Theme: Holocene coastal development
Photo: The Skagen Odde (spit), by Ole Malling, SNS
Locality: Skagens Odde
Description of a Danish GeoSite
1. GeoSite no.:
GS - 5-1.
2. National locality no.:
NGI - 1.
3. GeoSite name:
Denmark; Northernmost Jutland.
5. Co-ordinates UTM:
System ED50 Zone 32, x=597823, y=6401359.
6. Type of locality:
Primary geological features
7. Main topic:
Building of spits.
Large scale complex of spits capped by aeolian sand and active parable dunes, dating back ca. 7000 years, in front of an eroded slope in glacial deposits (the Zirphaea sea liff). The spit complex, which is presently prolonged by 3-4 m/y, continues into an offshore bar.
The spits are accumulated under considerable addition and transport of material ( ca. 1 mio. m³/år). The material was (and is) trapped during varying isostatic/eustatic conditions following the Weichselian glaciation. The Postglacial eustatic rise caused a transgressive culmination ca. 7,200 y. bp. followed dominantly by isostatic regression until present.
The development of the system of spits may be followed in detail in the morphology, as well as vertical and horisontal succession of sea peat and beach ridges.
In the wave eroded cliffs of the North Western coast of the spit, and in inland profiles the spit complex is demonstrated to consist of 4 characteristic successive units. In the bottom there are storm sands. These are overlain by longshore bars/chanels, followed by beach sand, and finally peat.
9. Frame / context:
11. Primary value:
Full scale natural laboratory of marine processes and the building fo spits. Model area for dynamic morphological-sedimentological processes in sand dominated spit complexes, building into deep, high energy water.
12. Comparative evaluation:
Uniquely well exposed and documented example of dynamic building of a complex of spits.
13. Comparable GeoSites:
In Denmark: None are equally well developed.
Supplementary data in support of the locality
14. Delineation on a map:
15. Higth of the GeoSite:
Up to 13 m above msl.
16. Area of the GeoSite:
Ca. 300 km2.
17. Subordinate geological interests:
Geomorphology, Tzunami bed.
18. "Non"-geo interests:
Archeology, Holiday resort, Tourism, Art, Ornithology.
Hauerbach, P., 1992: Skagen Odde - Skaw Spit. An area of land created between two seas. Folia Geographica Danica, 20, 119 pp.
Jessen, A., 1936: Vendsyssels Geologi. Danm. Geol. Unders., Rk. V, Nr. 2, 193 pp.
Knudsen, K.L., Conradsen, K., Heir-Nielsen, S. & Seidenkrantz, M.-S., 1996: Quaternary palaeoceanography and paleogeography in northern Denmark: a review of results from the Skaggen cores. Bull. Geol. Surv. Denmark, 43, 22-31.
Lønstrup, J. & Nielsen, I., 1997: Mellem tvende have. Skalk, 4, 20-30.
Nielsen, L.H., Johannesen, P.N. & Surlyk, F., 1988: A Late Pleistocene coarse-grained spit-platform sequence in Northern Jylland, Denmark. Sedimentology 35 (6), 915-937.
Nielsen, L.H. & Johannesen, P., 2001: Accretionary, forced regressive shoreface sand of the Holocene Skagen Odde spit complex, Demnark - a possible outcrop analogy to buried reservoirs. In: Martinsen, O.J. & Dreyer, T. (eds.): Sedimentary environments offshore Norway - Paleozoic to Recent. Norsk Petrol. Foren. Spec. Publ., 10, 457-472.
Schou, A., 1949: Atlas over Danmark. Det Kongelige Geografiske Selskab. København: Hagerup, H.
20. Data sources, collections:
Dansk Geologisk Forening & Det Kongelige Danske Geografiske Selskab.
23. Description by:
Based on Nielsen L.H. & Johannesen, P.N., 2004: Skagen Odde - et fuldskala, naturligt laboratorium. Geologi, Nyt fra GEUS, Nr. 1, Temanummer September 2004.
The entire spit and the Skagen barrier reef is a GeoSite.
26. Supplementary description: