Vermiculations in painted caves: New inputs from laboratory experiments and field observations

Vermiculations are aggregates of small particles commonly found on cave walls. They a major concern for the conservation painted caves, as they can potentially alter valuable prehistoric paintings. A previous rheological study fine sediment deposits walls revealed that this material undergo solid-to-liquid transition triggered by variations in chemical composition water film wall. Such could occur at origin vermiculations allowing to flow under low mechanical stress. In work, we provide quantitative information conditions leading and show importance complete understanding phenomenon will, however, require more field information. This includes monitoring evolution vermiculations, which have developed dedicated observation protocol. Based combination photogrammetry geographic system were able precisely map Hall Bulls Lascaux from past future photographs. To better understand vermiculation process, pictures need be taken regularly, thin covering needs analyzed with similar time step. The correlation between humidification phases walls, temperature changes should shed new light triggering vermiculations.