This applies the geological principle that under normal circumstances younger layers of sediment will be deposited on top of older layers.This 'law of superimposition' works in the well-defined layers of the Willandra lunettes, but only dates objects as younger or older than adjacent layers.
It is possible then to calculate the date of an organic object by measuring the amount of C14 left in the sample.
For those researchers working in the field of human history, the chronology of events remains a major element of reflection.
Relative dating includes methods that rely on the analysis of comparative data or the context (eg, geological, regional, cultural) in which the object one wishes to date is found.
This approach helps to order events chronologically but it does not provide the absolute age of an object expressed in years.
It is based on the knowledge that living organisms build up their own organic matter by photosynthesis or by using atmospheric carbon dioxide.