Late Holocene Vistula River floods recorded in grain size distributions and diatom assemblages of marine sediments of the Gulf of Gdańsk (Baltic Sea)

Szcześniak, Marta; Kokociński, Mikołaj; Jagodziński, Robert; Pleskot, Krzysztof; Zajączkowski, Marek; Szczuciński, Witold

Late Holocene Vistula River floods recorded in grain size distributions and diatom assemblages of marine sediments of the Gulf of Gdańsk (Baltic Sea)

dc.contributor.author	Szcześniak, Marta
dc.contributor.author	Kokociński, Mikołaj
dc.contributor.author	Jagodziński, Robert
dc.contributor.author	Pleskot, Krzysztof
dc.contributor.author	Zajączkowski, Marek
dc.contributor.author	Szczuciński, Witold
dc.date.accessioned	2023-03-20T07:00:02Z
dc.date.available	2023-03-20T07:00:02Z
dc.date.issued	2023-05-01
dc.description.abstract	During the large flood of the Vistula River in 2010, the riverine brackish water surface plume extended up to 70 km into the Gulf of Gdańsk (Baltic Sea), leaving a thin layer of medium-grained sand deposits. It inspired a search for palaeoflood records in marine sediments. Thus, we aimed to identify the most useful flood indicators and apply them to reveal palaeoflood records in sediment cores from the Gulf of Gdańsk. The study is based on analyses of surface samples, collected during and one year after the 2010 flood, and two long sediment cores, which were subjected to high-resolution grain size, diatom, and geochemical analyses, while chronology was based on the combined AMS 14C, 210Pb and 137Cs dating. It was found that, in a water depth of less than 30 m, modern large flood deposits were not preserved after a year. Sediment cores retrieved from greater water depths (over 60 m) were composed of sandy mud, and most of the 1 cm thick sediment samples were characterized by unimodal grain size distribution. However, some of the samples were bimodal, with the additional mode in fine-grained fractions, which is interpreted to be the result of direct deposition from riverine flood surface water plume. The diatom assemblages revealed a moderate downcore variability, except for the intervals characterized by bimodal grain size distributions. They contained elevated amounts of benthic oligohalobous (freshwater) and decreased euhalobous and mesohalobous taxa, supporting the likely interpretation of these layers as deposited during river flood events. During the last c. 4 ka, a dozen major flood events were identified. However, their application to flood climate reconstruction is challenging because of relatively frequent and partly unknown changes in major river mouth positions in the past. We suggest that thin deposits of major floods left on the seafloor and subjected to further mixing maybe still recognized using a combination of high-resolution grain size distribution and diatom analyses supplemented by a good understanding of the depositional system history.	pl
dc.description.sponsorship	Narodowe Centrum Nauki grant No. 2013/11/N/ST10/00491, 'Młodzi Naukowcy’ (2014-2015) z UAM Poznań	pl
dc.identifier.citation	Palaeogeography, Palaeoclimatology, Palaeoecology, 2023, Vol. 617, 111499.	pl
dc.identifier.doi	https://doi.org/10.1016/j.palaeo.2023.111499
dc.identifier.issn	0031-0182
dc.identifier.uri	https://hdl.handle.net/10593/27234
dc.language.iso	eng	pl
dc.publisher	Elsevier	pl
dc.rights	info:eu-repo/semantics/openAccess	pl
dc.rights.uri	http://creativecommons.org/licenses/by-sa/3.0/pl/	*
dc.subject	climate change	pl
dc.subject	Baltic Sea	pl
dc.subject	Continental shelf	pl
dc.subject	sedimentation	pl
dc.subject	diatoms	pl
dc.subject	grain size	pl
dc.subject	river floods	pl
dc.subject	Late Holocene	pl
dc.subject	Vistula River	pl
dc.subject	Wisła	pl
dc.subject	Gulf of Gdańsk	pl
dc.subject	Zatoka Gdańska	pl
dc.subject	TOC	pl
dc.subject	dating	pl
dc.title	Late Holocene Vistula River floods recorded in grain size distributions and diatom assemblages of marine sediments of the Gulf of Gdańsk (Baltic Sea)	pl
dc.type	Artykuł	pl