Croix, S., Gundersen, O. E., Kristiansen, S. M., Olsen, J., Sindbæk, S. M. & Søvsø, M. (2019). "Dating earthwork fortifications: Integrating five dating methods in Viking-age Ribe, Denmark", Journal of Archaeological Science: Reports 26.    

Abtract

Precise dating of earthworks with limited datable material is a well-known archaeological challenge. Here, based on artefact chronology, coin dates, radiocarbon dating of macroscopic and soil organic-matter fractions, and Bayesian modelling combining all these, we discuss the relative strengths and limitations of each method for dating an earthwork fortification from the Viking-age town of Ribe, Denmark. In a novel approach, we model the circulation time and loss rates of coin finds to obtain a detailed distribution curve, which is worked directly into a Bayesian model. It is shown that the earthworks, an early moat and rampart, belong neither to the ninth-century emporium or to the eleventh-century rise of the Cathedral town. The refined dates point to a construction in the period 889–974 CE and a use-life of at least 50 years, but the moat was filled-in by the mid 11th century CE. In consequence, Ribe's earliest fortification can be compared to the early fortification of two other Viking-age towns: Hedeby and Aarhus, possibly as a concerted defensive effort. Our integration of five dating methods reveals the strengths and weaknesses of each and provides a means to compare and correlate each component within a characteristically heterogeneous set of archaeological dates.