London, Oct 5 : A research led by scientists at Bristol University has revealed that prehistoric cave paintings took up to 20,000 years to complete.
Till date, it has been extremely difficult to pinpoint when prehistoric cave paintings and carvings were created, but a pioneering technique is allowing researchers to date cave art accurately for the first time and show how the works were crafted over thousands of years.
Experts hope that the new technique will shed light on how early human culture developed and changed as the first modern humans moved across Europe around 40,000 years ago.
"The art gives us a really intimate window into the minds of the individuals who produced them, but what we don't know is exactly which individuals they were as we don't know exactly when the art was created," Telegraph quoted Dr Alistair Pike, an archaeologist at Bristol University who is leading the research, as saying.
"If we can date the art then we can relate that to the artefacts we find in the ground and start to link the symbolic thoughts of these individuals to where, when and how they were living," he added.
Pike and his colleagues were able to date the paintings using a technique known as uranium series dating, which was originally developed by geologists to date rock formations such as stalactites and stalagmites in caves.
As water seeps through a cave, it carries extremely low levels of dissolved radioactive uranium along with the mineral calcium carbonate.
Over time small amounts of calcium carbonate are deposited to form hard layer over the paintings and this layer also traps the uranium.
Due to its radioactive properties, the uranium slowly decays to become another element known as thorium.
By comparing the ratio of uranium to thorium in the thin layers on top of the cave art, the researchers were able to calculate the age of the paintings.