Spanish cave paintings date back 36,000 years as tested by the radioactive decay of Uranium into Thorium and Helium. The same test used recently to establish age of gold smelter objects as pioneered by Dr. Otto Eugster at the Physics Institute Unversity of Bern, Switzerland.
For readers in Spain and parts of Latin America, Monday's Google Doodle celebrates the discovery of 36,000-year-old art in the Altamira Caves of northern Spain.
The cave and its secrets had been locked away for 13,000 years behind fallen rock. Botanist and archaeologist Marcelino Sanz de Sautuola found the cave in 1879 only because a tree had recently fallen, knocking aside some of the rocks in the process. Sautuola discovered animal bones and stone tools near the mouth of the cave, but it was his daughter Maria, on a return visit, who discovered the paintings on the walls and ceilings of the cave, stretching back nearly 1,000 meters (3,280 feet). The walls of the cave are a riot of color. Images in rich shades of yellow, red, black, and gray depict bision, horses, deer, goats, and a boar, along with abstract shapes and human handprints, all painted in charcoal and an iron-rich pigment called ochre.
To read more on Forbes:
* Code Hidden in Stone Age Art May be the Root of Human Writing
* India's forgotten caves* India's forgotten caves
* MURALS AND FRESCOS: A Potted History of Public Art