Vestnik of Saint Petersburg University Earth Sciences最新文献

{"title":"Kaalamo and Velimyaki paleoroterozoic gabbroid massifs of the Northern Ladoga area: thermodynamic modeling of crystallization and evolution trends of igneous rocks","authors":"R. L. Anisimov, M. Petrakova, S. Baltybaev","doi":"10.21638/spbu07.2023.204","DOIUrl":"https://doi.org/10.21638/spbu07.2023.204","url":null,"abstract":"Kaalamo and Velimyaki gabbroid massifs are located in the south-eastern part of the Raahe-Ladoga suture zone of the Karelian craton and the Sveсofennian mobile belt. These massifs were formed almost simultaneously 1.89 Ga ago, occupy the same tectonic position and are located in a single unit of the Early Proterozoic metamorphosed rocks: the intrusions are contained by the Early Proterozoic supracrustal stratas: garnet-biotite gneisses and micaceous shales of the Ladoga series, as well as amphibolites of the Sortavala series. Despite this, the gabbroids of the compared massifs differ sharply in their material composition, especially the content of alkalis in a differentiated series of rocks. The results of thermodynamic modeling of magmatic crystallization (Magma Chamber Simulator, MELTS packages) showed that a differentiated sub-alkaline series of rocks of the Velimyaki massif cannot be obtained from magma of the Kaalamo massif by slightly changing such parameters as pressure, water content in the melt, and oxygen fugacity. The assumption of a significant difference in these parameters for magmas of the Kaalamo and Velimyaki massifs is not confirmed at the mineralogical-petrographic level and other characteristics of the rocks of the compared ones. The effect of contamination at the level of the magma chamber also does not significantly shift the trend of rock compositions from the calc-alkaline region to the sub-alkaline region. Analysis of the results of thermodynamic modeling of magmatic mineral formation in the two massifs allows us to make it possible to conclude that the Kaalamo and Velimyaki massifs were formed either from various parent melts, or their initial melt was one, but the magma of the Velimyaki massif underwent contamination with enrichment with alkalis along the migration route of magma until the level of the upper crust was reached.","PeriodicalId":41676,"journal":{"name":"Vestnik of Saint Petersburg University Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72444352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Composition and formation conditions of noble metal ores of the Koykar-Svyatnavolok sill (Republic of Karelia)","authors":"S. V. Petrov, Aleksey P. Borozdin, Ivan L. Oleynik, Irina P. Tarasova, I. Kotova, S. Kotov, Yuliya S. Shelukhina, Olga S. Kolusheva","doi":"10.21638/spbu07.2023.203","DOIUrl":"https://doi.org/10.21638/spbu07.2023.203","url":null,"abstract":"The Viksha iron ore deposit is confined to the Koykarsko-Sviatnavolok sill, where as a part of ore bodies, in addition to the main components - iron and titanium, it contains gold, platinum, and palladium. The purpose of this publication is to determine the type and patterns of noble metal mineralization in gabbro-dolerites of the Koykar-Svyatnavolok sill, to consider the mechanisms of accumulation and localization of precious metals in ore bodies. The repeated occurrence in the section of the intrusion of an association of two rock varieties of contrasting composition (high-iron - titanomagnetite gabbro-dolerites, and high-siliceous - granophyres), as well as the revealed petrographic, petrochemical and geochemical regularities, allow us to consider liquid stratification of magmatic melt as a mechanism for the formation of ore titanomagnetite horizons ( segregation). This liquid immiscibility led to the accumulation of noble metals in the high-iron fluidized liquate in accordance with distribution coefficients of nobel metals between silicate and oxide melts and between melt and fluid. The confinement of noble metal mineralization to sulfide, cobaltite-bornite-chalcopyrite accumulations in ore titanomagnetite horizons has been established, which corresponds to the low-sulfide noble metal type of mineralization. Precious metal mineralization is represented by both native mineral forms (arsenides, sulfoarsenides, antimonides and intermetallides of platinum group metals, gold and silver tellurides, electrum, native gold) and isomorphic impurities in bornite and cobaltite. The relationship between the formation of minerals bearing noble metals and the process of chloritization against the background of the transformation of protolith titanomagnetite is shown. A model for the concentration of precious metals from basaltoid melt in several stages is proposed: enrichment of fluidized high-iron ore liquat with precious metals; their accumulation in the residual fluid and in the sulfide liquid during the crystallization of ore liquat; their partial entry into the hydrothermal solution during fluid cooling and hydrothermal metasomatism of earlier crystals. The localization of noble metals occurred as the residual fluid cooled, due to the destruction of complex chloride and sulfide compounds with noble and non-ferrous metals and the crystallization of sulfide-precious metal paragenesis within the ore horizons.","PeriodicalId":41676,"journal":{"name":"Vestnik of Saint Petersburg University Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85490072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Typomorphic features of placer gold of the Sololi River basin (northeast of the Siberian platform)","authors":"B. Gerasimov","doi":"10.21638/spbu07.2023.202","DOIUrl":"https://doi.org/10.21638/spbu07.2023.202","url":null,"abstract":"Mineralogical features of placer gold and gold-sulfide ore occurrences of the Sololi river basin from the Sololi uplift of the Olenek arch have been studied. According to the typomorphic indicators, two types of gold are distinguished. The first type is gold of a tabular and lumpy shape, often with mineral indentation imprints. The inner structure is represented by granulation, and recrystallization, high-grade intergranular veins, and high-grade shells typical of the gold of intermediate reservoirs. This type of gold is characterized by a high fineness. The sources of this type of gold were gold-bearing intermediate reservoirs of the Permian and Riphean widely developed in the studied area. The second type of gold includes subrounded and poorly rounded gold, ore gold of hooked, tabular, crystalline and angular-lumpy shapes with a pitted-bumpy or flat surface, as well as large growths of gold with quartz. The fineness of this type of gold varies from low to very high. Its primary sources were probably quartz veins genetically related to the metamorphic rocks of the Eekit series and Precambrian rhyolites. Ore occurrence formed by the Late Permian clastic rocks during the processes of the Mesozoic tectonomagmatic activation is considered as an additional source of feeding. Establishment of indicators of low–temperature hydrothermal processes as mineral parageneses, such as mercury gold, cinnabar and barite, suggests shallow and low-temperature formation conditions of this ore occurrence.","PeriodicalId":41676,"journal":{"name":"Vestnik of Saint Petersburg University Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78895309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changes in the spatial vulnerability of the large cities population to natural and man-made hazards under the influence of housing construction","authors":"S. Badina, R. Babkin, N. M. Skobeev","doi":"10.21638/spbu07.2023.208","DOIUrl":"https://doi.org/10.21638/spbu07.2023.208","url":null,"abstract":"The study purpose is to assess the degree of influence of the new large residential complexes commissioning on the main parameter of the spatial vulnerability of the Moscow population to natural and man-made hazards – its density. For this purpose, the key indicators of housing commissioning in Moscow for 2011-2021 were analyzed. The use of Big Data (data from mobile operators) made it possible to determine the actual change in population density for 2018-2019 on the largest possible scale – in cells of 500 by 500 m. The indicators of the present population density according to the mobile operators’ data on weekday winter nights in 2018 and 2019 were compared with indicators of growth in the housing stock for the considered period. The established dependence of these indicators can later be used to predict the intracity dynamics of the population in studies of natural and man-made risks, when longer time series of mobile operators’ data become available for Moscow. In addition, this study also considered the factors of increasing natural and man-made hazards in Moscow districts associated with housing construction. It was found that due to the limited free land resources for new construction on the territory of Old Moscow, most housing complexes are localized in areas of increased engineering-geological and technogenic danger. Additional risk factors are an increase in the number of storeys and building density. They are characterized by a steady positive trend over the period under review.","PeriodicalId":41676,"journal":{"name":"Vestnik of Saint Petersburg University Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89223067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative analysis of the effectiveness of bioindication methods in monitoring environmental studies in St Petersburg","authors":"M. Opekunova, A. R. Nikulina, Irina V. Smeshko, V. S. Kirichenko","doi":"10.21638/spbu07.2023.207","DOIUrl":"https://doi.org/10.21638/spbu07.2023.207","url":null,"abstract":"The purpose of the research is to evaluate the effectiveness of bioindication methods in determining the state of the environment in St. Petersburg on the example of Vasileostrovsky and Pushkinsky districts. The content of chemical elements in soils, poplar bark Populus balsamifera, Tilia cordata and Betula pendula leaves, moss (Sphagnum angustifolium) and lichen (Cladonia stellaris) traps was studied, the integral index of fluctuating asymmetry of linden leaves T. cordata and birch B. pendula was calculated, soil biotesting using Daphnia magna and Chlorella vulgaris was carried out. It is established that the main sources of pollution of the urban environment are motor transport, the Baltic plant in Vasileostrovsky district and the industrial zones \"Shushary\" and \"Pushkinskaya\" in Pushkin district. The territory of the park zone of the Pushkin district can be considered as a conditional background for environmental monitoring. The use of fluctuating asymmetry of tree species leaves in bioindication studies is recommended only in conjunction with the results of chemical analysis. Poplar bark seems to be the most convenient bioindicator for assessing environmental pollution over a long period, the chemical composition of the leaves of tree species (linden T. cordata and birch B. pendula) reflects information about the intake of pollutants during one growing season, analysis of the chemical composition of moss and lichen traps allows you to determine the intake of pollutants in a relatively short period of time and identify sources of pollution. To assess the ecological state of the urban environment on the basis of the Harrington desirability function, an integral bioindication parameter BIP has been developed, taking into account the degree of transformation of individual environmental components under the influence of anthropogenic load: a change in the chemical composition of plants relative to clark (background) values; the manifestation of fluctuating asymmetry of tree species leaves compared to the norm. The effectiveness of BIP application for geoecological assessment of the state of the environment in cities is shown.","PeriodicalId":41676,"journal":{"name":"Vestnik of Saint Petersburg University Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73250799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemistry of Holocene–Late Pleistocene sediments in the Berezovka River valley (Near-Yenisey Siberia)","authors":"N. Y. Zharinova, G. Yamskikh, Łukasz Zbucki, D. E. Makarchuk","doi":"10.21638/spbu07.2023.206","DOIUrl":"https://doi.org/10.21638/spbu07.2023.206","url":null,"abstract":"Despite their great importance, Holocene–Late Pleistocene sediments are poorly studied in the valleys of rivers in the Krasnoyarsk forest-steppe territory. We present the first detailed study of the geochemical composition of the first floodplain terrace sediments in the valley of the Berezovka River, and the continuous accumulation that occurred at the Late Pleistocene-Holocene (from 20833 ± 519 cal yr BP). This is of great fundamental importance and is the basis for further studies on the influence of anthropogenic activities on the natural environment in the Krasnoyarsk agglomeration. The sediments were covered by modern alluvial dark-humus hydrometamorphosed soil. Macromorphological studies and investigation of the humus content have revealed a well-developed process of humus formation and humus accumulation, a gley process. The measured contents of some elements (U, Pr, Rb, V, Bi, Cd, As, Th, Ga, Co, and Sm) exceeded the respective Clarke values for the Earth’s crust. The distribution of most elements and their accumulation in the Middle-Late Holocene (from to 5477–4985 to 1241–803 cal yr BP) in the middle of the sediment profile is explained by the high content of mud and clay minerals. Based on the coefficients of radial migration, we established that most of the studied elements were introduced into the sediments during high water levels and floods. The values of palaeomarkers indicate a change in climatic conditions in the Late Pleistocene and Holocene from dry and cold to more humid and warm, and from arid and cold (in the Early Holocene) to modern climatic conditions, respectively.","PeriodicalId":41676,"journal":{"name":"Vestnik of Saint Petersburg University Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74272329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial and temporal assessment of surface water quality in municipal water bodies of the city of Tyumen","authors":"Y. Petrov","doi":"10.21638/spbu07.2023.106","DOIUrl":"https://doi.org/10.21638/spbu07.2023.106","url":null,"abstract":"The purpose of the study is a spatio-temporal assessment of the quality of surface water for water bodies of municipal importance in Tyumen in the current conditions of urban economy. A grouping of 16 municipal ponds and waterlogged quarries was carried out according to the results of the water quality assessment. The period of water sampling for the study: 2018–2021; spring, summer and autumn dates of each year of study, a total of 12 observation dates. Analyzed indicators: biochemical oxygen consumption (BOD5), chemical oxygen consumption (COD), dry residue, General, Zn, Na, chloride-anions. The results of the study: all municipal reservoirs of Tyumen during the study had repeatedly exceeding the established values of the maximum permissible concentrations for water bodies of fishery significance in three or more indicators. Most municipal facilities are included in the group of highly hazardous reservoirs, characterized by fixing the excess of the MPC value in water for several indicators, including the heavy metal Zn. The group of reservoirs of the background concentration of pollutants includes the watered quarry “Willow”, in which exceedances were recorded for BOD5, COD and Fe, which is typical for Tyumen natural conditions. The waterlogged quarry “Chistye” and the pond “On Dambovskaya” are classified as extremely dangerous reservoirs, they are characterized by the presence of exceeding the values of the MPC in the water for all indicators, with the exception of the dry residue. The waterlogged quarry “Maisky” is classified as a group of extremely dangerous degraded reservoirs, since during the analyzed time period it recorded exceedances of the MPC values in the water for all indicators. On the example of bottom sediments of the pond “Yuzhny”, a partial section of the ratio of pollutant content at 2 sampling points within the boundaries of the municipal reservoir is shown. Based on the results of the study, recommendations are given for the city authorities to conduct a differentiated approach to the organization of water use for water bodies from different groups.","PeriodicalId":41676,"journal":{"name":"Vestnik of Saint Petersburg University Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79583330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Urban regimes and socially significant projects of the urban environment transformation in the Russian Federation","authors":"K. Axenov, Kirill A. Galustov","doi":"10.21638/spbu07.2023.101","DOIUrl":"https://doi.org/10.21638/spbu07.2023.101","url":null,"abstract":"The authors of the article aim to identify the principles and patterns of mutual influence of socially significant projects of transformation of the urban environment and urban regimes in the Russian Federation. Clarence Stone's concept of urban regimes is used as a theoretical framework. Based on the author's system of criteria of social significance, 6 projects of urban environment transformation in 4 cities were selected and analyzed: Okhta Center and Tuchkov Buyan in St. Petersburg, Zaryadye Park and the development of fields of the Timiryazev Academy in Moscow, St. Catherine's Church in Yekaterinburg and concreting of the embankments of the river Vologda in Vologda. If the initial phase of all projects took place in the realities of local urban growth regimes, with the predominance of the interests of the established coalitions of business and government, then the subsequent increase in the role of public activism in all projects and the change of goal-setting under its influence led to a change in the local urban regime during their implementation. It is shown that in five studied cases, during the implementation of projects, there was a transition of local urban regimes from “growth” to “progressive”, and in one – from “growth” to a greater extent towards the “status quo” regime. The general principles and patterns of mutual influence of socially significant transformation projects and urban regimes in the Russian Federation are identified and described: competitive public interaction of all types of actors; change or relocation of the project as a spatial way of conflict resolution; the prevailing shift from the realization of the interests of government and business in favor of society; involvement of paternalistic tools as a way to achieve consensus. Such conditions of mutual influence of socially significant projects and urban regimes can develop in a certain period in any major Russian city, then we can expect in it similar to the described results of space transformation. The results of the study clearly demonstrate the beginning of the process of local transformation of the dominant urban regimes in the Russian Federation.","PeriodicalId":41676,"journal":{"name":"Vestnik of Saint Petersburg University Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76547351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regional dimension of socio-cultural modernization of the population: results of expeditionary research in Uzbekistan and southern Kyrgyzstan","authors":"L. Imangulov, Ya. K. Kuksin","doi":"10.21638/spbu07.2023.104","DOIUrl":"https://doi.org/10.21638/spbu07.2023.104","url":null,"abstract":"The article attempts a regional measurement of the socio-cultural modernization of the population based on field observations and the results of in-depth interviews with the local population in Uzbekistan and southern Kyrgyzstan. Expedition research route: Osh — Kokand — Tashkent — Samarkand — Bukhara. For the regional measurement of population modernization, the following groups of indicators were used: “characteristics of the cultural landscape” (for example, the layout of settlements, home and space arrangement, land use, etc.) and “social portrait of local residents” (for example, clothing, food preferences, behavior in space, time budget and attitudes of the population). It was revealed that the most conservative and traditional population lives in the regions of the Fergana Valley, the less modernized — in Osh, Samarkand and Bukhara, the most modernized population — in Tashkent, Chirchik and Angren. It is found that regional differences in the socio-cultural modernization of the population correlate with the main provisions of the center-peripheral model. Deviations from it are determined by the nature of settlement, the ethnic structure of the population, the involvement of the population in labor migration, the measure of centrality and the absolute height of the settlement above sea level, etc. Thus, the intra-urban division of most cities into mahalla contributes to the preservation of the traditional community in the east and acts as a barrier to the socio-cultural modernization of the population. In the final part of the article, the national features of the socio-cultural modernization of the population of the studied countries are outlined (for example, the high stability of the national socio-cultural tradition, the multidirectional nature of modernization processes), and brief recommendations are given on the use of the research results in managing the socio-economic development of different regions.","PeriodicalId":41676,"journal":{"name":"Vestnik of Saint Petersburg University Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83923961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Upper Devonian environments and ostracods biofacies of the Kuznetsk Basin","authors":"B. Popov, S. V. Saraev, A.S. Ganashilin","doi":"10.21638/spbu07.2023.110","DOIUrl":"https://doi.org/10.21638/spbu07.2023.110","url":null,"abstract":"The volcanogenic-carbonate-terrigenous Upper Devonian complex of deposits of the margin of the Kuznetsk Basin has been studied. The results of the studying of sedimentological processes, the composition of sedimentary rocks, the specifics of the petrographic composition of impurity pyroclastic material, make it possible to reconstruct the sedimentation conditions here in the Late Devonian. The predominance as an impurity and sometimes as the main component in sedimentary rocks of andesitic fine pyroclastics with a lower value of acidic and basic volcanic components has been established. From the Late Givetian — Early Frasnian to Famenmian, an uneven increase in the content of acid pyroclastics occurs in the rocks. The studied sections relate to the vast shelf and continental slope of the Siberian paleocontinent. The western direction of the paleoslope is determined. The studied sediments belong to the slope and basin type, they are represented by fine-grained tephroid and volcanomictic sandstones, fine-detrite limestones, olistostromes and slope landslide breccias, turbidites and rarer turbidite canalites, peculiar “conglomerate limestones” (paleoseismites). The composition of pyroclastics and volcanoclastics in sedimentary rocks indicates the manifestation of andesitic volcanism synchronously with sedimentation and the existence of paleogeodynamic conditions corresponding to the active continental margin possibly of the Andean type in the Late Devonian in the studied area. Based on the data obtained as a result of quantitative calculation of the generic composition of the ostracod associations from the studied sections of the Middle (upper part) and Upper Devonian within three structural-facies subdistricts of the margin of the Kuznetsk Basin, the analysis of ostracods was carried out. The features of the biofacial distribution of ostracods allowed us to identify 10 associations and establish their matching with certain parts of the basin from the Late Givetian to the Late Famennian time. The influence of volcanism on the composition of ostracod associations is traced, the appearance of pyroclastics in rocks reduces the taxonomic diversity of ostracod associations and quantitative composition. Variations in the taxonomic composition of ostracod associations correlate well with trends in T-R cycles, the genus is Bairdia is dominant during transgression.","PeriodicalId":41676,"journal":{"name":"Vestnik of Saint Petersburg University Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87384103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}