Art dating com
In nearly all cases, such data are subject to significant qualifications, which in archaeological use are not adequately taken into account.
Even attempts to compensate for the routine misuses of dating results have been misguided. carbon isotope ‘dates’ is misleading, in that it elicits a false sense of security in practitioners.
All components of a geological sediment possess an ‘age’, most are significantly ‘older’ than the deposit and may have been redeposited many times by a variety of processes, while some are younger.
Instead of referring to the ‘age’ of such a sediment or deposit it is more appropriate to refer to the time of its most recent deposition.
For instance, the introduction of once fashionable terms such as ‘absolute dates’ and ‘relative dates’, or the use of ‘calibrated’ radiocarbon dates have only provided cures worse than the disease; rather than correcting the problem they tried to conceal it. Reference to a calibration curve proposed for bristlecone pine in some part of California does not compensate for the numerous inherent qualifications of radiocarbon results, it merely compounds interpretational confusion.
Apart from some rare exceptions, archaeometry does not provide results that could reasonably be defined as ‘absolute dates’, and radiocarbon assay results are no basis for calculating ‘absolute calibrated dates’. The difficulties of estimating the age of rock art are considerably greater than those of ‘dating’ archaeological finds in most cases, and the methodologies developed for these two entities differ considerably.
The radiometric method most used in estimating archaeological time is the analysis of carbon nuclides.Even when the charcoal is extracted from a well-defined hearth, there is the possibility that charcoal or wood of various ages has been used.Moreover, the presence of charcoal in the vicinity of stone tools offers no proof that it is of anthropic origin, especially in a region that is prone to natural fires.Dendrochronology has documented major variations in past carbon regimes. The decay rate is expressed in the half-life of radioactive substances.This is now thought to be about 5733 years for radiocarbon, but we continue to use Libby’s original estimate of 5568 years, for consistency. The assumption that the ratio of carbon isotopes in the carbon reservoir of the Earth are the result of a complete and rapid equalisation is not necessarily valid. The assumption that the ratios of carbon isotopes are only altered by radioactive decay is only approximately valid. The levels of radiocarbon cannot be measured with real accuracy.