A 4D analysis (3D + time) of Chauvet Pont d’Arc cave entrance (Ardèche, France)

Résumé 0

‪Since its discovery in 1994, the Chauvet cave has been the focus of numerous radiometric dates on archaeological material (charcoal, etc.), palaeontological material (bones, etc.) and geological objects (stalagmites, walls, etc.). In the area of the prehistoric entrance, dating has made it possible to effectively constrain the chronology of the cave’s closure. These dates, initially taken from the calcites sealing the collapse deposit, were supplemented by 36Cl dates on the wall above the palaeo-entrance. At the same time, 3D lasergrammetry surveys were used to better define the geomorphological limits of the deposit that permanently sealed the entrance to the cavity. This geomorphological analysis, based on maps, cross-sections and 3D TIN models (Triangulated Irregular Network), has identified several landmark surfaces, i.e. surfaces corresponding to a fixed, synchronous time (e.g. a scar) or a diachronous time (e.g. a prograding fan). These surfaces are linked to the chronological model, which is constrained both by the way the objects fit together (relative chronology) and by the dates recorded on the site (absolute chronology). We propose here a visualization of this relative chronology, draped over the 3D model of the entrance area to the Chauvet cave. This 4D visualization (3D + time) represents a new method of analyzing the succession of events that led to the development of the current landscape. It offers the possibility of better associating the different objects (surfaces) on the basis of their geometry and age. This approach could prove to be an effective complementary tool for reconstructing palaeo-landscapes (visualization using landmark surfaces) and for guiding future sampling strategies.‪