Calibration Technique for 14C Data Clusters: Fitting Relative Chronologies onto Absolute Time Scales
Radiocarbon: An International Journal of Cosmogenic Isotope Research
Application of radiocarbon dating to a short chronology is often limited by the wide probability ranges of calibrated dates. These wide ranges are caused by multiple intersections of the14C age with the tree-ring curve. For a single unrelated14C date, each intersection presents a probable solution. When several dates on different events are available, identification of the most probable solution for each event is possible if one can obtain some information on the relation between these events.
... ween these events. We present here a method for such identifications.To demonstrate the method, we selected a series of14C dates from mortuary monuments of the Egyptian Old Kingdom. Corrected14C dates from seven monuments were used. Calibration of these dates produced three absolute ages with single intersections and four ages with 3–5 intersections. These data are compared to a historical chronology, which places the dated events at a younger age. If each intersection is chosen as a potential anchor point of the "correct" chronology, 17 solutions must be tested for the best fit against the historical chronology. The latter is based on the length of the reign of each pharaoh during the studied time span. The spreadsheet has the function of determining the probability of fit for each of the solutions. In a second step the 17 probability values and their offset between the historical and the14C chronology are graphically analyzed to find the most probable offset. This offset is then applied as a correction to the estimated chronology to obtain an absolute time scale for the dated events.