Holocene relative level fluctuations of Lake Ladoga in the Taipalovskii Bay area

During the Holocene, the level of Lake Ladoga was constantly changing. As a result, the coastal area of the water basin is characterized by the presence of accumulative landforms creating coastal morphosystems. The study of these paleomarkers allows us to detail the history of the lake’s development. This paper presents the results of a study of the Lake Ladoga Taipalovskii Bay coastal area. To achieve the aim geomorphological profiling of the Taipalovskii Bay coastal morphosystem was executed. It was supported with sediment sampling from sand landforms (beach ridges, barrier ridges, strandplains) and peatbogs for age determination using OSL and radiocarbon dating techniques. In summary, three peat cores and three coastal landforms were sampled during the fieldwork. It resulted in three OSL-datings and nine radiocarbon datings, which are presented in this paper. In addition, the materials of previous studies carried out on the sediment sections of the Vyun River first terrace were correlated with the data obtained. As a result, two phases of the relative lake-level rising were identified — Boreal-Atlantic and Subboreal-Subatlantic. The first one includes two stages corresponding with the Ancylus and Littorina transgressions of the Baltic Sea. During the Boreal (Ancylus) stage the relative lake-level reached its maximum around 8100 years BP. Its shoreline is marked at the altitude of 17–18 m above sea-level (a. s. l.). The Atlantic (Littorina) maximum shoreline, with an age around 6500 BP, is assumed to be at 14–15 m a. s. l. The end of the Atlantic-onset of the Subboreal climatic phase is characterized by lake-level decline. The second phase of lake-level rising started 3600–3700 years BP. This stage is correlated with the Ladoga transgression. The maximum rising of the transgression is defined at the altitude of 14 m with an age around 2600 years BP. After the maximum stage a second one is reported as well, which is determined at 2500 years BP. A shoreline at 11,5 m a. s. l. marks this event. As a result, it was established that the coastal morphosystem of Taipalovskii Bay was formed throughout the Holocene under the influence of the level fluctuation phases listed.