Cross dating by uranium-thorium, uranium protactinium and radiocarbon of secondary carbonate cave deposits: the search for validation criteria of samples and ages. Application to rock art (ApART)
The ApART project responds to the challenges described in the 2018 ANR action plan "Innovative, integrative and adaptive societies" and its axis 5: "Cultures, creation, heritage". The objective of the ApART project is twofold: to develop methodologies of study adapted to the conservation of heritage objects, while extending our knowledge of parietal art.
Obtaining relevant results when dating samples of cave carbonates is a real scientific issue that will have a significant impact in the field of prehistory. While decorated Paleolithic caves are very abundant, especially in France, the majority of them contain wall decorations engraved or traced with metal oxides which cannot be dated directly by the carbon 14 method; their chronology therefore remains very uncertain. The fact that many drawings are covered with carbonate deposits that can be dated by radionuclear methods makes it possible to meet this challenge by opening up a new field of investigation for research on Paleolithic art. Until now, researchers involved in the dating of these parietal deposits have used only the uranium-thorium method, without information on the geochemical evolution of the system, hence the impossibility of assessing the reliability of the results obtained. The ApART project, in contrast, will focus on combining several dating methods (231Pa/235U and 230Th/234U and 14C) on the same sample in order to compare their respective results. Our previous studies have also shown that it is essential to characterize the mineralogical structure and diagenesis of samples with physico-chemical methods to verify that they can be reliably dated.
The investigations carried out in ApART are thus manifold: they relate to the definition of validation criteria for the different dating methods thanks to preliminary characterization studies of the samples. The second part concerns the miniaturization of samples, an essential objective for studies concerning samples of decorated walls.
The multidisciplinary approach of ApART is based on the close collaboration of several laboratories with complementary skills, internationally recognized expertise and state-of-the-art instrumentation. ApART also integrates parietalist prehistorians and curators whose role will be crucial in the choice of samples and the interpretation of the results.
In order to preserve the decorated caves, our protocols will first be developed and tested on samples taken from caves without parietal art, before being put into practice on samples of decorated caves (the cave at the Points, Bois d’Argeville rockshelter in France; Nerja, Navarro, and Askondo caves in Spain). This field work will be conducted in close consultation with the prehistorians in charge of their study, who have already filed sampling applications with the authorities. The objective of the ANR ApART, based above all on the consultation of the different partners, both in archaeological sites and in laboratories, will, in the long term, enable a reliable methodology to be developed that will be able to respond to both the requirements of maximum conservation of cave walls and parietal art while obtaining fully relevant and validated dates. In the more distant future, the contributions of ApART will open up new perspectives for the study of parietal art.
Madame Helene Valladas (Laboratoire des Sciences du Climat et de l'Environnement)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
LSCE Laboratoire des Sciences du Climat et de l'Environnement
UPSud - GEOPS Université Paris Sud - Géosciences Paris-Sud
IPREM INSTITUT DES SCIENCES ANALYTIQUES ET DE PHYSICO-CHIMIE POUR L'ENVIRONNEMENT ET LES MATERIAUX
Help of the ANR 286,929 euros
Beginning and duration of the scientific project: October 2018 - 36 Months