Paleoclimate change record in the Dejvice loess-paleosol sequence (Prague, Czech Republic): preliminary results
Abstrakt
Introduction: Loess-paleosol sequences often record information useful for the reconstruction of paleoenvi-ronmental processes such as periods of increased dust accumulation, erosion or landscape stability (soil formation) triggered by climate changes. This study is focused on a loess-paleosol sequence exposed in Dejvice, located near downtown Prague, Czech Republic, which was investigated during a rescue research.
Methodology: The loess-paleosol sequence was studied using a multi proxy approach. Magnetic susceptibility and magnetic fabric (anisotropy of magnetic susceptibility) methods and geo-chemical approaches (total organic carbon, XRF elemental analyses, XRD mineralogy, 13C and 18O stable isotopes) were used to interpret the paleoenvironmental record.
Optically stimulated luminescence (OSL) dating was used to determine the chronology of the section which is essential for understanding the link between climatic shifts and depositional and post-depositional regimes. Results and Preliminary Conclusions: The loess-paleosol sequence is 15 m thick and includes loess and colluvial deposits, representing cold stages, and at least 4 different paleosol hori-zons, developed during warmer periods.
The section records the climatic oscillations during the last two glacial stages. The Dejvice sequence contains a partly eroded weakly developed paleosol classified as PK I (MIS 3), a Chernozem and a Luvisol of PK III (MIS 5e).
The ol-dest detected paleosol is a Luvisol of PK IV. The Dejvice sequence was highly affected by several erosion events.
There is a hiatus of approximately 50 ka corresponding to the Early Weichselian. Gravel and colluvial deposits are present in a number of layers in the section.
The record preserved in the section corresponds well to other sections exposed in central Bohemia and shows significant paleoclimate changes.