Prof Christopher Ramsey

Abstract:

A radiocarbon dating method which uses Accelerator Mass Spectrometry (AMS) to directly detect the 14C atoms is described. The method eliminates the problem of long half life from the measurement. This allows the sample size to be reduced to about 1 mg of carbon, a level where the method almost classifies as a nondestructive technique for many types of archaeological materials.

Abstract:

People usually study the chronologies of archaeological sites and geological sequences using many different kinds of evidence, taking into account calibrated radiocarbon dates, other dating methods and stratigraphic information. Many individual case studies demonstrate the value of using statistical methods to combine these different types of information. I have developed a computer program, OxCal, running under Windows 3.1 (for IBM PCs), that will perform both 14C calibration and calculate what extra information can be gained from stratigraphic evidence. The program can perform automatic wiggle matches and calculate probability distributions for samples in sequences and phases. The program is written in C++ and uses Bayesian statistics and Gibbs sampling for the calculations. The program is very easy to use, both for simple calibration and complex site analysis, and will produce graphical output from virtually any printer.