bluuebunny/crossref_metadata_2025 huggingface dataset:
MORPHOFUNCTIONAL AND MOLECULAR CHANGES IN PLACENTA AND PERIPHERAL BLOOD IN PREECLAMPSIA AND GESTATIONAL DIABETES MELITUS
Authors: Artemieva K. A. , Stepanova Yu. V. , Stepanova I. I. , Shamarakovа M. V. , Tikhonova N. B. , Nizyaeva N. V. , Tsakhilova S. G. , Mikhaleva L. M.
Published: April 2024

Gestational diabetes mellitus (GDM) and preeclampsia (PE) are common pregnancy complications with similar risk factors. Although GDM is associated with PE, the exact mechanism underlying the association of these diseases is unclear. The aim of the work: to study morphofunctional and molecular changes in the placenta and peripheral blood both in PE and GDM. In the study, we evaluated local and systemic changes in the production of several placental proteins, markers of inflammation and metabolic disorders. Changes in villi expression of placental lactogen, trophoblastic β1-glycoprotein, placental alpha-1-microglobulin, and proteinase3 were noted in the groups of complicated pregnancies. The present study shows the similarity of the pathogenic mechanisms underlying PE and GDM.
CONTENT OF 13С AND 15N ISOTOPS IN BONE COLLAGEN OF GEOGRAPHICAL, AGE AND SEX GROUPS OF THE URAL CAVE BEAR (MAMMALIA, CARNIVORA, URSIDAE, URSUS (SPELAEARCTOS) KANIVETZ VERESTCHAGIN, 1973)
Authors: Kosintsev P. A. , Konovalova K. Yu. , Simonova G. V.
Published: April 2024

Data on the content of δ13C and δ15N isotopes in the collagen of bones of the Ural cave bear (Ursus (S.) kanivetz Verestchagin, 1973) from the Northern and Middle Urals were analyzed. The bones date from the first half of MIS 3. The bones of newborn individuals, individuals at the age of 1 year, males and females at the age of 2 years, 3 years, 4 years and older than 4 years were studied. Differences in δ13С values between age, sex, and geographical samples are not significant. With age, the value of δ15N significantly decreases, which is associated with the transition from milk nutrition to independent nutrition. The proportion of meat food in the diet of adult bears in the Middle Urals was higher than in the diet of adult bears in the Northern Urals. There are no noticeable differences in isotope signatures between males and females of different ages. The large cave bears of the Urals and Europe had a similar type of diet.
ACTIVITY OF NSP14 EXONUCLEASE FROM SARS-COV-2 TOWARDS RNAS WITH MODIFIED 3'-TERMINI
Authors: Yuyukina S. K. , Barmatov A. E. , Bizyaev S. N. , Stetsenko D. A. , Sergeeva O. V. , Zatsepin T. S. , Zharkov D. O.
Published: April 2024

The COVID-19 pandemic has shown the urgent need for new treatments for coronavirus infections. Nucleoside analogs have been successfully used to inhibit replication of some viruses, through the incorporation into the growing DNA or RNA chain. However, the replicative machinery of coronaviruses contains nsp14, a a non-structural protein with a 3'→5'-exonuclease activity that removes misincorporated and modified nucleotides from the 3' end of the growing RNA chain. Here we studied the efficiency of hydrolysis of RNA containing various modifications in the 3'-terminal region by SARS-CoV-2 nsp14 exonuclease and its complex with the auxiliary protein nsp10. Single-stranded RNA was a preferable substrate compared to double-stranded, consistent with the model of transfer of the substrate strand to the exonuclease active site proposed on the basis of structural analysis. Modifications of the phosphodiester bond between the penultimate and last nucleotides had the greatest effect on nsp14 activity.
MODULAR NANOTRANSPORTERS CAPABLE OF BINDING WITH SARS-COV-2 VIRUS NUCLEOCAPSID PROTEIN INTO TARGET CELLS
Authors: Khramtsov Y. V. , Ulasov A. V. , Lupanova T. N. , Georgiev G. P. , Sobolev A. S.
Published: April 2024

Based on the literature data, an antibody-like molecule, a monobody, was selected that is capable of interacting with the nucleocapsid protein (N-protein) of the SARS-CoV-2 virus with high affinity (dissociation constant 6.7 nM). We have previously developed modular nanotransporters (MNTs) to deliver various molecules to a selected compartment of target cells. In this work, a monobody to the N-protein of the SARS-CoV-2 virus was included in the MNT using genetic engineering methods. In this MNT, a site for the cleavage of the monobody from the MNT in endosomes was also introduced. It was shown by thermophoresis that the cleavage of this monobody from MNT by the endosomal protease cathepsin B leads to a 12-fold increase in the affinity of the monobody for the N-protein. Cellular thermal shift assay showed the ability of the obtained MNT to interact with the N-protein in A431 cells transfected with the SARS-CoV-2 N-protein fused to the mRuby3 fluorescent protein.
INCUBATION OF LYMPHOCYTES WITH IL-2 CAUSES THE APPEARANCE OF ANTITUMOR T CELLS CARRYING FC, CD25 AND LFA-1 ON THE SURFACE
Authors: Ivanova O. K. , Sharapova T. N. , Romanova E. A. , Yashin D. V. , Sashchenko L. P.
Published: April 2024

To carry out antitumor activity against cells that have lost surface antigens, human lymphocytes must have a certain repertoire of surface proteins capable of contacting a tumor cell and inducing programmed cell death in it. In this work, we showed that activation of healthy donor cells by IL-2 cytokine within 6 days causes the appearance of FasL, CD25 and LFA-1 proteins on CD8+CD25+ T lymphocytes, and also converts the LFA-1 protein into an active form having a high affinity for its target, ICAM-1 integrin. The appearance of these proteins on the surface of this subpopulation of lymphocytes allows them to induce programmed cell death in HLA-negative tumor cells.
STRUCTURAL MECHANISM OF IONIC CONDUCTIVITY OF THE TRPV1 CHANNEL
Authors: Trofimov Yu. A. , Minakov A. S. , Krylov N. A. , Efremov R. G.
Published: April 2024

The so-called “hydrophobic gating” is widely discussed as a putative mechanism to control water and ion conduction via ion channels. This effect can occur in narrow areas of the channels pore lined by non-polar residues. In the closed state of the channel, such regions may spontaneously transit to a dehydrated state to block water and ions transport without full pore occlusion. In the open state, the hydrophobic gate is wide enough to provide sustainable hydration and conduction. Apparently, the transport through the open hydrophobic gate may by facilitated by some polar residues that assist polar/charged substances to overcome the energy barrier created by nonpolar environment. In this work, we investigated the behavior of Na+ ions and their hydration shells in the open pore of the rat TRPV1 ion channel by molecular dynamics simulations. We show that polar protein groups coordinate water molecules in such a way as to restore the hydration shell of ions in the hydrophobic gate that ensures ion transport through the gate in a fully hydrated state.
MUSTELA PALERMINEA (MUSTELIDAE, CARNIVORA) FROM THE EARLY PLEISTOCENE OF CRIMEA
Authors: Gimranov D. O. , Jiangzuo Q. , Lavrov A. V. , Lopatin A. V.
Published: April 2024

The mandibles of two individuals of Mustela palerminea (Petenyi, 1864) are described from the Lower Pleistocene deposits of the Taurida cave in Crimea (Late Villafranchian, 1.8–1.5 Ma). This extinct mustelid species was a typical representative of the Villafranchian faunas of Europe. It is the first record of M. palerminea in Russia.
ANTIDIABETIC EFFECT OF A NEW ORIGINAL NT-3 DIPEPTIDE MIMETIC
Authors: Yagubova S. S. , Chernyshevskaya M. A. , Ostrovskaya R. U. , Gudasheva T. A. , Seredenin S. B.
Published: April 2024

It was previously established that the original dipeptide mimetic of the 4th loop of NT-3, hexamethylenediamide bis-(N-monosuccinyl-L-asparaginyl-L-asparagine) (GTS-301), has a pronounced neuroprotective effect in vitro at concentrations of 10–5–10–12 М. In the present study, experiments on the streptozotocin-induced diabetes model in C57Bl/6 mice showed that GTS-301, administered intraperitoneally for 32 days at doses of  0.1 and 0.5 mg/kg, has antidiabetic activity manifested in the reduction of hyperglycemia, polydipsia, and in the increase of animal survival. The results obtained confirm the concept of the similarity of neurochemical mechanisms underlying the regulation of neurons and β-cells functions.
TWO LINEAGES OF ORIBATID MITES MORPHOLOGICALLY CORESPOND TO THE CIRCUMPOLAR SPECIES AMERONOTHRUS NIGROFEMORATUS (ACARI, ORIBATIDA) BUT DIFFER GENETICALLY AS DISTINCT SPECIES ARE REVEALED ON THE KOLGUEV ISLAND
Authors: Artamonova V. S. , Bizin M. S. , Efeykin B. D. , Makarova O. L.
Published: April 2024

Until recently, data on the genetic characteristics of the oribatid mite Ameronothrus nigrofemoratus have been reported only from the Northern Canada. Analysis of the partial cytochrome oxidase I gene (COI) mtDNA sequence of the mites from Kolguev Island that morphologically correspond to this species has revealed two highly divergent phylogenetic lineages of A. nigrofemoratus (divergence of 7%), neither of which was found on the Canadian coast. One lineage differs by four COI amino acid substitutions from North American A. nigrofemoratus. This corresponds to the degree of difference between A. nigrofemoratus and its sister species A. lineatus.
THE ROLE OF THE GRASS SNAKE NATRIX NATRIX (REPTILIA, COLUBRIDAE) IN THE TRANSFER OF POLYUNSATURATED FATTY ACIDS FROM AQUATIC TO TERRESTRIAL ECOSYSTEMS TO LAND
Authors: Dgebuadze Yu. Yu. , Neymark L. A. , Bashinskiy I. W. , Sushchik N. N. , Rudchenko A. E. , Gladyshev M. I.
Published: April 2024

As a result of analyses of fatty acid (FA) composition in the grass snake Natrix natrix and its food objects, tadpoles and metamorphs of two amphibian species: the moor frog Rana arvalis and the Pallas’ spadefoot Pelobates vespertinus, it was shown for the first time that the high total content of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids in the biomass of the snake indicates its important role in the transfer of these essential substances from aquatic ecosystems to land. It was found that since food sources of DHA are absent in terrestrial ecosystems, its high level in R. arvalis and grass snakes may be provided only by synthesis from biochemical precursors contained in food of aquatic origin.
RARE EARTH FLUOROCARBONATES IN ROCKS OF THE SAFYANOVSKY COPPER-ZINC-PYRITE DEPOSIT (MIDDLE URALS)
Authors: Soroka E. I. , Pritchin M. E. , Leonova L. V. , Bulatov V. A.
Published: April 2024

For the first time, rare earth (REE)-fluorocarbonates were found in the ore-bearing rocks of the Safyanovsky copper-zinc-pyrite deposit (Middle Urals): synchysite, bastnasite, in association with fluorite, calcite, dolomite, barite, pyrite, sphalerite. Samples with REE-fluorocarbonate mineralization were found at a depth of 262 m in an altered near-ore zone of pyrite-carbonate-kaolinite-sericite-quartz composition in contact with massive pyrite-chalcopyrite and pyrite-sphalerite ores. It is assumed that REE-fluorocarbonates were formed from a hydrothermal solution together with fluorite and calcite. This event may be associated with a period of hydrothermal activity manifested at the post-collision stage of the development of the Ural folded system.
GENERATION OF INTERNAL WAVES BY A SUB-MESOSCALE EDDY AT CAPE SVYATOY NOS IN THE BARENTS SEA
Authors: Serebryany A. N. , Khimchenko E. E. , Zamshin V. V.
Published: April 2024

Data on generation of soliton-like internal waves by a mesoscale eddy in the region of the Barents Sea near Cape Svyatoy Nos, widely known for its dynamic activity, are presented here. The results are based on the analysis of satellite optical (Sentinel-2 MSI) and radar (Sentinel-1 SAR) images obtained sequentially on August 8 and 9, 2021. A detailed analysis of the dynamics of the eddy and internal waves was made possible due, among other things, to the phytoplankton bloom, which created the necessary optical contrasts that make it possible to monitor the dynamics of currents in the near-surface layer of the sea. Significant parameters of recorded internal waves were measured using satellite methods and analyzed using the TPXO9.0 model and numerical solution of the internal wave equation. It has been shown, that internal waves were caused by a submesoscale eddy formed near the cape. Waves had quite low velocity (0.10–0.16 m/s) what was due to weak stratification of the water environment.
GEOCHEMICAL AND ISOTOPIC CHARACTERISTICS OF DISSEMINATED SULFIDE MINERALIZATION OF OROGENIC GOLD DEPOSITS OF THE YANA-KOLYMA METALLOGENIC BELT (NORTH-EAST OF RUSSIA)
Authors: Fridovsky V. Yu. , Polufuntikova L. I. , Kudrin M. V.
Published: April 2024

The results of the study of the chemical composition and isotopic characteristics of the sulfur of disseminated pyrite and arsenopyrite from metasomatites of the Malo-Taryn, Badran, Khangalas, V’yun and Shumniy orogenic gold deposits of the Yana-Kolyma metallogenic belt are presented. Pyrites and arsenopyrites have a non-stoichiometric composition. Arsenopyrites are characterized by sulfur enrichment (As/S from 0.77 to 0.99), minor of Sb, Co, Ni and Cu with a total concentration of up to 0.15 wt %. Pyrites contain the same elements (total concentration up to 3.71%), less often Pb, depleted with S and enriched with As (up to 3.16 wt %). The ratio of Ni/Co in pyrite is 10.0 Ni/Co 0.1, it is characteristic of hydrothermal negatively charged pyrite with high conductivity (p-тип). It is assumed that the “invisible” Au+ is found in disseminated pyrite and arsenopyrite mainly in an isomorphic structurally related form. A range of values δ34S from –6.4 to +5.6‰ in sulfides, is characteristic of juvenile/magmatic sources of sulfur of the studied deposits.
RARE EARTH ELEMENT CONTENTS AND COMPOSITIONS IN FERROMANGANESE FORMATIONS OF THE EAST SIBERIAN SEA: A RESPONSE TO RECENT SEDIMENTATION AND DIAGENESIS CONDITIONS
Authors: Kolesnik O. N. , Kolesnik A. N. , Astakhov A. S. , Selutin S. A. , Ren Xiangwen , Shi Xuefa
Published: April 2024

The distribution of rare earth elements (REEs) has been studied for the first time in different morphotypes of ferromanganese formations (FMFs) from the East Siberian Sea, namely, ferruginous and ferromanganese crusts, discoid nodules, and biomorphoses. The FMFs were formed at different distances from the land and, accordingly, from the main sources of sedimentary material during (sub)oxic diagenesis. Seaward, with an increase in the oxidation of sediments, primarily because of reducing sedimentation rates, FMFs, against a rising manganese content in them (Mn from 0.09% to 12.34%, Mn/Fe from 0.01 to 1.15), show a decrease in the total REE content (ΣREE from 166.90 ppm to 96.86 ppm), depletion in cerium (Cean from 0.90 to 0.71), and enrichment with middle REEs. Due to the rapid growth of FMFs, which should be faster than sedimentation rates, reactive REE species do not have time to accumulate; therefore, REE total content in FMFs is everywhere lower than in sediments.
PRIMARY PRODUCERS SIZE STRUCTURE IN THE MARGINAL ICE ZONE OF EUROPEAN ARCTIC IN SUMMER
Authors: Kudryavtseva Е. A. , Kravchishina M. D. , Pautova L. A. , Rusanov I. I. , Silkin V. A. , Glukhovets D. I. , Torgunova N. N. , Netsvetaeva O. P. , Politova N. V. , Klyuvitkin A. A. , Savvichev A. S.
Published: April 2024

Primary production (PP) and chlorophyll “a” concentration (chl “a”) estimates in the Eurasian Arctic are discussed, where the continued climatic warming with increased “Atlantification” advance the sea ice losses. The maximum integrated PP and the total chl “a” content observed in the marginal ice zone (MIZ) of the Barents Sea with weakened stratification of the water column and reached 1109 mgC m–2 day–1 and 118 mg m–2. Nearby the ice edge in the Nansen Basin, the main part of PP formed in the upper mixed layer and did not exceed 469 mgC m–2 day–1, the chl “a” content of 56 mg m–2. In the early and late phytoplankton bloom in MIZ, the typical leading role of picophytoplankton in carbon fixation revealed. Large centric diatoms, microphytoplankton, dominated at the peak bloom stage in 2020 with the dense marine ice cover of the Nansen Basin. A similar phenomenon was previously observed only in the Arctic shelf seas and was not recorded in the high-latitude basins of the Arctic Ocean. With the sparse ice cover of the Nansen Basin in 2021, the main primary producers at the peak bloom were pico- and nanophytoplankton. The low variability of assimilation numbers at all bloom stages (1.7 ± 0.3 mgC mg chl “a”–1 h–1) indicates the acclimatization of phytoplankton to changing environment. The ecological flexibility of the primary production are link of the MLZ ecosystems in the studied seas of the European Arctic during the period of climate change is confirmed.
AGE OF THE FORMATION OF EARLY PRECAMBRIAN CARBONATITES IN THE SOUTH-EASTERN PART OF THE CHARO-OLEKMINSKY GEOBLOCK, ALDAN SHIELD
Authors: Stifeeva M. V. , Vladykin N. V. , Kotov A. B. , Salnikova E. B. , Sotnikova I. A. , Adamskaya E. V. , Kovach V. P. , Plotkina Y. V. , Tolmacheva E. V. , Alymova N. V.
Published: April 2024

Presents the results of U–Pb geochronological (ID–TIMS) studies of garnet and U–Th–Pb (LA–ICP–MS) “screening” geochronological studies of zircon from pyroxene-carbonate rocks of the Ukduska massif. The U–Pb age of garnets (1881 ± 8 million years) and age of zircon rim (1865 ± 16 million years) indicate the early Proterozoic age of these rocks. The results of geochronological studies allow to identify a new stage of carbonate magmatism within the southeastern part of the Charo-Olekminsky geoblock.
OXYGEN ISOTOPE SYSTEM OF LEUCOGRANITES OF THE OMSUKCHAN TROUGH (NE RUSSIA): CONDITIONS AND MECHANISMS OF WATER-ROCK INTERACTION
Authors: Filimonova L. G. , Avdeenko A. S. , Chizhova Yu. N. , Kossova S. A. , Zhilicheva О. М. , Aranovich L. Ya. , Dubinina Е. О.
Published: April 2024

The oxygen isotopic composition of minerals (Qtz, Zrn, Kfs) and bulk samples of Late Cretaceous porphyritic leucogranites of the Omsukchan trough, which are associated with the formation of tin and Sn-polymetallic mineralization, was studied. The δ18O values of bulk samples of leucogranites decrease from +9.7‰ (outside the Dukat ore field) to 10.6‰ (within the ore field), and the light isotope characteristics are mainly an attribute of feldspars and correspond to isotope exchange with meteoric fluid (δ18О = –15‰), over a wide range of T at limited fluid-to-rock ratios (W/R from 0.9–1.6 to 0.3–0.1). Unlike feldspars, the δ18O values of quartz and zircon are partially changed, in the former, probably, by the diffusion mechanism, and in the later, by the dissolution-precipitation one.
WINTER ATMOSPHERIC BLOCKINGS IN THE NORTHERN HEMISPHERE UNDER CLIMATE CHANGES IN RECENT DECADES (1980–2018)
Authors: Mokhov I. I.
Published: April 2024

The analysis of winter atmospheric blockings in the Northern Hemisphere (NH) under climate changes in 1980–2018 was carried out. The results of the analysis indicate a significant increase in the total duration of winter atmospheric blockings τ in the NH in recent decades. The noted trend was revealed against the background of a rapid increase in the NH surface air temperature T in winter seasons. The parameter of sensitivity of the atmospheric blockings duration to changes in the NH surface air temperature in winter seasons for the period 1980–2018 was estimated. The statistically significant estimate obtained means an increase in τ by more than one and a half times with an increase in the mean winter surface air temperature of the NH by 1K. A more significant relationship with T was obtained for values of τ above the average value of τc for the period 1980–2018, while at τ τc, the relationship was found to be statistically insignificant. The noted features are associated with differences in different phases of the key modes of climatic variability. In particular, the mean value of the surface air temperature of the NH in winter in the positive phase of the Atlantic Multidecadal Oscillation (AMO) within the analyzed period of 1980–2018 significantly exceeded the corresponding mean value of T in the negative phase of AMO. At the same time, it was found that the mean value of the winter blockings duration in the NH in the positive AMO phase is one and a half times longer than in the negative AMO phase. For winter seasons, the estimates of the relationship between τ and the intensity of the Arctic anticyclonic center of action depending on the AMO phase were obtained.
ON THE MECHANISM OF THE UPFLOW HELICITY GENERATION DUE TO INHOMOGENEOUS FRICTION ON THE UNDERLYING SURFACE
Authors: Ingel L. Kh. , Makosko A. A.
Published: April 2024

Inhomogeneous friction on the underlying surface leads to horizontal divergence, vertical motions, and helicity generation. The paper presents an analytical model that allows one to establish some general laws and estimate the amplitudes of the corresponding perturbations depending on the values of the parameters. In particular, the possibility of generating noticeable vertical motions and a contribution to helicity that goes far beyond the boundaries of the boundary layer is shown.
THE AGE OF VOLCANIC TUFFS FROM THE BASU AND ZIGAN FORMATIONS OF THE VENDIAN (EDIACARAN) ASHA GROUP IN THE SOUTHERN URALS: RESULTS OF U–Th–Pb (SIMS and La–ICP–MS) DATING OF ACCESSORY ZIRCON
Authors: Ryazantsev A. V. , Razumovskiy A. A. , Novikov I. A. , Kurtukova A. I. , Kanygina N. A. , Yashunskiy Yu. V. , Dubensky A. S. , Sheshukov V. S.
Published: April 2024

For accessory zircon from ash tuffs of the Basu and Zigan Fms of the Asha Vendian (Ediacaran) Group of the Southern Urals obtained isotopic U–Pb age (SIMS (SHRIMP II) и La–ICP–MS). The compositions of rare-metal enriched tuffs correspond to rhyolites, comendites, trachytes, trachyandesites. The concordant value of the U–Pb age of zircon from the tuffs of the Basu Formation is 578 ± 7, 577 ± 7 and 568 ± 5 Ma (SHRIMP II). The age of the zircon from the other two points of the Basu Formation is 573 ± 4 and 574 ± 3 Ma (La–ICP–MS). The age of zircons from the tuffs of the Zigan Formation is 566 ± 5 Ma (SHRIMP II). Tuffs accumulated in the hinterland of the marginal continental volcanic belt.
A VARIETY OF TRANSFORMATIONS OF NONLINEAR INTERNAL TIDAL WAVES ON THE NORTH-WEST AUSTRALIAN SHELF
Authors: Holloway P. E. , Serebryany A. N.
Published: April 2024

Highly non-linear internal waves at the continental margin on the northwest shelf of Australia are discussed using detailed velocity and temperature time series recorded from moored current meters. The region has a vigorous semidiurnal inland tide that propagates towards the shore along the shelf. In this area, there is an increase in the internal tide and the formation of bore-like formations, often accompanied by internal solitary waves. In this paper, the emphasis is on the analysis of the shape and properties of the internal tide. The frequency spectrum of internal waves is presented, calculated from the records of the current component directed along the normal to the coast. Five different types of waves are distinguished, which consist of burrs on the front or back side of the wave, “square” waveforms with a bores on both the front and back sides of the wave at the same time, as well as linear waves of small and large amplitude. The statistics of transformations of the types of internal tides during their propagation along the section of the route from the slope to the shelf is given. The main types of waves passing without transformation and waves with a short lifetime, which include “square” tidal waves and waves with bores on the back slope of the wave, are revealed. In general, the analysis showed a real picture of the ongoing nonlinear transformations of tidal internal waves occurring on the north-west shelf of Australia.
FIRST DATA OF MODERN SEDIMENTATION RATE IN THE SOUTHERN TATAR STRAIT OF THE SEA OF JAPAN
Authors: Aksentov K. I. , Melgunov M. S. , Alatorsev A. V. , Shi Xuefa , Zou Jianjun , Prushkovskaya I. A. , Bosin A. A. , Sattarova V. V.
Published: April 2024

The study of natural archives, such as bottom sediments of lakes and seas, becomes promising for paleoreconstructions due to the conditions of rapid changes of the environment, anthropogenic impact, and insufficient data of instrumental measurements. Based on a radioisotope dating using the non-equilibrium 210Pb, the modern sedimentation rates for the last 150 years in the southern part of the Tatar Strait have been established. According to the two models (CIC and CRS), the sedimentation rate was 0.20–0.22 сm/year.
GEOCHEMICAL AND Sr-Nd ISOTOPE SYSTEMATICS OF THE LATE PERMIAN–EARLY TRIASSIC TRAPS FROM THE KUZNETSK BASIN: MAGMA SOURCES AND CORRELATION WITH THE NORIL’SK REGION VOLCANICS
Authors: Svetlitskaya T. V.
Published: April 2024

The study provides whole-rock geochemical and Rb-Sr and Sm-Nd isotope examinations of Permian-Triassic volcanics (basalts, basaltic andesites) and sills (trachydolerites, monzodiorites) from the Kuznetsk Basin, which is part of the Siberian Large Igneous Province. It is shown that the volcanic section of the Kuznetsk Basin consists of the Lower (I and II units: TiO2 = 1.6–1.9 wt.%, Gd/Yb = 2.0–2.1) and Upper (III–VIII units: TiO2 = 1.4–1.8 wt.%, Gd/Yb = 1.7–1.9) Sequences. The Mayzass sill is geochemically correlated with the Unit II basaltic andesite of the Lower Sequence, and the Syrkashev sill is geochemically akin to the Upper Sequence. The Kuznetsk traps originated from the partial melting of a Sr-Nd isotopically heterogeneous subduction-modified lithospheric mantle. They are geochemically comparable to low-Ti basalts of the low–middle Nadezhdinsky suite from the Noril’sk region, but differ in Sr-Nd isotope composition. The Sr-Nd isotope signatures of the uncontaminated lavas and Syrkashev sill rocks (εNd(T) = (+4.6)–(+2.4), (87Sr/86Sr)T = 0.7047–0.7054) are inherited from the ancient lithospheric mantle and do not represent the contribution of the Siberian plume. The Mayzass sill rocks (εNd(T) = (+2.2)–(+2.1); (87Sr/86Sr)T = 0.7055–0.7063)are derived from a parental melt contaminated with crustal carbonates.
AGROECOLOGICAL ASSESSMENT OF HEAVY METALS AND ARSENIC CONTENT IN CHERNOZEM IN THE COMMON CENTRAL BLACK EARTH REGION OF RUSSIA
Authors: Lukin S. V.
Published: April 2024

Agroecological assessment of the content of Mn, Zn, Ni, Cr, Cu, Pb, Co, As, Cd, Hg in the chernozems of common light-clay was carried out in the steppe zone of the Central Black Earth Region. As a result of studies, it was found that the content of the studied elements in virgin black soil was within the range of varying their concentrations in arable analogues or even lower. Only the gross content of Mn in virgin soil was above the upper limit of variation in the content of this element in arable soils. By average gross content in arable chernozems, common elements form the following descending series (mg/kg) Mn (397) Zn (42.9) Ni (33.1) Cr (23.7) Cu (15.8) Pb (11.2) Co (9.51) As (5.48) Cd (0.35) Hg (0.023), and in terms of the average content of mobile forms, the dependence is slightly different: Mn (4.14) Pb (0.75) Ni (0.59)  Zn (0.36) Cr (0.31) Cu (0.1) Co (0.09) Cd (0.04) There was no excess of the established UEC and MAC standards for the studied elements in the studied soils, therefore there is no danger to obtain environmentally safe crop production. There was no excess of the established UEC and MAC standards for the studied elements in the studied soils, therefore there is no danger to obtain environmentally safe crop production. The content of mobile forms Mn, Zn, Cu, Co corresponds to a low level of availability, therefore, these elements must be introduced into agrocenoses with micro-fertilizers to increase the yield and quality of agricultural products.
AGE AND TECTONIC SETTING OF THE KOPRI-TYPE GRANITOIDS OF THE JUNCTION ZONE OF THE DZHUGDZHUR-STANOVOY AND WEST-STANOVOY SUPERTERRANES OF THE CENTRAL ASIAN FOLD BELT
Authors: Larin A. M. , Kotov A. B. , Salnikova E. B. , Velikoslavinskii S. D. , Kovach V. P. , Skovitina T. M. , Ivanova A. A. , Plotkina Yu. V. , Zagornaya N. Yu.
Published: April 2024

Geochemical, geochronological (U-Pb on ID TIMS zircons), and isotope-geochemical (Sm-Nd) studies of the Kopri-type granitoids of the Tukuringra Complex have been done. The granitoids localized exclusively in the zone of the Dzheltulak suture, which separates the Dzhugdzhur-Stanovoy and West Stanovoy superterranes of the Central Asian fold belt. It has been established that they can be classified as postcollision granitoids of elevated alkalinity and basicity of the adakite type, formed in the age range of 127 ± 1–126 ± 1 Ma, which are part of the Late Mesozoic postcollision Stanovoy volcano-plutonic belt extending in the sublatitudinal direction from the Sea of Okhotsk inland continent subparallel to the Mongolo-Okhotsk suture zone for more than 1000 km and stitching the Dzhugdzhur-Stanovoy and West- Stanovoy superterranes. The structural position of massifs of the Kopri-type granitoids fixes the upper age boundary of the formation of the Dzheltulak suture. The formation of the initial magmas of these granitoids is connected with an essentially lithospheric source formed as a result of mixing of the Early Precambrian and younger, apparently, Phanerozoic component. The similarity in the Nd isotopic composition of the granitoids of the Kopri-type with similar in composition and age granitoids of the West Stanovoy superterrane most likely indicates the similarity of their sources, as well as the fact that the Dzheltulak suture zone “plunges” in the northeast direction under the structures of the Dzhugdzhur–Stanovoy superterrane. This is in full accordance with modern ideas about the features of the deep structure of the junction of the Eurasian and Amur lithospheric plates.
STABILITY OF CARBONATES DURING SUBDUCTION: INFLUENCE OF THE DEHYDRATION REGIME OF CHLORINE-BEARING METAPELITE
Authors: Sokol A. G. , Kruk A. N. , Koz’menko O. A. , Palyanov Yu. N.
Published: April 2024

It was shown that at a pressure of 3.0–7.8 GPa and a temperature of 750–1030°C, a set of reactions occurred in carbonate-bearing and Cl-enriched pelite that is finally converted into eclogite-like assemblage and formed H2O–CO2 Cl-enriched fluid. The eclogite-like assemblage remains stable when P-T conditions change concordantly with hot subduction geotherms, whereas carbonate is completely dissolved in the fluid already at ≥5.5 GPa. In quenched fluid the content of CO2 reaches 30 wt. %. However, preliminary defluidization of pelite at 3.0 GPa and 750°С leads to chlorine removal and carbonate stabilization at 5.5 GPa and at 7.8 GPa in equilibrium with the next chlorine-free portions of fluid. Thus, the stability of carbonates under P-T conditions typical of subduction zones is dependent on the behavior of chlorine during defluidization of marine sediments.
THERMOCHRONOLOGY OF THE ANGARA-VITIM GRANITOID BATHOLITH AS A CHRONICLE OF THE EVOLUTION OF THE MONGOL-OKHOTSK OROGEN
Authors: Travin A. V. , Buslov M. M. , Bishaev Yu. A. , Tsygankov A. A.
Published: April 2024

The thermal history of the Late Paleozoic granitoids of the Angara-Vitim batholith (ABB) was reconstructed using a multi-system approach including U/Pb, 40Ar/39Ar, and fission track dating methods. The rocks of the Barguzinsky and Chivyrkuysky complexes were studied at sites in the southwestern and northeastern parts of the batholith, as well as on the Svyatoy Nose Peninsula and the eastern shore of Lake Baikal. The similar thermal history is reconstructed for the rocks of all sites as a whole. The steep position of the thermal history graph immediately after the formation of the ABB rocks indicates a major denudation epoch with an amplitude of about 7–5 km associated with the Late Paleozoic orogeny. After the epoch of tectonic stabilization, characterized by the time-stretched closure of the biotite isotope system, the closure of the feldspar/plagioclase isotope system occurs in the range of 170–140 Ma. This interval coincides with the closure of the Mongol-Okhotsk Ocean and the beginning of the formation of the orogen of the same name and is characterized by an amplitude of denudation of about 3 km. Further, in the period of 60–3 Ma, a slow denudation took place on the territory of Transbaikalia, which ended with a relatively sharp cooling of rocks during the last 3 Ma and denudation with an amplitude of about 3–2 km. This may be due to the long-range tectonic impact of the Indo-Eurasian collision. The obtained data on the tectonic-thermal evolution of AVB rocks can serve as a basis for identifying the relationship with the formation of the Mongol-Okhotsk orogen and sedimentation in the Jurassic-Early Cretaceous Irkutsk, Kansk-Achinsk, Tuva, Kuznetsk and West Siberian basins.
ON THE RELATIONSHIP OF THE FREQUENCY OF THE FUNDAMENTAL 0S2 MODE AND THE VELOCITY OF THE EARTH ROTATION
Authors: Spivak A. A. , Loktev D. N. , Tikhonova A. V. , Kharlamov V. V.
Published: April 2024

Based on the results of instrumental observations of geomagnetic variations at the Mikhnevo observatory of the IDG RAS and data from the IERS catalog, it was found that the frequency F of the main spheroidal mode of the Earth’s natural oscillations 0S2, distinguished in the spectra of magnetic field variations, changes with time, and the values of F are higher during periods of a decrease in the rotation speed Earth and below with its increase, An empirical relationship between the variations of F and the speed of the Earth’s rotation is obtained,
SUBALKALINE BASALTOIDS IN ULTRAMAFIC ROCKS OF THE RAI-IZ MASSIF (POLAR URALS) AND THEIR PETROGENETIC SIGNIFICANCE
Authors: Vakhrusheva N. V. , Ivanov K. S. , Puchkov V. N. , Shiryaev P. B.
Published: April 2024

The composition and age of subalkaline dolerites localized in chromite-bearing ultramafic rocks of the Rai-Iz massif are investigated. Dolerites are traced along tectonic zones inside ultramafic rocks and are not observed beyond their boundaries, spatially tending to deposits and occurrences of chromites.The studied dolerites are characterized by high concentrations of alkalis, TiO2, P2O5, enrichment with large-ion lithophilic elements and Th; the amount of REE varies from 103.3 to 164.2 ppm; (La/Sm)n = 1.3–1.7. The age of subalkaline dolerites was determined by the method 40Ar/39Ar (402.7 ± 3.8 million years). At this time, a deep metamorphic processing of ultramafic rocks of most of the Rai-Iz massif occurred with the formation of high-chromium chrome mineralization and the isolation of a vein series of subalkaline dolerites in the discharge zones.
RETRIEVING ANGULAR DISTRIBUTIONS OF SEA WAVE ENERGY ACCORDING TO SATELLITE IMAGERY SPECTRA
Authors: Bondur V. G. , Dulov V. A. , Kozub V. A. , Murynin A. B. , Yurovskaya M. V. , Yurovsky Yu. Yu.
Published: April 2024

Here we elaborate the method for retrieval of 2D spatial spectra of sea wave elevations using high-resolution satellite imagery. Such an elaboration allows us to assess angular distributions of wind wave energy. The method was validated based on the results of a comprehensive experiment that involved optical satellite imaging of the Black Sea water area and sea truth measurements under controlled conditions using a stationary oceanographic platform. Angular distribution of sea wave energy, retrieved by spatial spectra of satellite image fragments, were compared with the results of measurements of frequency-angular spectra using data from an array of string wave recorders. It has been demonstrated that the results of measurements by remote and in-situ methods are consistent in the range of sea wavelengths from 2.8 to 30 m, and the mean absolute error is 0.3.
EXPERIMENTAL JUSTIFICATION OF THE INFLUENCE OF S AND Ni ON CRYSTALLIZATION OF LOW-NITROGEN DIAMONDS IN A MELT OF Fe AT HIGH PRESSURE
Authors: Sonin V. M. , Zhimulev E. I. , Chepurov A. A. , Tomilenko A. A. , Chepurov A. I. , Pokhilenko N. P.
Published: April 2024

Based on the analysis of the results on the synthesis and growth of diamonds in metal-sulfide melts at high pressure, the reason for the crystallization of low-nitrogen diamond crystals is substantiated. The introduction of sulfur into the iron melt leads to a decrease in the solubility of nitrogen, which, in turn, leads to a decrease in the content of nitrogen atoms in the melt and the probability of their capture by growing diamond crystals in the form of a structural impurity. The addition of nickel lowers the melting point of the growth system, increases the amount of melt, and, accordingly, promotes the dissociation of molecular nitrogen into individual atoms, which are captured by diamonds during growth as a structural impurity.
FIRST RECORD OF GONIATITE GENUS PARAMEXICOCERAS IN THE CHANGHSINGIAN DEPOSITS OF THE UPPER PERMIAN OF NORTHEAST ASIA
Authors: Kutygin R. V. , Kilyasov A. N. , Biakov A. S.
Published: April 2024

Ammonoids Paramexicoceras aldanense Popow were found at the base of the Nekuchan Formation (upper part of the Changhsingian Stage) in the Dyba River basin, South Verkhoyanie. The first discovery of goniatites in the Upper Permian of Northeast Asia made it possible to clarify the biostratigraphic subdivision of the boundary Permian-Triassic deposits. The Otoceras concavum Zone in its lower part is reduced due to the establishment of the Paramexicoceras aldanense Beds at the base of the Nekuchanian Regional Stage. The data obtained indicate that the genus Paramexicoceras, previously considered long-lived, belongs to the youngest and short-lived taxa of the Cyclolobidae, representing the terminal phase of the goniatite development. This record made it possible to compare the base of the Nekuchanian Regional Stage in South Verkhoyanie with the upper part of the Foldvik Creek Group in East Greenland.
IDENTIFICATION OF SOURCES OF TERRIGENIC SEDIMENTARY ROCKS BASED ON GEOCHEMICAL DATA USING A LINEAR PROGRAMMING MODEL
Authors: Graunov O. V. , Podkovyrov V. N. , Kovach V. P. , Kotov A. B. , Velikoslavinsky S. D. , Scovitina T. M. , Adamskaya E. V. , Khorovoi V. A.
Published: April 2024

The possibility of identifying sources of terrigenous rocks based on geochemical data using a linear programming model is considered on the example of metasedimentary rocks of the Sakukan Formation of the Kemen Group of the Udokan Complex, Aldan Shield. It is shown that tonalite-trondhjemite gneisses (56.9%) and gneiss-granites (17.3%) of the Olekma complex, Paleoproterozoic granitoids of the Kuanda complex (7.6%) of the Chara-Olekma geoblock, metavolcanic rocks of the Fedorov Formation (15.4%) and gneiss-granites developed within it (1.8%) of the West Aldan megablock could be the sources of metasandstones of the Sakukan Formation. The results obtained are in good agreement with the Nd isotopic and geochronological data available for the metasandstones of the Sakukan Formation, which indicates the wide possibilities of identifying and searching for sources of terrigenous deposits using a linear programming model.
GEOLOGICAL MARKERS OF THE UPPER PLEISTOCENE DEPOSITS IN MAIN RIVER VALLEYS OF WESTERN SIBERIA
Authors: Zolnikov I. D.
Published: April 2024

During the second half of the 20th century by the end of the first quarter of the 21st century the problem of differentiation and correlation of the main rivers of Western Siberia (primarily the Ob and Yenisey) valleys sediments was intensively discussed. Traditionally, the regional Quaternary history of the river valleys was considered as the “terrace flight” paradigm. According to it in the Neogene-Quaternary time alluvial terraces formed by sequentially from the older upper to the younger lower ones. It was considered that terrace formed by neotectonics, paleoclimate dynamics changed the fullness of the rivers, advance of the sea and dereliction influenced on base of erosion and blocking river valley by northern glaciers. As a result, in outside glacier zone appeared barrier basins and periglacial alluvium. However, on the official maps of the Quaternary deposits the heights, age and even the number of terraces differ significantly. Nowadays a lot of data are contrary to theory about flight consistently carved cycloclimatic terraces and periglacial alluvium facies replacing the ice-dammed northern lakes in the south of Western Siberia. In the article it was performed the updated concept of the sedimental structure of the Upper Neopleistocene in the main valleys of the region and taking into account data on glacier outburst floods from intermountain area to the plain. Its intensive erosional and accumulative activity has so far been underestimated.
REGIONAL EFFECTS OF GLOBAL CLIMATE CHANGE IN THE URAL RIVER BASIN
Authors: Sivokhip Zh. T. , Pavleychik V. M. , Chibilev А. А.
Published: April 2024

The results of the study of regional climate changes (surface layer temperature and precipitation) in the Ural River basin at the current level are presented. Conclusions about the transformation of the main parameters of the regional climate in the studied basin were obtained on the basis of standard methods of statistical data analysis, as well as calculation of integral climate anomaly indices. Statistically significant values of linear trend coefficients illustrate a steady increase in the average annual air temperature in the Ural River basin. The largest contribution to the growth of this parameter is made by the first three months of the calendar year (January–March) and the autumn months (October–November). The long-term course of precipitation values is characterized by the absence of unidirectional and statistically significant trends. An important macro-regional trend in the dynamics of the precipitation regime is an increase in the proportion of precipitation of the cold period. In conclusion, it is noted that the diversity of the physical and geographical conditions of the formation of the regional climate determines the spatial heterogeneity of the response to global and macro-regional changes.
COPPER ISOTOPE COMPOSITION OF Pt-Fe MINERALS FROM THE NIZHNY TAGIL MASSIF, MIDDLE URALS: FIRST RESULTS
Authors: Malitch K. N. , Soloshenko N. G. , Votyakov S. L. , Badanina I. Yu. , Okuneva T. G. , Sidoruk A. R.
Published: April 2024

In order to identify the source of copper, for the first time in world practice, the features of the Cu-isotopic composition of Pt–Fe minerals are characterized using the example of the Nizhny Tagil massif, the world standard of Ural-type zoned complexes. The chemical and isotopic composition of Pt-Fe minerals were determined by electron probe microanalysis, chemical sample preparation with selective separation of copper from the solution of the studied sample, and subsequent high-precision determination of the δ65Cu value using multiple-collector inductively coupled plasma mass-spectrometry. The majority of platinum group minerals (PGM) from bedrock deposits of the Nizhny Tagil massif, represented by chromitites of the Alexandrovsky and Krutoy logs, are formed by Pt–Fe minerals, among which high-temperature ferroan platinum (Pt2Fe) with inclusions of Os–Ir alloys and laurite (RuS2) dominates. The concentrations of copper in the studied samples of ferroan platinum vary in the range of 0.4–1.4 wt. % Cu. The δ65Cu values for Cu-bearing PGM vary in the range from –0.37 to 0.26‰. Secondary low-temperature PGM assemblage is represented by solid solutions of tetraferroplatinum (PtFe) – tulameenite (PtFe0.5Cu0.5) series. The concentrations of copper in these PGM vary in the range of 6.8–11.3 wt. %; the values of δ65Cu are characterized by lighter isotopic compositions of copper that range from –1.15 to –0.72‰. The lightening of the Cu-isotopic composition in secondary Cu-bearing PGM compared with that in ferroan platinum (δ65Cu = –1.01 ± 0.17, n = 8 and δ65Cu = 0.03 ± 0.23, n = 7, respectively) is consistent with the secondary nature of isotopic variations, due to the evolution of the composition of the ore-forming fluid during the low-temperature formation of the tetraferroplatinum (PtFe) – tulameenite (PtFe0.5Cu0.5) series.
ISOTOPE Sm–Nd JUVENILE CRUST CHARACTERISTICS OF THE CENTRAL PART OF MONGHOL-OKHOTSK OROGENIC BELT
Authors: Dril S. I. , Kuzmin M. I. , Noskova Ju. V. , Zarubina O. V.
Published: April 2024

In the Phanerozoic, the production of the continental crust was associated with convergent geodynamic settings and, therefore, with intracontinental orogenic belts developed after the closure of paleooceans. Evaluation of the proportions of juvenile versus older recycled material is a key parameter for understanding how the crust in orogens formed and evolved. The Mongol-Okhotsk orogenic belt is one of the major structural part of Central Asia. Its central – Trans-Baikal part contains the well-reserved fragments of island-arc system as well as the entire spectrum of accretionary prism formations, allowing evaluation of the proportions of juvenile to recycled sedimentary material in the crust of this orogen. In this part of the belt, the best preserved fragments of juvenile crust are the Late Paleozoic volcanogenic-sedimentary sequences of the Kamensk and Urtui suites. The first suite is an indicator of the subduction along the northwestern margin of the Mongol-Okhotsk Paleocean beneath the Siberian paleocontinent, and the second one is an indicator of the subduction along the southeastern beneath the Argun superterrane. The entire compositional spectrum of volcanics from basalts to rhyolites demonstrate positive values εNd(254МА) = +1.4–(+3.8) and TNd(DM) = 896–920 MA. The basalts of the Urtui formation are also characterized by positive εNd(350МА) values, lying in the range of +1.7–(+6.0) at TNd(DM) = 773–939 MA. Therefore, the juvenile crust of the orogenic belt is characterized by positive ɛNd(t) values and model TNd(DM) age of 1000 Ma. The meta-sedimentary rocks of the accretion wedge of the Mongol-Okhotsk orogenic belt are significantly dominated by older recycled crustal material, whose source is likely the Late-Riphean formations of the Argun superterrane.
FORMATION OF WINTER SURFACE TEMPERATURE ANOMALIES IN THE NORTH ATLANTIC IN DECADES OF NEGATIVE AND POSITIVE VALUES OF THE NORTH ATLANTIC OSCILLATION INDEX
Authors: Sizov A. A. , Bayankina T. M. , Pososhkov V. L.
Published: April 2024

An analysis of the variability of the winter surface temperature anomaly in the North Atlantic in decades of negative and positive values of the North Atlantic Oscillation Index is presented. It was found that in the decade with negative values of the North Atlantic Oscillation Index, the slope waters of the Gulf Stream system and Labrador Current waters decrease the temperature of the Gulf Stream at the mixing zone on the Scotia Peninsula shelf and in the area of the quasistationary anticyclonic vortex to a maximum. In the decade with positive values of the North Atlantic Oscillation Index, the temperature of the slope waters is close to the climate. Taking into account the increased speed of the Gulf Stream in the years with positive values of the North Atlantic Oscillation Index, the spreading of the surface ocean temperature anomaly over the North Atlantic water area occurs for a shorter time than in the years with its negative values.