Dating Littorina sea shore levels in Denmark on the basis of data from a mesolithic coastal settlement on Skagens Odde, Northern Jutland

The Mesolithic settlement site of Yderhede on Skagens Odde is interesting because it lies on Denmark's highest Littorina coastline, 13 m above present-day sea level. The settlement was founded on peaty ground on the shore of a sheltered fjord. Pollen-analytical investigations have been carried out on marine/brackish gyttja deposits containing refuse from the settlement. These marine sediments were formed as a result of a transgression starting around 5300 cal. BC, reaching a maximum of 13 m above present sea level. Settlement took place during a subsequent regression and ceased in connection with a new Atlantic transgression. Subsequently, the lagoon silted up partly due to isostatic land upheaval of the area. The settlement lies on flat ground below the marked raised coastal cliff that runs from Frederikshavn to Hirtshals, see figure 1. The formation of this cliff has previously been assigned to the time of the Littorina Sea, but it is now suggested that it was formed in Late Glacial times. The two transgressions demonstrated here have been fitted into the overall pattern for sea-level change in Denmark. Subsequently, on the basis of well-dated sea-level curves for Southern Scandinavia, dates are given for the highest shore levels of the Littorina Sea. As a result of the interaction between increasing upheaval in a north-easterly direction and the general sea-level rise during the Littorina transgression, the maximum in the Gothenburg area (23 m-isobase) occurs as early as 6300 cal. BC, whereas the maximum at the 0m-isobase in Southern Denmark first occurs around 3600 cal. BC.