Highly respected archaeologist and prehistorian Jean Clottes has raised a question mark on the AMD datings of the Iberian rock art, recently claimed to be older than 40,000 years in some cases. He essentially questions the method of dating, frontally clashing with João Zilhão, who in the press conference[es] defended the high reliability of the Uranium series method, which he says has not yet been fully demonstrated in its efficiency.
In my opinion one should be very cautious about the sensational results announced, because:
1. that method is new and certainly needs to be tested and refined (see below);
2. they compare Useries dates with radiocarbon dates which were obtained with a different method: it would be necessary to date the same artefact with both methods and see if they concur; this is what Valladas and her team tried to do in 2003 in Borneo and they encountered problems;
3. finally, the relation to Neandertal is pure speculation: there has never been portable art discovered in Neandertal occupation sites and there is no relationship ever established between the Neandertals and a painted rock art site. Until there is, such speculation is entirely gratuitous.'
Another highly reputed expert questioning the dating is Hellene Valladas, who dated Grotte Chauvet.
I feel unqualified to judge the merit of these objections but certainly if C14 and U-series datings of the same object are inconsistent, it means that either method (or both) must be refined.
 |
| Red dots from El Castillo, one of which is claimed to be older than 40,000 years |
I remember talking once with Joao Zilhao about exact this issue. Luminiscence reaches further than the rough 40000 years of radiocarbon dating, but we have not yet a really reliable method to calibrate all others. So we must stay cautious!
ReplyDelete