Figure 435

Two examples of radiocarbon dating results generated using OxCal 4.4 software (see ). The radiocarbon determination is represented, along with its uncertainty, as the red curve along the vertical axis; the narrower the curve, the more precise was the instrumental measurement. The blue band represents the IntCal20 calibration curve, which accounts for minor variability in carbon-14 concentration in the atmosphere over time (see ). The gray curves along the horizontal axis (calibrated date) represent the probability that the sample actually originated at any given time; the higher the curve, the greater the probability that the date below is correct. The brackets below the gray curves show the time period that is 95.4% certain to contain the true age. Depending on the precision of the measurement and the shape of the calibration curve, a radiocarbon analysis can yield results of varying precision, and can even yield results with more than one possible date range.