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A. V. Maslov - One of the best experts on this subject based on the ideXlab platform.
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U–Pb LA–ICP–MS Age of Detrital Zircons from the Lower Riphean and Upper Vendian Deposits of the Luga–Ladoga Monocline
Doklady Earth Sciences, 2018Co-Authors: A. S. Ivleva, Victor N. Podkovyrov, V. B. Khubanov, V. B. Ershova, A. K. Khudoley, S. N. Sychev, N. I. Vdovina, A. V. MaslovAbstract:The results of LA–ICP–MS U–Pb analyses of detrital zircons from the Precambrian deposits of Luga–Ladoga monocline are discussed. The age spectra of the zircons separated from the Riphean to Upper Vendian sandstones from the Shotkusa-1 well demonstrate dominance of the Paleo- and Mesoproterozoic grains while the Archaean zircons are subordinate. The Riphean debris sources were local swells of the Northern Ladoga basement. The sequence interval presumably corresponding to the Vasilieostrov Formation (Upper Vendian) has yielded not only Paleo- and Mesoproterozoic zircon ages, but Neoproterozoic as well, implying a Timanide provenance: these zircons (527 ± 9 and 516 ± 13 Ma) allow deposition of a significant part of the Shotkusa-1 sequence at the very beginning of the Cambrian.
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u pb la icp ms age of detrital zircons from the lower riphean and upper Vendian deposits of the luga ladoga monocline
Doklady Earth Sciences, 2018Co-Authors: A. S. Ivleva, Victor N. Podkovyrov, V. B. Khubanov, V. B. Ershova, A. K. Khudoley, S. N. Sychev, N. I. Vdovina, A. V. MaslovAbstract:The results of LA–ICP–MS U–Pb analyses of detrital zircons from the Precambrian deposits of Luga–Ladoga monocline are discussed. The age spectra of the zircons separated from the Riphean to Upper Vendian sandstones from the Shotkusa-1 well demonstrate dominance of the Paleo- and Mesoproterozoic grains while the Archaean zircons are subordinate. The Riphean debris sources were local swells of the Northern Ladoga basement. The sequence interval presumably corresponding to the Vasilieostrov Formation (Upper Vendian) has yielded not only Paleo- and Mesoproterozoic zircon ages, but Neoproterozoic as well, implying a Timanide provenance: these zircons (527 ± 9 and 516 ± 13 Ma) allow deposition of a significant part of the Shotkusa-1 sequence at the very beginning of the Cambrian.
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lithostratigraphy and geochemistry of upper Vendian lower cambrian deposits in the northeastern baltic monocline
Stratigraphy and Geological Correlation, 2017Co-Authors: Victor N. Podkovyrov, A. V. Maslov, A. B. Kuznetsov, V. B. ErshovaAbstract:The results of investigations of Upper Vendian‒Lower Cambrian deposits in the northeastern part of the Baltic monocline specify views on the evolution of depositional environments of sedimentary successions constituting the basal part of the sedimentary cover in inner areas of the northwestern East European Platform. It is shown that the Late Vendian and initial Cambrian were characterized by the consecutive influx of relatively mature terrigenous detrital material that originated from both the weathering crust of the Baltic Shield and new sources. Its deposition was interrupted by notable, although likely asynchronous, hiatuses, which are registered at the base of the Upper Vendian Vasileostrovskaya and Voronkovo formations and Lower Cambrian Lomonosov Formation. In the Late Vendian, sedimentary material was transported from the Baltic Shield, while beginning from the initial Early Cambrian the additional contribution to the formation of the sedimentary cover of the Baltic monocline was provided by coarse-grained sedimentary material from the Timan margin of the Baltica as follows from U‒Pb isotopic ages obtained for detrital zircons. At the same time, lithogeochemical parameters of fine-grained rocks experienced no substantial changes.
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the results of geochronological and isotope geochemical study of zircons from tuff of the sylvitsa group western slope of the middle urals the origin of ash layers in Vendian rocks of the east european platform
Doklady Earth Sciences, 2017Co-Authors: N. B. Kuznetsov, T. V. Romanyuk, E. A. Belousova, M T Krupenin, A. V. MaslovAbstract:New LA-ICP-MS data on the U–Pb isotope age, Hf isotope characteristics, and concentrations of trace elements in zircons from volcanic tuff of the Upper Vendian Sylvitsa Group on the western slope of the Middle Urals are reported.
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Lithostratigraphy and geochemistry of Upper Vendian‒Lower Cambrian deposits in the northeastern Baltic monocline
Stratigraphy and Geological Correlation, 2017Co-Authors: Victor N. Podkovyrov, A. V. Maslov, A. B. Kuznetsov, V. B. ErshovaAbstract:The results of investigations of Upper Vendian‒Lower Cambrian deposits in the northeastern part of the Baltic monocline specify views on the evolution of depositional environments of sedimentary successions constituting the basal part of the sedimentary cover in inner areas of the northwestern East European Platform. It is shown that the Late Vendian and initial Cambrian were characterized by the consecutive influx of relatively mature terrigenous detrital material that originated from both the weathering crust of the Baltic Shield and new sources. Its deposition was interrupted by notable, although likely asynchronous, hiatuses, which are registered at the base of the Upper Vendian Vasileostrovskaya and Voronkovo formations and Lower Cambrian Lomonosov Formation. In the Late Vendian, sedimentary material was transported from the Baltic Shield, while beginning from the initial Early Cambrian the additional contribution to the formation of the sedimentary cover of the Baltic monocline was provided by coarse-grained sedimentary material from the Timan margin of the Baltica as follows from U‒Pb isotopic ages obtained for detrital zircons. At the same time, lithogeochemical parameters of fine-grained rocks experienced no substantial changes.
Victor N. Podkovyrov - One of the best experts on this subject based on the ideXlab platform.
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Late Vendian Kotlinian Crisis on the East European Platform: Lithogeochemical Indicators of Depositional Environment
Lithology and Mineral Resources, 2019Co-Authors: Alekseevich Vladimir Maslov, D V Grazhdankin, Victor N. PodkovyrovAbstract:Sharp changes in the biodiversity of fossil organisms in the Upper Vendian of the East European Platform are considered as the manifestation of global crisis immediately prior to the “Cambrian Explosion.” However, they could be caused by local environmental perturbations. Variations of some lithogeochemical indicators of depositional environment (indicators of paleoclimate, exhalation activity, redox settings, and paleobioproductivity) were analyzed in order to establish the possible influence of sedimentary systems on evolutionary processes in the Late Vendian and at the boundary with the Cambrian. The applied algorithm of lithogeochemical studies revealed no significant perturbations in physical properties of the environment on a scale of sedimentary basins. The obtained data suggest that local factors did not affect the evolution of Ediacaran biota on the East European Platform and confirm the global nature of transitions between the Redkinian, Belomorian, and Kotlinian biotas.
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U–Pb LA–ICP–MS Age of Detrital Zircons from the Lower Riphean and Upper Vendian Deposits of the Luga–Ladoga Monocline
Doklady Earth Sciences, 2018Co-Authors: A. S. Ivleva, Victor N. Podkovyrov, V. B. Khubanov, V. B. Ershova, A. K. Khudoley, S. N. Sychev, N. I. Vdovina, A. V. MaslovAbstract:The results of LA–ICP–MS U–Pb analyses of detrital zircons from the Precambrian deposits of Luga–Ladoga monocline are discussed. The age spectra of the zircons separated from the Riphean to Upper Vendian sandstones from the Shotkusa-1 well demonstrate dominance of the Paleo- and Mesoproterozoic grains while the Archaean zircons are subordinate. The Riphean debris sources were local swells of the Northern Ladoga basement. The sequence interval presumably corresponding to the Vasilieostrov Formation (Upper Vendian) has yielded not only Paleo- and Mesoproterozoic zircon ages, but Neoproterozoic as well, implying a Timanide provenance: these zircons (527 ± 9 and 516 ± 13 Ma) allow deposition of a significant part of the Shotkusa-1 sequence at the very beginning of the Cambrian.
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u pb la icp ms age of detrital zircons from the lower riphean and upper Vendian deposits of the luga ladoga monocline
Doklady Earth Sciences, 2018Co-Authors: A. S. Ivleva, Victor N. Podkovyrov, V. B. Khubanov, V. B. Ershova, A. K. Khudoley, S. N. Sychev, N. I. Vdovina, A. V. MaslovAbstract:The results of LA–ICP–MS U–Pb analyses of detrital zircons from the Precambrian deposits of Luga–Ladoga monocline are discussed. The age spectra of the zircons separated from the Riphean to Upper Vendian sandstones from the Shotkusa-1 well demonstrate dominance of the Paleo- and Mesoproterozoic grains while the Archaean zircons are subordinate. The Riphean debris sources were local swells of the Northern Ladoga basement. The sequence interval presumably corresponding to the Vasilieostrov Formation (Upper Vendian) has yielded not only Paleo- and Mesoproterozoic zircon ages, but Neoproterozoic as well, implying a Timanide provenance: these zircons (527 ± 9 and 516 ± 13 Ma) allow deposition of a significant part of the Shotkusa-1 sequence at the very beginning of the Cambrian.
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lithostratigraphy and geochemistry of upper Vendian lower cambrian deposits in the northeastern baltic monocline
Stratigraphy and Geological Correlation, 2017Co-Authors: Victor N. Podkovyrov, A. V. Maslov, A. B. Kuznetsov, V. B. ErshovaAbstract:The results of investigations of Upper Vendian‒Lower Cambrian deposits in the northeastern part of the Baltic monocline specify views on the evolution of depositional environments of sedimentary successions constituting the basal part of the sedimentary cover in inner areas of the northwestern East European Platform. It is shown that the Late Vendian and initial Cambrian were characterized by the consecutive influx of relatively mature terrigenous detrital material that originated from both the weathering crust of the Baltic Shield and new sources. Its deposition was interrupted by notable, although likely asynchronous, hiatuses, which are registered at the base of the Upper Vendian Vasileostrovskaya and Voronkovo formations and Lower Cambrian Lomonosov Formation. In the Late Vendian, sedimentary material was transported from the Baltic Shield, while beginning from the initial Early Cambrian the additional contribution to the formation of the sedimentary cover of the Baltic monocline was provided by coarse-grained sedimentary material from the Timan margin of the Baltica as follows from U‒Pb isotopic ages obtained for detrital zircons. At the same time, lithogeochemical parameters of fine-grained rocks experienced no substantial changes.
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Lithostratigraphy and geochemistry of Upper Vendian‒Lower Cambrian deposits in the northeastern Baltic monocline
Stratigraphy and Geological Correlation, 2017Co-Authors: Victor N. Podkovyrov, A. V. Maslov, A. B. Kuznetsov, V. B. ErshovaAbstract:The results of investigations of Upper Vendian‒Lower Cambrian deposits in the northeastern part of the Baltic monocline specify views on the evolution of depositional environments of sedimentary successions constituting the basal part of the sedimentary cover in inner areas of the northwestern East European Platform. It is shown that the Late Vendian and initial Cambrian were characterized by the consecutive influx of relatively mature terrigenous detrital material that originated from both the weathering crust of the Baltic Shield and new sources. Its deposition was interrupted by notable, although likely asynchronous, hiatuses, which are registered at the base of the Upper Vendian Vasileostrovskaya and Voronkovo formations and Lower Cambrian Lomonosov Formation. In the Late Vendian, sedimentary material was transported from the Baltic Shield, while beginning from the initial Early Cambrian the additional contribution to the formation of the sedimentary cover of the Baltic monocline was provided by coarse-grained sedimentary material from the Timan margin of the Baltica as follows from U‒Pb isotopic ages obtained for detrital zircons. At the same time, lithogeochemical parameters of fine-grained rocks experienced no substantial changes.
Vadim A Kravchinsky - One of the best experts on this subject based on the ideXlab platform.
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palaeomagnetic study of Vendian and early cambrian rocks of south siberia and central mongolia was the siberian platform assembled at this time
Precambrian Research, 2001Co-Authors: Vadim A KravchinskyAbstract:Abstract A palaeomagnetic study of Vendian and Early Cambrian sediments from the Angara block of the Siberian platform: Shaman (52.08°N, 108.83°E) and Minya (58.0°N, 110.0°E) Formations, and the Tuva-Mongolian block: Tsagan-Olom and Bayan-Gol Formations (46.76°N, 96.37°E) isolated three different components of magnetization through thermal demagnetization. The stable high-temperature characteristic remanence directions show both normal and reverse polarities. The mean palaeopoles computed after these high-temperature components are: 32.0°S/71.1°E (dp/dm=6.9°/13.8°) for the Vendian Shaman Formation (10 sites, 80 samples), 33.7°S/37.2°E (dp/dm=8.6°/14.7°) for the Vendian Minya Formation (12 samples), 22.8°S/28.4°E (dp/dm=10.8°/21.6°) for the Vendian Tsagan-Olom Formation (4 sites, 25 samples) and 21.4°S/167.1°E (dp/dm=9.6°/19.1°) for the Early Cambrian Bayan-Gol Formation (6 sites, 49 samples). From a compilation of Vendian and Early Cambrian palaeopoles from the Anabar, Angara and Aldan blocks of the Siberian platform and Tuva-Mongolia block, we propose a model where these blocks were situated in an equatorial to low south palaeolatitude position, with their present-day southern boundaries facing the north pole. From the analysis of the scatter of these poles, we conclude that the Siberian platform might not have fully amalgamated by this time, and that significant rotations occurred after the Early Cambrian. Our new palaeopoles for the Tuva-Mongolia block, together with previously published ones, show that this block was already adjacent to Siberia by the Vendian and Early Cambrian. We propose that the large counterclockwise rotation of the Tuva-Mongolia block with respect to Angara block could mark the end of the closure of the part of the Palaeo-Asian ocean separating these two blocks, and could account for the occurrence of Vendian-Early Cambrian ophiolites in the region.
A. B. Kuznetsov - One of the best experts on this subject based on the ideXlab platform.
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the lower boundary of the Vendian in the southern urals as evidenced by the rb sr age of glauconites of the bakeevo formation
Stratigraphy and Geological Correlation, 2019Co-Authors: T. S. Zaitseva, A. B. Kuznetsov, I. M. Gorokhov, V M Gorozhanin, T A Ivanovskaya, G V KonstantinovaAbstract:This work presents the results of the mineralogical, crystallochemical, and geochronological study of globular phyllosilicates (GPS) of glauconite–illite series from the Bakeevo Formation. This formation is the basal member of the Vendian Asha Group in the Southern Urals. The monomineral GPS fractions representing the globules varying in size and density are composed of Al-glauconite and illite. The Rb–Sr dating of the GPS of the Bakeevo Formation in combination with the modeling of cation distribution in their structure and comparison of the model data with Mossbauer and IR spectroscopy data was performed for the first time. The Rb–Sr age of the Bakeevo glauconite is 642 ± 9 Ma. The mineralogical and geochemical characteristics in combination with model calculations show that the stratigraphic significance of this age is quite reasonable. The initial 87Sr/86Sr ratio in the glauconitization environment is 0.7080 ± 0.0009 and is consistent within the experimental error with this ratio in the Vendian seawater. Thus, the lower boundary of the Vendian in the Southern Urals has an age of about 640 Ma.
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the base of the Vendian in the south urals rb sr age of glauconite of the bakeevo formation
Стратиграфия, 2019Co-Authors: T. S. Zaitseva, A. B. Kuznetsov, I. M. Gorokhov, V M Gorozhanin, T A Ivanovskaya, т с зайцева, а б кузнецов, в м горожанин, и н горохов, т а ивановскаяAbstract:The mineralogical, crystallochemical and geochronological study of globular phyllosilicates (GPS) of glauconite–illite series from the Bakeevo Formation was performed. This formation is the basal member of the Vendian Asha Group in the South Urals. Monomineral GPS-fractions representing the globules of varied size and density are composed of Al-glauconite and illite. Rb–Sr dating of the GPS of the Bakeevo Formation in combination with modeling of cation distribution in their structure and comparison of the model data with Mossbauer and IR spectroscopy data was carried out for the first time. Rb–Sr age of the Bakeevo glauconite is 642 ± 9 Ma. Mineralogical and geochemical characteristics in combination with theoretical calculations show that the stratigraphic significance of this age is quite reasonable. The initial ratio 87 Sr/ 86 Sr in the glauconitization environment is 0.7080 ± 0.0009 and within the experimental error is consistent with this ratio in Vendian sea water. Hence the lower boundary of the Vendian in the South Urals has an age of about 640 Ma.
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lithostratigraphy and geochemistry of upper Vendian lower cambrian deposits in the northeastern baltic monocline
Stratigraphy and Geological Correlation, 2017Co-Authors: Victor N. Podkovyrov, A. V. Maslov, A. B. Kuznetsov, V. B. ErshovaAbstract:The results of investigations of Upper Vendian‒Lower Cambrian deposits in the northeastern part of the Baltic monocline specify views on the evolution of depositional environments of sedimentary successions constituting the basal part of the sedimentary cover in inner areas of the northwestern East European Platform. It is shown that the Late Vendian and initial Cambrian were characterized by the consecutive influx of relatively mature terrigenous detrital material that originated from both the weathering crust of the Baltic Shield and new sources. Its deposition was interrupted by notable, although likely asynchronous, hiatuses, which are registered at the base of the Upper Vendian Vasileostrovskaya and Voronkovo formations and Lower Cambrian Lomonosov Formation. In the Late Vendian, sedimentary material was transported from the Baltic Shield, while beginning from the initial Early Cambrian the additional contribution to the formation of the sedimentary cover of the Baltic monocline was provided by coarse-grained sedimentary material from the Timan margin of the Baltica as follows from U‒Pb isotopic ages obtained for detrital zircons. At the same time, lithogeochemical parameters of fine-grained rocks experienced no substantial changes.
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Lithostratigraphy and geochemistry of Upper Vendian‒Lower Cambrian deposits in the northeastern Baltic monocline
Stratigraphy and Geological Correlation, 2017Co-Authors: Victor N. Podkovyrov, A. V. Maslov, A. B. Kuznetsov, V. B. ErshovaAbstract:The results of investigations of Upper Vendian‒Lower Cambrian deposits in the northeastern part of the Baltic monocline specify views on the evolution of depositional environments of sedimentary successions constituting the basal part of the sedimentary cover in inner areas of the northwestern East European Platform. It is shown that the Late Vendian and initial Cambrian were characterized by the consecutive influx of relatively mature terrigenous detrital material that originated from both the weathering crust of the Baltic Shield and new sources. Its deposition was interrupted by notable, although likely asynchronous, hiatuses, which are registered at the base of the Upper Vendian Vasileostrovskaya and Voronkovo formations and Lower Cambrian Lomonosov Formation. In the Late Vendian, sedimentary material was transported from the Baltic Shield, while beginning from the initial Early Cambrian the additional contribution to the formation of the sedimentary cover of the Baltic monocline was provided by coarse-grained sedimentary material from the Timan margin of the Baltica as follows from U‒Pb isotopic ages obtained for detrital zircons. At the same time, lithogeochemical parameters of fine-grained rocks experienced no substantial changes.
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Isotope age of boundaries between the general stratigraphic subdivisions of the Upper Proterozoic (Riphean and Vendian) in Russia: The evolution of opinions and the current estimate
Stratigraphy and Geological Correlation, 2015Co-Authors: M. A. Semikhatov, A. B. Kuznetsov, N. M. ChumakovAbstract:The evolution of opinions about the isotope age of the general stratigraphic subdivisions of the Upper Proterozoic in Russia (Lower, Middle, Upper Riphean and Vendian) during the second half of the 20th century and the beginning of the 21st century is considered, and the current data on the age of these subdivisions are analyzed in detail. It is shown that the isotope age of the lower boundaries of the Lower, Middle, and Upper Riphean and Vendian should be estimated at 1750 ± 50, 1400, 1030, and 640 ± 5 Ma, respectively. The role of the historical–geological criteria in the substantiation of these boundaries is studied.
G A Karlova - One of the best experts on this subject based on the ideXlab platform.
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a section of Vendian in the east of west siberian plate based on data from the borehole vostok 3
Russian Geology and Geophysics, 2008Co-Authors: A E Kontorovich, D V Grazhdankin, A I Varlamov, G A Karlova, A G Klets, V A Kontorovich, S V Saraev, A A Terleev, Yu S Belyaev, I V VaraksinaAbstract:Abstract The Borehole Vostok 3 drilled in the east of the West Siberian Plate (Tomsk Region) revealed a Vendian section in the depth range 5002–3870 m, which was subdivided into the Poiga, Kotodzha, and Raiga Formations based on geological, geophysical, and paleontological data. In the Kotodzha and Raiga Formations, typical Upper Vendian fossils of Cloudina hartmanae and Namacalathus sp. were found along with diverse Platysolenites , which are commonly considered to be of zonal significance in Lower Cambrian strata. Hence, the stratigraphic interval with abundant diverse Platysolenites has a wider stratigraphic range than it was believed earlier and seems to cover the Upper Vendian and Lower Cambrian deposits. The Borehole Vostok 3 is the first Siberian occurrence of the fossils Namacalathus , the world's fourth occurrence of the Cloudina-Namacalathus association, and the first site where coexisting Platysolenites and typical Vendian organisms have been found. Therefore, the borehole provides one of the most informative (in paleontological context) Upper Vendian sections.
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biostratigraphy of the Vendian cambrian beds and the lower cambrian boundary in siberia
Geological Magazine, 1993Co-Authors: V. V. Khomentovsky, G A KarlovaAbstract:General agreement exists that the position of the base of the Cambrian (Precambrian–Cambrian boundary) should coincide with a biostratigraphic marker that can be widely traced and is linked to the evolution of the small shelly fauna. On the Siberian platform the presence of distinct facies during the Vendian–Cambrian interval has made biostratigraphic correlation based on palaeontological data highly contentious. A solution to this problem appears to exist with the recognition of an almost uninterrupted profile in the Aldan–Uchur watershed where key sections expose the eastern and transitional facial region. On this basis we present a general biostratigraphic scheme for the Vendian–Cambrian across the southern Siberian platform that connects separate facies. Further correlation with key sections in northern Siberia leads to the recognition of three biostratigraphic zones for the Vendian–Cambrian interval. These are: Anabarites trisulcatus Zone; Purella antiqua Zone; Aldanocyathus sunnaginicus Zone. The abundance of Chinese-type small shelly fossils in the region of the eastern facies suggest correlation of the A. sunnaginicus Zone with the Siphogonuchites–Paragloborilus Zone of China, and the P. antiqua Zone with the Circotheca–Anabarites–Protohertzina Zone. In places, at the base of the Circotheca–Anabarites–Protohertzina Zone in China, analogies to the A. trisulcatus Zone can be identified. It is proposed that in Siberia the base of the A. sunnaginicus Zone (= base of Tommotian Stage) be taken as the base of the Cambrian. This would correspond with Marker B of the Meishucunian in China