Open AccessImpact of climate change on sedimentation processes in the eastern Gulf of Finland during the Middle to Late Holocene
Author(s) -
Ryabchuk Daria V.,
Sergeev Alexander Yu.,
Prishchepenko Diana V.,
Zhamoida Vladimir A.,
Elkina Daria V.,
Piskarev Alexey L.,
Bashirova Leyla D.,
Ponomarenko Ekaterina P.,
Budanov Leonid M.,
Grigoriev Andrey G.,
Evdokimenko Anton V.
Publication year - 2021
Publication title -
boreas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.95
H-Index - 74
eISSN - 1502-3885
pISSN - 0300-9483
DOI - 10.1111/bor.12500
Subject(s) - marine transgression , geology , holocene , littorina , oceanography , anoxic waters , sedimentary rock , benthic zone , bottom water , deglaciation , bioturbation , sediment , siliciclastic , glacial period , biogenic silica , sedimentology , structural basin , paleontology , sedimentary depositional environment , mollusca
This paper presents the results of high‐resolution sedimentological analyses of sediment cores from the eastern Gulf of Finland (Baltic Sea). Sampling sites in the periphery of sedimentary basins were selected on the basis of acoustic profiling analyses. The research allowed tracing of the transition from the freshwater Ancylus Lake to the Littorina Sea. A specific transitional layer of ‘blue clays’, indicating the first stage of brackish water inflow into the Gulf of Finland, was dated to 9.1 ka BP. The date of first appearance of Littorina silty clay sedimentation was as follows: from 8.0 ka BP near Gogland Island, from 7.0 ka BP near Moshchny Island and from 5.9 ka BP near the Berezovye Islands. Holocene cycles of hypoxia, associated with periods of warming, were identified and cycles of ‘warming – transgression – anoxic conditions’ and ‘cooling – regression – oxygen‐rich conditions’ were revealed. During the first stage of Littorina transgression (8.0–7.0 ka BP), the near‐bottom environment in the deepest sedimentary basin of the eastern Gulf of Finland was characterized by oxygen deficiency. In contrast, 7.0–6.0 ka BP was dominated by oxygen‐rich conditions and active processes of bioturbation. Anoxic conditions occurred again from 6.0–4.8 ka BP (Holocene Climatic Optimum), resulting in the accumulation of undisturbed silty clays with subhorizontal lamination. The interval from 4.8–2.0 ka was then characterized by oxygen‐rich near‐bottom conditions favourable for benthic organisms. The grain‐size distributions throughout the sediment cores from the easternmost sedimentary basins suggest a relative lowering of the sea level from 3.5–1.8 ka and a rise after 1.8 ka BP.