A.A. Tsygankov, G.N. Burmakina
Dobretsov Geological Institute of Siberian Branch of Russian Academy of Sciences, Ulan-Ude, Russia
Keywords: Angara-Vtitm batholith, U-Pb isotopic age, Lu-Hf, sources of magma sources, geodynamics, Western Transbaikalia.
The Late Paleozoic granitoid province of Transbaikalia (Angara-Vitim batholith, AVB, Russia), located in the northeastern part of the Central Asian Orogenic Belt (CAOB), covers an area of about 200,000 km2 and is composed of rocks ranging in composition from monzonites and quartz syenites to leucocratic granites. This work is aimed at: 1) determination of the total duration and dynamics of the formation of granitoids of the Angara-Vitim batholith; 2) finding the causes that determined the spatial and temporal heterogeneity of granitoids; 3) reconstruction of the sources of salic (granitoid) magmas, assessment of the contribution of mantle-crustal interaction processes to the petrogenesis of granitoids. The article is based on new petro-geochemical, isotopic (Lu-Hf) and isotopic-geochronological (U-Pb) data on the northern part of the AVB. Combined with the results of previous studies, it has been established that one of the largest granitoid provinces on Earth (AVB) was formed ~ 45 million years ago (from 320 to 275 million years). About 90% of the batholith rocks were formed during this time. Mainly crustal metagravaccian protoliths were the source of salic magmas. Formation of monzonitoids, quartz syenites, and granodiorites is associated with melting of mixed protoliths, in which the proportion of juvenile mafic material could reach 40-50%. The Late Paleozoic granitoid magmatism of Transbaikalia began with the actual introduction of calcareous-alkaline granites, granodiorites, and quartz syenites, which make up the bulk of the first stage of magmatism. At the second stage, magmatism was concentrated in a relatively narrow (200-250 km) permeable zone of the northeastern strike. This zone drained crustal foci of salic magmas and favored the entry of mafic mantle melts into the upper horizons of the Earth's crust. The granitoids of the Angara-Vitim batholith were formed at the post-collisional stage of the evolution of the eastern segment of the CAOB under the influence of mantle plume on the crust of the young orogen.
D.V. Metelkin1,2, E.V. Vinogradov1,2, A.A. Eliseev1,2, M.E. Luzan1,2, V.V. Abashev3 1Novosibirsk State University, Novosibirsk, Russia 2Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia 3Geological Institute Russian Academy of Sciences, Moscow, Russia
Keywords: Hotspots, mantle plumes, geodynamo, geomagnetic reversal frequency, paleointensity, geocentric axial dipole, equatorial dipole, anomalous geomagnetic field, global magnetic anomalies, absolute plate reconstructions
We present an analysis of modern paleomagnetic data from large igneous provinces and palaeorift structures in Siberia and the High Arctic that are potentially related to mantle plumes. The interrelationship between plume magmatism, geomagnetic reversal frequency, and field intensity over the last 600 Myr exhibits a periodicity of 70–100 Myr. Periods of mantle plume activity were preceded by an increase in geomagnetic reversal frequency, accompanied by a decrease in geomagnetic field intensity. Our proposed hypothesis explains this effect by changes in the thermal convection in the Earth’s outer core while mantle plumes are regarded as regulators of the state of the hydromagnetic dynamo. “Overheating” of the core increased the turbulence of convective currents, and therefore, the amount of reversals. During reversals, the value of the main component of the geomagnetic field – the geocentric axial dipole – first fell to zero and returned to high values only afer a full reversal of the poles. Reduction of relaxation time in periods of frequent reversals led to prolonged low values of the absolute intensity of the geomagnetic field. Mantle plumes forming during such periods could remove the excess heat and stabilize the state of the geodynamo, even almost completely stopping reversals. We link the Vendian and Devonian geomagnetic phenomena to periods of ultra-frequent reversals. During these extended periods of low value of the axial dipole, the configuration of the geomagnetic field was determined by low-order non-zonal harmonics and by the global magnetic anomalies. We observe a qualitative coincidence of the position of paleopoles with centers of lower mantle gravitational and magnetic anomalies and postulate that the anomalies were stationary. This is the basis for substantiating a new reference framework for paleotectonic reconstructions in absolute coordinates. Examples of reconstructions made using this system also agree with the hypothesis of stationary hotspots. From the terminal Precambrian to the Mesozoic inclusively, the Siberian paleocontinent was located in the area of effect of the African mantle hot field, migrating northwards along the 0° meridian from the latitude of Tristan da Cunha to that of Iceland.
V.S. Shatsky1,2,3, A.L. Ragozin1, V.N. Reutsky1, V.V. Kalinina1 1 V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Science, Novosibirsk, Russia 2 Novosibirsk State University, Novosibirsk, Russia 3 A.P. Vinogradov Institute of Geochemistry, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia
Keywords: inclusions in diamonds, diamond formation, mantle, subduction zone
Evidence of the involvement of Fe-C-O melts in diamond formation from placers in the northeastern Siberian Craton, along with our previously obtained data on iron carbide inclusions and literature sources, has provided a new perspective on processes diamond formation in subduction zones. Iron carbide and oxide inclusions in diamonds, along with the presence of moissanite and carbonates in polyphase inclusions, indicate a heterogeneous diamond environment. Extreme variations in oxygen fugacity during diamond formation processes can be caused by the generation of hydrogen and hydrocarbons during the interaction of carbonated rocks of the subducting oceanic lithospheric plate with aqueous fluids. Separated hydrocarbon fluids can create local areas of ultra-reduced mantle, where silicon carbide can be formed under conditions of the absence of equilibrium with the surrounding rocks.. A characteristic feature of the diamonds studied is that they were subjected to brittle deformation, followed by crack healing, accompanied by the formation of polyphase inclusions of iron carbides and oxides, which we interpret as melt inclusions. Brittle deformations of diamonds, in the conditions of the lower lithosphere, are explained by high deformation rates, which can be realized in the hypocenters of deep-focus earthquakes of the subducting lithospheric plate, during dehydration processes or the formation of carbonatite melts.
A.N. Didenko1,2, M.Y. Nosyrev2, G.Z. Gilmanova2, M.D. Khutorskoy1 1Geological Institute of the Russian Academy of Sciences Moscow, Russia 2Institute of Tectonics and Geophysics FEB RAS Khabarovsk, Russia
Keywords: Amur Plate, Curie Point Depth, plate boundaries, thermal anomalies and tectonic structures
Based on the results of spectral analysis of the anomalous magnetic field, the depths of the roof and the sole of the magnetically active layer of the Amur Plate and adjacent territories are calculated. The causes of variations in the depth of the sole of the magnetoactive layer (CPD) from 14 to 38 km (average 24 km) have been determined. Maximum CPD depths are observed within sedimentary basins (Erlian, Songliao, Sredneamursky) in the southwest and in the central part of the plate. The areas of minimum depths in the continental part are located in the northwest within the giant granitoid batholiths (Angara-Vitim, Khentei) and in the northeast within the Bureinsky province. The third area of minimum CPD values is located within the waters of the Sea of Japan.
The relatively high elevation of the bottom of the magnetically active layer in the Sea of Japan is associated with rifting processes in the back-arc basin, which began at the end of the Oligocene, and the generation of fluids and magma chambers above the Pacific slab, sinking under the Amur Plate. Two areas of high CPD standing in the continental part of the plate are associated with the presence of two thermal anomalies. The north-western one is explained by the presence of a thermal crustal anomaly due to the process of radioactive heat generation by granitoids of the giant Angara-Vitim, Khangai and Khentei batholiths. Northeastern Bureinskaya – the presence of an anomalous temperature of the mantle here.
A comparison of the newly constructed CPD map with the boundaries of the Amur Plate, previously determined mainly from seismic data, shows that the surface boundaries of the plate coincide mainly with the zones of the greatest CPD gradients. All of them are associated with areas of increased seismic energy generation, with the exception of one small area on the southern border of the Amur Plate at its junction with the Yangtze Plate. In our interpretation, plate boundaries are not just lines on the surface, they are fairly wide zones from tens to the first hundreds of kilometers that encircle the plate.
L. L. UBUGUNOV1,2, V. I. UBUGUNOVA1, T. A. AYUSHINA1, TS. N. NASATUEVA1, A. S. SYRENZHAPOVA2, E. I. LASTOCHKIN3, A. D. ZHAMBALOVA1, O. V. VISHNYAKOVA1, E. YU. ABIDUEVA1 1Institute of General and Experimental Biology of SB RAS, Ulan-Ude, Russia 2Buryat State Agricultural Academy named after V. R. Filippov, Ulan-Ude, Russia 3Institute of Geology named after N. L. Dobretsov of SB RAS, Ulan-Ude, Russia
Keywords: biophilic macro- and microelements, halomorphic soils of oases, Uldza-Torey endorheic lake basin, biotic and abiotic components of ecosystems
The content of biophilic elements in soils and minerals of coastal depressions of highly mineralized chloride lakes of the Uldza-Torey endorheic basin (Russia, Dauria) and the microbiota involved in the cycles of these elements were studied comprehensively for the first time. Obtained data on the gross content and mobile forms of biophilic macro- (N, P, K, Na, Ca, Mg, Fe, S) and microelements (Mn, Zn, Cu, Cr, Ni, Co) in soils of the local “node” of biota concentration of the Uldza-Torey basin revealed differences in the geosphere-biosphere interactions of biotic and abiotic components in quasi-gley solonchaks, saline humus-gley and saline light-humus soils. High significance of halomorphic soils for preserving the biodiversity of steppe territories (Dauria, Transbaikalia) has been established. Maximal concentrations of the total content of biophilic elements and mobile forms of nitrogen, sulfur, calcium, sodium, manganese, and magnesium were revealed within the Sg, ca horizon of the quasi-gley solonchak. This layer is characterized by the highest index of microbial diversity, a significant proportion of taxa participating in the cycles of biophilic elements, and formation of new minerals with wide variations of silicon, aluminum, and sodium. The underlying horizons of solonchak (CQs) are enriched in sodium, magnesium, and sulfur under the impact of sulfate-chloride-sodium ground waters. Calcite, calcium amphiboles, and monocyte predominate in their mineralogical composition. Enrichment of solonchaks with mobile forms of biophilic elements, presence of various minerals containing Na, Ca, Mg, Fe, and rare earth elements (Ce, La, Nd, Sm, Th) confirm both the sodium and rare-earth hypotheses of animal lithophagy. A significant deficit of most gross and mobile forms of biophilic elements, decrease in microbial diversity, and typical for acidic rocks minerals, rarely basites, were noted in the upper horizons of humus-gley saline and light-humus saline soils. In the lower layers formed by paleohydromorphic lake sediments, oxides with a low proportion of chlorine, sulfur and sodium (8-15 %), and enrichment in easily soluble salts and mobile forms of sodium and sulfur were revealed. The content of other biophilic elements was estimated as low and very low.
V. V. ANIKINA1,2, E. YA. YAVID3, Yu. V. KRYLOVA4, E. A. KURASHOV4, V. A. GREBENNIKOV1, E. V. PROTOPOPOVA2, P. V. BASH2 1Federal state budgetary scientific institution "Russian Federal Research Institute of Fisheries and Oceanography", St. Petersburg Branch, St. Petersburg, Russia 2St. Petersburg Federal Research Center of the Russian Academy of Sciences, St. Petersburg, Russia 3GazEnergoStroy LLC, Novy Urengoy, Russia 4Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok settlement, Russia
Keywords: low molecular weight metabolome, component composition, low-molecular weight organic compounds, gas chromatography-mass spectrometry, Nuphar lutea, cyanobacteria, allelochemicals, Kuznechnoye Lake, trophic status, indication of ecological status
For the first time, a chromatograph mass spectrometric study of the essential oil of the yellow water lily (Nuphar lutea (L.) Sm.) growing in Lake Kuznechnoye in the Leningrad Region on the Karelian Isthmus was carried out at the peak of plant development in the flowering-fruiting phase in 2020 and 2021. The aim is to study the interannual variability of the component composition of low-molecular organic compounds (LMWOC) and assess the possibility of using its low-molecular metabolome (LMWM) to indicate the ecological state of water bodies. The limnological characteristics of the reservoir in the place where the yellow water lily grows are given. The main research method of the work is gas chromatograph mass spectrometry (GC-MS). It was revealed that under changing environmental conditions in different years, including depending on a specific biotic environment (phytoplankton) and abiotic factors, plants are able to synthesize different numbers of LMWOC. The decrease in the trophic status of the lake ecosystem and the decrease in the development of cyanobacteria, as the dominant component of phytoplankton, leads to a significant increase in the content of all groups of components in the LMWM of the yellow water lily. Intraspecific interannual variability of the LMWM of the yellow water lily can serve as an indicator of stability/changes in the state of the aquatic ecosystem. High quantitative indicators of the content of LMWOC, especially allelochemical substances, identified in N. lutea from Lake Kuznechnoye, typical for the Karelian Isthmus, allow us to consider the yellow water lily growing in the lakes of the Karelian Isthmus as an underutilized natural resource of valuable LMWOC, which has the potential for diverse economic use.
N. V. RYGALOVA1, V. S. MYGLAN2, Z. YU. ZHARNIKOV2, A. V. TAYNIK2, M. O. FILATOVA3, I. L. VAKHNINA2, V. V. BARINOV2 1Altai State University, Barnaul, Russia 2Siberian Federal University, Krasnoyarsk, Russia 3Institute of Archaeology and Ethnography of SB RAS, Novosibirsk, Russia
Keywords: tree-ring chronologies, Pinus sylvestris L, ribbon pine forests, Obiskie pine forests, south of Western Siberia, forest-steppe and steppe zones
The paper presents a new network of tree-ring chronologies (TRW) completed for ribbon pine forests, Priobsky pine forest and pine forests in the south of Western Siberia (Altai region and Novosibirsk region) and describing the growth of annual ring widths of common pine ( Pinus sylvestris L.). Measurements of annual ring parameters were made on high-resolution digital images. A statistically significant relationship (from 0.83 to 0.46) was observed between all tree-ring series (maximum distance between points 330 km). On the basis of cluster and correlation analysis the local steppe and forest-steppe chronologies were combined into three regional chronologies (Pl5, Pl6, Pl7). Comparison of parameters of chronologies in Altai Krai and Novosibirsk region showed that the border between regions (and in physiographic terms - the border between southern and middle forest-steppe) is conditionally a kind of line dividing TRW chronologies into groups characterized by different sensitivity of radial growth to changes in environmental factors. At the same time, chronologies from stony slopes (spurs of the Kolyvan ridge) have maximum sensitivity. The results of the study allowed us to compare the dendroindication potential of pine forests of the study area and neighboring regions (the Urals, Siberia and Russian far East). The importance of purposeful selection of sample plots in ribbon pine forests and Priobsky pine forests was shown, since the use of a random set of chronologies will not allow to correctly reconstruct climatic conditions of tree growth.
I. G. VOROB’EVA1, D. A. FILIMONOVA1, E. V. BANAEV2 1Novosibirsk State Pedagogical University, Novosibirsk, Russia 2Central Siberian Botanical Garden of the Siberian Branch of RAS, Novosibirsk, Russia
Keywords: discomycetes, ecological groups of fungi, specially protected natural area, biodiversity
The article presents the results of a study on the ecological structure of discomycetes on the territory of the Central Siberian Botanical Garden of the Siberian Branch of the Russian Academy of Sciences - a specially protected natural area. The taxonomic diversity of fungi includes 37 species belonging to 30 genera, 16 families, 5 orders, and 3 classes. Saprotrophic discomycetes are categorized into five ecological groups, among which the largest proportion is occupied by lignophilic and phyllophilic species (81 %), while the smallest proportion is occupied by herbophilic species (4 %). Inoperculate species predominate in all groups. Lignophilic fungi prefer wood of the fourth and fifth stages of decomposition (about 90 %); they have not been found on wood of the first and second stages of decomposition. Edaphophilic discomycetes are mainly represented by operculate species from the order of Pezizales (81.8 %). The group of herbophilic fungi is represented only by inoperculate species from the order of Helotiales.
Yu. V. Savinykh, S. P. Zadorozhnykh, V. S. Ovsyannikova
Institute of Petroleum Chemistry of SB RAS, Тоmsk, Russia
Keywords: soil, oil pollution, remediation, plant test objects, photosynthetic pigments, oil-destructing microorganisms
The paper presents data on the effect of hydrocarbon vapors and oil pollution of soil on morphological parameters and the content of the main photosynthetic pigments - chlorophylls and carotenoids - in green parts of plants of different systematic position. Under laboratory experimental conditions, an increase in the content of chlorophylls and carotenoids in the above-ground parts of leafy moss (brium), plants of the umbrella family (chervil and femur) and cereals (foxtail) during growth in the atmosphere of oil vapors and in soil containing 0.75-3.21 % oil was observed. Under field conditions, an increased content of photosynthetic pigments in the leaves of Ledum and fagus was detected, and below background - in the leaves of plantain. Addition of hydrocarbon-oxidizing bacteria (HOB) to the soil with oil increased the concentration of pigments by 30-40 %, indicating an additional stimulating effect of HOB introduction.
N. A. Ryapisov, T. L. Chepel
Novosibirsk State Pedagogical University, Novosibirsk, Russia
Keywords: evidence-based approach, evidence-based practice, evidence-based education, scientific and methodological support, competencies, chemical education
Introduction. Teachers who use a set of pedagogical technologies presented in modern didactics in their practice tend to use them intuitively, without referring to well-founded checks of their effectiveness and safety. This fact highlights the relevance of the evidence-based approach in education, which is widely represented in foreign studies of educational practice and is just beginning to take shape in the scientific and educational space of our country. Methodology. The research is based on a reflective analysis of foreign and domestic publications characterizing the meaningful meanings of the formation, development and application of an evidence-based approach in the process of solving scientific and practical problems in various fields of knowledge, including in the educational field during the formation of professional competencies of chemistry teachers. Discussion. Evidence-based education is an approach to educational processes that uses methods based on reliable evidence obtained experimentally in scientific research. The evidence-based approach is currently widely used in the foreign educational field (J. Hattie et al.) and is beginning to be used in the system of training and advanced training of Russian teachers. At the same time, a kind of reference point for the implementation of the ideas of the evidence-based approach in educational processes is the Standard of Evidence-Based Practices in the Field of Childhood, developed as part of the implementation of the state program “The Decade of Childhood” (2018), which is focused on identifying social (including educational) practices with proven effectiveness. Conclusion. The unified federal system of scientific and methodological support for teachers and managers, which has been created and is being developed in Russia, is aimed at continuous improvement of the professional skills of teachers and managers. It is likely that one of the main drivers of the implementation of the ideas of evidence-based education in the field of chemistry is the professional pedagogical communities (the All-Russian Public Organization of Teachers and Lecturers of Chemistry and its regional branches, which are represented in almost all regions of the Russian Federation).
