Dating prehistoric paintings
All these methods are based on hypotheses and present interpretative difficulties, which form the basis of the discussion presented in this article.The accuracy of the radiocarbon dating method decreases as the age of the sample increases.Calcium oxalate deposits can be mixed in with pigments and skew the results as their age can vary from the age of the paintings to the present-day (see below the paragraph on oxalates).
The calibration curves vary according to research progress and are regularly revised (Cal Pal-2007, Int Cal09, Intcal13; figure 2).
An ultrafiltration technique isolates collagen macromolecules, which often results in much older dates (Higham , 2006; table 2).
If the samples are "clean", the different methods give similar results, but if they are very polluted, purification by ultrafiltration can yield ages several thousand years older, which calls into question certain archeological hypotheses, like for example the notion of a Neanderthal "refuge" south of the Ebre (Wood C concentration.
At certain periods, this was very different from the current value, resulting in a first cause of error.
A second cause of error is due to what we call the reservoir effect of oceans.
Search for dating prehistoric paintings:
The effects of this correction become very significant and inaccurate beyond 30 ka.