TY - JOUR

T1 - New Findings and Stratigraphic Distribution of Foraminifera from Permian–Triassic Boundary Deposits in the Southern Verkhoyansk Region

AU - Yadrenkin, A. V.

AU - Biakov, A. S.

AU - Kutygin, R. V.

AU - Kopylova, A. V.

N1 - Funding Information: The work was supported by the Basic Research project no. 0331 -2019-0005, by the Russian Foundation for Basic Research (grants nos. 17-05-00109 and 18-05-001 91), and also partially by the Russian Government Program for competitive growth of the Kazan Federal University among World’s leading scientific and education centers. ACKNOWLEDGMENTS Publisher Copyright: © 2020, Pleiades Publishing, Ltd. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/9/1

Y1 - 2020/9/1

N2 - The first study results on foraminifera from the Permian–Triassic boundary deposits in the southern Verkhoyansk region (the lower part of the Nekuchan Formation, Suol section located in the basin of Setorym River, a tributary of the East Khandyga River) are presented. The studied foraminifera constitute a novel group for this section and have not been used in paleontological-stratigraphic studies. The foraminiferal assemblage is represented exclusively by ammodiscids (Ammodiscus, Glomospira, and Glomospirella genera), among which Ammodiscus septentrionalis Gerke dominates. The distribution of foraminifera in the Suol section is compared to the previously constructed carbon isotope curve, which reflects global environmental changes. Three intervals are identified in the stratigraphic distribution of foraminifera. In the lower interval, foraminifera are relatively numerous and diverse. In the middle interval, foraminifera are not detected; the maximum negative values of δ13Corg isotope is also recorded here. This interval obviously corresponds to the main extinction episode in the Tethyan basins. In the upper interval, a gradual restoration of the abundance and structure of the foraminiferal complex occurs. A comparative analysis of the distribution and dynamics of taxonomic reorganization of the foraminiferal assemblages from the Permian–Triassic deposits within the Suol section and the assemblages from the Tethyan and Boreal sections has been carried out; as a result of this analysis, the common features and regularities are established. Brief descriptions of four foraminiferal species and a plate with their images are given.

AB - The first study results on foraminifera from the Permian–Triassic boundary deposits in the southern Verkhoyansk region (the lower part of the Nekuchan Formation, Suol section located in the basin of Setorym River, a tributary of the East Khandyga River) are presented. The studied foraminifera constitute a novel group for this section and have not been used in paleontological-stratigraphic studies. The foraminiferal assemblage is represented exclusively by ammodiscids (Ammodiscus, Glomospira, and Glomospirella genera), among which Ammodiscus septentrionalis Gerke dominates. The distribution of foraminifera in the Suol section is compared to the previously constructed carbon isotope curve, which reflects global environmental changes. Three intervals are identified in the stratigraphic distribution of foraminifera. In the lower interval, foraminifera are relatively numerous and diverse. In the middle interval, foraminifera are not detected; the maximum negative values of δ13Corg isotope is also recorded here. This interval obviously corresponds to the main extinction episode in the Tethyan basins. In the upper interval, a gradual restoration of the abundance and structure of the foraminiferal complex occurs. A comparative analysis of the distribution and dynamics of taxonomic reorganization of the foraminiferal assemblages from the Permian–Triassic deposits within the Suol section and the assemblages from the Tethyan and Boreal sections has been carried out; as a result of this analysis, the common features and regularities are established. Brief descriptions of four foraminiferal species and a plate with their images are given.

KW - foraminifera

KW - Permian–Triassic boundary

KW - Russian Northeast

KW - southern Verkhoyansk region

KW - Permian-Triassic boundary

KW - DOLOMITES

KW - LAGENIDE FORAMINIFERS

KW - TRANSITION

KW - MARINE-SEDIMENTS

KW - RECOVERY

KW - GLOBAL STRATOTYPE SECTION

KW - MEISHAN SECTION

KW - MASS EXTINCTION

KW - CRISIS

KW - POINT

UR - http://www.scopus.com/inward/record.url?scp=85092329135&partnerID=8YFLogxK

U2 - 10.1134/S1819714020050097

DO - 10.1134/S1819714020050097

M3 - Article

AN - SCOPUS:85092329135

VL - 14

SP - 447

EP - 459

JO - Russian Journal of Pacific Geology

JF - Russian Journal of Pacific Geology

SN - 1819-7140

IS - 5

ER -