Sr Chemostratigraphy of the Lower Permian of the Omolon Massif (Northeast Asia): First Data and Importance for Correlation with the International Stratigraphic Scale

• Published in: Doklady earth sciences 2024-10, Vol.518 (2), p.1640-1646
• Main Authors: Biakov, A. S., Kuznetsov, A. B., Ganelin, V. G., Brynko, I. V., Chebotareva, V. A., Vedernikov, I. L.
• Format: Article
• Language: English
• Subjects: Correlation; Earth and Environmental Science; Earth Sciences; Marine invertebrates; Marine sediments; Massifs; Permian; Scale (ratio); Sediments; Stratigraphy; Strontium 87; Strontium isotopes
• ISSN: 1028-334X; 1531-8354
• DOI: 10.1134/S1028334X24602517

The Sr chemostratigraphic characteristics of marine sediments of the Lower Permian in the Omolon massif of Northeast Asia have been obtained for the first time based on a study of well-preserved brachiopod shells. The 87 Sr/ 86 Sr ratio in brachiopods from the Lower Permian regional horizons (regional stages) is within the following ranges: 0.70786–0.70794, Orochian; 0.70744–0.70786, Ogonerian; 0.70745–0.70748, Koargychanian; and 0.70742–0.70735, Khalalian. The obtained Sr-isotope data demonstrate good agreement with the standard variation curve of the 87 Sr/ 86 Sr ratio in the Permian Ocean. New Sr-isotope data can be used to correlate the units of the Regional Stratigraphic Scale of Northeast Russia directly with the stages of the International Permian Stratigraphic Scale. Based on recent data, the Asselian age of the Orochian regional stage of the lower part of the Permian section in the Omolon massif has been proved, and the regional correlation of the Upper Sakmarian interval established previously from biostratigraphic data has been refined.