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Evolution of Arkona Basin environment in the Holocene in the light of diatom research

Janczak-Kostecka B.

Landform Analysis

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2015

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Vol. 29

19--25

EN

This article presents the results of diatom studies from three cores taken from the Arkona Basin. The main stages of the Baltic Sea evolution in the Holocene – Ancylus Lake, Mastogloia Sea, Littorina Sea, and Post-Littorina Sea – were identified in diatom assemblages. The transition stage between Ancylus Lake and Littorina Sea, called Mastogloia Sea, was not such a long period as in the Mecklenburg Bay but was essential in the evolution of the Baltic Sea. The most pronounced feature of this period was an increase in the number of halophilous species, which reflected the existence of the littoral environment at the onset of this stage. The appearance and development of halophilous species was stimulated by stepwise inflows of saline waters. The composition of diatom assemblages reflected natural eutrophication of the Baltic Sea during the Littorina Sea stage.

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Holocene evolution of the Pomeranian Bay environment, southern Baltic Sea

Kostecki R., Janczak-Kostecka B.

Oceanologia

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2011

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No. 53 (1-TI)

471-487

EN

This article focuses on the diatom assemblages and geochemical composition of sediment cores retrieved from the Pomeranian Bay. We also discuss similarities and differences in the diatom assemblages and the palaeogeographic development of nearby regions. Our main objective was to determine the characteristics and rate of the Littorina transgression in the Pomeranian Bay area. Sediments were divided into units based on differences in the distribution of diatom ecological groups and in geochemical ratios, such as Mg/Ca, Na/K and Fe/Mn. This study identified lacustrine sediments deposited during the time of the Ancylus Lake. This lacustrine-period sedimentation took place in a shallow lake under aerobic conditions. The record of the onset of marine environment dates to 8900-8300 cal BP and corresponds to the Littorina transgression. After about 8300 cal BP, sedimentation took place in a deeper marine environment with higher biogenic production and anaerobic conditions. The abrupt appearance of marine diatom species and increased geochemical salinity indicators reflect the large impact of the Littorina transgression on the Pomeranian Bay environment.

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Zapis procesów prehistorycznej antropopresji w otoczeniu stanowiska archeologicznego w Bruszczewie (centralna Wielkopolska) na podstawie badań osadów rynny glacjalnej Samicy

Hildebrandt-Radke I., Janczak-Kostecka B., Spychalski W.

Landform Analysis

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2011

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Vol. 16

87-91

EN

The sedimentological, geochemical and diatomological research into the core taken from the fossil lake located in the glacial channel of Samica river prove the increasing anthropogenization of the landscape in the microregion surrounding the settlement in Bruszczewo. Anthropogenic indices of the Early Bronze Period in the palynological research include: high decline in the percentage of tree pollens caused by deforestation, indicators of grazing animals and farming as well as noticeable eutrophication of the lake (fungal spores and algae thriving on dung, droppings and excrement). In the sedimentological research, cultural layers correspond with accelerated mineral sedimentation in the basin (mediumand fine-grained sands). Each time it is preceded with organic sedimentation (from humus levels). Above results might signify the initiation of erosion-denudation processes in the catchment, settled and economically exploited by individual cultural groups. Results of the anthropogenic activity are visible also in the geochemical composition of the deposits. Cultural layers are marked with increased percentage of heavy metals, while the Cu : Pb : Zn ratios suggest their anthropogenic character. Additionally, the increase in phosphorus percentage confirms eutrophication of the basin in the settlement periods, that is in the Early and Late Bronze, and Early and Roman Iron Ages.

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Diatomological and geochemical evidence of littorina transgression in Pomeranian Bay, Southern Baltic Sea

Kostecki R., Janczak-Kostecka B.

Studia Quaternaria

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2010

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Vol. 27

27-33

EN

This article presents results of the analysis of 3 sediment cores taken from the bottom of Pomeranian Bay, southern Baltic Sea. These results are part of a larger project that aims to determine the characteristics and rate of the Atlantic marine ingression in the Pomeranian Bay area. The main geochemical elements and diatom assemblages from the cores were identified, revealing lacustrine sediments deposited during the time of Ancylus Lake and marine sediments deposited during the Littorina transgression. Distinct changes in the geochemical composition and diatom assemblages suggest that the Littorina transgression had a very large impact on the environment of Pomeranian Bay.