UK: Archaeologists delve into ice age

Remarkable prehistoric paintings hidden away in the caves of northern Spain could be dated accurately for the first time by experts from the University of Bristol. 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.

"Taking the samples can be quite tough," said Dr Alistair Pike, the project leader. "Some of the paintings were deliberately done in the least accessible parts of the caves so there's often a lot of crawling. It's not unusual for us to spend 10 hours a day underground, but the paintings are so spectacular it's always worth it."

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: 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 over a hundred abstract symbols and several series of isolated dots.

The project, funded by Britain's Natural Environment Research Council, will use a new dating method based on the radioactive decay of uranium to find out how old the cave paintings are.

Pike 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. We don't even know if the tradition of painting caves arrived with the first modern humans in Europe around 40,000 years ago, or was a much later development.

"Traditional methods of dating the pigments, such 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, and relate their findings to the expansion and contraction of human populations in response to the changing climate of the last ice age.

Further details can be found on NERC's Planet Earth online: www.planetearth.nerc.ac.uk