Multiproxy evidence of Middle and Late Pleistocene environmental changes in the loess-paleosol sequences of Central Bohemia (CzechRepublic)
Abstrakt
Central Bohemia is a loess area on the border between continental and oceanic climate that has shifted in the past. Numerous profiles have been studied in the past century but without modern methods.
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, and a loess-paleosol sequence in Bůhzdař, situated 9 km NW of Prague, Czech Republic. Magnetic susceptibility and magnetic fabric (anisotropy of magnetic susceptibility) analyses were combined with geochemical approaches (total organic carbon, XRF elemental analyses, and XRD mineralogy, 13C and 18O stable isotopes) and particle-size distribution.
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. Both sequences contain the records the climatic oscillations during the last two glacial stages and both were affected by erosion.
The Dejvice sequence is 15 m thick and contains a partly eroded weakly developed paleosol classified as PK I (MIS 3), a Chernozem and a Luvisol of PK III (MIS 5e). The oldest detected paleosol is a Luvisol of PK IV (MIS 7).
The Bůhzdař sequence is 5 m thick and contains a partly eroded weakly developed paleosol classified as PK I (MIS 3) and a Chernozem and a weak Luvisol of PK IV (MIS 7). Eemian paleosols are completely missing in the Bůhzdař sequence.
The records preserved in the sections correspond well to other sections of same age in Europe and shows significant paleoclimate changes.