Theme: Climate archives
Locality: Lille Vildmose
Description of a supplementary Danish GeoSite
1. GeoSite no.:
GS – 10-3.
2. National locality no.:
3. GeoSite name:
5. Co-ordinates UTM:
System ED50, Zone 32, x=573111, y=6300797.
6. Type of locality:
Primary geological features
7. Main topic:
Raised bog peat on fossil glacial coast. The raised bog rests on Post Glacial coastal deposits from the Littorina Sea, which during a period of eustatic rise ca. 7000 years b.p. transgressed the low areas in between relict glacial topography. To the West a deeply indented fossil sea cliff cuts into the prequaternary Cretaceous Chalk, whereas Eastward, towards the present sea of Kattegat, relict glacial hills were gradually bundled by spits during isostatic rise. 2500 years b.p. the spits isolated a lagoon with brackish water and with restricted Northern and Southern entrances, in front of the Western glacial landscape, in which the bog developed. Continued isostatic rise until present has dried op the lagoon and left the bog fully fed by meteoric water since 500 years ago.
The changes through time of climate becoming more humid, the lagoon beeing overgrown, and the bog becoming gradually less influenced by groundwater, are reflected in the stratigraphy of the bog. A basal layer of reed, and peats of swamps and water meadows, is common in the central and Western parts of the bog, where the lagoon was situated and influence of groundwater rich in nutrients most pronounced. The basal peat is generally 1,5-2,0 m thick and has a brown or dark brown colour. The overlying and uppermost layer of peat consists of plant tissue which is only slightly decomposed, and which has grown in an acid environment with low supply of nutrients (meteoric water only). This peat, which is coarse and has a light yellowish or brownish colour, makes up a thickness of 0,5-3,0 m. The greatest thickness of up to 5 m is reached in the southern area, where the bog is least disturbed and where the yearly accumulation is ca. 1 mm.
9. Frame / context:
11. Primary value:
Post glacial eu-/isostatic history.
12. Comparative evaluation:
With its ca. 20 km2 the Lille Vildmose is the biggest preserved and living raised bog within the belt of deciduous forest in the North European lowland. The lagg-zone in the circumference of the raised bog and its edge is well preserved in many places.
13. Comparable GeoSites:
In Denmark: Store Vildmose, Kongens Mose (GS 10-4). Outside of Denmark: e.g. 7110 in UK.
Supplementary data in support of the locality
14. Delineation on a map:
15. Higth of the GeoSite:
16. Area of the GeoSite:
17. Subordinate geological interests:
Active peat accumulation, Geomorphology, Edge preserved.
18. "Non"-geo interests:
Wild life resort (plants and animals). Pleaing for Natural amenity (1990).
Mikkelsen, V., 1943: Bidrag til Lille Vildmoses Strataigrafi og Vegetationshistorie. Medd. Dansk Geol. Foren., 10. Milioeministeriet, Landbrugsministeriet, Sejlflod Kommune og Nordjyllands Amt, 1989: Lille Vildmose. Toerveindvinding og naturgenopretning. Nordjyllands Amt, 1981: Raastofkortlaegning i Lille Vildmose. Aaby, B., 1989, In: Miljøministeriet, Landbrugsministeriet, Sejlflod Kommune og Nordjyllands Amt: Lille Vildmose, Tørveindvinding og naturgenopretning.
20. Data sources, collections:
Field descriptions by Bent Aaby, 1990.
Geological Society of Denmark and The Royal Danish Geographical Society.
23. Description by:
Based on Andersen, S. and Sjørring, S., 1997: Geologisk set, Det nordlige Jylland, Geografforlaget, Brenderup. p 174-179.
It is a GeoSite.
26. Supplementary description: