A calibration curve based on annual samples, applied to radiocarbon dates from the oldest town in Scandinavia

We are currently performing high-precision radiocarbon dating of annual tree ring samples to construct a new calibration curve for the period AD 650-900. We will present preliminary results from the intervals AD 650-750 and AD 800-900. The period AD 750-800 is covered by the poster by Fogtmann-Schulz et al. (session A6).The new calibration curve will be used for high-precision dating of the stratigraphy of Ribe, the oldest town in Scandinavia and an important site for the chronology of the Viking age. Many Viking Age artefact types are dated based on their stratigraphical position in the Ribe sequence. The older layers, containing preserved timber, are well-dated by dendrochronology. However, not all of the phases in Ribe have been dated by absolute dating methods yet. The latest dendro-date is AD 741, but activities at the site continue more than 100 years after that date. The calendar ages of some important typological reference points for Viking Age chronology are thus only estimated by relative methods, e.g., the duration of phases derived from the thickness of the layers. Therefore, a precise radiocarbon chronology of the entire occupation history of Ribe has the potential to consolidate or shift the dating of important artefact types. Our measurements could thus have an impact on Viking Age chronology in general. As Ribe was embedded in global networks of transcontinental trade, reflected by finds such as Early Islamic trade commodities, our results have the potential to resonate in the wider research field of urban networks.We are developing an age model for the Viking Age activities at Ribe based on the ongoing excavations by the Northern Emporium project. We will present the first radiocarbon dates from Ribe and will illustrate the effect of using different calibration curves based on decadal or annual samples.