We collected a set of continuous gravity and piston cores
with varved sediments from four lakes that probably cover the entire
Holocene (i.e. the last 11,600 years) or even include the Late-Glacial
(i.e. the last ca. 14,000 years).
Our research strategy will be as follows:
The use of non-destructive and high-resolution XRF
scanning techniques enable us to carry out a precise and fast
preliminary evaluation of the recovered sediment cores.
chronologies will be elaborated by microstratigraphic thin section
Continuous record of varve thickness variations will be
cross-checked by radiocarbon dating. Additionally,
will be carried out to link records to the present.
to use the capabilities of the ITRAX XRF core scanner to produce
continuous high-resolution (200 Ám) XRF scans that show short-term fluctuations in
Analyses of discrete samples will be
performed with 10 cm resolution and with 1 cm resolution within the
time-windows of special interest. A wide range of proxies will be
geochemical indicators (TIC, TOC, BSi) and isotopic data will provide a
measure of primary productivity. We will use the C/N ratio and stable
isotope composition of organic matter to decipher the origin of organic
values will provide insight into temporal variations of lacustrine
primary productivity and human induced eutrophication as this proxy is
directly linked to the dissolved inorganic carbon pool.
Oxygen stable isotope data of endogenic carbonates and
calcareous microfossils will provide
information about hydrological and water temperature changes.
The comparison between the
patterns of the four records distributed along a transect
from W to E in northern Poland will allow separating regional
hydrological variations due to climatic changes from local watershed
The biological studies
related to pollen and diatoms will shed light on questions related to
lake internal productivity and changes of limnological conditions in
general, reconstruction of vegetation cover and land use patterns and
climatic variability as one of the main forcing factors.
All these data and
interpretations will be supported by the study of modern processes in
the lakes and their catchment areas which helps to understand the
mechanisms that work together and form the sedimentary record.
well-dated records with a large variety of proxy parameters will become
available along this ca. 700 km long W-E transect through northern
Poland. Thus spatiotemporal climate and environmental changes can be
investigated in detail.