prehistoric art
Prehistoric find: The caves in northern Spain contain more than 300 images of animals - the largest ever found on the Iberian peninsula
British scientists are set to unlock the secrets of hidden cave paintings which could reveal how humans survived during the changing climate of the Ice Age more than 15,000 years ago.

The paintings, concealed in the caves of northern Spain, will be dated accurately for the first time by experts from the University of Bristol using a new technique based on the radioactive decay of uranium.

A team from the Department of Archaeology and Anthropology has just returned from an expedition to the Cantabria and Asturias regions of Spain, where they removed samples from more than 20 prehistoric painted caves.

The project, which is funded by the Natural Environment Research Council, will use the new dating method which could shed some light on how humans survived the changing conditions.

Traditional methods have so far failed to date the paintings.

Dr Alistair Pike, 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.

'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.'

spanish caves
The scientists will use a new method based on the radioactive decay of uranium to date the images and hope it will shed light on how humans survived during the changing climate of the Ice Age
Over the next three years the researchers hope to more than double the numbers of dates on European prehistoric cave art.

The archaeologists took samples from the cave of Tito Bustillo in Asturias and La Pasiega Cave in Cantabria, which contains almost 300 drawings of animals and is the largest number of cave paintings showing pictorial representations on the Iberian Peninsula.

As well as representations of horses, deer and cattle, the cave also contains more than a hundred abstract symbols and several series of isolated dots.

Dr Pike said getting to the cave paintings was a challenge for the scientists, who had to go deep underground.

'Taking the samples can be quite tough,' he said.

'Some of the paintings were deliberately done in the least accessible parts of the caves so there's often a lot of crawling.

'It wasn't unusual for us to spend 10 hours a day underground, but the paintings are so spectacular it's always worth it.'