bluuebunny/crossref_metadata_2025 huggingface dataset:
TWO STAGES OF MINERALIZATION IN THE SOUTHERN TIEN SHAN Au-W METALLOGENIC BELT: ISOTOPIC U-Pb DATING (LA-ICP-MS METHOD) OF ZIRCON FROM INTRUSIVE ROCKS AT THE JILAU W-Au DEPOSIT (TAJIKISTAN)
Authors: Soloviev S. G. , Kryazhev S. G. , Semenova D. V. , Kalinin Y. A. , Bortnikov N. S.
Published: April 2024

The paper presents new isotopic U–Pb zircon data (LA–ICP–MS method) on the intrusive rocks from the Chinorsai massif, which is spatially and probably genetically related to the large Jilau tungsten-gold deposit. This deposit, together with the other large Au deposits (Muruntau, Zarmitan, Kumtor, etc.) is part of the largest Au (Au–W) metallogenic belt of Tien Shan. The deposit is represented by small zones of scheelite-bearing skarn and later (overprinting) large stockwork of veins and veinlets with scheelite-gold mineralization that occurs within and near the intrusion. The concordant isotopic zircon U-Pb data (301.0 ± 2.6 Ma; MSWD = 2.6) are older than the isotopic zircon U–Pb data previously reported (about 288 Ma). This indicates a substantial extent of the magma emplacement and crystallization process that probably corresponded to several intrusive events or phases, which is a prerequisite for the formation of associated intrusive-related Au deposits. Also, the isotopic age determined highlights the earlier formation of gold-polymetallic-tungsten deposits as compared to Mo–W and Sn-W deposits in the region, which are related to the later Early Permian intrusions. In addition, zircon xenocrysts with much older age (from ca. 970 Ma to ca. 2200 Ma) have been identified; they probably represent the age of the orogenic basement including that of the basement terranes of the Tarim and Karakum cratons.
FIRST RESULTS OF STRATIGRAPHIC DRILLING IN THE EAST SIBERIAN SEA FOCUSED ON THE GEOLOGICAL STUDIES OF THE SUTURE ZONE OF THE CONTINENTAL SHELF’S MARGINAL STRUCTURES A ND DEEP-WATER AREAS OF THE ARCTIC OCEAN
Authors: Petrov O. V. , Nikishin A. M. , Petrov E. I. , Tatarinov V. Yu. , Kashubin S. N. , Prishchepenko D. V. , Malyshev N. A. , Danilkin S. M. , Verzhbitsky V. E. , Kolyubakin A. A. , Komissarov D. K. , Stavitskaya V. N. , Shurekova O. V. , Razumkova E. S. , Tolmacheva T. Yu. , Leontiev D. I. , Tokarev M. Yu. , Ponimaskin A. I. , Zamotina Z. S.
Published: April 2024

At the initiative of the Federal Agency on Mineral Resources (Rosnedra), in August 2022, a shallow well was drilled in the East Siberian Sea for the first time with a purpose of geological studying the suture zone of deep waters of the Arctic Ocean and marginal structures of the continental shelf. The well was drilled by VSEGEI and Rosgeologia with the assistance of NK Rosneft and linked to the Rosneft’s long-term stratigraphic drilling program. Drilling was accompanied by continuous seismoacoustic profiling and well thermometry. The maximum well depth was 472 m from the bottom surface; in it, 147.5 m of core was taken to a depth of 268 m. Two sedimentary sequences were identified in the section: the lower Jurassic-Lower Cretaceous gently deformed sequence and the upper Neogene-Quaternary horizontally lying sequence. The sequences are separated by a thick unsampled interval with horizons of ascending thermal water. The Jurassic-Lower Cretaceous sequence occurs as a northwestern-dipping monocline, broken by faults and probably belongs to the complex filling the Zhokhov marginal trough of the Verkhoyansk -Chukotka orogen on the Eastern Arctic shelf.
EFFICIENT APPROACH TO THE SEQUENCE STRATIGRAPHIC STUDY OF MONOTONOUS HOLOCENE SEDIMENTS FROM THE ARCTIC SHELF
Authors: Kolesnik A. N. , Selyutin S. A. , Kolesnik O. N. , Bosin A. A. , Astakhov A. S. , Vologina E. G. , Sukhoveev E. N. , Bazhenov I. I.
Published: April 2024

The article faces an approach in which already at sea, based on the results of an express analysis of visually similar cores of Arctic Holocene sediments and their comparison with dated and generally studied in detail cores of region’s sediments, it is possible to determine material that is promising for sequence stratigraphic correlation and paleoreconstructions. Parameters analyzed include lithological, colorimetric (CIE L*, CIE a*, CIE b*), geophysical (magnetic susceptibility – MS), and geochemical (Fe/Rb, Mn/Rb, Ti/Rb). The most informative characteristics are the CIE b* color coordinate, MS, and the Fe/Rb ratio.
NEW DATA ON MUD VOLCANISM IN THE ARCTIC ON THE YAMAL PENINSULA
Authors: Bogoyavlensky V. I.
Published: April 2024

A wide range of geological and geophysical methods was carried out on the Yamal Peninsula in the Arctic in the period 2014–2022. The results were analyzed together with data from remote sensing of the Earth. Fundamentally new data on the gas-dynamic mechanisms of dangerous processes in permafrost have been obtained. These data included catastrophic gas blowouts and explosions with the formation of giant craters. More than three thousand zones of powerful gas blowouts with the formation of craters at the bottom of thermokarst lakes, rivers, and the coast of the Kara Sea have been discovered. According to data on remote sensing of the Earth, large mud volcanic structures, located at the bottom of the Labvarto and Yambuto thermokarst lakes, were discovered on the Yamal Peninsula in 2022–2023 for the first time. Monitoring of their state with the use of retrospective satellite images showed the presence of periodic release of underground fluids, including gas. A conclusion was made about the discovery of active mud volcanoes on the Yamal Peninsula
URANIUM IN THE WATER OF THE BAIKAL ECOSYSTEM
Authors: Grebenshchikova V. I. , Kuzmin M. I. , Demjanovich V. M.
Published: April 2024

The analysis of distribution of uranium concentrations in the water of conjugated components of Baikal ecosystem in the water of Baikal, tributaries, Angara headwaters and in underground water from the wells on Olkhon island and in south-western coastal part of Baikal has been carried out. The significant differences of the maximum uranium contents in the ground water of the Baikal and its inflows and the close average and median values of the element in the water of the Baikal and the Angara River flowing into it were determined. The data on uranium distribution fix the influence of geological and geochemical peculiarities of the structure of the Baikal ecosystem and its surroundings and the climatic and catastrophic (earthquakes, seismo-geodynamic activation etc.) events which take place in the region. An analysis of changes in the concentration of uranium in the water of Lake Baikal in relation to the seismic process was carried out on the example of strong earthquakes (M ≥ 5) in the region of Lake Baikal.
INTENSE QUANTUM OF THE DEFORMATION IN DEEP CRUST, AS SEEN FROM GEOMECHANICAL MODELING IN SOUTHERN CALIFORNIA
Authors: Bondur V. G. , Gokhberg M. B. , Garagash I. A. , Alekseev D. A.
Published: April 2024

In a detailed analysis of the local features of the stress-strain state within the framework of the geomechanical model of Southern California, a rapidly developing high-amplitude shear deformation anomaly was identified in the upper crustal interval (at depths of up to 10 km) – the so-called “intense deformation quantum” – with a maximum increase in deformation by two orders of magnitude within 0.5 month. Such “quanta” can be integral elements of the entire deep deformation process associated with seismicity. The paper discusses the quantitative characteristics of deep deformation “quanta” and the conditions for their occurrence.
TO A QUESTION OF SULFUR SITES IN CRYSTAL STRUCTURES OF TETRAHEDRITE GROUP MINERALS: RELATIONSHIPS BETWEEN OCCUPANCY, EFFECTIVE ION SIZES, AND UNIT CELL PARAMETERS
Authors: Lyubimtseva N. G. , Marchenko E. I. , Eremin N. N. , Bortnikov N. S.
Published: April 2024

In this work, a crystal chemical analysis of the known experimentally deciphered crystal structures of tetrahedrite group minerals was carried out in order to reveal the relationships between the occupancies of anion crystallographic sites in the structures, their effective sizes and unit cell parameters. To achieve this aim, we analyzed the effective sizes of the 24g and 2a anion sites in 68 deciphered crystal structures of tetrahedrite group minerals according to the published data. The analysis was carried out using the TOPOSPro software package by partitioning the space into Voronoi–Dirichlet polyhedra (VDP). It has been shown theoretically for the first time that the content of a large sulfur ion and its deficiency affect the unit cell parameter. A linear correlation between the VDP volume of the anionic site of S2– (24g) and the unit cell parameter in minerals of the tetrahedrite group was established, which shows that the anionic substructure dictates the structural motif in this class of compounds. It was found that the change in the VDP volumes of sulfur anions is associated with different occupancies of anionic sites. It is found that the formula (unit cell) of the compound contains fewer than 13 sulfur ions in almost all deciphered crystal structures of tetrahedrite group minerals. It was concluded that the calculated VDP volume of the 24g anionic position less than 22 Å3 indicates a significant deficit in the anionic substructure. It was shown that, using information about the VDP volumes of all anionic and cationic sites in the structure, it is possible to predict the unit cell parameters of minerals of the tetrahedrite group with an accuracy of 0.01 Å
GEOCHEMICAL VIEW ON “INOFFENSIVE” DEPLETED URANIUM
Authors: Zhmodik C. M. , Ponomarchuk V. A.
Published: April 2024

The interaction of alpha radiation from UO2 micro- and nanoparticles (uraninite) with the substance was visualized using alpha-autoradiography data on A-2 thick-layer nuclear photographic emulsions. The spherical area of action of alpha particles around UO2 micrograins, up to 100 microns in size, is a deeply transformed substance with a high density of radiation defects. The translation of these results on a living organism leads to the conclusion about the specific type of impact of micro- and nanoparticles of depleted uranium, in which prolonged internal irradiation in small doses of the whole organism is combined with catastrophically high doses of alpha radiation in local zones, near micro- and nanoparticles UO2.
DISTURBANCE OF GEOPHYSICAL FIELDS AND IONOSPHERE DURING A STRONG GEOMAGNETIC STORM ON APRIL 23, 2023
Authors: Adushkin V. V. , Spivak A. A. , Rybnov Yu. S. , Riabova S. A. , Soloviev S. P. , Tikhonova A. V.
Published: April 2024

We present the data of instrumental observations made at the Mikhnevo geophysical observatory of the IDG RAS of magnetic field variations and the response of microbaric oscillations and the electric field in the Earth’s surface atmosphere to a strong magnetic storm on April 23, 2023 (Kp = 8). When determining the response of the ionosphere to a magnetic disturbance in the form of a change in the critical frequency of the F2 layer, we use the results of ionospheric sounding performed at the IAP (Leibniz-Institut Fur Atmospharen Physik). It is shown that during periods of maximum magnetic field variations, increased microbaric variations are recorded and increased electric field variations are noted. The magnetic storm was also accompanied by a change in the critical frequency f0F2, as well as in the spectral characteristics of variations in the electric field strength.
KIMILTEI IS A NEW LATE CAMBRIAN LAGERSTÄTTE WITH THE FAUNISTIC COMPLEX OF ARTHROPODS (EUTHYCARCINOIDEA, SYNZIPHOSURINA, AND CHASMATASPIDIDA)
Authors: Naimark E. B. , Sizov A. V. , Khubanov V. B.
Published: April 2024

A new locality Kimiltei, Irkutsk region, where unmineralized remains of arthropods were buried en masse, is described. U-Pb zircon dating indicated the Cambrian age and gave the youngest values 491 ± 6 Ma. Arthropods in Kimiltey are represented by Chasmataspidida, Synziphosurina and Euthycarcinoidea. The last two groups have not been known on the Siberian platform, and the first one has been described here only from the Devonian rocks. The Irkutsk finds fall into the ranks of the most ancient representatives of their groups, and their ranges turned out to be wider than previously known. Attention was drawn to their co- burial as the representatives of these groups have never been found together before. Taking into account that the descendants of all three groups gave rise to terrestrial lines of chelicerates and insects, thus the Kimiltey assemblage is the entire fauna of the land arthropods ancestors. Their co-habitation indicates they started their expansion on land from some close ecological niches in the intertidal zone.
THE FIRST FIND OF CAMBRIAN VOLCANITES AND PLAGIOGRANITES IN TEKTURMAS OPHIOLITE ZONE (CENTRAL KAZAKHSTAN): AGE AND COMPOSITION
Authors: Degtyarev К. Е. , Luchitskaya М. V. , Тretyakov А. А.
Published: April 2024

The complex of felsic rocks, intruded by plagiogranitic bodies are first revealed in the west of the Tekturmas ophiolite zone of Central Kazakhstan. The U–Pb (SIMS) geochronological study of one of the plagiogranitic bodies was carried out and the Early Cambrian age (537 ± 5 Ma) was first obtained. The peculiarities of effusives and plagiogranites composition indicate their formation in the supra-subduction setting within primitive volcanic island arc. Formation of this arc was not related to the evolution of the oceanic structures, which complexes participate in the structure of the Tekturmas zone.
FIRST DATA ON PALEOGEOGRAPHICAL SETTINGS AND CHRONOLOGY OF THE LAST INTERGLACIAL ON ZIMNII COAST OF THE WHITE SEA
Authors: Zaretskaya N. E. , Taldenkova Е. Е. , Ovsepyan Ya. S. , Ruchkin M. V. , Baranov D. V. , Rudenko O. V. , Stepanova A. Yu.
Published: April 2024

Field lithostratigraphic studies, microfaunistic and palynological analyses, as well as optically stimulated luminescence (OSL) dating revealed for the first time that the lower part of Quaternary sediment sequences exposed along Zimnii Coast of the White Sea accumulated in marine and nearshore environments during the Boreal transgression at the beginning of the Last Interglacial and thus form the Upper Pleistocene Mikulinian Horizon. This is confirmed by lithology of sediment beds; species composition of foraminifers, ostracods and aquatic palynomorphs; and OSL dates in the range of 118–104 ka. The composition of benthic microfossils indicates that during the early Boreal transgression the entire Zimnii Coast was occupied by an coastal arctic ice-covered basin with water depths of 50 m, high sedimentation rates, and water stratification induced by melt/river water inflow. At the stage of regression, sedimentation in shallow marine environments was dominant along Zimnii Coast.
THE FIRST DATA OF THE CONTENT OF MERCURY AND ITS FORMS FINDING IN THE FERROMANGANESE AND FERROUS FORMATIONS OF THE CHAUN BAY
Authors: Aksentov K. I. , Ivanov M. V. , Yaroschuk Е. I. , Charkin A. N. , Sattarova V. V. , Alatortsev A. V. , Kim D. V. , Zarubina N. V. , Startsev A. V.
Published: April 2024

For the first time, the data of mercury content and its forms in the ferromanganese and ferruginous formations of the Chaun Bay (East Siberian Sea) were obtained. According to the geochemical classification, the studied formations belong to diagenetic. The level of mercury content ranges from 8 to 26 µg/kg, that is two to five times lower than the clarke for the upper part of the continental crust. The isomorphic (mineral) form of mercury is predominant in ferromanganese and ferruginous formations.
NEW DATA ON THE GEOLOGICAL STRUCTURE AND PRECAMBRIAN EVOLUTION OF THE DENMAN GLACIER WEST SIDE MOUNTAIN FRAME (EAST ANTARCTICA): FIRST PALEOARCHEAN AGE FOR PLAGIOGNEISES
Authors: Мaslov V. А. , Kaminsky V. D. , Rodionov N. V. , Vorobiev D. М.
Published: April 2024

Mountain frame of the Denman Glacier is a little explored and at the same time an most essential region of East Antarctica in the context of studying the Precambrian geological history and geodynamic evolution of the Archean protocratons of East Antarctica. Present paper provides original U–Pb isotope geochronology data from zircons of metamorphic and intrusive rocks sampled from the Denman Glacier western flank outcrops. Geodynamic interpretation of geochronology data are also presented. For the first time, for such East Antarctic location, crystallization time (3355 ± 5.4 Ma) for plagiogneisses magmatic protolith was obtained. The Davis Paleoarchean protocraton in the Archean time interval of evolution was subject to multistage polymetamorphism in the intervals ~3100–3000, 2900–2800 Ma ago. The late stage is associated with crustal extension, which is marked by syntectonic intrusion of ultramafic dikes and pyroxenite sills (2827 ± 6 Ma). The formation time of granite veins and subalkaline granitoid pluthons corresponds to the time of tectono-thermal activisation in the interval of 550–510 Ma traced also along significant part of East Antarctic (the Pan-African tectono-thermal event). The Davis terrane shows a significant similarity in the time of formation and evolution of geodynamic processes with the Paleo-Mesoarchean protocratons of East Antarctica, as well as India and Australia.
PECULIARITIES OF THE PROPERTIES OF SOIL INVOLVED IN MUDFLOW PROCESS IN CHUKOTKA
Authors: Lobkina V. A. , Ukhova N. N. , Gensiorovskiy Yu. V. , Muzychenko A. A.
Published: April 2024

During laboratorial study we have get data about mineral and granulometric composition, some physical and physico-chemical parameters of mudflow deposit, which made it possible to identify soil features in mudflows in Chukotka. Made a try to estimate influence this influence of these features on the formation of mudflow suspension, which is the transport substance of mudflow. In terms of structural rheological movement model, mostly cohesionless mudflow suppose to be formed within reviewed territory, in which main mass of water is in free state. However, laboratory investigations have shown high contain of fine-grained particles in samples of mudflow deposit, which is in aggregated state. When flooded, these particles saturate water flow with clay suspension that allows classification this flows as cohesive. The cohesion of mudflow mass is acquired by flows in the process of movement at the expense of aggregates destruction that leads to changing physical characteristics of the mudflow.
A NEW VARIETY OF CHLADNIITE FROM VOLCANIC EXHALATIONS. GENETIC CRYSTAL CHEMISTRY OF CHLADNIITE
Authors: Pekov I. V. , Zubkova N. V. , Agakhanov A. A. , Turchkova A. G. , Zhitova E. S. , Pushcharovsky D. Yu.
Published: April 2024

A new, unusual Fe-free and As5+-enriched variety of chladniite, a rare phosphate of the fillowite group was found in exhalations of the active Arsenatnaya fumarole, Tolbachik volcano, Kamchatka, Russia. It belongs to the high-temperature (500–750°С) paragenesis with calciojohillerite, fluorapatite, metathénardite, diopside, enstatite, forsterite and hematite. This genetic type is novel for fillowite-group minerals. The crystal  structure of Tolbachik chladniite is solved, R1 = 4.32%. It is trigonal, R–3, a = 14.9831(2), c = 42.8050(7) Å, V = 8322.1(3) Å3. The structural formula is: M13(Na0.56\(\square \)0.44)\(_{2}^{{M21}}\)(Na0.81Ca0.19)\(_{2}^{{M31}}\) (Na0.97\(\square \)0.03)\(_{6}^{{M12}}\)(Ca0.64Na0.36)\(_{6}^{{M1}}\)MnM2(Mg0.54Ca0.46)M3–9Mg\(_{{30}}^{{M10}}\)(Mg0.94Ca0.06)\(_{6}^{{M11}}\)Mg6(P33.53As2.47)O144 (Z = 3). The crystal chemical features of chladniite and their correlation with mode of occurrence are discussed for all chladniite findings known in meteorites and terrestrial objects of different genetic types.
IMPRINTS OF PLUME PROCESSES IN THE MODERN LITHOSPHERIC VELOCITY STRUCTURE OF THE KHIBINO-LOVOZERO REGION
Authors: Adushkin V. V. , Goev A. G.
Published: April 2024

The paper presents new deep velocity of the earth’s crust and upper mantle in the Khibiny-Lovozero tectonic region located on the Kola Peninsula. The artifacts of plume-lithospheric interactions that occurred in the investigated area from the Proterozoic to the Paleozoic time are discussed. A detailed comparison of the velocity structure of the Imandra-Varzug rift, the Khibiny and Lovozero plutons, and the adjacent Archean part of the Fennoscandinavian Shield has been carried out. A significant heterogeneity of the structure of the crust, upper mantle, as well as the structure and depth of the crust-mantle transition is shown. The presence of a zone of low seismic velocities in the upper mantle associated with the mid-lithospheric discontinuity (MLD) has been revealed. Structural features of the Moho zone and the upper mantle in the region of the Khibiny and Lovozero plutons were interpreted as artifacts of the plume process.
RADIOCARBON AGE AND STABLE OXYGEN ISOTOPES IN HOLOCENE ICE WEDGES ON THE COAST OF THE BAYDARATA BAY: RECONSTRUCTION OF THE JANUARY PALEOTEMPERATURE
Authors: Vasil’chuk Yu. K. , Budantseva N. A. , Tokarev I. V. , Ginzburg A. P. , Vasil’chuk A. C. , Vasil’chuk J. Yu.
Published: April 2024

For the first time AMS radiocarbon dating was used to date microinclusions of organic material extracted directly from Holocene syngenetic ice wedges in the European North of Russia on the coast of the Baydarata Bay near the Yarynskaya village, 500 m south of the mouth of the Ngarka-Tambyakha River (68°51′20.27″ N, 66°52′6.51″ E). Dated ice wedges formed about 6.4, 5.0 and 1.9 ka BP. According to isotope oxygen data, the average January air paleotemperature in the Middle and Late Holocene at the coast of the Baydarata Bay was calculated. It is shown that the average January air temperature during this period here varied from about –20 to –25°C, however, during milder winters it could be about –18°C.
DETERMINATION OF “FORERUNNER”-WAVES FORMATION ZONES FOR TYPHOONS PASSING OVER THE EAST CHINA AND JAPAN SEAS
Authors: Dolgikh G. I. , Budrin S. S. , Shvets V. A. , Yakovenko S. V.
Published: April 2024

During the passage of Typhoon Hinnamnor from September 5 to 6, 2022, typhoon-generated swell waves were discovered to arrive at the point of observation 20 hours before the typhoon itself entered the Sea of Japan. During the analysis of data obtained by laser instrument measuring fluid pressure variations, it was possible to determine the area of formation of the main group of swell waves generated by a passing typhoon, and to localize the area of generation of “forerunner” waves, as well as to describe the mechanisms of their formation and propagation.
PHTALATES IN SEDIMENTS OF BAIKAL REGION LAKES
Authors: Nikitina E. P. , Taraskin V. V. , Budaeva O. D. , Shiretorova V. G. , Bazarzhapov Ts. Zh. , Bazarsadueva S. V. , Pintaeva E. Ts. , Radnaeva L. D. , Tulokhonov A. K.
Published: April 2024

Phthalates are one of the most common pollutants, the concentrations of which in the environment in the near future, according to scientists, will only grow. High concentrations of these substances pose a serious threat to water bodies, especially for lake ecosystems, which are characterized by slow water exchange and accumulate pollutants faster, thereby reflecting anthropogenic load and environmental changes. The paper presents for the first time the results of determining the phthalate content in the bottom sediments of lakes Arangatui, Bormashovoe, Dukhovoe, Kotokel, Shchuchye. The total content of 6 phthalates varied from 51 to 2222 mkg/kg of dry weight, while the highest concentrations were noted for central stations. The distribution profile of phthalates in the bottom sediments of lakes is basically quite similar – DBP (average content of 213 mkg/kg) and DEHP (189 mkg/kg) prevailed. It is noted that the accumulation of the studied substances occurs mainly in silty sediments, which is indicated by medium and high positive correlations between phthalates, granulometric composition, the content of organic carbon and heavy metals. The high levels of individual phthalates in the sediments of the studied lakes indicate the need to study in detail the sources and distribution mechanisms in the system of “water-bottom sediments”.
A COMPOSITE MODEL OF MICROWAVE SCATTERING FROM WATER SURFACE IN EXTREME WIND SPEED CONDITION
Authors: Rusakov N. S. , Baydakov G. A. , Troitskaya Yu. I.
Published: April 2024

Experiments were carried out in the wind-wave flume of Large Thermo-Stratified Wind-Wave Tank of IAP RAS aimed at studying the mechanisms of cross-polarized microwave radiation scattering from water surface under conditions of extremely high wind speeds. It is shown that the normalized radar cross-section (NRCS) can be represented as the result of an incoherent addition of contributions from breaking wave crests and from non-breaking wind waves. The effect of smoothing the water surface after passing the breaking crest made it possible to measure the NRCS of the breaking area on cross-polarization, while no dependence of the NRCS on wind speed and incidence angle was revealed. NRCS on non-breaking wind waves was calculated within the framework of the small slope approximation (SSA) using experimentally measured wind wave spectra. It is shown that the NRCS on cross-polarization increases monotonically with increasing wind speed, including hurricane conditions. In this case, the contribution of non-breaking wind waves to the NRCS saturates at wind speeds above 25 m/s. The monotonous increasing NRCS at higher wind speeds is associated with a breaking area increasing. A composite model of microwave radiation scattering from wave-covered water surface has been constructed, which has been verified on the basis of comparison with measurement data. The possibility of constructing a geophysical model function for ocean conditions based on the proposed composite model is shown, which can be used for remote sensing of sea storms and hurricanes.
THE FIRST PALEONTOLOGICAL EVIDENCE OF THE PRESENCE WORDIAN BIVALVES IN THE MIDDLE PERMIAN OF THE OMOLON MASSIF (NORTHEAST RUSSIA)
Authors: Biakov A. S.
Published: April 2024

Paleontological evidence of the presence Wordian bivalves in the Middle Permian deposits of the Omolon massif, originally described by N. Newell from the Wordian Formation of the Glass Mountains (West Texas), is presented for the first time. In the Kolymia multiformis bivalve Zone of the Bocharian Regional Horizon, pectinids of the genus Heteropecten – H. gyrtyi (Newell) and H. gryphus (Newell), were found, which allow this Zone to be confidently correlated with the Wordian Stage of the International Stratigraphic Scale (ISS) of the Permian and indicate the relationship of the Kolyma-Omolon basins with the North American basins.
NEW FINDINGS OF MUD VOLCANISM IN NORTHWEST COAST OF LAKE BAIKAL BASED ON UNDERWATER VIDEO RECORDING
Authors: Lunina О. V. , Kucher K. M. , Naumova T. V. , Sitnikova T. Ya.
Published: April 2024

We present new data on manifestations of mud volcanism accompanied by gas emissions in Lake Baikal. Brittle deformations of the bottom with traces of erupted liquefied sediments were found in the Malaya Kosa Bay and the Goryachinskaya Bay in the North Baikal depression at depths of 105–163.6 m. The deposits outcropping in the extended scarps and mud craters are mainly represented by highly-porous clays. In places there are ledges of boulder-pebble sediments. The areas of the mud volcanism distribution are confined to the damage North Baikal fault zone, indicating its current activity. Disturbance of the clays and soft sediments covering them indicates the recent eruption of gas-saturated fluid and mud. At depths of 157–162 m in the Goryachinskaya Bay, cone-shaped structures ∼5 × 5 cm in size with a crater in the top part were found in them. Similar griffons were revealed in the Solontsovaya Bay along rectilinear faults opposite the paleoseismic rupture of the same name. It is necessary to continue studying the revealed shallow-water manifestations of mud volcanism and rupture deformations of the bottom by staging complex geological and geophysical studies.
EVIDENCES OF MINERAL MELTING IN THE ORES OF THE SVETLINSK GOLD DEPOSIT, SOUTH URALS, RUSSIA
Authors: Vikent’eva O. V. , Bortnikov N. S.
Published: April 2024

For the large Svetlinsk gold deposit (South Urals) evidences of partial melting of minerals and possible participation of polymetallic melts in the concentration and redistribution of gold and other metals are given. Finding of bismuth and antimony minerals in ores, among which there are gold minerals new to the deposit (pampaloite, montbrayite and aurostibite), specific mineral intergrowths (polymineral Sb–Bi–Pb–Te–Ag–Au drop inclusions), enrichment of early sulphides with Low-Melting-point Chalcophile Elements (LMCE), high formation temperatures for ore assemblages (up to 400°C), as well as the occurring metamorphism of amphibolite facies indicate the possibility of the formation of such melts. Polymetallic melts at the deposit could be formed both by partial melting of early sulphides and directly from hydrothermal fluids. The signs of melting also include simplectites of calaverite and native gold in the marginal parts of the large montbrayite grain.
NECESSARY CONDITIONS FOR THE EXISTENCE OF SPACECRAFT IN CLOSED ULTRA-LOW ORBITS
Authors: Filatyev A. S. , Golikov A. A.
Published: April 2024

The problem of spacecraft stabilization in ultra-low (120–250 km for the Earth) orbits with the help of air-breathing electric propulsion (ABEP), which uses the gases of the surrounding atmosphere as a propellant, is considered. Qualitative differences of ABEP from traditional electric propulsion are emphasized and, on the basis of the fundamental laws of mechanics and electrodynamics, the necessary conditions for the existence of spacecraft with ABEP in closed ultra-low orbits are substantiated.
COMPARATIVE ANALYSIS OF THE DARCY AND BRINKMAN APPROXIMATIONS FOR THE TRANSITION TO INSTABILITY IN A POROUS MEDIUM
Authors: Il’ichev A. T. , Tsypkin G. G.
Published: April 2024

We studied the stability of the evaporation front in a porous media. To describe the flow, the generalized Brinkman equation is used. Comparison of the obtained results with the results found within the framework of the Darcy approximation is presented. It is shown, that the use of the Brinkman approximation eliminates the unboundedness of the perturbation growth rate at small scales arising in the case of Darcy’s law. Interface becomes more stable, and in the case of instability the most unstable mode corresponds to the finite value of the wave number.
A STUDY OF IMPACT OF STRONG MAGNETIC STORM ON CONSOLIDATED POWER SYSTEM OF CENTRE OF RUSSIA
Authors: Trenkin A. A. , Voevodin S. V. , Koblova O. N. , Selemir V. D. , Vakhnina V. V. , Kuvshinov A. A. , Chernenko A. N.
Published: April 2024

This article represents results of simulation of geomagnetically induced current impact on Consolidated power system of Centre of Russia during strong magnetic storm. The paper shows that complex of factors appears during this impact which can induce progress of blackout: significant decrease of voltage on a set of electrical power elements, mass cutoff of power transmission lines under the influence of relay protection and dangerous heating of construction elements of power transformers.
ELASTIC-WAVE SCATTERING BY A PLANE CRACK: FLAW DETECTION APPLICATION
Authors: Aleshin N. P. , Mogilner L. Yu.
Published: April 2024

The 3D problem of elastic wave scattering by a crack in the form of a half-plane in an elastic medium is considered. It is noted that the previously published solutions do not fully cover the issues relevant to ultrasonic flaw detection, for example, to detect transverse cracks in welds. The proposed solution is made by the Wiener–Hopf tecnique. It is shown that scattered longitudinal and transverse waves can be generally written in the closed form. Some features of the identification of the tip of transverse cracks are noted, including scattering features during sonication of cracks along their surface and the influence of critical angles.
APPROXIMATION OF THE FIELD OF ATTRACTION OF A BODY CLOSE TO DYNAMICALLY SYMMETRIC ONE, BY THE FIELD OF ATTRACTION OF THREE BALLS
Authors: Burov A. A. , Nikonov V. I.
Published: April 2024

The field of attraction of a rigid body is studied. It is assumed, that the body is close to dynamically symmetric one. The problem of approximation of body’s field of attraction by the field of attraction of three homogeneous balls is considered. The goal of such approximation is to provide coincidence of the terms up to the fifth order of smallness in the series expansions for gravitational potentials of the body and three balls. As an example, the approximation of asteroid (433) Eros by three balls is considered.
DIRECT EXPERIMENT ON THE PASSAGE OF ULTRA-WIDEBAND PULSES OF SUBNANOSECOND DURATION IN THE EARTH’S ATMOSPHERE
Authors: Garnov S. V. , Selemir V. D. , Bukin V. V. , Gorbenko D. A. , Dolmatov T. V. , Zhdanov V. S. , Efanov M. V. , Lebedev E. F. , Ostashev V. E. , Semenov A. V. , Ulianov A. V. , Fedorov V. M. , Shurupov M. A.
Published: April 2024

The results of the first direct experiments on the passage of pulses of ultra-wideband radiation of subnanosecond duration in the Earth’s atmosphere at a distance of more than 10 km are presented. In contrast to the calculated work, the preservation of the amplitude-time shape of the pulses in the process of increasing the distance is shown. The establishment of this fact is of decisive importance in the practical application of ultra-wideband pulses in new technological developments.
OBTAINING THERMOELECTRIC MATERIAL Cu2Se BY THE SELF-PROPAGATING HIGH-TEMPERATURE SYNTHESIS METHOD
Authors: Nigmatullina G. R. , Kovalev D. Yu. , Alymov M. I.
Published: April 2024

Using the method of self-propagating high-temperature synthesis in the combustion mode, a product based on the α-Cu2Se phase was obtained from a 2Cu + Se powder mixture. The effect of synthesis conditions on the composition of the combustion product was studied and the unit cell parameters of the synthesized phases were determined. It has been established that as a result of combustion of pressed 2Cu+Se mixtures at an Ar pressure of 0.5–1.5 MPa, a product is formed containing two modifications of Cu2Se – low-temperature monoclinic α-Cu2Se and high-temperature cubic β-Cu1.8Se phases. Combustion of a 2Cu+Se mixture of bulk density at an Ar pressure above 0.5 MPa yielded a single-phase product, the monoclinic α-Cu2Se phase.
FEATURES OF NITROGEN DEGASSING OF DHAJALA CHONDRITE (H3.8)
Authors: Voropaev S. А. , Dushenkо N. V. , Fedulov V. S. , Senin V. G.
Published: April 2024

Samples of the Dhajala meteorite (ordinary chondrite, type H 3.8) were kept isothermically in a specially designed device in the temperature range from 300 to 800°C for 90 minutes. The composition and content of the released gases were studied on a gas chromatograph. The following were detected: CO, CO2, H2O in concentrations of 300–1000 μg/g of the sample; also H2, CH4 and H2S in concentrations of 0.1–40 μg/g. The total nitrogen content during degassing increased quasi-linearly over time from 40 to 500 μg/g at each fixed temperature. Based on experimental observations of the change in the rate of nitrogen release depending on temperature, it was concluded that the effect of phase transitions on the permeability of the mineral matrix.
DYNAMIC MODEL OF PROCESS OF SEPARATION THE LARGE-SIZED ELASTIC SPACE-ROCKET DESIGNS
Authors: Bakulin V. N. , Borzykh S. V.
Published: April 2024

The approach to working out of dynamic model of one of key stages of flight of space-rocket systems – process of separation of large-sized designs is offered. The urgency of the account of own elastic properties of the separated objects, caused by growth of their sizes at simultaneous minimisation of weight of a “dry” design, by application of new materials with good strength and the expressed elastic properties, considerable on size (to hundreds kilonewtons) the concentrated forces created by special means of branch is proved. On the basis of assumptions, characteristic for investigated process (a little angular speeds in the course of relative movement at separation in comparison with the lowest frequencies of divided objects). Transition from the differential equations of elastic fluctuations in private derivatives to system of the ordinary differential equations describing excitation of the limited set of the lowest forms that has allowed to formulate the effective approach supposing evident mechanical interpretation is carried out: full movement at separation is displayed on portable movement (rotary and forward as whole) and the small elastic relative fluctuations described in the universal modal formulation. Process of separation of the aerospace plane and the carrier rocket is analysed. The effect of “loss” of relative speed of branch because of elastic fluctuations is revealed, the recommendation about a rational choice of installation sites of means of branch is formulated.
THE PROBABILISTIC MODEL OF ULTRASHORT PULSES SCATTERING ON A FREE ELECTRON
Authors: Bugaev A. S. , Khramov E. S. , Astapenko V. A.
Published: April 2024

We devoted our study to the generalization of the traditional approach for the description of photon scattering on free electrons in the case of ultrashort laser pulses (USLP). In the framework of the second order of quantum mechanical perturbation theory with the use of the Klein–Nishina formula, we derived the expression for the total scattering probability during the whole time of the pulse action that is applicable in the relativistic limit. The redshift of scattered pulse spectra at the scattering angle increase in the relativistic case was studied. The trends of the total scattering probability on the USLP duration were categorized.
CRITICAL CONDITIONS OF SELF-IGNITION AT BIFURCATION POINTS
Authors: Philippov А. А. , Berlin A. A.
Published: April 2024

The article summarizes the results of the main research in the field of self-ignition theory. For symmetrical vessels, the following are presented: critical conditions of spontaneous ignition in dimensional coordinates, temperature distribution in the vessel, pre-explosive heating of fuel and the critical size of the vessel at the time of explosion. It is noted that the self-ignition conditions for different vessels differ only by a digital multiplier, which indicates that the shape of the vessel does not affect the physic-chemical processes going on in the fuel at the time of the explosion. Each singular point, being a bifurcation point, determines a number that allows finding a single critical condition of self–ignition from the set of solutions to the heat equation. This condition, in the coordinates of its variables, represents a multidimensional surface separating the zone of stationary existence of a combustible system from the zone of “no return”, where a combustible system cannot exist.
INFLUENCE OF A UNIFORM MAGNETIC FIELD ON THE GENERATION OF STRONG SMALL-SCALE MAGNETIC FIELDS DURING THE INJECTION OF A PLASMA WITH HOT ELECTRONS INTO AN INHOMOGENEOUS COLD PLASMA LAYER
Authors: Kocharovsky V. V. , Garasev M. A. , Derishev E. V. , Nechaev A. A. , Stepanov A. N.
Published: April 2024

We carry out a numerical modeling of plasma injection with hot electrons into a thin layer of cold plasma in the presence of an external magnetic field. We show that the latter can significantly affect the emerging small-scale current filaments and sheets, even if it does not magnetize the particles and does not change the overall dynamics of the redistribution of the total plasma density in the process of injection. The effect observed depends on the orientation of the external magnetic field that is parallel to the plane that bounds the cold plasma layer, if the injection occurs from a narrow strip lying in this plane. In this situation, which corresponds to the ablation of a flat target by a femtosecond laser beam using cylindrical focusing, we study the evolution of the characteristic structures of the formed small-scale magnetic field. It is established that its generation is associated with instabilities of the anisotropic velocity distribution of electrons, and its value can be many times greater than the value of the external magnetic field.
SYNCHRONIZED ACTIVE ANTENNA ARRAYS FOR STUDYING THE PASSAGE OF ULTRA-WIDEBAND SIGNALS IN THE ATMOSPHERE AND IONOSPHERE
Authors: Lebedev E. F. , Ostashev V. E. , Ulyanov A. V. , Fedorov V. M. , Shurupov M. A.
Published: April 2024

Active synchronized antenna arrays generating ultra-wideband radiation with an electric field strength of about 1 V/m at a distance of several hundred kilometers have been studied. They are designed to study the passage of ultra-wideband signals in the surface layer of the atmosphere and through ionosphere. Synchronous antenna arrays with 4 and 9 radiating modules have been created. Their radiation has a symmetrical radiation pattern along the X and Y axes with a pulse duration at half-height of about 100 ps. They have a pulse energy potential (E × R) of about 60 and 150 kV, with a gross weight of 50 and 100 kg, respectively. Such characteristics allow these arrays to be placed on air carriers. The option of using air balloons when radiating in the surface layer of the atmosphere and the option of the meteorological rockets placing when radiating from a height of 300 km to the Earth surface is considered.
STRUCTURE AND MECHANICAL CHARACTERISTICS OF COMPOSITES WITH HIGH DAMPING PROPERTIES
Authors: Rabinskiy L. N. , Lomakin E. V. , Lurie S. A.
Published: April 2024

The damping characteristics of hybrid composite materials reinforced with elastic spherical and fibrous inclusions with viscoelastic coatings are studied. It is shown that in composites with particles morphology, the effect of significant increase of dissipation loss can be realized, andᵇ the effective composite properties loss can exceed the dissipation loss of viscoelastic coatings more than twenty times. The analytical estimations for optimal parameters of hybrid composite materials are proposed. The influence of possible imperfections in composite structure on their effective dissipation properties are analyzed.
EXPERIMENTAL AND THEORETICAL INVESTIGATIONS OF HIGH-TEMPERATURE CREEP OF ENAW 5251 (AMg2) ALUMINUM ALLOY UNDER STEP LOADING
Authors: Arutyunyan A. R. , Saitova R. R.
Published: April 2024

In conditions of high-temperature creep, the evolution of the damage of metallic materials is observed. To describe this effect, the damage conception of the Kachanov-Rabotnov is used. The damage parameter is defined as the relative changes of the material density, which is an integral characteristic of the damage. Taking into account this parameter and the law of conservation of mass, interrelated kinetic equations for creep deformation and damage parameter are formulated. Analytical solutions of these equations are obtained for the case of two-stage loading. Experimental studies of uniaxial stress state under conditions of high-temperature creep under two-stage loading of aluminum alloy ENAW 5251 (AMg2) at a temperature of 250°C were conducted. A good agreement of the obtained theoretical curves with the experimental results is observed.
ON THE WORST DISTURBANCE OF AN OSCILLATOR WITH QUADRATIC-LAW DAMPING BY MEANS OF A FORCE WITH GIVEN INTEGRAL
Authors: Bolotnik N. N. , Korneev V. A.
Published: April 2024

A worst disturbance problem for an oscillator with quadratic-law damping is stated. The role of the disturbance is played by an external force applied to the oscillator. It is assumed that this force acts in one direction, that the integral of this force with respect to time is given, and that at the initial time instant the oscillator is resting in the equilibrium position. It is required to find a time history of the disturbing force that maximizes the maximum (with respect to time) of the absolute value of the displacement of the oscillator’s body from the equilibrium position. The worst disturbance is found and investigated from among rectangular pulses under which the disturbing force is constant on an initial time interval and is equal to zero outside of this interval.
ON ONE ENERGY CONDITION FOR THE DEVELOPMENT OF AN ISOLATED CRACK
Authors: Dunaev V. I. , Kozhevnikov V. V. , Tereshchenko I. A.
Published: April 2024

Based on the energy approach to the brittle fracture process, a new energy criterion of fracture is obtained in the case when an arbitrary normal symmetrical load acts on the surface of an isolated crack.
DEPENDENCE OF THE POSITION OF PHONON IR ABSORPTION BANDS OF GERMANIUM ISOTOPES ON THEIR MASS NUMBER
Authors: Kropotov G. I. , Bulanov A. D. , Rogalin V. E. , Kaplunov I. A. , Shakhmin A. A.
Published: April 2024

For the first time, in a single experiment, the dependence of the position of the phonon absorption peaks in the IR spectrum (range 11–40 μm) for all five stable monoisotopic germanium single crystals was studied. The dependence obtained can be used to study the mass composition of germanium of various isotopic purity.
CRYSTALLOGRAPHIC CHARACTERISTICS OF PHASE TRANSFORMATIONS IN THE FIELD OF MEDIUM-CARBON STEELS JOINT OBTAINED BY ROTARY FRICTION WELDING
Authors: Schastlivtsev V. M. , Yakovleva I. L. , Lobanov M. L. , Priymak E. Yu.
Published: April 2024

Orientation (EBSD) and transmission electron microscopy have been used to study the structure and orientation relationships of α' and γ-phases in medium-carbon steels during rotational friction welding. It is shown that, as a result of phase recrystallization, martensite with interlayers of the γ phase is formed in the structure of the welded joint. The formation of secondary (reverted) austenite was established by the form of the spectrum of angular deviations of interfacial boundaries. It is shown that, in this case, an orientation relation close to the Bein one is realized between the crystals of the α and γ phases.
SURFACE PLASMON-POLARITONS IN THE VO2-DIELECTRIC-METASURFACE STRUCTURE BASED ON GRAPHENE IN AN EXTERNAL MAGNETIC FIELD
Authors: Usik M. O. , Kuzmin D. A. , Bychkov I. V. , Bugaev A. S. , Shavrov V. G.
Published: April 2024

In this paper presents the results of a study of the behavior of surface plasmon polaritons in the layered structure of VO2–SiO2-graphene-based hyperbolic metasurface under the influence of an external magnetic field before and at the beginning of the phase transition of vanadium dioxide. As a result of calculations, it is shown how the Isofrequency contour of surface plasmons changes taking into account the different direction of the external magnetic field. It is also shown how an external magnetic field affects the direction of static magnetization caused by the inverse Faraday effect. This work can offer additional ways to control the behavior of surface plasmons, as well as become the basis for the study of new self-adjusting structures.
THE SIGNIFICANCE OF RETAINED AUSTENITE IN THE HIGH STRENGTH AND PLASTICITY OF MEDIUM CARBON Q&P STEEL
Authors: Mishnev R. V. , Borisova Y. I. , Erokhin M. N. , Gaidar S. M. , Kaibyshev R. O.
Published: April 2024

The Fe–0.44%C–1.8%Si–1.3%Mn–0.82%Cr–0.28%Mo steel treated by the quenching-partitioning process showed a product of strength and elongation of 30 GPa·% with yield stress of 1350 MPa. Such combination of high ultimate tensile strength and good ductility is attributed to a high portion of retained austenite (≥20%) transforming to martensite under tension. The high yield stress is provided by carbon supersaturation of austenite and a high dislocation density in this phase.
RAMAN-GEOTHERMOMETER FOR CARBONACEOUS CHONDRITES
Authors: Voropaev S. А. , Krivenkо A. P. , Dushenkо N. V.
Published: April 2024

Samples of the Murchison meteorite (carbonaceous chondrite, type CM2) were kept isothermally in a specially designed device at temperatures of 200, 500 and 800°C. After the samples cooled down in an inert helium atmosphere, Raman scattering spectra were taken. An increase in the intensity of the G- and D-lines of graphite was detected depending on the degree of heating. It is shown that using such a characteristic parameter of these lines as the area ratio, SD/SG, it is possible to define a geothermometer to determine the maximum temperature of thermal metamorphism of the parent bodies of carbonaceous chondrites. A comparison with the known data for carbonaceous chondrite Allende (CM3), which has experienced a significant thermal metamorphism, is carried out.