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Stratigraphy and Geological Correlation
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ISSN (Print) 0869-5938 - ISSN (Online) 1555-6263
Published by Springer-Verlag

[2469 journals]

Representatives of the Miaohe Biota from the Ediacaran (Vendian)
Pre-Shuram Strata of the Patom Highland, Siberia
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  Abstract: The carbonaceous macrofossils which belong to multicellular algae and which were previously known from the younger (>570 Ma) Miaohe biota are found for the first time in the Lower Vendian (Middle Ediacaran, ~580 Ma) rocks of the Ura Formation of the Patom Basin in Siberia. The Ura macrofossils include phytoleims of unbranched ribbon-like thalli preserved on the surfaces of silty mudstones. Among the fossils, the species Liulingjitaenia alloplecta and Jiuqunaoella simplicis are identified. The features of their structure are considered. The in vivo forms of the organisms and their colonies are interpreted. It is shown that these organic macrofossils were a noticeable detritus-forming component of the Ura Basin. The Ura macrophytes coexisted with the Early Ediacaran microbiota and composed a common ecosystem of the paleobasin, which formed shortly before the Shuram event and was significantly transformed after it.
  PubDate: 2022-02-01
Gastropoda from Lower Cretaceous Deposits of Nimbolook Area, Eastern Iran
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  Abstract: Early Cretaceous gastropods occur on the eastern margin of Lut Block in Eastern Iran. The gastropod assemblage reported herein is from the Nimbolook section located in the west of Qayen. The section mostly includes marls and limestones. It was dated as Aptian owing to the findings of foraminifers, nannofossils and ammonites. The exposure provides a relatively well-preserved gastropod fauna from marls and limestones. New species Oligoptyxis khorasanica sp. nov. from the family Nerineidae is the first find of the genus in the Cretaceous of Iran. Finally, the new genus Purpuripullina, gen. nov. was proposed. It was previously included in the family Ampullinidae.
  PubDate: 2022-02-01
Supracrustal Rocks of Uneven-Aged Archean Greenstone Structures of the
Karelian Craton of the Fennoscandian Shield at the Border with the
Svecofennian Block: Composition, Age, and Origin
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  Abstract: New data have been obtained on composition and age of the Archean supracrustal complexes of the Yalonvara–Pertinjarvi, Korpijarvi, and Pastajarvi structures in the marginal part of the Karelian Craton of the Fennoscandian Shield in the conjunction area with the Svecofennian Orogen. The structures were typically attributed to the single Yalonvara–Ilomantsi greenstone belt. On the basis of geochronological, petrographic, and geochemical data, only the Korpijarvi and Pastajarvi structures with an age of 2.73 Ga can be considered as a continuation of the Hattu greenstone belt in the Ilomantsi province (Finland). More ancient rocks of the Yalonvara–Pertinjarvi structure, estimated at 2.95–2.93 Ga, can be compared with the Mesoarchean basalt–andesite–dacite–rhyolite stratotectonic association of the Hautavaara greenstone structure. The younger Neoarchean rocks metamorphosed under the high-temperature amphibolite facies conditions are composed of gneisses and amphibolites. The ancient greenstone rocks metamorphosed under the greenschist and epidote–amphibolite facies conditions are of tuff nature. The rocks of both complexes are similar in terms of geochemistry to volcanic rocks of the suprasubduction settings, but they are different in proportions of the material of the mantle wedge and subduction plate.
  PubDate: 2022-02-01
Provenances of the Upper Precambrian Clay Rocks in the Southern Urals:
Results of Geochemical and Sm–Nd Isotope Geochemical Investigations
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  Abstract: Changes in (La/Yb)N, Eu/Eu*, tNd(DM), and εNd(t) values in Upper Precambrian clay rocks on the western slope of the Southern Urals are considered. The (La/Yb)N, Eu/Eu*, and εNd(t) average values in Riphean and Vendian clay rocks are 5.7–15.1, 0.58–0.74, and –14.6 to –5.1, respectively. This reflects the change in the composition of the source areas and fits well into the general outline of subglobal events established by traditional geological methods in the conjunction area of the eastern regions of the East European Platform and the modern Southern Urals. The Early and Middle Riphean sedimentary sequences (1750–1250 Ma) were formed mainly owing to the erosion products of the mature continental crust of the East European Platform (tNd(DM) = 2.8–2.4 Ga). However, the pre-Upper Riphean hiatus led, probably, to a significant change in the composition of source areas about 1 Ga. The increase in magnitude of εNd(t) to –5.9 and decrease in tNd(DM) to 2.0 Ga in clay rocks of the Biryan Subformation of the Upper Riphean Zilmerdak Formation compared to underlying deposits suggest the appearance of the juvenile crust in the erosion area. This indicates the accumulation of fine-grained sediments at the beginning of the Late Riphean under the influence of active rifting processes, which is not recorded by traditional geological methods. The significant increase in (La/Yb)N (to 13.1 on average), decrease in εNd(t) to –14.6, and increase in tNd(DM) up to 2.5 Ga in clay rocks of the Vendian Bakeevo Formation compared to the Riphean rocks are interpreted as the result of the accumulation of the Bakeevo deposits due to the supply of the products of glacial exaration of the basement mature rocks during the Marino glacial period. The significant increase in εNd(t) to –6.8 and rejuvenation of tNd(DM) to 1.8 Ga in Vendian mudstones of the Basa and Zigan formations compared to the rocks of the lower part of the Asha Group reflect the appearance of a new mantle or volcanogenic material in the catchment areas during the Middle Vendian.
  PubDate: 2022-02-01
Biostratigraphy of the Lower–Middle Callovian of the Saratov Area (Volga
Region) Inferred from Microfauna
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  Abstract: The results of micropaleontological analysis of the boundary interval of the lower–middle Callovian in the TETs-5 section (Saratov) are presented. The taxonomic composition and distribution of foraminifera and ostracods in the section are studied. The ranges of the biostratigraphic units inferred from microfauna and their correlation with the ammonite scale are refined. Two foraminiferal zones of the East European Platform are established: Haplophragmoides infracalloviensis–Guttulina tatarensis and Lenticulina cultratiformis–Lenticulina pseudocrassa. The volume of the Lenticulina cultratiformis–Lenticulina pseudocrassa Zone ranges from the upper part of the lower Callovian (the upper part of the Koenigi Zone and the Calloviense Zone) to the middle Callovian. Two biostratigraphic units by ostracods are established: (1) the Acantocythere milanovskyi–Procytheridea cinicinnusa Zone corresponding to the Subpatruus Zone of the lower Callovian, to the lower part of the Ch. saratovensis biohorizon, and (2) Beds with Praeschuleridea wartae–Pleurocythere kurskensis corresponding to the terminal part of the Subpatruus Zone (the upper part of the Ch. saratovensis biohorizon), the Koenigi and Calloviense zones of the lower Callovian, and the lower part of the Jason Zone of the middle Callovian. The images of typical taxa are provided.
  PubDate: 2021-12-01
New Data on the Middle Devonian Biostratigraphy of the Salair,
Southwestern Siberia
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  Abstract: The biostratigraphic data on the ammonoid, brachiopod, conodont, and ostracod assemblages of the Mamontovo and Zarechnoe horizons of the Salair were revised and analyzed. The stratigraphic succession of the Middle Devonian deposits of the Salair is clarified, and the new Zarechnoe Horizon, including the Akarachkino, Safonovo, and Kerlegesh beds, is proposed. The upper Eifelian ammonoid assemblage of the Agoniatites Zone, established in the upper part of the Akarachkino Beds, is the biostratigraphic level for global correlations. The upper Eifelian and lower Givetian brachiopod assemblage (Indospirifer padaukpinensis (=I. pseudowilliamsi)) characterizes the Safonovo Beds. Two middle Givetian brachiopod zones were recognized in the Kerlegesh Beds: Rhynchospirifer hians (=Ilmenia subhians) and Subrensselandia' salairica (=“Chascothyris” salairica). The conodont assemblage of the Akarachkino Beds characterizes the upper Eifelian. The middle Givetian conodont assemblage, including Icriodus difficilis Ziegler et Klapper, Polygnathus linguiformis klapperi Clausen, Leuteritz et Ziegler, Po. parawebbi Chatterton beta morphotype, Po. ovatinodosus Ziegler et Klapper, and Po. pseudofoliatus Wittekind, was found in the upper part of the Safonovo Beds. No conodont assemblage was found in the Kerlegesh Beds.
  PubDate: 2021-12-01
Upper Cretaceous Deposits in the Volsk Structural Zone of the East
European Platform: Turonian–Lower Campanian of the Kommunar Section:
Paper 1. Geological Setting, Benthic Foraminifers, and Magnetostratigraphy
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  Abstract: The results of microfaunistic (benthic foraminifers) and magnetostratigraphic (paleomagnetic and petromagnetic) studies obtained in the lower part of the Upper Cretaceous deposits of the Kommunar section are presented. On the basis of the study of benthic foraminifers, the section consists of middle and upper Turonian, Coniacian, lower and upper Santonian, and basal horizon of the lower Campanian. In addition, all Coniacian zones and subzones of the East European Platform have been established. These data confirm the importance of the Kommunar section as a stratotype of the Volsk Formation (Coniacian of the Middle and Lower Volga region). In the Kommunar section, the Turonian and Coniacian are characterized by a normal polarity, and the Santonian and lower Campanian are characterized by a reversed polarity.
  PubDate: 2021-12-01
Traces of Catastrophic Volcanic Eruptions in the Moscovian Stage (Middle
Pennsylvanian, Carboniferous) in the Central East European Platform
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  Abstract: Traces of extremely powerful explosive volcanic eruptions are documented in the southern Moscow Syneclise; the eruptions occurred in the Moscovian Age about 309 million years ago in Variscan orogenic regions adjacent to the East European Platform. Interbeds of altered volcanic ash, 5–15 cm thick, can be traced over the distance of tens of kilometers in the sediments referring to the Podolskian and Myachkovian substages of the Moscovian Stage. These interbeds are composed of calcareous clays of montmorillonite composition and contain grains of zircon, apatite, ilmenite, biotite, K-feldspar, and quartz. Two types of K-feldspar (authigenic and volcanic) referring to the sanidine group are identified. U–Pb SIMS dating of pyroclastic zircons from the tuffaceous bed at the boundary between the Podolskian and Myachkovian showed an age of 308.9 ± 2.3 Ma, and 40Ar/39Ar dating of volcanic sanidine at a higher level showed the age of 305.5 ± 2.7 Ma, which agrees well with the available age estimates for the stage boundaries in the Pennsylvanian. Analysis of the Late Paleozoic volcanism in the nearby regions showed that the most likely area where catastrophic explosions took place, with subsequent transportation of volcanic ash to the southern Moscow Syneclise, is the zone of the North Caucasus.
  PubDate: 2021-12-01
Kimmeridgian–Volgian Palynological Assemblages of the Eganovo Section
(Moscow Region) and Their Possible Application for Biostratigraphy,
Correlation, and Facies Analysis
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  Abstract: — The results of study of marine and terrestrial palynomorphs in the Lower Kimmeridgian and Middle-Upper Volgian in the Eganovo section (Moscow region) are presented. The section is well characterized by ammonites providing a biostratigraphic control of the palynostratons. Beds with spores and pollen are identified for the Volgian interval and beds with dinocysts are distinguished for the entire section. Certain taxa allow comparison of synchronous successions of dinocysts of the European part of Russia, Siberia, and Western Europe. By spores and pollen, a correlation is possible with coeval rocks of the northern Urals, Western Europe, and Australia. The facies analysis of two palynological groups allowed reconstruction of features of marine algoflora and their interrelation with transgressive–regressive dynamics of the paleobasin, climatic fluctuations, and change in coastal landscapes. The comparative analysis of the lateral distribution of coeval dinocyst assemblages from the Eganovo section and other Boreal regions showed a significant similarity of algoflora of European Russia, the North Sea region, and Bulgaria in the Kimmeridgian, but the lateral differentiation of algoflora increased to the end of the Volgian. At the same time, the diversity of the dinocyst assemblages in the European part of Russia remained high. It is suggested that this was caused by favorable temperature and trophic conditions, which are interpreted using the results of facies analysis of terrestrial palynomorphs. The features of their taxonomic composition are typical of the Euro-Sinian paleogeographic area with a subtropical climate. Gradual cooling in the second half of the Volgian was accompanied by recovery of small climatic maxima, which are also traced in Western Europe, Siberia and the northern Urals. No period of aridization typical of the terminal Jurassic of Western Europe was revealed. Wet conditions led to the formation of specific palynoflora with abundant gleicheniaceous ferns in the European part of Russia and adjacent territories of the Urals and margins of Western Siberia.
  PubDate: 2021-12-01
Lower Callovian of Kanev Dislocations, Cherkasy Oblast, Ukraine: Ammonites
and Stratigraphy
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  Abstract: The Jurassic rocks of the area of Kanev glacial dislocations (Central Ukraine) with the Bathonian coastal marine (lagoon) and the Lower Callovian normal marine sediments have been studied, the upper part of which was unknown to the predecessors. The zonal and infrazonal scale of the Lower Callovian of Kanev dislocations are elaborated by ammonites and include four zones, five subzones, and 14 biohorizons: Elatmae Zone (the upper part: P. elatmae and P. vasily biohorizons); Subpatruus Zone (the uppermost part: Ch. saratovensis (G. toricelli) Biohorizon); Koenigi Zone with the Gowerianum (G. metorchum and G. gowerianum biohorizons), Curtilobum (G. indigestum, G. curtilobum, and G. crucifer biohorizons), and Galilaeii (G. galilaeii, s.l. Biohorizon) subzones; Calloviense Zone with the Calloviense (S. khvalynicum and S. kiselevi biohorizons) and Enodatum (C. enodatum planicerclus, C. e. enodatum, and C. e. aeeta biohorizons) subzones. This scale is compared with those of European Russia and Western Europe. It is found that the base of the Proplanulites koenigi Zone, which was distinguished by Karitzky (1887) in the sections of the north Kanev dislocations, biostratigraphically corresponds to the base of the eponymous Zone, which was distinguished by Buckman (1913) in North Yorkshire and used in a standard scale of Europe. The ammonites of the families Cardioceratidae, Kosmoceratidae, Perisphinctidae, and Macrocephalitidae common in the Early Callovian in the East European marine basin are revised and their evolution and biogeography are analyzed. It is shown that, at the beginning of the Callovian, this vast young epicontinental basin was a “pot” of neoendemic evolution of various groups of ammonites, which migrated from Arctic, West European, and West Tethyan biochorems. The western (Dnieper–Donets) marine area of the basin, which also includes the area of Kanev dislocations, was a main way for migration of marine organisms between the West and East European paleobiogeographic provinces. New species are described: Paracadoceras vasily Gulyaev, sp. nov., Sigaloceras fundator Gulyaev, sp. nov., and S. kiselevi Gulyaev, sp. nov.
  PubDate: 2021-12-01
  DOI: 10.1134/S0869593821070029
Erratum to: On the Composition and Age of Taphofloras of the
Krivorechenskaya Formation (Upper Cretaceous) of the Anadyr River Left
Bank, Northeast Asia
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  Abstract: An Erratum to this paper has been published: https://doi.org/10.1134/S0869593821330017
  PubDate: 2021-11-01
  DOI: 10.1134/S0869593821330017
Erratum to: Middle Permian (Late Murgabian) Fusulinids of the Jamal
Formation, Tabas Area, Iran
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  Abstract: An Erratum to this paper has been published: https://doi.org/10.1134/S0869593821330029
  PubDate: 2021-11-01
  DOI: 10.1134/S0869593821330029
Age and Provenance of the Riphean Rocks of the Chetlas Group of the Middle
Timan: U–Th–Pb (LA-ICP-MS) Dating of Detrital Zircons
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  Abstract: — The U–Th–Pb (LA-ICP-MS) dating of detrital zircons from the Upper Precambrian metaterrigenous rocks of the Chetlas Group in the Middle Timan Range (Svetlinskaya, Novobobrovsk, and Vizingskaya formations) enabled the reconstruction of the provenance of detrital material and establishing the maximum depositional age (MDA) of these sediments (middle–terminal Middle Riphean). It was found that the studied terrigenous rocks contain Archean–Early Proterozoic and Early and Middle Riphean zircons. The possible sources of the pre-Riphean and Early Riphean zircons could have been the rocks of the basement of the East European Craton (Baltica). The presence of a significant proportion of Middle Riphean grains among detrital zircon populations in all three formations indicates a significant role of the Sveconorwegian–Grenvillian Orogen as a source of detrital material for the sedimentary deposits of the Middle Timan. The obtained data along with the published data on the ages of detrital zircons in the Upper Precambrian rocks of the Middle Timan and some other regions at the northern and eastern (in the present-day coordinates) peripheries of Baltica suggest a much wider extent of the Sveconorwegian–Grenvillian Orogen than is deemed to be at present.
  PubDate: 2021-11-01
  DOI: 10.1134/S0869593821060022
Acritarch Elektoriskos' williereae (G. & M. Deflandre, 1965)
Vanguestaine, 1979 emend. nov. from the Upper Ordovician of the Siberian
Platform: New Morphological and Stratigraphic Data
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  Abstract: The morphology of acritarch species Elektoriskos' williereae (G. & M. Deflandre, 1965) Vanguestaine, 1979, previously considered as a Silurian index of the Llandovery, has been clarified, the diagnosis emended, and the stratigraphic distribution expanded. According to new data, the first appearance of E.' williereae was confined to the upper part of the Baksan Horizon near the boundary of the Sandbian and Katian stages of the Upper Ordovician. Co-occurrence of E.' williereae with representatives of the genera Gordonirundum, Nirundella, Peteinosphaeridium, and Sacculidium is a distinct, well-recognizable palynological characteristic of the Katian deposits of the Siberian Platform which can serve for identification, dating, and correlation of the acritarch-bearing strata. Morphological variations in E.' williereae are a stable diagnostic feature of the species that distinguishes it from other taxa. It is possible that the species was sensitive to paleoenvironments and, probably, highly adaptive, which allowed it, remaining almost unchanged, to overcome the global Late Ordovician cooling, which became fatal for many other groups of organisms.
  PubDate: 2021-11-01
  DOI: 10.1134/S0869593821060071
Distribution of Microfossils in the Vendian Deposits of the Orsha
Depression of the East European Platform, Belarus
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  Abstract: — The complete sections of the Lower and Upper Vendian of the East European Platform were opened in the boreholes of Belarus. This allows us to consider this region as a stratotype area. In order to update the paleontological characteristics of the Vendian, organic-walled microfossils from the Bogushevsk-1, Bogushevsk-2 (Liozno), and Lepel-1 reference boreholes drilled in the north of the Orsha Depression were studied. The transitive assemblage I with Leiosphaeridia minutissima–Leiosphaeridia tenuissima was recognized in the Lower Vendian Liozno Formation of the Volyn Series and the Upper Vendian Kotlin Formation. The Redkino microfossil assemblages were identified at three stratigraphic levels in the Nizy, Selyava, and Chernitsa formations: assemblage II with Morania zinkovi, assemblage III with Morania zinkovi–Tynnia precambrica, and assemblage IV with Morania zinkovi–Tynnia precambrica–Striatella coriacea, respectively. The Kotlin assemblage V with Vendotaenia antiqua–Primoflagella speciosa was distinguished in the upper part of the Kotlin Formation (Bogushevsk-1 borehole). On the basis of the taxonomic composition, assemblages III and IV are correlated with the first Redkino biota of the Starorusskaya Formation; assemblage V is correlated with the third Kotlin biota of the Vasileostrovskaya Formation of the northwestern part of Russia. Our data show a high biostratigraphic potential of organic-walled microfossils, which should be used to substantiate regional stratigraphic units of the Upper Vendian in the updated stratigraphic scheme of the East European Platform.
  PubDate: 2021-11-01
  DOI: 10.1134/S0869593821060034
New Data on Stratigraphy of the Jurassic (Pliensbachian–Aalenian)
Sediments of the Cape Tsvetkov Region, Eastern Taimyr
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  Abstract: On the basis of the results of studying the faunal collections of bivalves and foraminifera collected in the period of 1976–2014 in the Cape Tsvetkov region in Eastern Taimyr, the knowledge of the Pliensbachian–Aalenian part of the section of the Tsvetkov geological region is expanded. The bedding in the section is described, and a comprehensive paleontological characteristic is given. For the first time for this section, the following taxa are included in the composition of characteristic bivalve assemblages: Praemeleagrinella deleta, Siungiudella cf. parvula, Mytiloceramus (Lenoceramus) vilujensis, Mytiloceramus (Pseudomytiloides) oviformis, Oxytoma ex gr. kirinae, Arctotis (Praearctotis) similis, and Arctotis (Arctotis) tabagensis. On the basis of the use of auxiliary biostratigraphic subdivisions—beds with bivalves and F-zones based on foraminifera—the section is correlated with the standard boreal ammonite scale. The age of the local stratigraphic units of the Eastern Taimyr structural-facies zone is refined. The Kiterbyutskaya Formation is considered within the Tiltoniceras antiquum–Dactylioceras commune zones, the Korotkinskaya Formation is considered within the Dactylioceras commune–Pseudolioceras falcodiscus zones, and the Aprelevskaya Formation is considered within the Pseudolioceras maclintocki Zone. For the first time, images of the leading species of bivalves are presented.
  PubDate: 2021-11-01
  DOI: 10.1134/S0869593822010026
Problems of the Stratigraphy of Quaternary Deposits in the Anui Valley and
the Age of the Karama Site in the Altai Mountains
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  Abstract: The controversial problems of stratigraphy, geomorphology, and chronology of the Early Paleolithic Karama site in the Altai Mountains are considered. This work is a response to the article by Ya.V. Kuzmin and A.Yu. Kazansky “Comments on the ‘Debatable Aspects of Initial Human Colonization of Siberia and Age of the Karama Site in the Altai Mountains’” by V.S. Zykin, V.S. Zykina, and L.G. Smolyaninova, published in the journal Stratigraphy and Geological Correlation (2020, vol. 28, no. 5, pp. 157–160).
  PubDate: 2021-11-01
  DOI: 10.1134/S0869593821060083
Geological Features of the Bajocian–Bathonian in the Reference Section
of the Izhma River Basin (European North of Russia) and the Succession of
Ammonites of the Subfamily Arctocephalitinae Meledina
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  Abstract: The article discusses the main disagreements between two published models (the authors’ model and the previously published model by V.V. Mitta et al.) of the structure and stratigraphic subdivision of the Bajocian–Bathonian reference section in the north of European Russia (near the Dreshchanka River mouth, Izhma River basin). Calculation of dip and strike makes it possible to verify mutually exclusive correlation schemes for key outcrops exposed near the Dreshchanka River mouth. It is shown that the correlation model for outcrops proposed by V.V. Mitta is inconsistent. According to this model, the actual thickness of the Bajocian part of the succession is understated. Some disagreements in ammonite stratigraphy are also discussed. Ammonites occurring in the lower Bathonian Ishmae Zone of the Timan–Pechora region belong to a single species, Arcticoceras ishmae, characterized by a wide range of intraspecific variability. The available data for the studied region does not allow any further division of the Ishmae Zone into either subzones or biohorizons. The classical succession, including four consecutive biohorizons in East Greenland, is based on the change of chronosubspecies/chronovariations of the species A. ishmae, which differ in the ratio of intraspecific morphs of the proposed variability. Currently, it is impossible to define these horizons in the Timan–Pechora region sections because representative sets of well-referenced samples are absent.
  PubDate: 2021-11-01
  DOI: 10.1134/S0869593821060046
Biochronological Scale of the Upper Toarcian–Lower Aalenian of Eastern
Siberia by Bivalve Mollusks of the Genus Arctotis Bodylevsky, 1960
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  Abstract: On the basis of the study of shell morphogenesis, the classification of the Toarcian–Aalenian representatives of the genus Arctotis Bodylevsky, 1960 was refined. A sequence of species was established in the reference sections of Anabar Bay and Cape Tsvetkov (Eastern Taimyr), traced in a series of Toarcian and Aalenian sections in Eastern Siberia, and correlated with the Boreal ammonite scale. The biochronological scale was developed for the upper Toarcian–lower Aalenian on the basis of bivalve mollusks of the genus Arctotis (family Oxytomidae Ichikawa, 1958). This scale has its own chronological periodization and consists of four so-called oxyto-zones. The scale was used to carry out an interregional correlation of the upper Toarcian–lower Aalenian sections of Eastern Siberia (Anabar Bay, Cape Tsvetkov, Markha, Tyung, Kelimyar, Molodo, and Motorchuna rivers, boreholes drilled in the Vilyui syneclise) and northeastern Russia (Levy Kedon River basin). The chronostratigraphic volumes of oxyto-zones are determined by comparison with ammonite zones of the Boreal Standard: the Praearctotis milovae oxyto-zone corresponds to the Zugodactylites braunianus and Pseudolioceras compactile ammonite zones, the Praearctotis marchaensis oxyto-zone corresponds to the Pseudolioceras wuerttenbergeri Zone, the Praearctotis similis oxyto-zone corresponds to the Pseudolioceras falcodiscus Zone, and the Arctotis tabagensis oxyto-zone corresponds to the Pseudolioceras maclintocki Zone.
  PubDate: 2021-11-01
  DOI: 10.1134/S086959382106006X
Environmental Evolution of Cape Maly Chukochy (Kolyma Lowland) in the
Middle–Late Neopleistocene: Micropaleontological Evidence
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  Abstract: — This paper presents results of the micropaleontological study of permafrost sediments exposed by CHUK 1/17 borehole at Cape Maly Chukochy, on the coast of the East Siberian Sea (Kolyma Lowland). Micropaleontological analysis, together with the lithological structure and the main physicochemical characteristics, enabled reconstructing sedimentation conditions during transition from nearshore marine to continental environments in the Middle and Late Neopleistocene. The existence of a tundra-steppe biome was confirmed for this region, which shows its significant advancement to the north. This study, using the example of this territory, shows the importance of studying microfossils for understanding the history of the region in the Quaternary and lays the basis for further microbiological and metagenomic studies of the sediments exposed by the borehole.
  PubDate: 2021-11-01
  DOI: 10.1134/S0869593822010075