Chrono- and Lithostratigraphy of Lake Sediments of Anzer Island (Solovetsky Islands) in the Context of the Post-Glacial History of the White Sea
Paleolimnological studies have been performed at 9 lakes at the Anzer Island (Solovetsky Islands, the White Sea). Changes in lithostratigraphy and organic matter content in the sediment sequences reflect changes in sedimentation environments related to the isolation from larger basins. Based on the...
Published in: | Hydrology and Earth System Sciences |
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Main Authors: | , , , , , , , , , , , , , , , , , |
Other Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | Russian |
Published: |
Izvestiya Rossiiskoi Akademii Nauk. Seriya Geograficheskaya
2023
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Subjects: | |
Online Access: | https://izvestia.igras.ru/jour/article/view/1667 https://doi.org/10.31857/S2587556622060085 |
Summary: | Paleolimnological studies have been performed at 9 lakes at the Anzer Island (Solovetsky Islands, the White Sea). Changes in lithostratigraphy and organic matter content in the sediment sequences reflect changes in sedimentation environments related to the isolation from larger basins. Based on the Holocene dynamics of organic matter content, three periods of the organic accumulation were distinguished in the lakes located below 22 m a.s.l. corresponding to the main stages of the lakes’ evolution. At the earliest stage, lake basin was incorporated into a larger basin (glaciolacustrine or marine), and the lowest organic matter content is characteristic for its sediments. At the isolation stage, laminated sediments form, and organic matter content rapidly increases. At the isolated-lake stage, organic-rich sediments are accumulated. The calculated rate of the lacustrine (gyttja) sedimentation is ca. 0.2–0.3 mm year–1. Organic sedimentation in the lakes located at 22– 35 m a.s.l. at Solovetsky Islands have been taking place since 10500–11000 cal. years BP. The age of the lakes’ isolation was found to correlate to their elevation above sea level. Based on the time of the isolation and the onset of the lacustrine sedimentation, the shoreline displacement curve for the Anzer Island was constructed for the second half of the Holocene. Ca. 4800–4400 cal. years BP, the relative sea level was below 11 m a.s.l., while ca. 1900–1700 cal. years BP the shoreline regressed below 2 m a.s.l. The calculated rate of the shoreline retreat is ca. 2–3 mm year-1. The Holocene marine limit at the Solovetsky Islands was corrected, and established at 17–21 m a.s.l. Проведены палеолимнологические работы на 9 внутренних озерах о. Анзер (Соловецкие острова, Белое море). Выявленные изменения в литостратиграфии и содержании органического вещества в донных отложениях отражают изменения условий осадконакопления, связанные с изоляцией от крупных бассейнов. Изучение голоценовой динамики накопления озерных органогенных отложений ... |
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