�mosen

Theme: Climate archive  

Locality: �mosen
Description of a Danish GeoSite

Primary identification

1. GeoSite no.:
GS - 10-1.

2. National locality no.:
NGI - 142.

3. GeoSite name:
�mosen.

4. Location:
Denmark; Zealand.

5. Co-ordinates UTM:
System ED50 Zone 32, x=659244, y=6161978.

6. Type of locality:
Bog.

Primary geological features

7. Main topic:
Late and Postglacial geological development.

8. Geo(morpho)logy:
Research site for combined geological and archaeological investigations in Late- and Postglacial time. The succession consists of 16-20 metres of lake-sediments and peat, representing the change from an open meltwater lake to a bog. The Quaternary history of the Store �mose lake basin dates back to 13,000-14,000 years BP. The development is inferred from analyses of sedimentary facies, palaeobiology and stable isotopes. The Younger Dryas - Preboreal transition is marked by a rapid lowering of lake level, causing a forced regression, resulting in erosion of Late Glacial lake-margin deposits and deposition of a coarse-grained boundary layer. This layer separates the mainly clastic-dominated Late Glacial lake deposits from the Postglacial organic sediments. The lowering of lake level about 10,000 years BP was probably caused by tapping of the lake when dead ice, blocking the outlet of the basin, melted away. A similar sedimentary development is recorded in other lake basins on Zealand, indicating a regional rapid shift from the cold climate of the Yonger Dryas to the warmer and more humid Preboreal climate.
Postglacial lake-level changes in the open �mosen lacustrine basin inflicted high stress on the vertebrate fauna living in and around the lake, and ultimately on man, living next to the lake basin.
The vertebrate fauna underwent changes in both diversity and body size of individual species from 8,200-4,900 BP, caused by the isolation of Zealand, which became an island during that period, and the forest development, which led to a reduction in diversity of suitable habitats for the larger animals.

9. Frame / context:
Palaeoclimate, Ecology, Sedimentology.

10. Chronostratigraphy:
Pleistocene (Latest Weichselian) to Holocene.

11. Primary value:
Archive for detailed studies of climate, flora and fauna since the melting of the Weichselian glaciers up to our time. Through this period, an undisturbed sedimentary sequence has been deposited and has been preserved and thus may show the development of nature in Denmark and Northwest Europe during the last 14,000 years.
Also the interplay of human culture is recorded.

12. Comparative evaluation:
The �mosen has an outstanding position among European history of modue to the complete sequence and intense investigation . Extensive essential literature stems from this area. There are still widespread well preserved layers of mud despite drainage and peat cutting, and the area has still great scientific potential.

13. Comparable GeoSites:
In Denmark: T�velde (GS 10-2).


Supplementary data in support of the locality

14. Delineation on a map:
...

15. Higth of the GeoSite:
Topographic level is 25-30 m a.s.l.. Profiles must be dug or drilled.

16. Area of the GeoSite:
50km2.

17. Subordinate geological interests:
...

18. "Non"-geo interests:
Archaeology.

19. References:
Fischer, A. 1998: Stone Age �mose, Denmark - stored in museum boxes and the living bog. In: Coles, B. & J�rgensen, M.S. (edit.) Bog bodies, sacred sites and wetland archaeology. Exceter.
Noe-Nygaard, N. 1995: A dynamic model for changes in palaeoclimate, environment and ecology in Late and Postglacial time, Sj�lland, Denmark. A multidisciplinary study. Fossil and Strata, 37, 1-437.
Noe-Nygaard, N., Abildtrup, C.H., Albrechtsen, T., Gotfredsen, G. & Richter, J. 1998: Pal�obiologiske, sedimentologiske og geokemiske unders�gelser af Sen Weichsel og Holoc�ne aflejringer i Store �mose, Danmark. Geologisk Tidsskrift 1998, h�fte 2.

20. Data sources, collections:
...

21. Illustrations:
Photo:

22. Proposers:
Dansk Geologisk Forening & Det Kongelige Danske Geografiske Selskab.

23. Description by:
Compiled from various sources.

24. Recommandation:
It's a GeoSite.

25. Comments:
...

26. Supplementary description:
Traces of human activity on the bone material yield information on the hunting, butchering and marrow-fracturing methods applied by humans living at sites with different functions such as summer and winter hunting camps or more or less permanent living sites.