TARA, Hill noted, is the only organization he knows of that's dedicated to preserving rock art across the entire continent of Africa. "This is a world heritage that is used by scientists, visited by some tourists, damaged and stolen by vandals, ignored for the most part by governments, and left otherwise to vanish from sight," said Hill, who is also the founding chairman of the Institute of Human Origins at Arizona State University.
Of the African rock art that has been scientifically dated so far, the oldest images are in Namibia, from about 27,000 years ago. Yet most experts agree that some of Africa's rock art may date to more than 50,000 years ago, Coulson said.
In the Sahara, much of the rock art depicts animals that no longer live in the region. When the paintings and engravings were made, the Sahara was not a desert. Until 2,000 years ago it was somewhat green and fertile, supporting at times large herds of game and relatively large human populations. Nine thousand years ago the region was covered with lakes and forests.
With support from the National Geographic Society's Committee for Research and Exploration, Coulson and his colleagues will travel to Algeria in November to document engravings that may be the largest pieces of prehistoric art on Earth.
"Herding and hunting peoples all over our planet have created extraordinary rock art," said Henry Wright, curator of archaeology at the University of Michigan's Museum of Anthropology and a member of the National Geographic Society's Committee for Research and Exploration. "These representations are among our best pathways to ancient systems of thought. From these images we learn how long-disappeared people viewed their universean invaluable testimony from the past."
Questions of Size
The large engravings Coulson will be searching for on the National Geographic-supported expedition are thought to have been made thousands of years before the pyramids were built and are virtually unknown, Coulson said.
Among the giant engravings Coulson and his team documented on previous field trips, for example, was an image on rocks in Niger of a giraffe 18 feet (5.4 meters) high (see the accompanying photo gallery).
Why did the ancient artists make such outsize engravings?
The subject matter offers clues to why the artists engraved such large images, Couslon said. "Giraffes appear to have been important animals through many different ancient cultures in Africa," he said. "They were painted and engraved more frequently, with greater care and artistry, and to a greater size. We think that many cultures may have considered them as rain animals, possessing power over the rains."
Coulson expects to find paintings as well as engravings in southern Algeria. "From what I have heard, I believe that there may be paintings from the early pastoral period on the northern Tassili plateau, and possibly from the Roundhead period [about 9,000 years ago]," he said. "I have heard that there are many incredible engravings in other wadis [river beds], some as old as the big giraffes."
The Tassili plateau resembles the surface of the moon, and much of it is inaccessible even by four-wheel-drive vehicles, Coulson said. Getting to the sites where the ancient engravings and paintings of giraffes can be found will require his team to travel on camel and by foot in the final stages of the journey. They will traverse river beds in 1,000-foot (300-meter) gorges.
"Southeast Algeria is about as remote as you can get," Coulson said. "We have traveled hundreds of miles, and occasionally over a thousand in the central Sahara, without seeing a single living soul."
Coulson plans to document the rock paintings and engravings in a variety of formats to add to his growing archives of the continent's rock art. In addition to reporting on the art in magazines and the scientific press, he will film a television documentary on African rock art and his work in Africa.
With support from the Ford Foundation, he and others are also developing a program to increase awareness among people in Africa about the importance of the continent's rock art and the need to preserve it. The materials will include videos for schools in urban and rural areas.
Research Supported by the National Geographic Society:
David Coulson is one of a distinguished group of scientists from around the globe, in fields ranging from astronomy to zoology, who have been awarded grants from the National Geographic Society's Committee for Research and Exploration (CRE).
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