• Development of the Radiocarbon Calibration Program

      Bronk Ramsey, Christopher (Department of Geosciences, The University of Arizona, 2001-01-01)
      This paper highlights some of the main developments to the radiocarbon calibration program, OxCal. In addition to many cosmetic changes, the latest version of OxCal uses some different algorithms for the treatment of multiple phases. The theoretical framework behind these is discussed and some model calculations demonstrated. Significant changes have also been made to the sampling algorithms used which improve the convergence of the Bayesian analysis. The convergence itself is also reported in a more comprehensive way so that problems can be traced to specific parts of the model. The use of convergence data, and other techniques for testing the implications of particular models, are described.
    • Radiocarbon and Dendrochronological Dating of Logboats from Poland

      Pazdur, Anna; Krąpiec, Marek; Michczyński, Adam; Ossowski, Waldemar (Department of Geosciences, The University of Arizona, 2001-01-01)
      The earliest dating of samples taken from logboats found in the area of Poland was done at the Gliwice Radiocarbon Laboratory in the late 1970s and early 1980s. After a 10-year break, the study of their chronology was renewed. The 14C dates (56) include all previously published and new, unpublished results obtained during last several years. Here, we discuss and provide probabilistic interpretation of the calendar age of the dated boats. The calibration of 14C dates was done with the OxCal program for dates less than 300 BP, and with the GdCALIB program for all remaining dates. In distribution of calibrated dates we find a lack of samples between the ages of around 800 BC and 300 AD. This result is surprising and differs from results observed for Central Europe. The remaining age ranges, with high frequency of dates, are in good coincidence with similar periods obtained for Central Europe. Tree-ring dating of oak logboats was carried out on 60 growth sequences, dated against standard chronologies defined for the area of Poland. The results of 14C dating and tree-ring analyses give consistent chronologies.