New method used to date cave art The paintings show horses, deer and cattle: photo Rodrigo de Balbin Experts from the University of Bristol are to attempt to accurately date prehistoric caves. The team from the Department of Archaeology and Anthropology travelled to northern Spain to collect samples of paintings from more than 20 caves. They will use a new method, based on the radioactive decay of uranium, to date the paintings. Samples have been taken from the cave of Tito Bustillo in Asturias and La Pasiega Cave in Cantabria. Dr Alistair Pike, the project leader said: "These cave paintings are one of the most intimate windows into the minds of people who lived more than 15,000 years ago, but have proved extremely difficult to date. It's not unusual for us to spend 10 hours a day underground, but the paintings are so spectacular it's always worth it Dr Alistair Pike "Traditional methods of dating the pigments, such as radiocarbon, are destructive to the paintings, and the samples are prone to contamination. "We are using a new method that can date thin calcite layers that have formed over the surface of the paintings." In the course of the three year project, the researchers hope to more than double the numbers of dates on European prehistoric cave art. They will then relate their findings to the expansion and contraction of human populations in response to the changing climate of the last Ice Age. "Some of the paintings were deliberately done in the least accessible parts of the caves so there's often a lot of crawling," said Dr Pike. "It's not unusual for us to spend 10 hours a day underground, but the paintings are so spectacular it's always worth it." As well as representations of horses, deer and cattle, the caves also contain more than 100 abstract symbols and several series of isolated dots. http://news.bbc.co.uk/2/hi/uk_news/england/bristol/somerset/7656338.stm