By Rhitu Chatterjee
A team of archeologists excavating a cave in South Africa has found what may be the world's oldest artists' workshop. The team discovered two ancient tool kits that were used to make a reddish paint.
The tool kits were found in a cave called Blombos, which lies on the southern coast of South Africa, about a hundred and eighty five miles from Cape Town.
Christopher Henshilwood is an archaeologist at the University of the Witwatersrand. He has been excavating Blombos for nearly two decades.
In 2008, he and his team began finding signs that humans had lived in the cave as long as 100,000 years ago.
"We had bone, we had shell fish, we had hearths, many things like that," said Henshilwood.
Deeper inside Blombos was an area covered by sand, where Henshilwood and his team came upon unusual find: two abalone shells that seemed to be part of a prehistoric tool kit.
"Centre of the toolkit was the shell, the abalone shell," he said. "And above and below and next to the shell were a number of different components."
The components of the kit included hammer stones, rounded cobbles, grind stones, and pieces of bone.
"First of all we realized that the shells were used as containers," said Henshilwood. "It looked like they were plugged, so the liquid didn't run out of them. And at the bottom of them was this thick, quite red deposit."
That ancient red deposit was dried up paint made out of ochre, a stone that comes in shades of yellow and red.
Francesco d'Errico is the director of research at the Centre National de la Recherche Scientifique (CNRS) in France, and Henshilwood's collaborator on this study.
According to him, scientists have known that humans used ochre as paint for more than a hundred thousands years.
"But we have never found before the association with all the tools involved in the production of pigment, nor the container in which the pigment was kept," he said.
And the intact containers gave d'Errico and his colleagues the opportunity to analyze the paint still inside.
"And for the first time we were able to reconstruct the recipe of the paint, and how the paint was produced, processed and stored in the shells," he said.
The analysis revealed that ancient people ground pieces of ochre with hammers and grindstones. Then they put the powder into the shells and mixed it with bone marrow to act as a binder. The scientists say the ancient paint makers also added water, or urine to make the paint liquid.
d'Errico said he was surprised at the paint makers' sophistication.
"This clearly shows that these people were combining different types of stone and bone to create something," he said.
Henshiwood and d'Errico's findings appear in the latest issue of the journal, Science.
The study suggests that human understanding of the chemistry of paints started very early, according to Philip Ball. He is the author of the book, Bright Earth:The Invention of Color.
In later periods, say for example in the renowned Altamira cave paintings in Spain, humans showed more sophistication in the chemistry of paint making, said Ball.
"Other minerals are mixed in with ochres to give them different properties to make them stick better. People started increasingly to use fire to change their color. So they were gradually getting a better grip on the kind of chemistry that can be used."
As for the ancient paint makers from Blombos, it is not clear whether they were artists. The study authors say it is possible that the paint was used for practical purposes, like preserving animal hides.
Still, early humans took a lot of care to create the tool kit, says Philip Ball. So the paint must have been culturally important.