Climate of a cave laboratory representative for rock art caves in the Vézère area (south-west France)

Leye Cave (Dordogne, France) is a laboratory cave in the Vézère area, a region that contains some of the most famous rock art caves in the world such as Lascaux, Font-de-Gaume and Combarelles, and is listed as Human World Heritage by UNESCO. Leye Cave was selected because it is representative of painted caves, with respect to parameters such as its geological stage, the presence of water and carbon dioxide, the geological state of its walls, and the size of the cave. These wall states are studied to better understand the conditions of conservation of rock art caves without damaging them. The choice of an equivalent medium, i.e., a non-painted cave, was made to be able to conduct experiments or take measurements that would not have been possible in a rock art cave. The climatic conditions (temperature, hygrometry, etc.) monitored since 2011 are central to our understanding of the genesis and evolution of wall states. Leye Cave is sub-horizontal then descendant, forming a cold air trap. The phenomenon of condensation is thought to be important in the genesis of these wall states. Our article presents a model which describes the competition that exists between the conduction of the rock heating the air and the convection cooling the rock, in the area named the “Throne Chamber”, located in the deepest parts of the cave.