bluuebunny/crossref_metadata_2025 huggingface dataset:
ALKALINE WATERS OF THE ULTRABASIC MASSIF OF Mt SOLDATSKAYA, KAMCHATKA: CHEMICAL AND ISOTOPIC COMPOSITION, MINERALOGY AND 14C AGE OF TRAVERTINES
Authors: Taran Yu. A. , Savelyev D. P. , Palyanova G. A. , Pokrovsky B. G.
Published: April 2024

For the first time, a detailed description of springs with alkaline waters (pH 10) found within the ultrabasic massif of the Mt. Soldatskaya on the Kamchatsky Mys Peninsula in Kamchatka is presented. The chemical composition of the springs and the dependence of the ratios and concentrations of some components on pH correspond to the formation of these waters due to modern serpentinization of ultramafic rocks. The most alkaline springs (pH 12.3) contain dissolved hydrogen at a concentration of about 0.6 mmol/l. The behavior of the isotopic composition of carbonate travertines precipitated from these springs (δ13C and δ18O) differs from the known trend for “meteogenic” travertines, associated with serpentinization of ultrabasic rocks in Oman and California. The age of travertines, determined by the radiocarbon method is close to the modern.
ON SIMILARITIES BETWEEN DEFORMATION PROCESSES PRECEDING ICE SHOCKS AND TECTONIC EARTHQUAKES
Authors: Bornyakov S. A. , Dobrynina A. A. , Shagun A. N. , Sankov V. A. , Salko D. V. , Miroshnichenko A. I. , Vstovsky G. V. , Sintsov A. E.
Published: April 2024

The instrumental monitoring reveals an autowave nature of ice deformation behavior prior to ice shocks. A few minutes or the first tens of minutes before the shock, this process shows an increase in the amplitude of oscillations, often with a multi-fold reduction in their period. An autowave dynamics of ice deformations is due to self-organization of a structurally heterogeneous ice environment under critical conditions. The self-organization ability of the deformation process is confirmed by the results of ice deformation time series processing by the structural function curvature analysis method (SFCAM) and by the Lomb-Scargle periodogram method. The results of seismic monitoring of ice showed that autowave processes are characterized by constant frequency of 0.1 Hz. Taking into account the ice deformation and microseismic fluctuation features preceding the ice shocks, spectral analysis was performed on the data of deformation and seismicity monitoring at the Buguldeika geodynamic polygon before the Kudara earthquake. According to the results, 14 hours before the earthquake the seismogram recorded a gradual increase in auto-oscillation amplitudes in the frequency range from 0.01 to 0.1 Hz. The maximum amplitude increase is 19.5 against the background.
ASSESSMENT OF SOIL POLLUTION WITH HEAVY METALS OF CERTAIN AREAS OF THE NEW MOSCOW
Authors: Guseva A. S. , Petrov V. A.
Published: April 2024

Since 2012 the territory of Moscow has increased by 2 times, the Troitsky and Novomoskovsky administrative districts (TiNAO) were annexed to Moscow. Due to the fact that earlier this territory was part of the Moscow region, detailed studies of the ecological state of soils were not carried out. In the period from 2019 to 2020 years to assess the soil pollution with heavy metals of certain areas of New Moscow, both in forest areas and near man-made objects that are potential sources of pollution, samples were taken up to 10 cm deep and analyzed by X-ray fluorescence analysis for the content of V, Ni, Pb, Cu, Zn. It was revealed that at present the surveyed areas are characterized by an acceptable level of pollution, exceeding the maximum permissible concentrations was not detected. It is shown that anthropogenic activity contributes to technogenic soil pollution. It is recommended to conduct annual environmental monitoring for the purpose of early detection of pollution foci.
GEOCHEMICAL ASPECTS OF METAPSAMMIT FRICTIONAL MELTING DURING SEISMIC MOVEMENTS (BY THE EXAMPLE OF PSEUDOTACHYLYTES OF THE LADOGA REGION)
Authors: Morozov Yu. A. , Matveev M. A. , Skublov S. G. , Smulskaya A. I. , Terekhov E. N. , Larkov A. S.
Published: April 2024

Based on geochemical analyses of tectonic pseudotachylytes and their host rocks the features of redistribution of major, rare and rare-earth elements during seismogenic frictional melting of arkose-type metaterrigenous rocks from different-temperature zones of regional metamorphism) of Northern Ladoga region are considered. Multidirectional trends in variations of the major elements oxides contents in the triad protolith-blastocataclasite-pseudotachylyte were revealed, but a unidirectional increase of the frictional melt basicity in comparison with the protolith was established. Geochemical evidence of partial selective melting of source rocks is considered. Peculiarities of rare and rare-earth elements fractionation during transition to the melt of protolithic material, as well as during its subsequent partial crystallization are shown. The appearance of positive europium anomaly in the melt matrix of all three sampling points is noted. By changes of these elements’ concentrations in zones of pseudotachylyte substrate generation and in areas of its injection their differential mobility during frictional melting in a zone of dynamic movement is estimated.
EFFECT OF STRONG EARTHQUAKES ON THE GEODYNAMO
Authors: Adushkin V. V. , Spivak A. A.
Published: April 2024

Using the data of magnetic observations performed at the INTERMAGNET network observatories during the period of the double earthquake on March 16, 2022 (Japan), the global nature of the induced geomagnetic variations was demonstrated. Their synchronism and comparable amplitude over a wide range of distances from 210 km to ~10 000 km, the delay time relative to the considered seismic events (~55 min) and the predominant period of variations ~30 min indicate that the source is a geodynamo perturbed by the action of seismic waves propagating deep into the earth.
FEATURES OF THE DISTRIBUTION AND COMPOSITION OF ORGANIC COMPOUNDS IN WATER AND BOTTOM SEDIMENTS CHERNAVKA RIVER FLOWING INTO ELTON LAKE
Authors: Nemirovskaya I. A. , Kanapatskiy T. A. , Khramtsova A. V.
Published: April 2024

Organic compounds: Corg, lipids, hydrocarbons (HCs) – aliphatic (AHCs) and polycyclic aromatic (PAHs) in suspended particulate matter of surface waters and in bottom sediments of the shallow Chernavka River, which flows into a self-sustaining Elton Lake were studied. High concentrations of organic compounds were found in surface waters: in averaged 692, 80 and 0.79 µg/L for lipids, AHCs, and PAHs respectively. The composition of alkanes in the aqueous suspension corresponded to the weathered oil hydrocarbons. HC transformation occurs here not in the course of sedimentation, but at the water–bottom sediment interface. As a result, the AHC composition of the sediments differed from that of the particulate matter in the presence of planktonogenic low molecular weight homologues of n C15–C17 and a sharp increase in the series of odd high molecular weight alkanes, while the PAH composition differed in the increase in the proportion of naphthalene.
NEW DATA ON LATE CRETACEOUS THEROPODS FROM THE BOSTOBE FORMATION OF NORTHEASTERN ARAL SEA REGION (KAZAKHSTAN)
Authors: Averianov A. O. , Lopatin A. V.
Published: April 2024

Two isolated metatarsals (III and IV) of theropod dinosaurs from the Bostobe Formation (Upper Cretaceous, Santonian–Campanian) of the Shakh-Shakh locality in Kazakhstan are assigned to the representatives of the families Caenagnathidae and Dromaeosauridae, respectively. The metatarsal III of Caenagnathidae indet. confirms the presence of oviraptorosaurs in the dinosaur assemblage from the Bostobe Formation. This bone is very similar morphologically with the metatarsal III of Elmisaurus rarus Osmólska, 1981 from the Maastrichtian of Mongolia. The metatarsal IV of Dromaeosauridae indet. is characterized by a lateral crest, which among dromaeosaurids is known only for Velociraptor mongoliensis Osborn, 1924 from the Campanian of Mongolia.
MAGNETO-MINERALOGICAL ANOMALIES AT THE PLEISTOCENE-HOLOCENE BOUNDARY IN LAKE SEDIMENTS OF NORTHEASTERN RUSSIA
Authors: Minyuk P. S. , Pozhidaeva D. K. , Sotskaya O. T. , Akinin V. V. , Morozova M. A.
Published: April 2024

The results of the study of lake sediments in the North-East of Russia are presented. The reasons for the abnormally high values of magnetic susceptibility in the transition layers from the Late Pleistocene to the Holocene are considered. The magnetic fraction of Lake Grand sediments is represented by detrital titanomagnetites and magnetites. In the sediments of the Gryazevoye, Sosednee, Vodorazdelnoye, and Sapog lakes, high values of magnetic susceptibility are due to autigenic iron sulfides, mainly greigite. The data obtained do not confirm the well-known assumption about the presence of an impact event at the boundary of the Pleistocene and Holocene.
NEW 254 ma PALEOMAGNETIC POLE OF THE EAST EUROPEAN PLATFORM: MOSCOW SYNECLISE, SUKHOBORKA AND SOSNOVKA SECTIONS
Authors: Fetisova A. M. , Veselovskiy R. V. , Golybev V. K.
Published: April 2024

The paper presents the results of paleomagnetic and rock magnetic studied of upper Permian continental red beds of the Sukhoborka and Sosnovka sections of the south-eastern part of the Moscow syneclise on the right bank of the Vetluga river in Nizhniy Novgorod region, Russia. Arguments in favor of the primary nature of the characteristic component of magnetization are given. A first securely dated upper Permian (254 Ma) paleomagnetic pole of the east part of the East European Platform is calculated: slat = 56.731°N, slong = 45.748°E, N = 44, plat = 55.3°, plong = 158.1°, dp/dm = 3.5°/5.1°, paleolat = 34.6°.
BUTUGOL METAMORPHIC COMPLEX – EXOTIC PRECAMBRIAN BLOCK IN THE STRUCTURE OF THE BASEMENT OF THE TUVA-MONGOLIAN MICROCONTINENT (EASTERN SAYAN)
Authors: Shkolnik S. I. , Belyaev V. A. , Letnikova E. F. , Demonterova E. I. , Bryansky N. V. , Kolesov K. K. , Ivanov A. V.
Published: April 2024

Isotope-geochronological and geochemical data and age of the metamorphic rock of the Butugol metamorphic Complex, located in the eastern part of the Tuva-Mongolian microcontinent of the CAOB, have been obtained. It has been established that the gneisses protolith is, in one case, volcanic rocks with an age of 1009 ± 8 Ma, in the other case, potassium meta-sedimentary rocks accumulating in continental marginal basins. The formation of the protolith of the metavolcanogenic rocks of this complex took place at the turn of the Meso- and Neoproterozoic on the formed crust, while the metasedimentary rocks formed due to the Mesoproterozoic, more rarely Paleoproterozoic and Archean continental provenances. It has been established that the rocks of the Butugol metamorphic Complex have a different history of development from other blocks of the earth’s crust as part of the composite Tuva-Mongolian microcontinent.
THE WINTER LAPTEV SEA POLYNYA AND ARCTIC OSCILLATION DURING THE LAST 300 YEARS: RECONSTRUCTIONS ON GEOCHEMICAL PROXY
Authors: Astakhov A. S. , Babich V. V. , Gukov A. Yu. , Alatorcev A. V.
Published: April 2024

It is shown that the area of winter Siberian polynya in the Laptev Sea has a negative correlation with the Arctic oscillation index (AO) for the winter period. Using this, a transfer function has been developed that connects the variations of winter polynya (the time series of the winter AO) and the geochemical time series of bottom sediments accumulated during the instrumental period (1898–2018) in the zone of distribution of the Lena polynya. The influence of winter polynya on sedimentation is determined by the formation of highly saline and cold waters entering to the bottom horizons. During the summer and in subsequent seasons, they determine the stratification of the water column of the shelf and make it difficult to convection. As a result, an oxygen deficit is formed in the bottom horizons, and the bottom sediments are enriched with redox-sensitive elements of anoxic environments and depleted of redox-sensitive elements of oxide environments. Reconstructions using the developed transfer function of the polynya during the last three centuries showed that its active development increases the average annual air temperature in the adjacent areas, but multidirectional affects the duration of the ice-free period.
LOW-TEMPERATURE GEYSERITE AND EPHEMERAL MINERALS OF THE MOGOYSKY THERMAL SPRING (NORTHERN TRANSBAIKALIA, BAIKAL RIFT ZONE)
Authors: Zamana L. V. , Solotchin P. A. , Sklyarov E. V.
Published: April 2024

During hydrogeochemical testing of the Mogoisky thermal spring in Northern Transbaikalia, 5 samples of modern mineral sediments were taken, in two of which opal is the main component of geyserite, and in the other three carbonates, fluorides and sodium sulfates predominated. Calculations of deep temperatures showed that the formation of geyserite is associated with low-temperature hydrotherms and is explained by a decrease in their temperatures during discharge. Deposits of easily soluble salt minerals occur on the evaporation barrier, during rainy periods they can completely dissolve and disappear.
HOLOCENE EXPLOSIVE ERUPTION ON THE VETROVOY ISTHMUS (ITURUP ISLAND) AS A SOURCE OF THE 2000 cal BP MARKER TEPHRA LAYER IN THE CENTRAL KURIL ISLAND ARC
Authors: Bergal-Kuvikas O. V. , Smirnov S. Z. , Agatova A. R. , Degterev A. V. , Razjigaeva N. G. , Pinegina T. K. , Portnyagin M. V. , Karmanov N. S. , Timina T. Yu.
Published: April 2024

Geochemical study of volcaniclastic material and radiocarbon dating of charred plant debris from Holcene deposits of the Guram site, which is located in vicinity of Vetrovoy Isthmus at Iturup Island, demonstrate that explosive eruption (VEI 4-5) occurred there by 2000 years ago. Geochemical and age similarity with the tephra of marker layer CKr that was distinguished at Iturup, Urup, Simushir, Rasshua, and Matua islands of the Kuril Island Arc led to the conclusion that this eruption is supposedly a source of this tephra. The data presented are proposed as a motivation for revision of volcanic hazard at Iturup Island.
GEOMAGNETIC EFFECT OF THE EARTHQUAKES Mw = 7.5–7.8 IN TURKEY ON FEBRUARY 6, 2023
Authors: Soloviev A. A.
Published: April 2024

We study the response in geomagnetic field variations caused by a series of earthquakes with magnitudes Mw = 7.5–7.8 in Turkey on 6 February 2023. Initial data represent high-precision observations of the geomagnetic field with a 1-s sampling rate recorded at magnetic observatories of Russia and neighboring countries from middle to high latitudes. The paper analyzes the morphology of the geomagnetic signal, its amplitude-frequency characteristics, pulses in the rate of change and delays of the geomagnetic field response to earthquakes with magnitudes Mw = 7–8 depending on the distance to the source. The results suggest that the geomagnetic effect is best detected in the rate of change recordings, reaching anomalous amplitudes of 10 nT/s. The signal delay is from 221 to 592 s depending on the magnetic field component and the distance to the epicenter, which for the selected observatories falls in the range from 765 to 2650 km.
EARTHQUAKES IN TURKEY 06.02.2023: MODEL OF THE RUPTURE SURFACE BASED ON SATELLITE RADAR INTERFEROMETRY
Authors: Mikhailov V. O. , Babayantz I. P. , Volkova M. S. , Timoshkina E. P. , Smirnov V. B. , Tikhotskiy S. A.
Published: April 2024

Satellite radar interferometry data made it possible to clearly map two faults, shear displacements along which caused catastrophic earthquakes on February 06, 2023 in Turkey. According to satellite data, the relative displacements of the sides of the East Anatolian Fault Zone (EAFZ), to which the first event with a magnitude of Mw 7.8 was associated, exceeded 5 m in the central segment. The rupture surface extends from the area of the Doğanyol-Sivris of 24.01.2020 Mw 6.7 earthquake in the north to the Mediterranean coast in the south, where the earthquake Mw 6.3 occurred on 20.02.2023. The second event of Mw 7.5 is associated with the Surgü-Çardak fault, and the relative displacements of its sides, according to satellite data, exceeded 7 m. The obtained displacement fields of the Earth’s surface were used to construct a model of the seismic rupture. The model is based on the solution [5], which defines displacements on the surface of a spherically stratified planet as a result of dip and strike displacements on a rectangular rupture located inside the sphere. Ignoring the spherical stratification of the planet leads to errors of up to 20%, especially in the presence of a large shear component [5]. Also, an error is introduced by ignoring sphericity when using the solution obtained for an elastic homogeneous half-space [6], as the US Geological Survey (USGS) did when building seismic rupture models for earthquakes in Turkey in 2023. The difference of our model is the detailed consideration of the fault geometry. For this purpose, the faults were approximated by 19 planes along the strike, divided into two levels along the dip. In the built model, shear displacements in the central segment of the EAFZ reached 12.7 m. In the southern segment of this rupture, the displacements are substantially smaller. It should be emphasized that we registered the displacements for the period from January 29 to February 10, 2023, i.e. together with coseismic ones, they also include postseismic displacements for 4 days after the main seismic events. The displacements on the rupture surface along the Surgü-Çardak fault, where an Mw 7.5 earthquake occurred, reached 10 m. The obtained results demonstrate, in particular, the efficiency of application of satellite radar interferometry in the operative study of catastrophic geodynamic phenomena and processes.
EFFECT OF SOIL GELS ON HYSTERESIS PHENOMENA IN SOILS
Authors: Fedotov G. N. , Shoba S. A. , Ushkova D. A. , Potapov D. I. , Gorepekin I. V.
Published: April 2024

Based on the analysis of the exist mechanisms of the hysteresis of soil water retention curve (WRC), as well as ideas about the nanostructural organization of soils, it is concluded that hysteresis can be caused either by stable (non-colloidal particles) or labile (gels) parts of the solid phase of soils. Due to the fact that until now the main attention has been paid to the study of the effect of stable solid phase of soils on the hysteresis of WRC, it was proposed to investigate the effect of soil gels on hysteresis. For this purpose, the effect of moisture content of soil samples prepared by drying and moistening on the initial viscosity of soil pastes was studied. It has been established that well-pronounced hysteresis is observed for samples of all studied soil types. To explain the hysteresis, two mechanisms based on changes in soil gels in the humidification-drying processes are proposed. One of them is based on the slowness of swelling and shrinkage of soil gels when they absorb and release water. The second is on the greater hydrophobicity of the surface of gels containing less water, and water slipping on hydrophobic areas of the surface with a decrease in the viscosity of pastes. Thus, the conducted studies have shown that hysteresis phenomena in soils are caused by soil gels and their changes during drying and moistening of soils.
METHODOLOGY OF REMOTE ASSESSMENT OF THE CHARACTERISTICS OF UNEXPLORED LAKES OF THE CONTINENTAL PART OF THE RUSSIAN TUNDRA
Authors: Zverev I. S. , Golosov S. D. , Kondratiev S. A. , Rasulova A. M.
Published: April 2024

A methodology has been proposed to assess the hydrophysical and chemical-biological characteristics of unexplored small and medium lakes (with an area of up to 100 km2) in the Arctic territories of Russia using remote sensing and mathematical modeling methods. The methodology is based on the use of a one-dimensional model of hydrothermodynamic and chemical-biological processes in water bodies FLake. The technique makes it possible to obtain an estimate of heat transfer between the atmosphere, ice, water, and bottom sediments, the date of ice cover formation, its thickness, and duration of existence of freeze-up, calculate profiles of water and bottom sediment temperature and dissolved oxygen by depth based on information on geographical coordinates and lake’s surface area. Contact measurements are not required, which is extremely important for hard-to-reach and poorly explored northern territories of our country.
ESTIMATION OF METHANE FLOW FROM THE BOTTOM OF THE KARA SEA
Authors: Voropaev S. A. , Sevastyanov V. S. , Dushenko N. V. , Bryukhanov A. L.
Published: April 2024

During the expedition on the R/V “Akademik Mstislav Keldysh” (81st cruise) in 2020, extensive material was selected, representing columns of bottom sediments up to 6 meters deep in the Kara Sea. After lithological description of the columns, sediment samples were taken from different horizons for degassing of pore gases. The extracted gas samples were analyzed for the content of the main gases – methane (CH4), carbon dioxide (CO2) and light hydrocarbons. The characteristic features of CH4 and CO2 content changes with depth of bottom sediment at station 6879 (Kara Sea shelf) were studied. A model of gas diffusion was constructed taking into account the biochemical reactions of methanogenesis and methane oxidation. The rate of methane formation can be estimated by the value J ≈ 3 × 10–10 μg sec–1 L–1 (per liter of sediment). The rate coefficient of methane consumption by microorganisms is K ≈ 0.5 × 10–10 sec–1. The methane flux from the bottom surface of the Kara Sea near station 6879 is q ≈ 3.47 × 10–2 μL m–1 year–1.
ARKOSE SANDSTONES OF THE KEBEKTA GROUP OF THE UGUI GRABEN (ALDAN SHIELD): AGE, SOURCES, AND DEPOSITION SETTING
Authors: Kovach V. P. , Samsonov A. V. , Kotov A. B. , Salnokova E. B. , Adamskaya E. V. , Bortnikov V. V. , Stepanova A. V. , Erofeeva K. G. , Plotkina Yu. V. , Fedossenko A. M. , Skovitina T. M.
Published: April 2024

The paper presents the results of U-Pb (ID-TIMS) and U–Th–Pb (LA-ICP-MS) geochronological studies of baddeleyite from dolerite dikes of the Sulumat Complex and detrital zircon from red arkose sandstones of the Kebekta Group of the Ugui graben, the Aldan Shield. It has been established that the Kebekta Group have an age of 2.011.87 Ga. The sources of the Kebekta Group deposits were the Archean (2.92–2.52 Ga) igneous and metamorphic complexes of the Chara-Olekma geoblock and the zone of its junction with the West Aldan megablock of the Aldan Shield, as well as unidentified on the present erosion level the Paleoproterozoic (ca. 2.01 Ga) complexes. The obtained geochronological data do not contradict the correlation of terrigenous rocks of the Kebekta Group of the Ugui graben and the Kemen Group of the Kodaro-Udokan trough. The deposition of arkose sandstones of the Kebekta Group correlates in age with the glaciations in Australia and Sweden (ca. 1.9–1.8 Ga) associated with the formation of the Columbia/Nuna supercontinent. It also cannot be ruled out that the deposition of the rocks of the Ugui graben was related to the inflow of glacial material into the intracontinental extensional basin from the southern and/or western (in modern coordinates) framing of the Chara-Olekma geoblock at the stage of collapse of the Paleoproterozoic orogen.
ACAUSTIC AND MAGNETIC EFFECTS OF THE BOLIDE FALL ON 04/19/2023
Authors: Adushkin V. V. , Rybnov Yu. S. , Spivak A. A.
Published: April 2024

The results of instrumental observations of acoustic oscillations and geomagnetic variations during the fall of the bolide on 04/19/2023 in the area of Kiev (Ukraine) are presented. It is shown that the explosion of the car was accompanied by an acoustic signal recorded at a considerable distance from the epicenter of the event (~755 km), and manifested itself in variations of the magnetic field. According to acoustic observations, 4 explosions of the largest fragments of the car were recorded. The total energy of the event was 4.2–1011 J, which corresponds to about 0.1 kt in TNT equivalent. The maximum amplitude of geomagnetic variations caused by the explosion of the bolide at distances in the range of 454–909 km was from 2.5 to 4 Nt.
GLOBAL GEODYNAMIC MODEL OF THE EARTH AND ITS APPLICATION FOR ANTARCTICA
Authors: Baranov A. A. , Lobkovsky L. I. , Bobrov A. M.
Published: April 2024

A geodynamic model of the modern Earth is constructed based on the SMEAN 2 global seismic tomography model. On the basis of mantle temperature anomalies, numerical modeling of spherical mantle convection is performed for the parameters of the real Earth. For Antarctica, an explanation was obtained for the existence of the West Antarctic Rift System, which contains one of the largest and least known volcanic provinces on Earth, which is consistent with the increased surface heat flow and modern volcanism of the West Antarctic Rift System and part of the Antarctic Peninsula. The increased heat flow and volcanoes in this region are causing instability and accelerating the flow of glaciers from the West Antarctic Ice Sheet into the ocean, which could lead to a significant rise in global sea level.
RESULTS OF SEISMOSTRATIGRAPHIC INVESTIGATIONS OF THE CRIMEAN SHELF BY THE METHOD OF CONTINUOUS S EISMO-ACOUSTIC PROFILING.
Authors: Khortov A. V. , Rimsky-Korsakov N. A. , Pronin A. A. , Mutovkin A. D.
Published: April 2024

The article discusses the results of seismoacoustic studies of the shelf of the southeastern part of Crimea, carried out in 2020–2023 by employees of the P.P. Shirshov Institute of Oceanology RAS an seismoacoustic profiler. The obtained data made it possible to refine the position of the paleovalleys, to perform a seismostratigraphic reference of the reflecting horizons with the identification of the main seismic complexes in the pleistocene-holocene part of the section. Seismic facies analysis of the wave field made it possible to clarify the paleogeographic conditions for the formation of paleovalleys.
EVIDENCE OF ULTRAHIGH-PRESSURE EVOLUTION OF GARNET PERIDOTITES IN THE POLAR URALS
Authors: Shmelev V. R. , Meng F-C.
Published: April 2024

In garnet peridotites of the Marunkeu eclogite-gneiss complex (Polar Urals), segregations of carbonates in association with chlorapatite were first established. They contain relics of dolomite, which is “replaced” by calcite with symplectite (graphic) intergrowths of brucite and hydrocarbonate. The formation of peridotites with unusual carbonate structures is the result of the evolution of this complex at different depths. During deep subduction and progressive with the formation of garnet peridotites, segregated dolomite experienced a solid-phase breakdown into aragonite and magnesite at the pressure peak (≥5 GPa). During exhumation and retrograde metamorphism, garnet peridotites, together with segregations, underwent low-temperature transformations; aragonite was replaced by calcite, and magnesite by brucite and hydrocarbonate. The presence of carbonates with deep-seated structures confirms that the garnet peridotites and eclogites of the Polar Urals belong to ultrahigh-pressure complexes.
FIRST DETAILED RECORD δ13 Corg. IN PERMIAN MUDSTONES OF THE TASKAN BASIN (OMULEVKA BLOCK): A REFLECTION OF BIOSPHERIC EVENTS IN NORTHEAST ASIA
Authors: Biakov A. S. , Vedernikov I. L. , Goryachev N. A. , Gareev B. I.
Published: April 2024

For the first time, a detailed record of the δ13Сorg value has been obtained in Permian mudstones of the Taskan Basin (Omulevka block, Northeast Asia), covering the interval from the Upper Kungurian, Roadian, Wordian, Capitanian, and Lower Wuchiapingian stages. The value of δ13 Corg. varies from –23.81‰ (middle Kungurian) to –26.97‰ (lower part of the Wuchiapingian). Three negative excursions of the δ13 Corg. value are clearly distinguished in the section – in the upper part of the Kungurian Stage of the Lower Permian, in the lower part of the Capitanian and at the boundary of the Capitanian – Wuchiapingian stages. These excursions are in good agreement with the episodes of mass extinctions established by us earlier (Biakov, 2012) and are most likely associated with periods of activity of island-arc magmatism in the region during the Permian.
THE FEATURES OF FORMATION OF RARE MINERALS DURING SHALLOW METAMORPHISM AND METASOMATOSIS
Authors: Reverdatto V. V. , Likhanov I. I. , Polyansky O. P.
Published: April 2024

The unusual composition of the protolith, its structural and textural heterogeneity, limited mass transfer and high temperatures are the causes of rare mineral formation and mineral associations during metamorphism and metasomatism. Most often, this is observed in shallow conditions (pressure up to 3 kbar) when additional heat is supplied to the rocks by magmatic intrusions. In the article, these issues are discussed on a number of geological complexes, in which the manifestations of metamorphism with the development of rare minerals and mineral associations have been studied in detail.
THE NARURE OF BONDS IN THE FORMATION OF WATER STABILITY OF SOIL AGGREGATES
Authors: Fedotov G. N. , Shoba S. A. , Ushkova D. A. , Gorepekin I. V. , Shvarov A. P.
Published: April 2024

There is an opinion that water stability is provided by hydrophobic bonds between organic soil particles, however, there are works in which the main role in the occurrence of this property is assigned to the presence of hydrophilic organic substances in soils. The aim of the study was to clarify the nature of the bonds (hydrophilic or hydrophobic) that ensure the water stability of soils. The work used samples of sod-podzolic and gray forest soil, as well as leached chernozem. Experiments on the assessment of water stability were carried out by the method of “blades”. It is based on the dissection of linearly arranged aggregates, which were previously moistened in vacuum to values close to saturation. The energy of hydrophobic bonds depends on temperature, so the effect of temperature on the determined value of water stability was studied. Experiments have shown that with an increase in temperature, the water stability of aggregates stored in a wet state from the moment of selection increased, and with a decrease, it fell. This indicates the leading role of hydrophobic bonds in the formation of water stability. For samples dried to an air-dry state, moistened again and kept in a wet state for more than 2 weeks, no temperature dependence of water stability was found. Taking into account that the strength of hydrophobic bonds increases with increasing temperature, and hydrophilic bonds decreases, the data obtained on the immutability of water stability values can be explained if we assume the joint participation of both hydrophobic and hydrophilic bonds in the water stability of soil samples that have passed through the stage of drying to an air-dry state. In fact, these results indicate a strong change in the structural organization of soils during drying.
GAS GEOCHEMICAL ANOMALIES IN THE BOTTOM SEDIMENTS OF THE TATAR TROUGH (SEA OF JAPAN)
Authors: Shakirov R. B. , Yatsuk A. V. , Sorochinskaya A. V. , Aksentov K. I. , Makseev D. S.
Published: April 2024

The paper presents the results of gas geochemical and lithogeochemical studies of bottom sediments in the Tatar Strait trough (Sea of Japan) based on cruise data from the R/V “Akademik M.A. Lavrentyev” (LV-81 and LV-85). Anomalies of hydrocarbon gases (HCG) and chemical elements in surface bottom sediments were determined. It has been established that sediments with anomalous methane contents are significantly enriched in Mn, Sc, V, Co, Ni, Cu, As, Se, Mo, Cd, Sb, Te, Tl, U, the concentration coefficients (Kk) of which are 1.3–5.9 times higher than their similar values at other stations. The data obtained allow us to assume the presence of gas sources of hydrocarbon migration, the continental slope and deep water area of the Tatar trough is promising for setting up detailed work on the assessment of oil and gas potential and gas hydrate content.
FIRST DATA ON VERTICAL PARTICLE FLUXES AND ENVIRONMENTAL CONDITIONS IN THE NORTHERN PART OF THE MOHNS RIDGE, NORWEGIAN SEA
Authors: Klyuvitkin A. A. , Kravchishina M. D. , Novigatsky A. N. , Politova N. V. , Bulokhov A. V. , Gulev S. K.
Published: April 2024

For the first time, a continuous two-year study of the particle fluxes and associated environmental parameters in the axial zone of the Arctic segment of the Mid-Atlantic Ridge at the junction of the Mohns and Knipovich Ridges (Norwegian Sea) was carried out. Sediment traps were deployed from the R/V Akademik Mstislav Keldysh in June 2019 in the northeastern part of the Mohns Ridge and realized in July 2020. It was shown that the sedimentation of sinking particles in the study area was influenced by the global transport of water masses in the northeastern direction, with Atlantic waters in the subsurface, and water masses of Arctic origin recirculating deeper in the subsurface. A weak positive temperature trend at a depth of more than 2500 m (0.02°C) is detected. The bimodal vertical distribution of fluxes and changes in the composition of sinking particles corresponded to the pattern of sediment recycling in the ocean. The annual course of fluxes in the subsurface layer was determined by the activity of silicon-concentrating and calcifying plankton, with the maximum bloom period also manifested in the deep layer. At the same time, the main significant moderator of flux deeper than 2000 m is the inflow of lithogenic matter from the benthic nepheloid layer.
THE CORRELATION OF SHORT-PERIOD WAVE DISTURBANCES IN THE PEAK ELECTRON DENSITY OF THE F2 LAYER AND THE TOTAL ELECTRON CONTENT (TEC) IN THE IONOSPHERE
Authors: Perevalova N. P. , Ratovsky K. G. , Zherebtsov G. A. , Yasyukevich A. S.
Published: April 2024

Using data of the vertical sounding ionosonde and the GNSS receiver operating in Irkutsk, we analyzed the correlation of short-period (periods less than 24 hours) wave disturbances of the peak electron density of the F2 layer (NmF2) and the total electron content (TEC) in the ionosphere. The measurement data for the period 2003–2020, which included almost two solar cycles, were processed. It has been established that the most probable case is a high positive correlation of short-period disturbances of NmF2 and TEC. With the growth of solar and geomagnetic activity, the number of cases of strong positive correlation increases (from 53% to 66%) and the number of cases of both positive and negative weak correlation decreases (from 46% to 33%). During powerful geomagnetic storms, the highest correlation (up to R = 0.89) is observed in the storm main phase and then decreases in the recovery phase up to negative R values. Possible physical mechanisms of the obtained results are considered.
GEODYNAMIC REGIMES IN THE LAPTEV SEA REGION ACCORDING TO THE LATEST SEISMOLOGICAL DATA
Authors: Krylov A. A. , Lobkovsky L. I. , Kovachev S. A. , Baranov B. V. , Rukavishnikova D. D. , Tsukanov N. V. , Dozorova K. A. , Semiletov I. P.
Published: April 2024

The results of the analysis of focal mechanisms and the general distribution of earthquake epicenters in the Laptev Sea region were presented. For four groups of clusters of events with known focal mechanisms, the directions of the principal stress axes were calculated by the formal stress inversion method. The distributions of earthquake epicenters and crustal thickness were compared. It has been revealed that, according to seismological data, the prolongation of the extension axis of the Gakkel Ridge on the Laptev Sea shelf is currently located in the vicinity of the group of extension detachments, which is extended along the eastern boundary of the Anisin, Zarya, and Belkovsko-Svyatonossky rift chains. The older extension axis, located along the group detachments marking the eastern boundary of the Ust-Lena and Omoloy rift systems, and continuing the axis of the Gakkel Ridge, is currently much less active, realizing residual stresses near its intersection with the Khatanga-Lomonosov fault zone in the northwestern parts of the shelf and with the Lena-Taimyr zone of boundary uplifts – in the southwestern. Near the Lena delta extension axes are oriented along the Olenekskaya and Bykovskaya channels and the border of the Siberian Platform, forming the extension conditions in the eastern part and the strike-slip regime in the western part of the vicinity of the Lena delta.
DEVELOPMENT TRENDS IN PLASMA AERODYNAMICS
Authors: Aleshin B. S. , Khomich V. Yu. , Chernyshev S. L.
Published: April 2024

The most promising areas of research in the field of plasma aerodynamics are proposed. On the basis of the presented experimental data obtained recently, the possibilities of using the volumetric force effect on the gas flow in aerodynamic applications, which is realized with the help of near-surface electric discharges, are considered. One of these applications is to increase the length of the laminar section of the boundary layer on the swept wing in order to reduce the aerodynamic drag of the aircraft in the cruise flight mode. The second direction is associated with the control of the three-dimensional separation of the boundary layer on the elements of the mechanization of the swept wing in the take-off and landing modes. And the third direction is the reduction of surface friction in the turbulent boundary layer, which is realized on most of the surface of modern near- and supersonic aircraft. The proposed studies are not only of applied, but also of fundamental importance due to the physical complexity of the studied phenomena.
RELAXATION ROTATION DURING MARTENSITIC TRANSFORMATION AND SCATTERING OF MARTENSITE TEXTURE
Authors: Gundyrev V. M. , Zel’dovich V. I. , Schastlivtsev V. M.
Published: April 2024

In the our crystallographic theory of martensitic transformation, a new characteristic of martensitic transformation appears – a relaxation rotation, which was not in the generally accepted phenomenological theory of martensitic transformation. The relaxation rotation is necessary to obtain an invariant plane. The calculated angle of relaxation rotation for iron alloys with non-thermoelastic martensite is 1.75–1.85 degrees, for thermoelastic Geisler alloys with multilayer martensite 0.19–0.36 degrees. The relaxation rotation leads to the scattering of the texture of martensite. The scattering angles of single X-ray reflections of martensite in different alloys were measured and it was found that the scattering angle corresponds to the angle of relaxation rotation. This result shows that the our crystallographic theory of martensitic transformation describes the real mechanism of martensitic transformation.
SIMULATION THE VIBRATIONS OF RAILWAY STRUCTURES BY THE GRID-CHARACTERISTIC METHOD
Authors: Petrov I. B. , Kozhemyachenko A. A. , Favorskaya A. V.
Published: April 2024

The aim of the study is to apply the grid-characteristic method on structured grids in various problems related to railway traffic safety; obtaining the results of full wave modeling using this method and analyzing them for a better understanding of the physical processes occurring in conditions of heavy and high-speed traffic on various sections of the track. The problem is to consider the traffic on a ballast and non-ballast bridge desk. In the course of computer simulation, various wave fields and dynamic distributions of the pressure and components of the Cauchy stress tensor were obtained during the traffic. An estimate of the calculation time during which the propagation of wave processes occurs in various bridge structures was made. The results obtained give an idea of wave phenomena during the traffic in the area of bridges and along the railway track as a whole.
THE WAVE MECHANISMS OF MICROCIRCULATION AND TRANSCAPILLARY EXCHANGE INTENSIFICATION
Authors: Veliev E. I. , Ganiev R. F. , Kubatiev A. A. , Reviznikov D. L. , Ukrainsky L. Е.
Published: April 2024

The influence of outside wave impact on filtration of fluids from capillaries into environment porous media and back is considered. Two mechanisms of filtration acceleration had installed. The first of them caused with changing the permeability of environment porous media and surface layer of capillary due to wave impact. The second caused by synchronous and in-phase boost of pressure into capillary and permeability environment porous media. It occurs in resonance case only. Both of those effects can be used for intensification of transcapillary exchange in medicine.
MONITORING MAGMATIC ACTIVITY OF THE ELBRUS VOLCANIC CENTER’S SMALL CHAMBER UTILIZING AN AEROSOL LIDAR
Authors: Pershin S. M. , Sobisevich A. L. , Makarov V. S. , Myasnikov A. V. , Grishin M. Ya. , Zavozin V. A. , Lednev V. N. , Likhodeev D. V. , Kazalov V. V.
Published: April 2024

We present the results of magmatic aerosol concentration monitoring carried out utilizing an aerosol lidar. The monitoring was performed in a hot dead-end tunnel of the Baksan Neutrino Observatory (BNO) of the Institute for Nuclear Research located above the Elbrus volcanic center’s small magma chamber. An abrupt 3-fold increase of the aerosol concentration was detected by the lidar on October 28, 2019, 22: 30 UTC in the hot tunnel of BNO. The lidar data were analyzed along with the data of radon volume radioactivity, air temperature and relative humidity sensors. Synchronous changes in the air temperature, relative humidity and aerosol concentration have been observed, as well as the correlation of these signals with Earth’s crust deformation measured by a strainmeter installed in BNO. However, neither one of these signals reflected the detected 3-fold aerosol concentration growth. The acquired data confirms the existence of a hot magma chamber found earlier under the Andyrchi mountain by the small-aperture seismometer group. A possible explanation of the 3-fold aerosol concentration growth is discussed: emanation of gases from the magma chamber could trigger this growth without influencing other measured parameters.
MULTISTABILITY IN A CHIRAL SEMICONDUCTOR MICROCAVITY
Authors: Dmitrieva O. A. , Gippius N. A. , Tikhodeev S. G.
Published: April 2024

The features of the bi- and multistability effects in the semiconductor Bragg microcavity with chiral photonic crystal slab on the upper mirror are investigated theoretically. It is shown that the response of such a chiral structure under a linearly polarized coherent resonant pump demonstrates sharp multistable transitions with abrupt jumps of the exciton intensity and degree of circular polarization. It is shown that of the thresholds of bistable transitions in the system with different sense of circular polarization differ slightly, i.e. in case of a non-optimized structure, we can expect to obtain even a larger amplitude of the jumps of the degree of circular polarization of the excitonic response due to the multistability than in a specially optimized chiral structure with a high degree of circular polarization at low pump intensity.
FORCED LONGITUDINAL OSCILLATIONS OF GAS AND AEROSOL IN AN OPEN TUBE WITH A CROSS-SECTION JUMP
Authors: Gubaidullin D. A. , Shaidullin L. R. , Fadeev S. A.
Published: April 2024

The forced longitudinal oscillations of gas and aerosol in an open tube with a cross-section jump near the resonance frequency are investigated experimentally. The intensification of gas oscillations in the tube with a cross-section jump in comparison with a homogeneous tube is observed, while preserving a close to harmonic, continuous pressure waveform. A non-monotone dependence of the aerosol deposition time on the frequency of oscillations with a minimum value at the resonance frequency is observed.
DETERMINATION OF THE ELECTRO-OPTICAL COEFFICIENTS OF BARIUM TITANATE
Authors: Shirokov V. B. , Timoshenko P. E. , Kalinchuk V. V.
Published: April 2024

Within the framework of thermodynamic theory, a method for determining the electro-optical coefficients is proposed. It is shown that for all ferroelectrics whose symmetry admits a diagonal susceptibility, the ratio of some electro-optical coefficients is expressed in terms of the ratio of susceptibilities. For barium titanate, the dependence of the electrooptical coefficients on the electric field has been revealed and studied. It is shown that large values of the electro-optical coefficients of barium titanate are associated with a nonlinear dependence of the dielectric susceptibility on the electric field.
PHOTOSENSITIVITY OF PbS COLLOIDAL QUANTUM DOTS BASED NANOSTRUCTURES WITH AN ENERGY BARRIER
Authors: Popov V. S. , Ponomarenko V. P. , Dymkin D. V. , Shuklov I. A. , Gadomska A. V. , Brichkin S. B. , Lavrentiev N. A. , Gak V. U. , Mirofyanchenko A. E. , Mirofyanchenko E. V. , Katsaba A. V. , Arsenov P. V. , Ivanov V. V. , Razumov V. F.
Published: April 2024

A new architecture of photosensitive elements for the near (0.7–1.4 μm) and short-wavelength (1.4–3.0 μm) infrared regions of the spectrum based on hybrid nanostructures consisting of PbS colloidal quantum dots and functional layers of ZnO and AgNW silver nanowires is proposed. Small-sized (12 × 12 μm) photosensitive elements with an energy barrier at the contact between layers of n- and p-type CQDs have been studied. The current-voltage characteristics, spectral dependences of optical absorption and relative spectral photosensitivity of Si(λ)/Si(λmax) barrier structures at room temperature have been studied. It is shown that the proposed architecture of barrier structures provides photosensitivity in a wide spectral range from 0.4 µm to 2.0 µm. An excess of the average value of the relative spectral sensitivity Si(λ)/Si(λmax) about 1.5 times compared to those previously observed in the wavelength range of 0.9–1.85 μm for barrier nanostructures from PbS CQDs was found.
CRITICISM OF THE “THEORY OF INCANDESCENT SURFACE IGNITION” BY Ya.B. ZELDOVICH. SELF-IGNITION OF INFINITE FUEL BY INCANDESCENT BODIES
Authors: Philippov A. A.
Published: April 2024

The basic principles of thermal explosion were studied and outlined by 1980. It seemed that fundamental research had been completed, but in 1984 A.A. Filippov discovered that the “ignition” condition obtained by Ya.B. Zeldovich did not correlate with the data of the experiment on ignition of a gas mixture by incandescent cylinders. Since Zeldovich’s “Theory of Incandescent surface ignition” has long been the basis of the ignition theory, its analysis was carried out and an error was found. It is proved that the above-mentioned work is not related to ignition, but to the self-ignition of infinite fuel. It is shown that a thermal explosion of fuel from an incandescent body can develop not only as ignition, but also as self-ignition. The conditions of self-ignition of infinite fuel by a flat surface and a cylinder are given, as well as the probable condition of ignition of fuel between parallel walls of different temperatures.
BENDING OF AN ELASTIC PLATE IN A HIGH PRESSURE FIELD
Authors: Ilgamov M. A.
Published: April 2024

The derivation of the equation of static cylindrical bending of a thin plate under the action of pressures on its surface and end edges is given. The reduction over the thickness of the plate is taken into account, the effect of which becomes noticeable at high average pressure. The refined value of the transverse distributed force is used. The dependence of the bending on the average pressure and the rigidity of the supports in the longitudinal direction is considered.
SYNTHESIS OF COMPOSITES DIAMOND-SiO2 WITH PHOTON CRYSTAL PROPERTIES IN THE VISIBLE
Authors: Sovyk D. N. , Odintsov K. A. , Bolshakov A. P. , Dyakov S. A. , Savin S. S. , Fedorova I. A. , Yurov V. Yu. , Masalov V. M. , Ralchenko V. G. , Konov V. I.
Published: April 2024

We report on synthesis of periodical structures by chemical vapor deposition in form of a composite “single crystal diamond – SiO2 nanospheres” which shows photon crystal properties in the visible.