 |
| Titel |
Holocene lake level changes at a lowland lake in northeastern Germany inferred from acoustic sub-bottom profiling and a transect of sediment cores |
| VerfasserIn |
Elisabeth Dietze, Izabela Zawiska, Michał Słowiński, Achim Brauer |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250109461
|
| Publikation (Nr.) |
 EGU/EGU2015-9368.pdf |
|
|
|
|
|
| Zusammenfassung |
| Holocene lake level changes were studied at Lake Fürstenseer See, a typical lake with
complex basin morphology in northeastern German sandur area. An acoustic sub-bottom
profile and a transect of four long sediment cores in the deepest lake sub-basin were analyzed.
The cores were dated with AMS-14C and correlated with multiple proxies (sediment
facies, μ-XRF, macrofossils, subfossil Cladocera, carbonate isotopes). At sites in 10
and 15 m water depth, shifts in the sand-mud boundary, i.e. sediment limit sensu
Digerfeldt (1986), allowed quantitative estimates of the absolute amplitude of lake
level changes. At sites in 20 and 23 m water depth, the negative correlation of Ca
and Ti reflect lake level changes qualitatively. During high lake stands massive
organic muds were deposited. Lower lake levels isolated the lake sub-basins which
reduced the overall water circulation and lead to the deposition of Ti-poor carbonate
muds. Furthermore, macrofossil and subfossil Cladocera analyses were used as
proxies for the intense reworking at the slope and for the trophic state of the lake,
respectively.
Lake levels were up to 4 m higher, e.g. around 5000 cal. yrs BP and during the Medieval time
period (see also Kaiser et al., 2014). During the early to mid-Holocene (between 9400 and
6400 cal. yrs BP), Lake Fürstenseer See fluctuated at an at least 3-m lower level. Further
water level changes can be related to known climatic events and regional human
impact.
Digerfeldt, G., 1986. Studies on past lake-level fluctuations. In Berglund, B. (ed.), Handbook
of Holocene Palaeoecology and Palaeohydrology: 127-144. John Wiley & Sons, New
York.
Kaiser, K., Küster, M., Fülling, A., Theuerkauf, M., Dietze, E., Graventein, H., Koch, P.J.,
Bens, O., Brauer, A., 2014. Littoral landforms and pedosedimentary sequences indicating late
Holocene lake-level changes in northern central Europe — A case study from northeastern
Germany. Geomorphology 216, 58-78. |
|
|
|
|
|
|