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Palaeomagnetic data from the late Cenozoic Tagay section (Olkhon Island, Baikal region, Eastern Siberia)статья
- Авторы: Kazansky Alexey Yu, Shchetnikov Alexander A., Matasova Galina G., Filinov Ivan A., Erbajeva Margarita A., Daxner-Höck Gudrun, Mörs Thomas
- Журнал: Palaeobiodiversity and Palaeoenvironments
- Том: 102
- Номер: 4
- Год издания: 2022
- Издательство: Springer Verlag
- Местоположение издательства: Germany
- Первая страница: 943
- Последняя страница: 967
- DOI: 10.1007/s12549-022-00559-7
- Аннотация: One of the most important fossil fauna localities in the Baikal region is the Tagay section. It is located on the shore of Tagay bay atthe northwestern coast of Olkhon Island in the Baikal Lake and consists of two different exposures, Tagay-1 and Tagay-2. TheTagay-1 section exposes predominantly lake sediments of Miocene age and contains a faunal complex. The Tagay-2 section iscomposed of slope wash and subaerial sediments of Early Pleistocene (Calabrian?) age with remains of small mammals. A total of95 samples for palaeomagnetic studies were taken in both sections. Magnetic susceptibility (MS), its frequency dependence (Fd) andanisotropy were measured from all samples. The stable component of the natural remanent magnetization (NRM) was obtainedusing stepwise alternating field (AF) demagnetization. The magnetic polarity pattern was constrained for the Tagay-1 section. Itincludes an extended zone of reversed polarity, complicated by three normal subzones of minor rank. Palaeontological data allowcorrelation of the Tagay-1 pattern with the magnetic chrons C5Dn to C5Cn.1n (late Burdigalian – early Langhian). Palaeomagneticdirections in the upper part of the Tagay-2 section are randomly distributed due to intensive slope-wash processes resulted inmechanical perturbation of the sediments. The lower part of Tagay-2 section demonstrates only reversed polarity, although thescatter of directions is quite large due to landsliding. This reversed interval may be correlated with the Matuyama chron betweenCobb Mountain and Jaramillo subchrons. Synchronous increase of MS and Fd values in palaeosols suggests a pedogenic (or“Chinese”) mechanism influencing magnetic properties of the Tagay-2 section under warm palaeoclimatic conditions.
- Добавил в систему: Казанский Алексей Юрьевич