bluuebunny/crossref_metadata_2025 huggingface dataset:
COMPARATIVE GEOTHERMOMETRY OF THE AJ-BOGD GRANTITOID MASSIF (SOUTHERN MONGOLIA) BASED ON ZIRCON STUDY
Authors: Andreeva O. A. , Aranovich L. Ya. , Kozlovsky A. M. , Golunova M. A. , Kaplanskaya D. D. , Borisovskii S. E.
Published: April 2024

The Aj-Bogd massif, located in the Trans-Altai Gobi within the Hercynides of the Central Asian fold belt, is composed of rocks from two main intrusion phases. The rocks of the early phase are represented by two-feldspar granites. while the late phase is characterized by alkali-feldspar granites. During the reconstruction of the thermal history of these granites zircon was chosen as a mineral-indicator of the temperature regime of their formation. Two main approaches to using this mineral as a geothermometer have been proposed: the zircon saturation index and the zirconium-hafnium geothermometer. Both approaches demonstrate a similar thermal picture of the formation of granites from Aj-Bogd massif. Alkaline feldspar granites of the late intrusion phase crystallized at temperatures of 810–850°C while two-feldspar granites of the early phase formed at temperatures of 700–770°C. According to thermobarogeochemical studies of melt inclusions in zircon of late-phase alkali-feldspar granites, a similar temperature range of their formation was defined (825–850°C). All obtained data of the formation temperatures of studied granites from Aj-Bogd massif indicate a significantly higher (by 100–120°C) temperature of formation of alkali-feldspar granites compared to earlier two-feldspar granites. The significantly higher crystallization temperature of late alkali feldspar granites allow us to suggest the appearance of an additional heat source that could be mantle derived melts. The evidence of such melt participation in the formation of Aj-Bogd massif are mafic dikes that separate granites of two intrusion phases. The contrast temperature regime of the calc-alkaline and alkaline intrusion phases close in time was determined for the first time in this work.
MORPHOLOGY OF LAKES OF THE CENTRAL TUNGUSKA PLATEAU (SIBERIA, EVENKIA): NEW INFORMATION ON THE PROBLEM OF THE “TUNGUSKA EVENT 1908”
Authors: Rogozin D. Y. , Krylov P. S. , Dautov A. N. , Darin A. V. , Kalugin I. A. , Meydus A. V. , Degermendzhy A. G.
Published: April 2024

The bottom morphology and thickness of bottom sediments of lakes Zapovednoye and Peyungda were studied by echo-sounding and seismic reflection profiling. The lakes are located in 60 km and 50 km from inferred explosion epicenter of “Tunguska event 1908”, respectively. We showed that both lakes have circular shape and funnel-like morphology with 60 and 34 m maximum water-depth, respectively, close to their geometrical centers. The shape of the lake is similar to famous Lake Cheko which is believed to be a secondary impact crater for Tunguska event of 1908. The shape of Lake Cheko was suggested to be highly unusual that was one of arguments to support the hypothesis of impact origin of Lake Cheko. We have shown that lakes Zapovednoye and Peyungda are examples of funnel-like deep lakes, and the age of both lakes exceeds are two thousand years. Therefore, we assume that all three lakes are most likely of karst origin. The similarity of the shape of the three reservoirs and their location in the riverbeds indicate the similar origin and testify against the hypothesis of the impact origin of Lake Cheko in 1908.
ENSEMBLE MODELLING OF ICE SHEET DYNAMICS IN THE LAST GLACIAL CYCLE
Authors: Ploskov A. N. , Eliseev A. V. , Mokhov I. I.
Published: April 2024

Ensemble simulations (taking into account uncertainty of paleoclimate reconstructions) with a models for ice sheets dynamics for the last glacial cycle (last 128 kyr) are carried out. The model realistically reproduces spatial structure of major ice sheets and heights of their domes in the Northern hemisphere as well as the associated changes in global sea level. Perturbations with a sufficiently large amplitude applied to the initial paleoreconstruction result in marked differences of the modelling, in particular, durimg the Last Glacial maximu and during 58–51 kyr before present (the initial part of MIS3). According to our simualtions, the uncertainty of temperature reconstructions durng the last galcial cycle is limited to 2°C in agreement with existing estimates.
ON THE VERTICAL DISTRIBUTION OF DUST AEROSOL IN WEAK AND MODERATE WINDS
Authors: Malinovskaya Е. A. , Chhetiani O. G. , Golitsyn G. S. , Lebedev V. A.
Published: April 2024

The height distribution of dust aerosol in the surface layer based on measurements made in the summer of 2020–2021 in arid conditions on the territory of the Republic of Kalmykia is considered. For profiles of aerosol concentration under conditions of weak winds, a characteristic gradual slope with an index close to the value of –0.5. When the wind strengthens, the profile slope takes values closer to the degrees known for the conditions of saltation. –0.7…–1.0 (and steeper). The observed regularities can be explained by the character of motion of dust particles rising from the hot surface together with the surrounding warmed air volume, which is different for fine (1 μm) and coarse (1 μm) particle fractions.
THE FIRST EVIDENCE OF PRECAMBRIAN DIAMOND SOURCES IN THE SOUTH OF THE SIBERIAN PLATFORM: RESULTS OF U–Pb (LA-ICP-MS) GEOCHRONOLOGICAL INVESTIGATIONS OF DETRITE ZIRCON FROM SEDIMENTARY ROCKS OF THE MOTSKAYA SERIES
Authors: Gladkochub D. P. , Ivanov A. V. , Donskaya T. V. , Motova Z. L. , Brianskiy N. V. , Reshetov E. V.
Published: April 2024

U–Pb (LA-ICP-MS) geochronological studies of detrital zircons from diamond-bearing sandstones of the Khuzhir Formation of the Motskaya series of the sedimentary cover of the south of the Siberian platform were carried out. Similar spectra were obtained for two samples with the most representative peaks at 620, 780, 1860 and 2550 Ma and single data in the intervals 985–1000, 1400–1500, 1150–1190, 2700–2880 and 3225–3230 Ma. The maximum age of sedimentation is 605 ± 6 Ma, which corresponds to the Ediacaran and close to the time of the carbonatite and alkali-silicate magmatism in the region. Neoproterozoic data reflect the ages of the rocks of the Tuva-Mongolian terrane of the Central Asian Orogenic Belt, and the most ancient peaks are typical for the basement complexes of the southern Siberian platform. The obtained result supports the Ediacaran age the sediments studied and could be consider as first evidence of the presence of Precambrian diamond-bearing rocks within the Siberian platform.
ANOMALOUS ABSORPTION OF SMOKE AEROSOL IN THE VISIBLE AND NEAR-INFRARED OF SPECTRUM INTERVALS
Authors: Gorchakov G. I. , Gushchin R. A. , Kopeikin V. M. , Karpov A. V. , Semoutnikova E. G. , Datsenko O. I. , Ponomareva T. Ya.
Published: April 2024

In large-scale smoke haze during mass fires in the boreal forests of Alaska in July 2019 in the visible and near infrared of spectrum intervals 440–1020 nm, according to monitoring data on the network of AERONET stations of the spectral dependences of the refractive index imaginary part, anomalous absorption of the fine smoke aerosol was found. Variations in the spectral dependences of the aerosol optical extinction and absorption depths, as well as the size distribution function of aerosol particles, are analyzed. With anomalous absorption, the imaginary part of the refractive index increased by a factor of 1.8–7.2 with increasing wavelength from 440 to 1020 nm, reaching a value of 0.315 for the wavelength of 1020 nm. A power-law approximation of the spectral dependence of the refractive index imaginary part with exponents approximately from 0.7 to 2.3 is proposed.
ALKALINE RHYOLITES OF THE PECHALNINSKY ORE FIELD (NORTH-EAST OF RUSSIA) – A POTENTIAL LARGE-VOLUME SOURCE OF HEAVY RARE EARTH ELEMENTS
Authors: Volkov A. V. , Galyamov A. L. , Murashov K. Y.
Published: April 2024

Trachyriolites and komendites of the Pechalninsky ore field contain high potentially industrial concentrations of a number of rare metals and REE. The enrichment coefficients vary from several times (Zn, Ga, LREE) to tens (Be, Y, Zr, Nb, Rb and heavy HREE). The REE distribution indicates a uniform enrichment of the HREE relative to the LREE, with a ratio (La/Yb)N in the range from 0.16–1.01). All samples show strongly negative Eu anomalies, with values of Eu/Eu* – 0.13. A comparative analysis with similar objects known in the world in alkaline volcanites has shown that the Pechalninsky ore field can become an unconventional large-volume source of HREE.
METASOMATIC ORIGIN OF LAMELLAR-LIKE INCLUSIONS IN CLINOPYROXENES FROM MANTLE XENOLITHS OF THE OBNAZHENNAYA PIPE (KUOIKA FIELD, YAKUTIAN DIAMONDIFEROUS PROVINCE)
Authors: Korolev N. M. , Nikitina L. P. , Kuznetsov A. B. , Goncharov A. G. , Galankina O. L. , Shilovskikh V. V. , Vlasenko N. S.
Published: April 2024

The article reports new data on previously undescribed lamellar-like (linearly oriented) structures in clinopyroxenes from mantle xenoliths of garnet pyroxenites (Obnazhennaya pipe, Northern Siberia). The origin and mineral diversity of lamellar structures in xenoliths from the Obnazhennaya pipe are supposed to be related to a breakdown of solid solutions during a decrease of P–T parameters. Our study shows that metasomatic recrystallization of initial clinopyroxene with linear exsolution structures leads to the formation of new secondary mineral assemblages. The secondary clinopyroxene reproduces (inherits) framework with linearly oriented inclusions, which are morphologically similar to the primary exsolution structures. Thus, the pyroxenite xenoliths from the Obnazhennaya pipe contain two generations of mineral associations with lamellar structures: primary and secondary. The primary association is composed of diopside, containing lamellae of enstatite, pyrope, spinel and rutile. The secondary (metasomatic) clinopyroxene contains half as much Al2O3 (3.4 wt %) and Na2O (1.7 wt %) and is enriched in MgO and CaO compared to the primary clinopyroxene. Nevertheless, the chemical composition of the secondary pyroxene still corresponds to diopside end-member. The metasomatic association comprises aligned pargasite (Al-rich amphibole) instead of orthopyroxene (enstatite) lamellae, and the secondary rutile is enriched in chromium (up to 3.1 wt % Cr2O3) in contrast to rutile from the primary mineral assemblage.
NEW RESULTS OF MULTIDISCIPLINARY STUDIES OF MAJOR PLEISTOCENE CLIMATIC EVENTS: GLACIATIONS, FORMATION OF ICE-DAMMED LAKES AND THEIR CATACLYSMIC DRAINING IN ALTAI (MOUNTAINS OF SOUTHERN SIBERIA)
Authors: Agatova A. R. , Nepop R. K. , Moska P. , Nikitenko B. L. , Bronnikova M. A. , Zhdanova A. N. , Zazovskaya E. P. , Karpukhina N. V. , Kuzmina O. B. , Nepop A. R. , Ovchinnikov I. Yu. , Petrozhitskiy A. V. , Uspenskaya O. N.
Published: April 2024

Application of geological geomorphological and geochronological (14C, OSL) methods allowed to establish that the bordering mountains of the Chuya basin (Russian Altai) were affected by glaciation already in the Middle Pleistocene – about 160–180 ka ago (MIS 6). However, the maximal ice-dammed lake with the highest (up to 2100 m a.s.l.) strandlines both in the Chuya and Kurai basins existed later than 90–80 ka ago, in the Late Pleistocene. This chronological benchmark limits the influence of the cataclysmic outburst floods from the largest ice-dammed lakes on the accumulation of the Inya formation in the Chuya and Katun river valleys. It is confirmed that a large ice-dammed lake existed and had a water level of at least 1730 m a.s.l. in MIS 2 in the Kurai basin. It was drained no later than 16 ka ago. Synchronously (about 17–16 ka ago) the accumulation of diluvial-lacustrine cyclites began in the Inya mouth. The Saldzhar formation had been depositing as a result of not only flood events, but also gradual hydrological processes in the Katun river valley between the mouths of the Chuya and Sema rivers during the entire MIS 2. It is necessary to revise the concept adopted by SibRISC in 2018. This concept assumes i) absence of ice-dammed lakes in intermountain basins of the Russian Altai in MIS 2 and ii) accumulation of the Inya and Saldzhar formations deposited by glacial megafloods in the valleys of the Chuya and Katun rivers before 90 ka ago.
INFLUENCE OF FULVIC ACID ON THE EGG LAYING OF QUEEN BEE IN THE SPRING PERIOD AND THE PRODUCTIVITY OF BEE FAMILY
Authors: Rumyantsev V. A. , Yaroshevich G. S. , Mazina G. S. , Mityukov A. S. , Puhalsky J. V. , Loskutov S. I.
Published: April 2024

The paper analyzes the effect of a promising additive (BAA) fulvic acid on the reproductive function of queen bees and the productivity of bee layers. A single dose of carbohydrate supplementation (40% sucrase) was 200 ml per family. A total of 12 feedings were carried out with an interval of three days. The effect of the drug on the reproductive function of queen bees was determined by counting the number of printed brood using a grid frame every 12 days. As a result of the research, a positive effect of fulvic acid on the reproductive function of queen bees was established. When using fulvic acid as a spring feeding of bee colonies, a significant increase was established on average by 22.5% over two years of research, and the honey productivity of bee layers increased by 17.7%.
ACOUSTIC PROBING OF THE ANISOTROPIC STRUCTURE OF THE ATMOSPHERE
Authors: Zakirov M. N. , Kulichkov S. N. , Chulichkov A. I. , Chunchuzov I. P. , Popov O. E. , Mishenin A. A. , Bush G. A. , Tsybulskaya N. D. , Golikova E. V.
Published: April 2024

A new decomposition method (decomposition into N and U-waves) of infrasonic signals corresponding to partial reflection of N-wave sounding pulses from anisotropic atmospheric layers and recorded in areas of geometric shadow at large distances from explosions and volcanic eruptions is presented. The decomposition method makes it possible to determine the vertical gradients of the effective sound speed (sound speed plus wind speed in the direction of propagation) that are not available for determination by other methods.
PALEOLIMNOLOGY OF THE WESTERN СRIMEA LAKES
Authors: Subetto D. A. , Sapelko T. V. , Stolba V. F. , Kuznetsov D. D. , Ludikova A. V. , Neustrueva I. Yu.
Published: April 2024

For the first time for saline lakes of the Crimean Peninsula, the results of a comprehensive study of lacustrine sediments using litho-, bio- and chronological methods were obtained. For the first time, radiocarbon dating of the Crimean lake sediments was performed. In lakes Saki and Dzharylgach, sediment sequences of closed highly mineralized reservoirs, which overlay marine deposits, were retrieved. The surface of marine sediments is dated to 5610–5340 cal BP for Lake Saki and 5590–5350 cal BP for Lake Dzharylgach. By this time, sand barriers began to form, which subsequently completely separated the lagoons from the sea and led to the formation of closed reservoirs. Full isolation of Lake Dzharylgach occurred about 4600 cal BP. The vegetation change at the first stage of the lakes’ existence was controlled by changes in the sea level, as well as by fluctuations of salinity, later changes being mainly influenced by changes in climate humidity. The first Cerealia-type pollen occurs in the Subboreal period. Human settlements in the area of Lake Dzharylgach represent the Eneolithic, Bronze Age, as well as the Greco-Roman and medieval periods. A notable demographic change is observed in the period from the early first millennium to the end of the 5th century BC. The majority of archaeological sites in the vicinity of Lake Saki belongs to the Greco-Roman period.
MONITORING OF LEAD CONTENT IN AGROECOSYSTEMS OF CENTRAL BLACK EARTH REGION OF RUSSIA
Authors: Lukin S. V.
Published: April 2024

Studies on the environmental assessment of Pb content in agroecosystems were carried out in the forest-steppe zone of the Belgorod region, which is located in the south-west of the Central Black Earth region. The soil cover was represented mainly by leached chernozems. As a result of studies, it was established that in the layer of 0–20 cm of arable soils, the average gross content of Pb is 13.1, the concentration of mobile forms is 1.09 mg/kg, which does not exceed the background values and is significantly lower than the levels of APC and MAC. There were no significant differences in the content of Pb in the soil layers of 0–20 and 21–40 centimeters. The excess of background concentrations of this element is established in the soils of roadside ecosystems. The main source of Pb supply to the agroecosystems of the Belgorod region is organic fertilizers, but this does not pose a danger to soil pollution and crop production. The average Pb content of corn, barley and winter wheat grains did not differ significantly and was 0.267, 0.275, 0.292 mg/kg, respectively. Of the studied cultures, the minimum amount of this element was contained in soybean grains (0.155 mg/kg), and the maximum amount in sunflower seeds (0.335 mg/kg). Of perennial legumes, the minimum amount of Pb was contained in clover hay (0.185 mg/kg), and the maximum amount was esparceta (0.344 mg/kg). Exceeding the levels of the maximum permissible concentration and the maximum permissible level of Pb in crop production was not detected.
FIRST LA-ICP-MS APATITE FISSION-TRACK AGES FROM THE SIBERIAN PLATFORM BASEMENT (NEPSKO-BOTUOBINSKAYA ANTECLISE)
Authors: Bagdasaryan T. E. , Gayduk A. V. , Khubanov V. B. , Latyshev A. V. , Veselovskiy R. V.
Published: April 2024

We present the first results of LA-ICP-MS apatite fission-track dating (AFT) from nine core samples from wells, that exposed the top of the crystalline basement of the Siberian platform within the Nepsko-Botuobinskaya anteclise on the ~2 km depth. Obtained AFT ages belong to three clusters with mean values of 200, 140, and 60 Ma. A thermal event of ~200 Ma is widespread throughout almost the entire Siberian platform and reflects the stage of its Early Jurassic uplift. Reset of the fission-track geochronometer in apatite ~140 Ma correlates with tectono-thermal event marking the final stage of the Mongol-Okhotsk fold belt collision. The youngest AFT ages of ~60 Ma, on the one hand, may reflect the early (crypto) stage of the Baikal rifting, and, on the other hand, be a consequence of the high content of uranium in apatite.
HUMIC SUBSTANCES AND VISCOSITY OF SOIL PASTES
Authors: Fedotov G. N. , Shoba S. A. , Ushkova D. A. , Gorepekin I. V. , Salimgareeva O. A. , Potapov D. I.
Published: April 2024

In the work, the influence of water content in soil pastes on their viscosity was studied by the method of vibrational viscometry and changes in viscosity were explained from the standpoint of the structural organization of humic substances (HS) of soils. It was found that the viscosity of pastes prepared from sod-podzolic soil, with a decrease in their water content below 36%, increases to values of 4000–4200 MPa sec, and then practically does not change. This contradicted the existing ideas about the viscosity of suspensions, which should continuously increase with a decrease in the water content in them. This phenomenon was explained from the standpoint of the presence in the soil paste another component in addition to water and soil particles (aggregates and microaggregates) – supramolecular formations (SF) from soil HS, which can separate from soil gels and pass into a dispersion medium. According to the literature data, SF of HS exist in soils in the form of fractal clusters (F-clusters) consisting of particles-molecules. Due to the high stability of F-clusters, it is possible to assume that soil particles sliding along F-clusters in pastes, and a change in the thickness of the F-cluster layer through which sliding occurs may not significantly influence the viscosity of soil pastes. The data obtained during the study of the viscosity of soil pastes confirm the importance of F-clusters in the occurrence of soil properties.
HELIUM ISOTOPIC COMPOSITION IN ALKALINE INTRUSIONS OF THE HOVSGOL AREA, NORTHWESTERN MONGOLIA
Authors: Vrublevskii V. V. , Petlina A. A. , Gudkov A. V. , Sidorov M. Yu. , Semiryakov A. S. , Shelepaev R. A. , Vishnevskii A. V. , Gertner I. F. , Fomina E. N. , Kozlov E. N. , Udoratina O. V.
Published: April 2024

The helium isotope composition of fluid inclusions has been studied in magnetite from alkaline and subalkaline intrusions of the Hovsgol area in NW Mongolia. The measured content of 4He is in the range from 6.6 × 10–7 to 114 × 10–7 см3/г. The 3He/4He isotopic ratio of most samples varies within 0.23–0.59 Ra and may indicate the presence of helium from different sources in the magmatogenic fluid. The largest amount of mantle He (2.51 Ra) is hosted by the magnetite of the subalkaline gabbro. During the generation of primary magma, which probably involved either SCLM-type material or a plume-like reservoir less enriched in 3He, the mantle component accounted for approximately 40–60%. In the evolution of foid and alkali-syenite melts, its share did not exceed ~10–15% due to mixing with crustal radiogenic He. We assume that the intrusions interacted with fragments of Precambrian accretionary-collisional complexes of the Tuva-Mongolian terrane. Such mixing of He isotopes in melts and fluids may be regarded as circumstantial evidence supporting the development of mantle magmatism at the active continental margin.
CARYOCHROITE IS A RARE MINERAL FROM THE GROUP OF TITANOSILICATES: CRYSTAL STRUCTURE, CRYSTAL CHEMISTRY AND THERMAL PROPERTIES
Authors: Soboleva S. V. , Boeva N. M. , Kartashov P. M. , Bortnikov N. S.
Published: April 2024

The crystal structure of rare titanosilicate cariochroite was deternined using X-ray powder and srlected area diffraction data. The crystallochemical formula proposed – [Na(Sr0.5Ca0.5)Mg]3[Fe\(_{8}^{{3 + }}\)Mn(\({\text{Fe}}_{{0.5}}^{{2 + }}{\kern 1pt} {{\square }_{{{\text{0}}{\text{.5}}}}}\))]10(Ti2Si12)O37(OH)14(Н2О)3. Monoclinic unit cell parameters are: a 16.550(3), b 5.281(2), c 24.25(3) Å, β 93.0°, Z = 2, sp. gr. P2/n. The crystal structure represent the new type of complex Ti–Si–nrt, provided the big volune canals contaning some exchange cations, OH groups and water molecules.
ATMOSPHERIC GRAVITATIONAL DISTURBANCES THE JAPANESE SEA REGION
Authors: Dolgikh G. I. , Bolsunovskii M. A. , Dolgikh S. G.
Published: April 2024

When processing satellite data of total electron content on the route between GLONASS satellites, GPS and receiving stations located on earth in the Primorsky Territory of Russia, infragravity disturbances caused by their own fluctuations of the atmospheric layers of the Jap-Sea region, which have a loading effect on the Earth’s crust and the sea/ocean surface, generating fluctuations in them for the corresponding periods, were identified.
THE FIRST FINDINGS OF FROGS (ANURA) FROM THE UPPER CRETACEOUS OF RUSSIA
Authors: Skutschas P. P. , Kolchanov V. V. , Bolotsky I. Y. , Kuzmin I. T. , Grigoriev D. V. , Bapinaev R. A. , Vitenko D. D. , Mazur E. V. , Parakhin I. A. , Gvozdkova V. A. , Lubchenkov D. A. , Bogoy А. P. , Bolotsky Y. L.
Published: April 2024

Here we describe the first findings of frogs (Anura) from the Upper Cretaceous of Russia – the distal part of the humerus and the tibiofibula fragment. They come from the Maastrichtian dinosaur locality in the city of Blagoveshchensk in the Amur region. The described remains possess an outer and inner structure typical for Anura. These are the easternmost and the youngest frog remains from the Upper Cretaceous of Asia.
PROJECTION OF CLIMATE CHANGE AND THE INTENSITY OF EXOGENOUS PROCESSES ON THE TERRITORY OF THE YAMALO-NENETS AUTONOMOUS DISTRICT
Authors: Vikulina Marina , Zheleznova Irina , Surlova Galina , Kraev Gleb , Kislov Alexander , Alyautdinov Ali , Baranskaya Alisa , Belova Nataliya , Bogatova Daria
Published: April 2024

The climate changes taking place in the Arctic are expressed in the increase in extreme values, as well as in a wide range of processes of degradation of permafrost, the state of which, being sensitive to climate change, causes the activation of rapidly proceeding exogenous processes. To predict the climate of the YaNAO for the middle of the 21st century, data from 42 models of the CMIP6 project were used. The temperature in January will increase by about 3.5 (on the coast of the Kara Sea even by 4.5°C), and in July by ~2.5°C everywhere. The 5 and 95% quantiles will increase by 3 and 4.5°С in January and by 2 and 3°С in July, respectively. Monthly precipitation will increase by an average of 10% in January and remain unchanged in July. The 95% quantile values will increase by 30% and 10% in January and July, respectively. The number of days with frost will be reduced. Warming in combination with an increase in precipitation will lead to an increase in the activity of avalanches, snow flows and mudflows on the eastern slopes of the Urals, as well as on the characteristics of landslides, abrasion, suffusion, erosion, thermokarst, and solifluction. Climate-dependent sectors of the economy should be ready for predictable changes in the natural environment.
MERCURY BACKGROUND IN BOTTOM SEDIMENTS OF THE EASTERN ARCTIC
Authors: Aksentov K. I. , Sattarova V. V. , Astakhov A. S. , Shi Xuefa , Ivanov M. V. , Alatorsev A. V. , Kim D. V.
Published: April 2024

On the basis of dated bottom sediment cores, layers accumulated in the pre-industrial period were selected. They determine the mercury concentrations, which are the geochemical background for the selected water areas. The variability of mercury concentrations in the sediments of the inner shelf is small (20–30 μg/kg) and can be used as a basis for environmental assessment in the economic development of the Arctic regions.
KHUBSGUL EARTHQUAKE OF JANUARY 12, 2021, Mw = 6.7, NORTHERN MONGOLIA: GEOLOGICAL EFFECTS AND TECTONIC POSITION OF THE SOURCE
Authors: Ovsyuchenko A. N. , Demberel S. , Butanayev Y. V. , Koshevoy N. G. , Batsaikhan T. , Baatar N.
Published: April 2024

The geological effects of the Khubsgul earthquake on January 12, 2021 with Mw = 6.7, which became the strongest in the Khubsgul region at the instrumental stage of seismological observations, were studied and mapped. Using the ESI-2007 scale, the epicentral zone was contoured with an intensity VIII. The primary seismic rupture is represented by a dextral normal fault with displacement up to 20 cm, which renewed the Late Holocene tectonic scarp in the western side of the Khubsgul rift basin. The dynamics of rupturing in the Late Holocene testifies to the gradual expansion of the depression due to the destruction of the adjacent mountain range. The data of satellite interferometry and seismological observations are in good agreement with the results of field studies, which allows us to consider the selected region of maximum shaking as a projection of the upper part of the source zone onto the surface.
SOSVA-LOZVA GRABEN – THE DEVONIAN-CARBONIFEROUS STRUCTURE OF EXTENSION IN THE REAR OF AN ACTIVE CONTINENTAL MARGIN ON THE EASTERN SLOPE OF THE NORTHERN URALS
Authors: Petrov G. A. , Maslov A. V.
Published: April 2024

Within the northern part of the Tagil paleo-island-arc structure in the Northern Urals, the Sosva-Lozva graben is identified. The graben is filled mainly with terrigenous and volcanic strata of the Devonian and Lower Carboniferous. The location of the graben to the west (in modern coordinates) of the supra-subduction magmatic complexes and the composition of volcanic rocks, which combines signs of igneous formations of convergent and divergent settings, suggest that this structure formed under extensional conditions in the rear of the active continental margin.
ELEMENTAL SULFUR AND ITS ISOTOPIC COMPOSITION IN THE BLACK SEA WATER
Authors: Dubinin A. V. , Demidova T. P. , Semilova L. S. , Rimskaya-Korsakova M. N. , Dubinina E. O. , Kossova S. A. , Zologina E. N.
Published: April 2024

As one of the main intermediate products of hydrogen sulfide oxidation, elemental sulfur plays an important indicator role in understanding the oxidative cycle of sulfur in the water of anoxic basins. The distribution of elemental sulfur in the Black Sea water column at stations located in the area of the continental slope is considered. For the first time, the concentration distributions of two forms of elemental sulfur depending on the depth in the Black Sea water were obtained: suspended elemental sulfur with a fraction of more than 0.45 μm (S0) and zero valency sulfur (ZVS), which includes the sum of elemental sulfur (suspended and colloidal) and polysulfide sulfur. In the upper anoxic waters, the concentration of S0 noticeably increases (almost 200 times relative to the 400 m depth) with an increase in the concentration of hydrogen sulfide and the density of water. At depths of more than 250 m, the concentration of both forms of sulfur remains almost constant (ZVS = 0.21 ± ± 0.03 µmol/kg, S0 = 0.05 ± 0.01 µmol/kg). A sharp increase in the concentration of S0 at the depths of 150–250 m is associated with the oxidation of hydrogen sulfide due to bacterial anoxygenic photosynthesis after sampling. The value of δ34S(ZVS) was determined in the waters of two stations Ash-26 and 149 at the depths of 450 and 600 m respectively, which turned out to be +2.2‰ higher than δ34S(Н2S) from the same depths, which indicates the bacterial origin of elemental sulfur.
CYCLOSTRATIGRAPHIC ESTIMATE OF THE DURATION OF THE NEGATIVE δ13C ANOMALY OF THE ZHUA GROUP (SHURAM-WONOKA EVENT) IN THE VENDIAN REFERENCE SECTION IN SOUTH OF THE SIBERIAN PLATFORM
Authors: Rudko D. V. , Rudko S. V. , Shatsillo A. V. , Latysheva I. V. , Kolesnikov A. V. , Fedyukin I. V. , Pokrovsky B. G.
Published: April 2024

A cyclostratigraphic study of the Late Precambrian Zhuya Group (Nikolskoye and Chencha Formations) and Torgo formation in the south of the Siberian Platform was carried out to determine the duration of the C-isotope anomaly imprinted in them. The similarity of the ratios of the period lengths of the cyclic components of the magnetic susceptibility in the coeval deposits of the remote sections of the Nikol’skoye and Torgo Fms. indicates the connection between the revealed cyclicity and the basin-scale environment changes. According to the obtained astrochronological model, the duration of the formation of the studied intervals of the Nikol’skoye (57 m) and Chencha (147 m) formations was 850 and 2500 ky, respectively. Extrapolation of the data obtained shows that the duration of the C-isotope anomaly of the Zhuya Group in the Vendian reference section of the on the Ura uplift was about 10 My, which is consistent with most estimates of the Shuram anomaly’s duration and its stratigraphic analogues.
UNPRECEDENTED INCREASE IN THE CHARCOAL MACROPARTICLES IN THE BOTTOM SEDIMENTS OF THE LAKES OF THE NORTH-MINUSINSK VALLEY (SOUTH OF SIBERIA) IN THE RECENT TIME AS A POSSIBLE EVIDENCE OF ANTHROPOGENIC INFLUENCE
Authors: Rogozin D. Y. , Burdin L. A. , Bolobanshchikova G. N. , Degermendzhy A. G.
Published: April 2024

In the bottom sediments of lakes Shira and Uchum, located in the south of Siberia in the steppe zone of the North Minusinsk depression (Republic of Khakassia and Krasnoyarsk Territory), distributions of charcoal particles 100 µm. The age of the studied sediments of the two lakes was up to 1400 and 500 years ago, respectively. Charcoal particles of three types were found in the sediments of both lakes. The first group has an elongated shape and is interpreted as the remains of herbaceous plants and/or needles. The second group looks like thin flat blades and is interpreted as the remains of leaves. The third group consists of bulk particles of various irregular shapes, which are presumably the remains of the combustion of wood and coal. Particles of the first type are mainly indicators of natural fires, and their flux does not show a noticeable increase in the modern period. The flow of coal particles of the second and, to the greatest extent, the third groups has increased sharply in the last about a hundred years, which reflects an increase in the amount of wood and coal burned by people in the vicinity of the studied lakes in the modern industrial period. The data obtained reflect an increase in the amount of wood and coal burned by people in the modern industrial period, as well as a possible increase in the number of wildfires, which may also be due to human activities in the form of accidental or deliberate arson. Thus, for the first time for this region, an increase in the influx of charcoal particles into the bottom sediments of lakes over the past about a hundred years has been revealed, which is unprecedented over the period covered by our study. Thus, evidence of the anthropogenic impact on the dynamics of charcoal particles in bottom sediments has been obtained. The information obtained can be useful for reconstructing the dynamics of natural fires and paleo-climate in this region of southern Siberia in the Late Holocene.
LATE-OROGENIC GRANITOIDS OF THE TERVU AGMATITIC ZONE IN THE SOUTHEASTERN PART OF THE SVECOFENNIAN BELT (THE NORTHERN LADOGA AREA, RUSSIA)
Authors: Baltybaev S. K. , Rizvanova N. G. , Kuznetsov A. B. , Petrakova M. E. , Vivdich E. S.
Published: April 2024

The formation of breccia zones was taking place with the simultaneous healing of them by granitic materials at the final stages of the Late Proterozoic magmatic and metamorphic activity in the region 1.86 Ga ago. The Tervu breccia zone with granitic agmatites has a sublatitude orientation, which is discordant in relation to the early structures and Kurkieki enderbite and Lauvatsari-Impiniemi diorite-tonalite complexes in the Svecofennian rocks of the Ladoga region. There are the largest granitic bodies in this area – Tervu and Peltola intrusions located in the Tervu breccia zone. The U–Pb age of monazite from granites of the Peltola intrusion is determined as 1859 ± 4 Ma, and coincides with the age of the granites of the Tervu intrusion (1859 ± 3 Ma). This assumes that the granites of both intrusions and some surrounded smaller bodies were intruded simultaneously into the tectonically weakened space when plastic deformations turned to elastic-plasticity ones during at the late-orogenic stage. The results obtained reveal the features of the tectonic development of the joint zone of the two largest blocks of the Fennoscandinavian shield – the Karelian craton and the Svecofennian belt.
CHANGES IN CONTENT AND COMPOSITION OF HYDROCARBONS IN THE BOTTOM SEDIMENTS OF THE NORILO-PYASINSK WATER SYSTEM A YEAR AFTER THE EMERGENCY DIESEL FUEL SPILL
Authors: Nemirovskaya I. A. , Glyaznetsova Yu. S. , Sokov A. V.
Published: April 2024

One year after the emergency diesel fuel spill in Norilsk, hydrocarbon concentrations in bottom sediments of the Norilo-Pyasinsky water system decreased. But on average in the areas they decreased in the same sequence (µg/g) as in 2020: the mouth of the Ambarnaya R. (835, σ = 1788) Bezymyanny Cr. – the Daldykan R. – the Ambarnaya R. (306, σ = 273) Pyasina R. (23, σ = 20) Lake Pyasino (12, σ = 8). Concentrations decreased due to degradation of low molecular weight hydrocarbons. The content of polycyclic aromatic hydrocarbons in 2021 also changed in a smaller range (0–1027 ng/g) than in 2020 (0–3865 ng/g). Petroleum origin of hydrocarbons in the sediments of the Ambarnaya R. (including the mouth), Bezymyanny Cr. and Daldykan R. confirms the dominance of alkylated naphthalene homologues in their composition. Hydrocarbons accumulation in some horizons of the sedimentary strata is caused not only by seepage of diesel fuel, but also to the introduction of organic matter from the surrounding swamps from wetlands and floodplain lakes, as well as the burial of the surface layer by the 2021 flood.
MODERN AND PROJECTED CHARACTERISTICS OF SEASONAL CYCLE OF ICE COVER IN THE RUSSIAN ARCTIC SEAS
Authors: Semenov V. A. , Cherenkova E. A. , Aldonina T. A.
Published: April 2024

The characteristics of the sea ice conditions in the Seas of the Russian Arctic during the period of satellite measurements were studied and quantitative estimates of their changes in the second half of the 21st century were made based on the results of the CMIP6 climate models’ ensemble using aggressive and moderate scenarios of anthropogenic forcing, SSP585 and SSP245 respectively. It has been revealed that the dates of closing (DOC) of the sea ice cover and the length of the open water season (LOWS) are in general successfully reproduced by the ensemble of models. It is shown that DOC on average over the studied Seas will be observed about forty days later under SSP245 scenario and two months later under SSP585 scenario in 2061–2080 compared to 1981–2020 period. At the same time, the increase of LOWS is more than two and a half months under SSP245 scenario and almost four months under SSP585 scenario. The most significant changes in DOC are expected in the north of the Barents and Kara Seas, as well as in the northwest of the Laptev Sea: 2–2.5 months and 2.5–3 months later for the SSP245 and SSP585 scenarios respectively.
DYNAMICS OF ONE-DIMENSIONAL WATER SPILLS OIL PRODUCT STAINS
Authors: Kistovich A. V. , Chaplina T. O.
Published: April 2024

The process of quasi-one-dimensional spreading of oil product spots on the water surface has been experimentally and theoretically investigated. The theoretical model is based on an approximate equation obtained using the laws of conservation of the mass of the decomposed product and the total energy of the system. Approximate solutions of this equation and the results of experimental studies on the spreading of machine oil and crude oil in a narrow extended container are presented, and their good compliance with the theory is shown. A comparison is made with the process of two-dimensional axisymmetric spreading of a spot of the same petroleum products.
MODERN CHANGES OF THE URBAN HEAT ISLAND IN MOSCOW
Authors: Lokoshchenko M. A. , Enukova E. A. , Alekseeva L. I.
Published: April 2024

According to the data of weather stations for the period 1991–2020, as well as radiometric measurements of the surface temperature TS of Moscow region by Terra and Aqua satellites for the period 2000–2020, the daily course and long-term changes of the urban ‘heat island’ (UHI) of Moscow in the field of both the air temperature T at a height of 2 m and the TS were studied. For the analysis of TS 1379 satellite images were selected for 21 years in clear and slightly cloudy sky, when the UHI analysis is possible. The average annual values of TS were obtained using their normalization for separate seasons. The daily course of Moscow UHI in the air is weakly expressed, especially when compared with the countryside not only of the city center, but also of its entire area: only the weakening of this phenomenon in autumn and in the pre-winter season (from October to December) is reliable. According to satellite data, the ‘surface UHI’ is marked by a maximum in June-July with the strongest vegetation development, a minimum in autumn when leaves fall, and intermediate values in winter and spring. The rapid growth of T took place in 1991–2020 both in Moscow and in rural areas with approximately the same speed. As a result, there have been no statistically significant directional changes in the UHI intensity both in the air and on the surface as a whole over the past 20–30 years. The probable reasons for the general stabilization of the UHI in Moscow are both natural and socio-economic factors: the approximate constancy of the probability of clear weather (which promotes the strengthening of this phenomenon) and the vegetative activity in the region (which determines heat losses due to transpiration by plants), slowing down and stopping the growth of the population and energy consumption of the city, as well as its deindustrialization. Additional reasons are the gradual relocation of residents to the new outskirts of Moscow, as well as quarantine restrictions due to the COVID-19 pandemic in 2020.
TARAGAI PERIDOTITE MASSIF AS AN EXPLOSIVE PIPE IN THE WESTERN BUREYA TERRANE (SOUTHERN RUSSIAN FAR EAST)
Authors: Berdnikov N. V. , Nevstruev V. G. , Kepezhinskas P. K. , Didenko A. N.
Published: April 2024

Taragai peridotite massif is interpreted as an explosive ultramafic pipe emplaced through the Neoproterozoic carbonate skarnoids and Early Paleozoic granites of the western Bureya terrane. Peridotites at the surface are represented by strongly eroded bowl-shaped structure filled with disintegrated explosive material containing abundant peridotite boulders and host rock xenoliths. Explosive character of the Taragai massif is further emphasized by the occurrence of magnetite, iron-carbonate-silicate (with magnetite) and Cu-Ag-Au microspherules characteristic of explosive eruptions. Formation of the Taragai ultramafic pipe is related to the assimilation of mantle wedge or lithospheric mantle material over the stagnant Izanagi slab by the ultra-hot and reduced upwelling fluid flow within the transform-type continental margin tectonic setting.
KAHRAMANMARASH EARTHQUAKES IN TURKEY: SEISMIC MOTION ALONG CONJUGATED FAULTS
Authors: Tikhotsky S. A. , Tatevosyan R. E. , Rebetsky Yu. L. , Ovsyuchenko A. N. , Larkov A. S.
Published: April 2024

Earthquakes in Turkey (Karamanmarash province) in February 2023 do not fit into the usual sequence: the main shock is aftershocks. According to Botha’s statistical law [1], the magnitude of the strongest aftershock is expected to be one less than the magnitude of the main shock. Meanwhile, for the aftershock sequence in Turkey, this difference is only 0.1. In Turkish publications, the first of the strongest earthquakes is called Pazardzhik (Mw = 7.8), and the second – Elbistan (Mw = 7.7) [2, 3]. Each of these earthquakes generated its own system of surface ruptures and aftershock sequences differently oriented in space. The purpose of the study is to assess whether the occurrence of the second earthquake is due to the stress field that existed earlier, or whether it arose as a result of the main shock. If the second scenario is implemented, this means that the stress field can change in the vicinity of a strong earthquake almost instantly (the time difference between earthquakes is less than 9 hours).
METAMORPHIC TRANSFORMATIONS OF ROCKS IN THE CENTRAL PART OF THE PRIMORSKY FAULT. WESTERN BAIKALIA
Authors: Grigor’eva A. V. , Kozlovskiy V. M. , Gridin G. A. , Ostapchuk A. A.
Published: April 2024

In this paper we compare metamorphic transformations in acid and mafic rocks in a zone of intense tectonic movements. The object of study is the exhumed part of damage zone of Primorsky fault – main collision suture, which connects the Siberian Craton and the Olkhon Terrane. The studied area is located near the Khorga River. Collected metamorphic rock samples are represented by both acid (plagiogranitegneiss) and mafic (amphibole-biotite plagiogneisses) rocks. The samples present two different parent rocks contacting each other but differ in chemical composition. The formation of identical metamorphic minerals belonging to the groups of garnet and epidote is noted in both types of rocks. Mineral formation was associated with high-pressure regional metamorphism and possibly with later collision. Studying chemical composition of rock-forming minerals has allowed to determine the P-T condition of metamorphism in these rocks via the method of multimineral thermobarometry. It was established that conditions of early metamorphism retain in amphibole-biotite plagiogneiss. Early metamorphism is characterized by high-pressure amphibolite facies of medium temperature next to eclogite facies. In plagiogranitegneisses were found conditions of later metamorphism that formed rocks at the same pressure but at a lower temperature in the paragonite-kyanite-zoisite subfacies of the eclogite facies next to the greenschist facies. Minerals formed in the early metamorphism are poorly preserved.
THE MANIFESTATION OF DEGASSING IN THE SEDIMENTARY COVER AND RELIEF OF THE YUZHNO-NOVOZEMELSKY TRENCH (PECHORA SEA)
Authors: Moroz E. A. , Eremenko E. A. , Denisova A. P. , Mutovkin A. D. , Ananiev R. A.
Published: April 2024

The results of detailed geological and geomorphological studies in the waters of the Pechora Sea using a complex of hydroacoustic methods in the 52 cruise of the R/V “Academic Nikolaj Strakhov” revealed numerous gas funnels (pockmarks) at the bottom of the Yuzhno-Novozemelsky trench. These forms are widespread on most of the bottom of the Barents Sea, while on the Pechora shelf there is very little information about their distribution. Analysis of seismoacoustic sections at the sites of development of gas funnels showed the presence of vertical chimneys in unconsolidated sediments of the Yuzhno-Novozemelsky trench, through which gas rises to the bottom surface and its release into the water column with the formation of negative landforms, which is accompanied by churning bottom sediments.
INFLUENCE OF FULVIC ACID ON INCREASING LIFE AND PHYSIOLOGICAL STATE OF BEEES
Authors: Rumyantsev V. A. , Yaroshevich G. S. , Mazina G. S. , Mityukov A. S. , Puhalsky J. V. , Loskutov S. I.
Published: April 2024

The article presents the results of research for (2020–2021). The results of the influence of different doses of fulvic acid on increasing the life span of bees kept in entomological cages and improving their physiological state are given. The studies were carried out in laboratory conditions at an air temperature of +27 ± 2°C, on bees of spring-summer generation. The experiment included three groups of bees in triplicate. The first group – control, in this group, the bees consumed 60% sucrose solution as top dressing. In the second group, the bees consumed a 60% sucrose solution, to which fulvic acid was added, at the rate of 0.1 ml per 200 ml of solution. The third group was fed a 60% sucrose solution, to which fulvic acid was added, at the rate of 0.2 ml per 200 ml of solution. According to the results of the research, it was found that fulvic acid at a dose of 0.1 ml per 200 ml of solution contributed to the prolongation of the life of bees. In this variant of the experiment, 30–40% death of bees occurred five, and 50% and 60% four days later than in the control. Fulvic acid, where an increased dose was used, did not have a significant effect on the lifespan of bees. As the bees aged, fulvic acid in both variants of the experiment reduced the load on the rectum and toxicity to the body, thereby improving their physiological state.
REGULARITIES OF HYDROCHEMICAL DYNAMICS IN A TWO-DIMENSIONAL TURBULENT FLOW OF NATURAL WATER
Authors: Danilov-Danilyan V. I. , Rosenthal O. M.
Published: April 2024

The variability of the composition and properties of natural waters, which creates numerous difficulties in water use, cannot always be explained by the influence of external influencing factors, such as weathering or leaching of rocks, a change in the phases of the water regime, etc. This is especially true for subdiurnal and subhourly quality variability, which can be caused by complex, previously unknown dynamic hydrochemical processes. Such a conclusion follows from the results of the study of turbidity and pH of natural water given in the work, obtained with an increased frequency of measurements. These results indicate the existence of a quasi-cyclic change in the controlled parameters with different periods, from every minute to daily. The study of observational data allows us to make an assumption that in this case the hydrochemical dynamics is due to direct and reverse energy cascades in a two-dimensional turbulent flow of natural water, in which the impurity subsystem is prone to stratification.