TY - JOUR

T1 - Возраст и хроностратиграфическое положение озерно-болотных отложений в бассейне р. Черной на севере Большеземельской тундры по результатам их 230Th/U-и 14С-датирования

AU - Maksimov, Fedor E.

AU - Andreicheva, Ludmila N.

AU - Kuznetsov, Vladislav Yu

AU - Grigoriev, Vasily A.

AU - Petrov, Alexei Yu

AU - Levchenko, Snezhana B.

AU - Marchenko-Vagapova, Tatyana I.

AU - Baranova, Nadezhda G.

N1 - Publisher Copyright: © 2021 St. Petersburg University Press. All rights reserved.

PY - 2021/5/6

Y1 - 2021/5/6

N2 - The main goal of this study was to elucidate the chronostratigraphic position of the sediments of lacustrine-bog stratum from the Ch-14 section located in the sub-latitudinal sector of the Chernaya River in the north of the Bolshezemelskaya tundra. This study presents data on their numerical age and time of their formation, obtained by the parallel 230Th/U and 14С dating of organic-rich layers. According to the results of spore-pollen analysis obtained earlier, the lacustrine-bog sediments were attributed to the Byzovaya (Middle Valdai) interstadial, together with the lake and alluvial deposits from the Ch-3 and Ch-4 sections in the same sector of the Chernaya River. The 230Th/U and 14C age data are in good agreement with each other, especially for the lower boundary of the lacustrine-bog sediments of the Ch-14 section. The time range of the lacustrine-bog stratum accumulation is estimated to be approximately 13.7-13.3 to ~12.0 thousand years ago. Thus, its formation (10.5-6.5 m layer) did not occur in the Middle Valdai, but in the Late Valdai time from the beginning of Allerød to the beginning of the Younger Dryas cooling. It has been suggested that a certain delay of late glacial climatic events took place in the Bolshezemelskaya tundra compared with their age-related estimation by the Greenland isotope-oxygen stages. For the first time, the isochronous approximation approach was applied to obtain the 230Th/U age of such young terrestrial organic-rich deposits. Earlier this approach was usually used in dating similar sediments not younger than MIS-3. The geochronological results presented in this paper allow us to recommend the 230Th/U method for determining the age of late glacial organic-rich deposits and climate events correlated with them.

AB - The main goal of this study was to elucidate the chronostratigraphic position of the sediments of lacustrine-bog stratum from the Ch-14 section located in the sub-latitudinal sector of the Chernaya River in the north of the Bolshezemelskaya tundra. This study presents data on their numerical age and time of their formation, obtained by the parallel 230Th/U and 14С dating of organic-rich layers. According to the results of spore-pollen analysis obtained earlier, the lacustrine-bog sediments were attributed to the Byzovaya (Middle Valdai) interstadial, together with the lake and alluvial deposits from the Ch-3 and Ch-4 sections in the same sector of the Chernaya River. The 230Th/U and 14C age data are in good agreement with each other, especially for the lower boundary of the lacustrine-bog sediments of the Ch-14 section. The time range of the lacustrine-bog stratum accumulation is estimated to be approximately 13.7-13.3 to ~12.0 thousand years ago. Thus, its formation (10.5-6.5 m layer) did not occur in the Middle Valdai, but in the Late Valdai time from the beginning of Allerød to the beginning of the Younger Dryas cooling. It has been suggested that a certain delay of late glacial climatic events took place in the Bolshezemelskaya tundra compared with their age-related estimation by the Greenland isotope-oxygen stages. For the first time, the isochronous approximation approach was applied to obtain the 230Th/U age of such young terrestrial organic-rich deposits. Earlier this approach was usually used in dating similar sediments not younger than MIS-3. The geochronological results presented in this paper allow us to recommend the 230Th/U method for determining the age of late glacial organic-rich deposits and climate events correlated with them.

KW - Bolshezemelskaya tundra

KW - Buried organic-rich deposits

KW - Late Glacial climate events

KW - Uranium-thorium (Th/U) and radiocarbon (С) dating methods

KW - Bolshezemelskaya tundra

KW - GEOCHRONOLOGY

KW - Late Glacial climate events

KW - SECTION

KW - buried organic-rich deposits

KW - uranium-thorium (Th-230/U) and radiocarbon (C-14) dating methods

UR - http://www.scopus.com/inward/record.url?scp=85106507362&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/8f3e5c23-e6a5-3ae6-a348-e3d80be81fec/

U2 - 10.21638/SPBU07.2021.206

DO - 10.21638/SPBU07.2021.206

M3 - статья

AN - SCOPUS:85106507362

VL - 66

SP - 1

EP - 30

JO - Вестник Санкт-Петербургского университета. Науки о Земле

JF - Вестник Санкт-Петербургского университета. Науки о Земле

SN - 1812-9323

IS - 2

ER -