Carbon dating rock art
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.
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).
It is thus essential to ensure that oxalates have been eliminated (Bonneau The significance of these contaminations explains why all current research is aimed at improving pretreatment procedures.
In sum, the classical method of charcoal preparation, called ABA (three steps consisting of an acid treatment, then basic, then acid again) has now been replaced by a variant known as ABOx-SC (an oxidation stage and step combustion are added to the acid and basic treatment).
In nearly all cases, the ABOx-SC procedure yields dates 3000 to 5000For bone dating, a new method of collagen extraction and purification has also been developed.
When solid matter such as flint or calcite is bombarded by cosmic rays, electrons are trapped in high energy levels.
A sample with a real age of 40000 years, only containing 1% of recent carbon, would yield an apparent age of 32800 years, which corresponds to a rejuvenation of 7200 years!
(figure 1Therefore the main cause of error in radiocarbon dating is the presence of recent carbon leading to more recent dates.
It is thus imperative to always indicate the Some intractable opponents of the early age of Chauvet Cave have questioned the fact that the dates were obtained by a single laboratory (Pettitt, Bahn, 2003), even though the six direct dates on pigment used for the paintings are remarkably consistent and compatible with a single episode in the cave, with an average date of 30890±250 BP (probability 95%).
In reply to this objection, three large pieces of charcoal retrieved from the Megaloceros Gallery were cut up and sent to four different laboratories (LSCE-Gif sur-Yvette, Oxford, Groningen and Poznan).
In this article on absolute dating methods, we will briefly recall the scientific principles on which the different methods are based, in order to allot more scope to the causes of error that blur our overall vision, but also to recent technological progress which offers an optimistic outlook for the future of our discipline.