Boreal (Eemian) Transgression in the Northeastern White Sea Region: Multiproxy Evidence from Bychye-2 Section

• Published in: Quaternary
• Main Authors: Taldenkova, Ekaterina, Ovsepyan, Yaroslav, Rudenko, Olga, Stepanova, Anna, Bauch, Henning A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI 2024
• Subjects: Sea ice; White Sea
• Online Access: https://oceanrep.geomar.de/id/eprint/59751/; https://oceanrep.geomar.de/id/eprint/59751/1/quaternary-07-00003.pdf; https://oceanrep.geomar.de/id/eprint/59751/2/quaternary-07-00003-s001.zip; https://doi.org/10.3390/quat7010003

Reconstructing interglacial marine environments helps us understand the climate change mechanisms of the past. To contribute to this body of knowledge, we studied a high-resolution 455 cm-thick sediment sequence of the Boreal (Eemian) marine beds directly overlying Moscovian (Saalian) moraine in the Bychye-2 section on the Pyoza River. We analyzed lithological and microfossil (foraminifers, ostracods, pollen, aquatic palynomorphs) variations at the studied site. Stratigraphical zonation is based on the local and well-established regional pollen zones, correlated with the western European pollen zones. The studied marine beds accumulated from the end of the Moscovian glacial (>131 ka) until ca. 119.5 ka. We distinguished three successive phases: a seasonally sea-ice-covered, relatively deep, freshened basin in the initial rapid flooding stage (>131–130.5 ka); a deep basin in the maximum flooding phase with less extensive sea ice cover (130.5–130.25 ka); and a shallow basin with reduced sea ice cover (130.25–119.5 ka). According to a pollen zone comparison with other sites, the regional glacioisostatic rebound started ca. 130 ka. The diverse warm-water assemblages of benthic foraminifers and ostracods containing typical Baltic Sea species occurred during the regression, mainly 128–124 ka, thus giving evidence for a relatively long-lasting connection between the White and Baltic Seas.