TY - JOUR

T1 - Geochemistry of Early Diagenesis in Sediments of Russian Arctic Glacial Lakes (Norilo–Pyasinskaya Water System)

AU - Maltsev, Anton E.

AU - Krivonogov, Sergey K.

AU - Vosel, Yuliya S.

AU - Bychinsky, Valery A.

AU - Miroshnichenko, Leonid V.

AU - Shavekin, Alexei S.

AU - Leonova, Galina A.

AU - Solotchin, Paul A.

N1 - Funding Information: Funding: The field work was supported by the AO Norilsk‐Taimyr Energy Company. The analytical work was funded from RFBR grants 19‐05‐00403_a and 21‐55‐53037 GFEN_a. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2022/4

Y1 - 2022/4

N2 - The Russian Arctic region is lacking in studies on geochemical changes reflecting early sediment diagenesis in lake environments. The paper presents new data on the compositions of bottom sediments and sediment pore water from two lakes of the Norilo–Pyasinskaya water system in Arctic Siberia. Lakes Pyasino and Melkoye occupy basins left by glaciers that originated from the Putorana Plateau during the Last Glacial Maximum (LGM). Clayey sediments were continuously deposited in the lakes, and the depositional environment has changed only slightly for the last ca. 20 ka. Two sediment cores with lengths of 4.0 and 3.2 m were collected in Lakes Pyasino and Melkoye, respectively, with a Livingstone‐type piston corer providing undisturbed, stratigraphically consistent sedimentary sequences. Their analyses revealed a change from oxidized to reduced conditions at a depth of ~10 cm. The concentrations of Ca2+, Mg2+, Na+, and K+, as well as the HCO3−/Ca2+ ratio in pore water, showed a depthward increase indicating the progressive degradation of organic matter. Another trend was the gradual decrease in SO42− alongside increasing HCO3−/SO42− caused by bacterial sulfate reduction, although this was rather weak, judging by the low concentrations of S (II) bound to Fe‐sulfides, H2S, etc. Additionally, the microbial digestion of organic matter caused a release of its mobile components, which led to the enrichment of the water in NO3−, PO43−, and DOC. Most of the analyzed elements (Al, B, Ba, Co, Cu, Mo, Ni, Si, Sr, V, and Zn) reach higher concentrations in the pore water than in the lake water above the water‐sediment boundary, which is evidence of diagenetic processes. As a result of redox change, immobile Fe (III) and Mn (IV) natural oxides were reduced to mobile Fe (II) and Mn (II) species and migrated from the solid phase to the pore water, and eventually precipitated as authigenic Fe sulfides and Mn carbonates. The results are useful for better understanding the early diagenesis processes in different geographical settings over the huge Eurasian continent.

AB - The Russian Arctic region is lacking in studies on geochemical changes reflecting early sediment diagenesis in lake environments. The paper presents new data on the compositions of bottom sediments and sediment pore water from two lakes of the Norilo–Pyasinskaya water system in Arctic Siberia. Lakes Pyasino and Melkoye occupy basins left by glaciers that originated from the Putorana Plateau during the Last Glacial Maximum (LGM). Clayey sediments were continuously deposited in the lakes, and the depositional environment has changed only slightly for the last ca. 20 ka. Two sediment cores with lengths of 4.0 and 3.2 m were collected in Lakes Pyasino and Melkoye, respectively, with a Livingstone‐type piston corer providing undisturbed, stratigraphically consistent sedimentary sequences. Their analyses revealed a change from oxidized to reduced conditions at a depth of ~10 cm. The concentrations of Ca2+, Mg2+, Na+, and K+, as well as the HCO3−/Ca2+ ratio in pore water, showed a depthward increase indicating the progressive degradation of organic matter. Another trend was the gradual decrease in SO42− alongside increasing HCO3−/SO42− caused by bacterial sulfate reduction, although this was rather weak, judging by the low concentrations of S (II) bound to Fe‐sulfides, H2S, etc. Additionally, the microbial digestion of organic matter caused a release of its mobile components, which led to the enrichment of the water in NO3−, PO43−, and DOC. Most of the analyzed elements (Al, B, Ba, Co, Cu, Mo, Ni, Si, Sr, V, and Zn) reach higher concentrations in the pore water than in the lake water above the water‐sediment boundary, which is evidence of diagenetic processes. As a result of redox change, immobile Fe (III) and Mn (IV) natural oxides were reduced to mobile Fe (II) and Mn (II) species and migrated from the solid phase to the pore water, and eventually precipitated as authigenic Fe sulfides and Mn carbonates. The results are useful for better understanding the early diagenesis processes in different geographical settings over the huge Eurasian continent.

KW - authigenic minerals

KW - diagenesis

KW - geochemistry

KW - lake sediments

KW - major and trace elements

KW - pore water

KW - Russian Arctic

UR - http://www.scopus.com/inward/record.url?scp=85128183941&partnerID=8YFLogxK

U2 - 10.3390/min12040468

DO - 10.3390/min12040468

M3 - Article

AN - SCOPUS:85128183941

VL - 12

JO - Minerals

JF - Minerals

SN - 2075-163X

IS - 4

M1 - 468

ER -