This is the challenge posed to the new scientific Council

There are only a part of fantasy on the safeguarding of Lascaux, as said Thursday the Minister of Culture, Frédéric Mitterrand, after visiting the cave Gathered two days before to discuss the subject under the dome of the Academy of sciences, the best specialists of the decorated caves ruled with the official discourse, suggesting the huge construction awaiting the Paleoanthropologist Yves Coppens, who will chair the new Lascaux Scientific Council put in place by the Government. In the heart of the controversy: the degradation of the bioclimatic equilibrium of the cave since the replacement in 2000 from the heat and humidity control system installed in 1965 to respond to the first colonization of fungi on the walls.

Toxic fungus

"This equipment stabilized the atmosphere and the temperature of the complex geometry of the cavity with an accuracy of a tenth of a degree, said its designer, Paul-Marie Guyon physicist." For forty years, we have maintained this fragile balance bioclimatic, but no data collected daily during this period was reused for the crisis. It is incomprehensible.

The degradation of the most beautiful jewel of prehistoric times been publicly denounced in 2004 with the creation of the international Committee for the safeguarding of Lascaux. Four years later, its President, Laurence Léauté-Beasley, submitted to the Unesco a report denouncing the mismanagement of the site and the "deaf rivalry between the administration of historical monuments and archaeologists for the management of this gem." The France is then officially required to carry out "of the substantial progress in the identification of the causes and the treatment of paintings", otherwise the site will be inscribed on the list of world heritage in danger, which would be an affront to the Habs scientific community and the State.

In important ways have therefore deployed since 2001 to try to overcome the dévoreurs of pigment. The first mold ("Fusarium solani"), appeared on the same system of management of the climate in the cavity, a few weeks after his replacement. This fungus, sometimes toxic to humans, is resistant to treatment, spreads to the paintings that he soon covered with mycelium and manages to find a symbiosis with bacteria - "Pseudomonas fluorescens" - which degrades the fungicide used. An antibiotic must then be added to the potion, but in dying, covered microorganisms secrete melanin which covers the walls of black spots. The cleaners are struggling and in April 2008, Marc Gauthier, President of the Scientific Committee of the cave announces that "the patient is recovering, almost healed by a miracle treatment", Targol Oxyt.

All observers do not share this optimism. "It completely wrong Lascaux, said Jean Clottes, General curator of the heritage. The new scientific team will have physical, chemical, microbiological, hydrogeological and climate extremely complex problems that have never been studied.

Genetic control

Among tracks, Census of the populations of microorganisms is first to develop new strategies for genetic control without side effects. "The question is: how to prevent the reproduction of fungi in the millions of microcracks of this sensitive to external influences cave: water flows, air renewal, pollution, global warming" summarizes Jean Clottes.

The question also sanctuarize Lascaux Hill all to control the effects of urbanization around and control the path of water infiltration in the limestone massif. A specification is in progress to replace the controversial system of air in the cavity. It will rely on numerical models of the new "Simulator Lascaux" mis developed by EDF R & D and the clover laboratory of the University of Bordeaux, to drive the equilibrium heat and humidity of the cave. Remains to adjust settings. This is the challenge posed to the new scientific Council.