The spatio-temporal distribution of elements in the bottom sediments of Lake Onego and small lakes located on the catchment area of Onego Ice Lake

• Published in: Vestnik of Saint Petersburg University. Earth Sciences
• Main Authors: Strakhovenko, Vera D., Belkina, Natalia A., Efremenko, Natalia A., Potakhin, Maxim S., Subetto, Dmitry A., Malov, Viktor I., Ovdina, Ekaterina A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: St Petersburg State University 2023
• Subjects: Lake Onego; small lakes; Onego Ice Lake; bottom sediments; mineralogy; geochemistry; sedimentation rate; 210Pb; 137Cs; karelia*; karelian
• Online Access: https://doi.org/10.21638/spbu07.2023.404; http://hdl.handle.net/11701/45659

The work presents the results of a comprehensive mineralogical and geochemical study of Late Pleistocene-Holocene bottom sediments of Lake Onego and small lakes located in the territory belonging to Onego Ice Lake. Methods of ICP-MS, atomic absorption spectrometry, X-ray fluorescence analysis, X-ray phase method (XRD), scanning electron microscopy (SEM), and gamma-spectrometric method were used. The geochemical composition of the terrigenous fraction reflects the mineral composition and is permanent for the all bottom sediments cores of Lake Onego and small lakes during time interval about 12.000 years. For the first time, detailed mineralogical studies of sediments have shown that the composition of mineral associations of the terrigenous fraction is similar in the bottom sediment cores of Lake Onego and small lakes. The association of authigenic minerals in bottom sediments is distinguished by the presence of pyrite framboids in small lakes, and crystalline aggregates of Fe-phosphate, ferruginous illites and chlorites in Lake Onego. Sedimentation rates established by the study of correlations the indicator technogenic radioisotope 137Cs and atmospheric 210Pb. In the bottom sediments of small lakes, sedimentation rates vary from lake to lake, as well as in various areas of Lake Onego in the range from 0.05 cm/year to 0.30 cm/year. The research was supported by the Russian Foundation for Basic Research project no. 19-05-50014 “Study of mineral and geochemical composition of sedimentary material and bottom sediments” and was done on state assignment of the Sobolev Institute of Geology and Mineralogy, of the Siberian Branch of the Russian Academy of Sciences no. 122041400193-7 “Estimation the rates of modern sedimentation by the activity of 137Cs and 210Pb”; state assignment of the Herzen State Pedagogical University of Russia, project VRFY-2023-0010 of the Ministry of Education of the Russian Federation; state assignment of the Northern Water Problems Institute of the Karelian Scientific Center of the Russian ...