Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
Detrital zircon age and biostratigraphic and chemostratigraphic constraints on the Ediacaran-Cambrian transitional interval in the Irkutsk Cis-Sayans Uplift, southwestern Siberian Platform. / Marusin, Vasiliy V.; Kolesnikova, Alena A.; Kochnev, Boris B. и др.
в: Geological Magazine, Том 158, № 7, 07.2021, стр. 1156-1172.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - Detrital zircon age and biostratigraphic and chemostratigraphic constraints on the Ediacaran-Cambrian transitional interval in the Irkutsk Cis-Sayans Uplift, southwestern Siberian Platform
AU - Marusin, Vasiliy V.
AU - Kolesnikova, Alena A.
AU - Kochnev, Boris B.
AU - Kuznetsov, Nikolay B.
AU - Pokrovsky, Boris G.
AU - Romanyuk, Tatiana V.
AU - Karlova, Galina A.
AU - Rud'Ko, Sergey V.
AU - Shatsillo, Andrey V.
AU - Dubenskiy, Alexander S.
AU - Sheshukov, Victor S.
AU - Lyapunov, Sergey M.
N1 - Publisher Copyright: © The Author(s), 2020. Published by Cambridge University Press. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/7
Y1 - 2021/7
N2 - A number of ecological and geochemical transformations occurred during late Ediacaran and early Cambrian time, the effects of which are difficult to overestimate. However, the strong linkage of biostratigraphic and chemostratigraphic methods with lithofacies makes the localization of the Precambrian-Cambrian boundary and its correlation with lithologically contrasting sections highly debatable. We analyse the taxonomy and stratigraphic distribution of small skeletal fossils and trace fossils, the carbonate carbon and oxygen isotope composition, and U-Pb detrital zircon age in the Ediacaran-Cambrian transitional interval of the Irkutsk Cis-Sayans Uplift (southwestern Siberian Platform). This interval (Moty Group) comprises a transgressive succession with red-coloured alluvial to deltaic siliciclastic deposits (Shaman Formation) and overlying shallow-marine carbonates (Irkut Formation). The lower Irkut Formation hosts sporadic and poorly preserved tubular Cambrotubulus fossils, which are known from both the terminal Ediacaran Period (c. 550-541 Ma) and the Terreneuvian Epoch (541-521 Ma), and typical Fortunian trace fossils, including an index ichnotaxon of the Cambrian boundary Treptichnus pedum. The biostratigraphic and carbonate carbon isotope data and U-Pb concordia ages of 531.1 ± 5.2 Ma (mean weighted, 530.6 ± 5.3 Ma) of the five youngest zircon grains from the lower Irkut Formation indicate that at least the shallow-marine carbonates of the upper Moty Group correspond to the Cambrian Stage 2 (c. 529-521 Ma). In the Irkutsk Cis-Sayans Uplift, the Cambrian Period tentatively began before or during the accumulation of the alluvial to deltaic siliciclastic Khuzhir and Shaman formations, and this crucial divide remained unmarked in the palaeontological and isotopic records.
AB - A number of ecological and geochemical transformations occurred during late Ediacaran and early Cambrian time, the effects of which are difficult to overestimate. However, the strong linkage of biostratigraphic and chemostratigraphic methods with lithofacies makes the localization of the Precambrian-Cambrian boundary and its correlation with lithologically contrasting sections highly debatable. We analyse the taxonomy and stratigraphic distribution of small skeletal fossils and trace fossils, the carbonate carbon and oxygen isotope composition, and U-Pb detrital zircon age in the Ediacaran-Cambrian transitional interval of the Irkutsk Cis-Sayans Uplift (southwestern Siberian Platform). This interval (Moty Group) comprises a transgressive succession with red-coloured alluvial to deltaic siliciclastic deposits (Shaman Formation) and overlying shallow-marine carbonates (Irkut Formation). The lower Irkut Formation hosts sporadic and poorly preserved tubular Cambrotubulus fossils, which are known from both the terminal Ediacaran Period (c. 550-541 Ma) and the Terreneuvian Epoch (541-521 Ma), and typical Fortunian trace fossils, including an index ichnotaxon of the Cambrian boundary Treptichnus pedum. The biostratigraphic and carbonate carbon isotope data and U-Pb concordia ages of 531.1 ± 5.2 Ma (mean weighted, 530.6 ± 5.3 Ma) of the five youngest zircon grains from the lower Irkut Formation indicate that at least the shallow-marine carbonates of the upper Moty Group correspond to the Cambrian Stage 2 (c. 529-521 Ma). In the Irkutsk Cis-Sayans Uplift, the Cambrian Period tentatively began before or during the accumulation of the alluvial to deltaic siliciclastic Khuzhir and Shaman formations, and this crucial divide remained unmarked in the palaeontological and isotopic records.
KW - carbon isotopes
KW - detrital zircon
KW - small skeletal fossils
KW - south Siberian Platform
KW - Terreneuvian
KW - trace fossils
UR - http://www.scopus.com/inward/record.url?scp=85097129542&partnerID=8YFLogxK
U2 - 10.1017/S0016756820001132
DO - 10.1017/S0016756820001132
M3 - Article
AN - SCOPUS:85097129542
VL - 158
SP - 1156
EP - 1172
JO - Geological Magazine
JF - Geological Magazine
SN - 0016-7568
IS - 7
ER -
ID: 26202956