TY - JOUR

T1 - The First Data on the Mineralogy and Geochemistry of the Suspension of Lake Onego

AU - Strakhovenko, V. D.

AU - Belkina, N. A.

AU - Efremenko, N. A.

AU - Potakhin, M. S.

AU - Subetto, D. A.

AU - Frolova, L. A.

AU - Nigamatzyanova, G. R.

AU - Ludikova, A. V.

AU - Ovdina, E. A.

N1 - Funding Information: The study was carried out with the financial support of the Russian Foundation for Basic Research within the framework of scientific project No. 19-05-50014 (study of the mineral, geochemical, diatomic, and micropaleontologic compositions of suspension, sedimentary material, and bottom sediments), the Russian Science Foundation, project No. 18-17-00176P (study of the mineral, geochemical, diatomic, and micropaleontologic compositions of bottom sediments) and the State Task of the Northern Water Problems Institute of the Karelian Research Center, Russian Academy of Sciences (Petrozavodsk) (R/V Ecologist, ST installation, and water analysis). Publisher Copyright: © 2022, Novosibirsk State University.

PY - 2022/1

Y1 - 2022/1

N2 - This paper presents the first data on the mineralogy, geochemistry, and quantitative distribution of suspension determined with the use of sedimentation traps installed in Lake Onego (the exposure time was one year (2019)). The obtained data on the mineralogic and geochemical composition of the recent suspension of the Onego water column are compared with the data for the surface layer of the lake bottom sediments (0–10 cm). Data on the sedimentation rates for the substance determined with the sedimentation traps have been obtained for the first time for Lake Onego. The estimates of the sedimentation rates differ slightly from the results of calculation of the sedimentation rates by radioisotope dating based on the distribution of210Pb activity in the upper layer of bottom sediments in combination with the data on137Cs. It has been established that the mineral part of the dispersed sedimentary matter that entered the lake reaches the bottom sediment without significant changes. The geochemistry of the sedimentation traps is similar in many respects to the geochemistry of the upper part of the bottom sediments (0–10 cm) in different areas of Lake Onego. The dispersed sedimentary material and the bottom sediment differ in the amount of the biogenic part (in the bottom sediment layer (0–10 cm), the biogenic part loses a significant part of organic matter). The bottom sediments are characterized by a strong predominance of the ferruginous varieties of illite and chlorite, in contrast to the suspension with the prevailing Mg–Fe varieties of these minerals. Degraded mica minerals brought by rivers are regenerated to normal ferruginous illites and chlorites directly in the uppermost part of the bottom sediments. The bottom sediments are characterized by higher manganese and molybdenum contents, and the material from the sedimentation traps, by high mercury contents.

AB - This paper presents the first data on the mineralogy, geochemistry, and quantitative distribution of suspension determined with the use of sedimentation traps installed in Lake Onego (the exposure time was one year (2019)). The obtained data on the mineralogic and geochemical composition of the recent suspension of the Onego water column are compared with the data for the surface layer of the lake bottom sediments (0–10 cm). Data on the sedimentation rates for the substance determined with the sedimentation traps have been obtained for the first time for Lake Onego. The estimates of the sedimentation rates differ slightly from the results of calculation of the sedimentation rates by radioisotope dating based on the distribution of210Pb activity in the upper layer of bottom sediments in combination with the data on137Cs. It has been established that the mineral part of the dispersed sedimentary matter that entered the lake reaches the bottom sediment without significant changes. The geochemistry of the sedimentation traps is similar in many respects to the geochemistry of the upper part of the bottom sediments (0–10 cm) in different areas of Lake Onego. The dispersed sedimentary material and the bottom sediment differ in the amount of the biogenic part (in the bottom sediment layer (0–10 cm), the biogenic part loses a significant part of organic matter). The bottom sediments are characterized by a strong predominance of the ferruginous varieties of illite and chlorite, in contrast to the suspension with the prevailing Mg–Fe varieties of these minerals. Degraded mica minerals brought by rivers are regenerated to normal ferruginous illites and chlorites directly in the uppermost part of the bottom sediments. The bottom sediments are characterized by higher manganese and molybdenum contents, and the material from the sedimentation traps, by high mercury contents.

KW - Bottom sediments

KW - Geochemistry and mineralogy

KW - Lake Onego

KW - Sedimentary material of sedimentation traps

KW - Sedimentation rate

UR - http://www.scopus.com/inward/record.url?scp=85123603352&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/0f78605b-221e-39d8-991e-103d820fd0a7/

U2 - 10.2113/RGG20204280

DO - 10.2113/RGG20204280

M3 - Article

AN - SCOPUS:85123603352

VL - 63

SP - 55

EP - 71

JO - Russian Geology and Geophysics

JF - Russian Geology and Geophysics

SN - 1068-7971

IS - 1

M1 - 5

ER -