Current Problems in Dating Palaeolithic Cave Art: Candamo and Chauvet. (Method)
Pettitt, Paul, Bahn, Paul, Antiquity
Introduction--style versus radiocarbon
It is now 12 years since Michel Lorblanchet first coined the term `Post-stylistic era' to denote the new period dawning in Palaeolithic art studies, in which direct dating was going to play the definitive role (Lorblanchet 1990: 20). Subsequent publications on this topic (e.g. Lorblanchet & Bahn 1991; 1993a) aroused controversy in some circles, but much of this was due to misunderstanding of the position adopted. In particular, some critics claimed that it was being argued that direct dating had entirely replaced, or would soon replace, the use of style in establishing chronologies. Nothing could be further from the truth. The use of the term `post-stylistic' merely denoted the arrival of a new phase, but did not reject the value of style: `It is self-evident that the impact of absolute dating methods on other areas of archaeological study, while enormous, has changed but by no means obliterated the role of typologies of stone tools or pottery. The term "post-stylistic" does not suggest the death of style, any more than the term "post-glacial" means that ice vanished from the face of the earth!' (Lorblanchet & Bahn 1993b: v).
It is obvious that style will continue to play a major role, because very few paintings are eligible for direct dating--few contain organic material, and in any case the procedure is extremely expensive, so the vast majority of Palaeolithic parietal figures will always have to be dated by other, indirect means. The present principle should be that direct dating and stylistic chronology will need to exist side by side, complementing each other or exposing inconsistencies. This paper discusses some examples where radiocarbon dating and stylistic dating are currently discordant. We suggest that while we must be ready to adapt traditional stylistic sequences to new absolute dates, the context and chemistry of the radiocarbon samples on the cave wall are critical, and can give rise to dates that may be anomalous.
Increasing numbers of radiocarbon determinations from samples of parietal art have been obtained over the past decade, with dates currently published from over a dozen caves in France and Spain (Bahn & Vertut 1997: 75). Most of the results conform well to stylistic dates which in turn are corroborated by comparisons with portable art--the Palaeolithic parietal art of Eurasia is blessed in that it stands alongside a corpus of thousands of contemporaneous portable images which are generally well dated. As predicted (Bahn 1993), radiocarbon has also proved useful in weeding out fakes and wrongly attributed motifs; for example, in the Pyrenean cave of Labastide, some `organised black dots' in three different places were thought to be Magdalenian signs, but have yielded radiocarbon dates of modern times, the 15th century AD, and (for `the most Magdalenian' examples) the 10th century AD (Simonnet 1999: 188).
Sources of error
At the same time, some radiocarbon dates seem to be in severe conflict with stylistic expectations, ostensibly demanding a startling new perspective on the artistic sequence. However, in these cases it may not always be the style that needs rethinking: sources of radiocarbon error are well known and can be determinant. For example, the date of charcoal used in drawing is the date of death of the tree-rings incorporated, not the date of the tree, or the date that the charcoal was made or used to draw with; so the date obtained can be much earlier than the drawing. The risks of contamination on an exposed rock surface are also high, both from material that is too old (fossil carbon) and material that is too young (microorganisms infesting the surface).
AMS dating, in particular, has taught us to be increasingly critical of what is measured, since very small samples adjacent to each other on a cave wall may in fact derive from different materials with different formation processes. …