garnet, sulfides; sample ISTD-151) and peridotitic (olivine, sulfides; sample ISTD-180) parageneses along with polyphase inclusions of carbonate melt. In diamond XLS-131, along with polyphase inclusions similar to those in diamonds ISTD-180 and ISTD-151, a polyphase inclusion of a fluoride melt is present. The polyphase inclusions of carbonate melts consist of two distinct zones: one composed predominantly of calcite, and the other of magnetite and carbonates. In all studied inclusions, the carbonate zone is represented by calcite with low contents of iron and magnesium impurities, regardless of whether the diamond contains mineral inclusions of eclogitic or peridotitic paragenesis. The compositional features of the inclusions are not consistent with compositions formed during melting of carbonatized peridotites and eclogites and differ fundamentally from the composition of inclusions of the natrocarbonatite association in superdeep diamonds. Thus, the melts represented in the inclusions were not in equilibrium with the host mantle rocks. The lack of equilibrium between the carbonate melts and the mantle is explained by their rapid entrapment and preservation by the growing diamonds. This suggests that these melts served as a source of carbon during diamond formation.
L.N. Sinitsa, A.P. Sherbakov
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: Fourier spectroscopy, absorption spectrum, liquid water, mode structure, hydrogen bond, regression analysis, temperature
The absorption bands of bulk water are characterized by a mode structure determined by the presence of a network of hydrogen bonds between water molecules with different degrees of OH bonding. Determining the parameters characterizing water structure is important for studying external effects on water. The temperature dependence of the absorption band of bulk water corresponding to ν + δ combination band (4500-5600 cm-1) was studied by Fourier-transform infrared spectroscopy in the temperature range from +10 to +90 °C. A technique for determining the sample temperature from its absorption spectrum in the 2 mm region was developed based on a regression analysis of the spectral data. The technique enables temperature estimation with an error of no more than 1-2 °C. Decomposition of the spectral contour revealed that the observed changes are due to a redistribution of intensity between constituent sub-bands (modes). These modes are interpreted as contributions from water molecules engaged in hydrogen bonds of different strengths. To characterize the structural state of water, a quantitative spectroscopic parameter C(T) is suggested, which is defined as the ratio of the intensity of the low-frequency mode (~ 4900 cm-1), which characterizes the number of strongly bound water molecules, to the intensity of the high-frequency mode (~ 5200 cm-1), which describes the number of weakly bound molecules. The value of C(T) systematically decreases with an increase in the water temperature, reflecting a reduction in the proportion of molecules with strong hydrogen bonds. The coefficient C(T) can be determined from a water absorption spectrum with a precision of ±4%. This approach provides a tool for investigating the effect of weak external perturbations on water structure.
E.V. Stepanov1,2, N.N. Nikifortseva1,2, V.V. Andreev2 1Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow, Russia 2Peoples' Friendship University of Russia, Moscow, Russia
Keywords: H2O absorption spectra, analysis of trace H2O concentration, low-temperature plasma generators, tunable diode laser
Highly sensitive analysis of neutral gas components, including H2O vapor, in high-vacuum electrical installations designed to generate low-temperature plasma is a pressing analytical and metrological challenge. This article presents a spectrophotometer based on tunable diode lasers designed for the spectral analysis of H2O traces in the vacuum chambers of low-temperature plasma generators using RF- and MW-discharges. The spectral range 7338-7370 cm-1 where vibration-rotational absorption lines of H2O of various symmetry and intensity are located was used for the analysis. Both the detection of the transmission spectra and their derivatives were used for highly sensitive analysis of traces of H2O at low pressures. The sensitivity to resonance absorption and concentration sensitivity in detecting traces of H2O in a rarefied gaseous medium were estimated.
O.B. Rodimova
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: continuum absorption, v2 H2O band, temperature behavior, line wing, dimer absorption
The paper considers the possible structure of the water vapor continuum absorption. The continuum absorption within the v2 H2O band and in its high-frequency wing was calculated based on the asymptotic line wing theory (ALWT) taking into account the violation of the long-wave approximation for the centers of mass of molecules. To explain the spectral and temperature behavior of the continuum absorption coefficient, the same line profile was used throughout the entire frequency range under study. The results are important for problems of spectroscopy and radiation propagation in different media.
V.A. Astapenko, S.V. Sakhno
Moscow Institute of Physics and Technology (State University), Dolgoprudnyiy, Russia
Keywords: laser pulse, water vapor, absorption cross section, total absorption coefficient, HITRAN database
The absorption of pico- and subpicosecond laser pulses in water vapor is described using the total absorption coefficient (TAC) in the spectral range 7000-7450 cm-1. The dependences of TAC on the carrier frequency, pulse duration, and absorbing layer thickness are calculated. The characteristic features of the process under study, caused by the specific nature of ultrafast electromagnetic interaction, are established. The suggested approach can simplify calculation and analysis of absorption of laser pulses in water vapor in the near-infrared range.
E.V. Nosov
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: convection, inclined optical beam, thermal trace
The second part of the article continues numerical studies of convective and dynamic turbulence fields in the vicinity of a group of extended inclined linear optical sources. This paper studies convective air motions in the vertical configuration of an open-side room of optical systems under external wind effect. The initial and boundary conditions of the boundary value problem being solved are similar to those for the horizontal configuration; the geometric and energy characteristics of the optical sources are analogous; the composition and scope of the study are the same as in the first part. The similarities and differences between the results for both configurations are shown.
A.I. Elizarov, V.N. Marichev, D.A. Bochkovsky
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: stratosphere, background aerosol, lidar monitoring, statistical analysis, seasonal trend, Western Siberia
This article presents the results of an experimental study of the dynamics of background aerosol filling of the stratosphere over Western Siberia in 2017-2025. The time period under study was characterized by the absence of large global-scale volcanic eruptions, which made it possible to identify natural variations in the background aerosol component. The observations were conducted using the lidar complex of Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences (Tomsk) by the elastic scattering method at a wavelength of 532 nm. To improve the reliability of the estimates, comprehensive statistical time series analysis technique was applied, including seasonal decomposition and iterative Z-score outlier removal. This enabled minimizing the impact of short-term local disturbances, including forest fire traces and instrumental anomalies. The analysis shows that, the overall background stratospheric aerosol level is statistically stable over the long term and does not exhibit a significant trend. At the same time, a clear seasonal asymmetry was revealed: the summer period is characterized by a statistically significant upward trend in aerosol loading, while a steady downward trend is observed in spring. The annual dynamics has a pronounced cyclical nature. The aerosol loading is maximal in winter and minimal in summer, which corresponds to a threefold difference in the integral aerosol backscatter coefficient. The results are valuable for the verification of climate models, as well as for the formation of a regional database of the background state of the stratosphere under conditions of minimal volcanic activity.
D.N. Timofeev1,2, I.V. Tkachev1,2, A.V. Konoshonkin1,2, N.V. Kustova1,2, V.A. Shishko1,2 1V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia 2National Research Tomsk State University, Tomsk, Russia
Keywords: atmospheric particle, lidar sounding, ice crystal, color ratio, physical optics, light scattering matrix, light backscattering
The main problem in studying atmospheric ice particles is the lack of information on their morphology and size. Traditional active and passive monitoring methods do not applicable to determination of these parameters due to physical limitations of the wavelengths and spatial resolution. There is a need in alternative methods, such as near-infrared lidars, where the absorption effect of ice particles is sufficient. This effect causes differences in lidar signals, thus opening a possibility of retrieving particle sizes from the spectral ratio. In this paper, the color ratio of atmospheric ice particles with sizes from 5 to 1000 mm, typical of high-altitude clouds, is studied. The dependence of the color ratio on particle size is derived. The study uses the ScIce-2023 light scattering matrix database for random spatial orientation of particles and single scattering approximation. Several particle shapes typical for ice clouds are studied at incident wavelengths from 0.355 to 2.150 mm. The results can be used for interpreting data of ground-based and satellite laser sensing of crystal clouds.
K.N. Visheratin1, V.M. Fedorov2 1Russian Federal Service on Hydrometeorology and Environmental Monitoring Research and Production Association «Typhoon», Obninsk, Russia 2Lomonosov Moscow State University, Moscow, Russia
Keywords: solar radiation, short-period variations of insolation, spectral analysis, Gibbs lobes, spatial and temporal variability
Variations in solar radiation caused by perturbations of the Earth's orbital motion by the Moon and some other planets of the solar system are studied. Short-period variations in the Earth's insolation in the range of periods 3 months to 30 years over the period from 1300 to 3000 are considered. The amplitudes, periods, and phases of the main short-period oscillations for 12 astronomical months in the latitude range 90° S to 90° N are 0. Calculations of seasonal and latitude dependences of periods and amplitudes of solar radiation arriving to the top of the atmosphere have shown that the periods of oscillations from 3 to 30 years are near constant and independent of latitude and time. Near the equinoxes, amplitudes in these oscillations caused by perturbations of the Earth's orbit by Venus, Mars, Jupiter, and Saturn are approximately symmetrical relative to the equator; near the solstices, the region of maximal amplitudes shifts towards the high latitudes of the summer hemisphere. Two closely spaced oscillations with periods of 2.6702 ± 0.0001 and 2.7154 ± 0.0001 years with different latitudinal and seasonal dependences are shown to exist in all latitudinal zones probably for the first time. The spatiotemporal variations in the 2.71-year oscillation are similar to the variations in the 18.6-year oscillation associated with the Moon, with a minimum at the equator and a maximum at high latitudes, and the 2.67-year variations are caused by perturbations of the Earth's orbit by Venus. The results of calculations of seasonal and latitudinal variations in solar radiation can be useful in climate modeling and analysis of the influence of short-period insolation variations on different geophysical and other processes.
A numerical study of the dynamics of far-field shock waves from a slender body of revolution with a disk has been carried out. The disk is placed in front of the body at an angle to the freestream airflow. The possibility of reducing the intensity of far-field shock waves is demonstrated. An increase in the freestream velocity reduces the range of disk inclination angles over which a decrease in shock waves intensity can be achieved.
Svetlana V. Ovchinnikova, Nikolai N. Lashchinsky
Central Siberian Botanical Garden SB RAS, Novosibirsk, Russia sv-ovchin@yandex.ru
Keywords: Poaceae, Puccinellia, sect. Montanae, new species, diagnostic features, ecological characteristics, habitat, relationships, position in the system, endemic, Bertek basin, Ukok plateau, Republic of Altai
Fieldwork in the Kosh-Agach District of the Altai Republic, review of collections stored in the LE, NSK, NS, and TK Herbariums, and literature review resulted in the identification of a new species, Puccinellia bertekensis Ovczinnikova et Lashch., from the section Montanae (Ovczinnikova) Ovczinnikova. This description of the new species includes a diagnosis, citation of the holotype and paratype labels, and a discussion of the morphological and ecocoenotic features of P. bertekensis and its differences from the closely related species P. schischkinii Tzvelev and P. hackeliana (V.I. Krecz.) C. Persson. The diagnostic features of the species are presented in the table and figure, and a photograph of the holotype and its habitat in the Bertek Depression are provided. For related taxa, the nomenclatural citation is provided, along with information on type specimens (including the lectotype of Atropis hackeliana V.I. Krecz.), ecological characteristics, and distribution. The map shows the locations of the three species within Northern Asia.
Sergey I. Genkal1, Viktor A. Gabyshev2 1Papanin Institute for Biology of Inland Waters RAS, Borok, Russia 2Institute for Biological Problems of Cryolithozone SB RAS, Yakutsk, Russia
Keywords: Bacillariophyta, Achnanthidium, water bodies and watercourses, plankton, epiliton, electron microscopy, morphology, State Nature Reserve “Olekminsky”, Republic of Sakha Yakutia
The morphology of the valve of Achnanthidium rivulare Potapova et Ponader, a rare species for the flora of Russia, was studied using scanning electron microscopy. It is found that valves show a wider variability of a number of quantitative features (length and width of the valve, the number of areolae in each striae in the center of the valve), which made it possible to specify the description of the specie
Yuriy V. Naumenko1, D. Nazyn Chechekmaa2 1Central Siberian Botanical Garden SB RAS, Novosibirsk, Russia 2Center for Biosphere Research, Kyzyl, Russia
Keywords: algal flora of the tributaries of Lake Azas, the Toora-Khem River, ecological and geographical analysis, saprobity, Republic of Tyva
This is the first report on the algae of a number of tributaries of Lake Azas and the Toora-Khem River in the Republic of Tyva. A list of algae has been compiled, including 227 species and subspecies belonging to 88 genera, 45 families, and 9 divisions. It has been revealed that diatoms make up the basis of the algal flora. Eighteen dominant species have been identified. An ecological and geographical analysis of the algae in these watercourses has been conducted. It was established that the algal flora of rivers is represented by benthic species, with a predominance of indifferent forms in relation to halobity and the active reaction of the environment. In all the studied watercourses, 166 species were identified as indicators of water saprobity. A predominance of betamesosaprobionts and oligosaprobionts was noted. In terms of geography, cosmopolitan and boreal species dominated.
Olga M. Legoshchina Dos Santos, Vladimir I. Ufimtsev
Federal Research Center Federal Research Center for Coal and Coal Chemistry SB RAS, Kemerovo, Russia
Keywords: Ascomycota, Basidiomycota, biota of macromycetes, coal dump, mycological findings, Novosibirsk Region, Western Siberia
Based on a study of the macromycete biota of the anthracite deposit waste dump, an annotated list was compiled, including 47 species of ascomycota and basidiomycota, from 8 orders, 27 families, and 36 genera. Two species are new to the Novosibirsk region: Conobolbitina dasypus (Romagn.) T. Bau & H.B. Song and Leucopaxillus tricolor (Peck) Kühner. Symbiotrophs and litter saprotrophs dominated the ecological-trophic structure, followed by humus saprotrophs, and occasional xylotrophs and mycotrophs. The majority of macromycete species were associated with birch forests within the waste dump. The ascomycetes and basidiomycetes identified in post-technogenic landscapes were characterized by very rare fruiting and sporadic occurrence. Latitudinally, the mycobiota exhibited features of Holarctic and multizonal geoelements, while regionally, it was characterized as Eurasian-North American, with a large proportion of multiregional and Holarctic species.
Irina A. Gorbunova1, Evgeny G. Zibzeev1, Pavel V. Golyakov2 1Central Siberian Botanical Garden SB RAS, Novosibirsk, Russia 2Federation Tigirekskiy State Nature Reserve, Barnaul, Russia
Keywords: Basidiomycetes, floral findings, rare species, Altai Territory, Russia
New data on the distribution of new species Crepidotus epibryus (Fr.) Quél. , Pluteus phlebophorus (Ditmar) P. Kumm. , Ripartites tricholoma (Alb. et Schwein.) P. Karst. , Scleroderma cepa Fr. and rare species Ganoderma lucidum (Curtis) P. Karst., Sparassis crispa (Wulfen) Fr. in Altai Territory are presented. Information is provided on the new location of the species Fomitopsis officinalis (Vill.) Bondartsev et Singer included in the monitoring list of fungi of Russia. Information about habitat, substrate, and distribution in the Russia and world is provided for each species. For rare species, photos in the natural environment are attached.
Tatiana V. Makryi1, Ilya A. Prokopiev2 1Central Siberian Botanical Garden, SB RAS, Novosibirsk, Russia 2Komarov Botanical Institute, RAS, St. Petersburg, Russia
Keywords: Parmeliaceae, Cetraria, lichen, new localities, chemotaxonomy, ecology and habitats, range and ways of it’s forming, Siberia, Russia
New data on the lichen species Cetraria rassadinae Makryĭ, described in 1984 from Pribaikalye and until now known from only a few localities, are presented. As a result of revision of materials stored in the Lichenological herbarium of the Komarov Botanical Institute RAS (LE-L) and the Lichenological division of the Popov Herbarium of the Central Siberian Botanical Garden SB RAS (NSK), 23 new localities of the species were discovered, including those from the Arctic part of Western Siberia. In total, taking into account literary data, 44 localities (from 25 regions) are currently known, on the basis of which a species distribution map has been compiled. A chemotaxonomic study showed that C. rassadinae does not differ in the component composition of secondary metabolites from the closely related species C. odontella , as well as C. nigricans , all of which contain lichesterinic and protolichesterinic acids. C. rassadinae is a “calciphile” and “mesophyte”, living on boulders (dolomite limestone etc.) - on thin layers of fine earth, as well as on rocky, poorly developed primitive soils. It inhabits mountain and arctic tundra, subalpine meadows, sparse Abies sibirica and Pinus sibirica woodlands, Pinus pumila thickets, as well as larch and, rarely, pine forests. It is an arcto-alpine, or more precisely, hyparctic-montane lichen. It can be argued that the species is relatively young, as evidenced by its narrow range. The formation of the species apparently took place during the Pleistocene. It initially formed in the mountains of Southern Siberia, from where it subsequently spread to the Central Siberian Plateau, the Putorana Plateau, and the Arctic parts of Western Siberia. If it had formed in the Arctic, it would have had a circumpolar distribution. All known localities are located in territories belonging to the basins of rivers flowing into the Arctic Ocean: the Pur, Yenisei (with its tributaries), and Lena (with the Kirenga and Vitim tributaries). While the rivers of the Yenisei and Lena basins originate in the mountains of Southern Siberia (Pribaikalie and the Eastern Sayan Mountains), the Pur River originates in the Siberian Uvaly. Altai localities belonging to the Katun River basin (the Ob River basin) are known only from the highlands. The species’ spread from the highlands to the lower mountain belts occurred under the influence of mountain glaciation, while from the mountains of Southern Siberia to the north of Siberia, along river valleys downstream. Another way for the species to disperse and expand its range was by spreading along mountain ranges. All mountain systems of Northern Asia are interconnected by common processes of florogenesis. Between the mountains of Southern Siberia (Altai, Sayan Mountains, Baikal mountains, and Stanovoye Nagorye Highlands), there is a natural migration route in northeast and southwest directions, along which, during the glacial and interglacial periods, there was a constant exchange of alpine and mountain species. The westernmost and easternmost points of the range of C. rassadinae are known in Altai (Kurai Range) and Stanovoye Nagorye Highlands (Kodar Range).
Andrey G. Belyaev
“YugydVa” National Park, Vuktyl, Russia
Keywords: Pinaceae, Pinus sibirica, Siberian pine, sable, range, historical documents, toponyms, East Europe
This article examines toponymic, historical, and historical-lexicological evidence of Pinus sibirica Du Tour growing west of its traditionally designated range. Both modern large-scale maps of the regions of interest and maps from past periods dating back to the late 18th century, when the General Land Survey plans were created, were examined. Based on the cartographic research conducted, a number of toponyms were discovered that indicate the possible presence in past times of both the Siberian stone pine itself and its consort, the sable ( Martes zibellina L.), hundreds of kilometers west of the boundaries of their current ranges. For the same purpose, historical documents were examined, ranging from 15th-century charters and census books to economic documents from the 19th and 20th centuries. These documents also provide evidence of the more western presence of the cedar in the North of European Russia in the past. The historical and lexical research included the study of dialects of the northern provinces of Russia in the 19th century and modern regional and dialectological dictionaries. As a result, linguistic traces of the presence of the cedar in the basins of the Northern Dvina and Sukhona rivers were identified, again significantly further west of the traditionally indicated area of P. sibirica . In addition to words related to the cedar itself, local names of certain animals were also found, indicating their connection with the Siberian cedar pine. Overall, the studies conducted have shown that the distribution boundary of the Siberian cedar may have previously been further west.
Natalya Yu. Egorova1,2, Venera N. Suleymanova1,2 1Russian Research Institute of Game Management and Fur Farming, Kirov, Russia 2Vyatka State Agrotechnological University, Kirov, Russia
Keywords: Orchidaceae, Epipactis atrorubens, cenopopulation, vitality, anthropogenic disturbed habitats, Kirov Region
Research aimed at identifying the adaptive potential of rare and protected plants in conditions of secondary biotopes is one of the relevant directions in studying the processes of anthropogenic transformation of flora. One of the species actively inhabiting the dumps of spent industrial quarries is the dark red dormouse Epipactis atrorubens (Hoffm.) Besser. The aim of the work is to assess the vital structure and viability of E. atrorubens cenopopulations in the conditions of industrially transformed ecosystems of the southern taiga within the Kirov Region. The study of E. atrorubens cenopopulations was conducted during the 2023 growing season at a non-reclaimed limestone quarry (near the village of Pervomaysky, Slobodskoy District, Kirov Region) in three areas with different ecological and coenotic conditions, as well as at the sludge dump of the Kirov Plant for the Processing of Non-Ferrous Metals (KZTNM) (Kirov). As a result of the research, it was found that E. atrorubens is characterized by significant cenotic plasticity and, in addition to natural habitats, successfully develops secondary phytocenoses formed on the site of post-anthropogenic territories. Vascular plants belonging to 5 ecological and cenotic groups are noted in the composition of the communities under consideration; meadow and meadow-fringed species are most represented in ecotopes of both types. The morphometric parameters of the vegetative and generative spheres of E. atrorubens vary significantly in the studied cenopopulations. The parameters of the generative sphere turned out to be highly plastic, with maximum response to changes in habitat conditions: the length of the inflorescence and the number of flowers. As a result of the analysis of the structure of the variability of morphological features of four groups of E. atrorubens traits are described: ecological, ecological-biological, biological, and genetic. The least variable features include the number of leaves and the length of the 2nd leaf from the base of the metamer shoot. The most variable feature is the length of the inflorescence. Data on the vital state of the studied E. atrorubens cenopopulations have shown that the studied cenopopulations are heterogeneous in their composition and, according to the complex of features of both vegetative and generative spheres, belong to the prosperous type (forest-meadow ecotonic biotopes) or depressive types (secondary forest communities).
Plant communities on saline soils are a characteristic of steppe and forest-steppe landscapes, significantly contributing to the floristic and coenotic diversity of many regions of Russia. In terms of syntaxonomy the halophytic vegetation of the mountains of the Southern Siberia has been poorly described. Pioneer coenoses dominated by obligate halophytes are characterized for Transbaikalia and Southeast Altai. Analysis of 43 original relevés revealed the vegetation diversity of communities dominated by annual halophytes at seven sites within the steppe belt of the Republics of Tyva and Khakassia. The studied vegetation belongs to the Eurasian class Therosalicornietea and the South Siberian order Suaedetalia sibiricae . Three associations and six communities are characterized. The alliance Suaedion sibiricae is indicated by the dominance of Chenopodiaceae species and represents the main diversity of the class. The alliance includes three associations previously described from Transbaikalia. The ass. Suaedo sibiricae-Salicornietum perennantis and ass. Suaedetum sibiricae are widespread in Tyva and Khakassia, while the ass. Suaedetum mongolicae has been recorded only in Tyva. Coenoses representing these associations formed in salt lake basins along drying shoreline, where they often presented by easily recognizable vegetation belts. They also occur as small patches along the bottoms of temporary streams, and in contact with forb-grass communities of steppes and meadows on saline soils. Five communities dominated by Suaeda tuvinica , S. prostrata , S. corniculata , Atriplex patens and Bassia scoparia are also described within the alliance. The alliance Artemision anethifoliae unites wormwood ( Artemisia anethifolia ) communities and includes the comm. Puccinellia tenuissima-Artemisia anethifolia from the South Minusinsk Basin. Most of the syntaxa are characterized by local distribution, due to their rarity and the fragmentary data about halophytic vegetation in Altai-Sayan Mountains.
Maxim Trushin1,2 1Kazan Federal University, Kazan, Russia 2S.I. Vavilov Institute for the History of Science and Technology of the Russian Academy of Sciences, Moscow, Russia
Keywords: K.F. Fuchs, Kazan University, Botanical Garden, plant collections, museum
The E.A. Eversman Herbarium, which is a botanical component of the museum complex of Kazan Federal University, has a long history of formation and formation. The botanical cabinet and the garden of the Imperial Kazan University were under unified management and served both educational and scientific purposes. In the early stages of its existence, plant collections were acquired, as a rule, in metropolitan cities or abroad at the expense of the university. This article traces the history of the acquisition of plants for the botanical garden in the early 19th century, examines the role of the famous Kazan naturalist K.F. Fuchs in this event, the 250th anniversary of which will be celebrated in September 2026. Information about the composition of the acquired collection is provided. The information introduced into scientific circulation for the first time expands our understanding of the history of the formation of botanical collections at Russian universities in the early 19th century.
