Although I had not discerned the meaning of the panel, I had shown that by the use of infrared light it was possible to begin an analysis of the Ice Age caves in a new way. As a result, I began tracking and probing the caves to try to understand the sets of dots, meanders, female figures, animals, and the many kinds of signs.
I FOUND that ultraviolet light causes dra¬matic effects in many caves. Various min¬erals and living organisms on the cave walls react to ultraviolet radiation, causing a ghost¬ly fluorescence. The ochers and manganese pigments themselves do not fluoresce.
When I trained an ultraviolet lamp on the walls of Pech-Merle, the effect was startling. Eerily, the stalactites and stalagmites there fluoresced as though they were wired intern¬ally for electricity. By noting the amount of fluorescence on the wall, one could tell that in different parts of the cave unequal processes of growth and aging were under way. The knowledge could be helpful in determining what might have happened to images painted on the walls.
These new analytic techniques demon¬strated that animal images and walls had been used and reused, just as the surfaces on the engraved objects were used and reused. For example, a single animal image such as a horse could be used in many different ways by the addition of different kinds, of symbols. Such discoveries opened up a new stage of cave research and offered a new insight into the complexity of the Ice Age symbol systems.
Ultraviolet light also revealed traces of modern man as well as of Cro-Magnon. In the famous cave of Lascaux, closed to the public since 1963 for protection of its paint¬ings, the ultraviolet lamp disclosed a color¬ful fluorescent dust on many shelves and ledges. The dust consisted of tiny blue-green specks and long twisting serpentine forms of brilliant red and blue-green. In total darkness mile inside the hill, and the farthest cham¬bers with images are almost a mile inside. Obviously Cro-Magnon man painted from memory rather than from a living animal so deep inside the cave.
We know that he entered barefoot, for his prints remain on the clay floors. He carried a flaming torch that lasted at least an hour or two, or a dish of oil with a floating wick. The area of Niaux actually offers two sets of paintings and engravings—one in the main cave and another across the valley in a small¬er rock shelter called La Vache. My plan was to compare the art of the cave and of the shelter and to relate the various images to the prehistoric ecology of the valley.