A05_P10

Chronology of Lake Lubińskie (W Poland) sediments

Piotrowska N ¹,  Bonk A², Żarczyński M², Tylmann W², Enters D^3,4, Makohonienko M⁵, Rzodkiewicz M⁵

¹Institute of Physics-CSE, Silesian University of Technology, Gliwice, Poland, ²Division of Geomorphology and Quaternary Geology, Faculty of Oceanography and Geography, University of Gdańsk, Gdańsk, Poland, ³Lower Saxony Institute for Historical Coastal Research, Wilhelmshaven, Germany, ⁴Institute of Geography, University of Bremen, Bremen, Germany, ⁵Institute of Geoecology and Geoinformation, Adam Mickiewicz University, Poznań, Poland

Landscape and ecosystem transformations depend on combined climatic forcing and human activity. The assessment of ecological baseline conditions and eutrophication trends requires, among others, the analysis of different proxies providing qualitative and quantitative results. Diatom and pollen preserved in lake sediments hold excellent potential for the reconstruction of lake trophic conditions. Combined with geochemical data and a robust chronology they allow a detailed reconstruction of long-term conditions for individual sites and precisely defining the timing of changes. Among them, lakes containing annually laminated (varved) sediments offer records with one of the highest time-resolution possible. We used a multiproxy combined dating techniques including varve microfacies analysis and varve counting, radiometric measurements (¹⁴C, ¹³⁷Cs, and ²¹⁰Pb), and Bayesian age-depth modelling. Due to some parts of poor varve preservation and possible hiatuses, the final chronology is based on combination of radiometric dating results analyzed statistically in OxCal and supported by varve counting. The composite 506-cm-long sediment core from Lake Lubińskie covers the time period from 2007 CE (year of coring) to 946 +113/-144 BCE.