Olduvai Gorge
From Wikipedia, the free encyclopedia
The Olduvai Gorge or Oldupai Gorge is commonly referred to as "The Cradle of Mankind." It is a steep-sided ravine in the Great Rift Valley, which stretches along eastern Africa. Olduvai is in the eastern Serengeti Plains in northern Tanzania and is about 30 miles long. The gorge is named after the Maasai word for the wild sisal plant Sansevieria ehrenbergii, commonly called Oldupaai.
It is one of the most important prehistoric sites in the world and has been instrumental in furthering understanding of early human evolution. Excavation work there was pioneered by Louis and Mary Leakey in the 1950s and is continued today by their family. Some believe that millions of years ago, the site was that of a large lake, the shores of which were covered with successive deposits of volcanic ash. Around 500,000 years ago seismic activity diverted a nearby stream which began to cut down into the sediments, revealing seven main layers in the walls of the gorge.
The stratigraphy is extremely deep and layers of volcanic ashes and stones allow radiometric dating of the embedded artifacts, mostly through potassium-argon dating. The first artifacts in Olduvai (pebble tools and choppers) date to circa 2 million years ago but fossil remains of human ancestors have been found from as long as 2.5 million years ago.
The earliest archaeological deposit, known as Bed I, has produced evidence of campsites and living floors along with stone tools made of flakes from local basalt and quartz. Since this is the site where these kinds of tools were first discovered, these tools are called Oldowan. It is now thought that the Oldowan toolmaking tradition started about 2.6 million years ago. Bones from this layer are not of modern humans but primitive hominid forms of Paranthropus boisei and the first discovered specimens of Homo habilis.
The Olduvai Gorge bears the distinction of having the oldest known evidence of mammoth consumption, attributed to Homo erectus around 1.8 million years ago.
Above this, in Bed II, pebble tools begin to be replaced by more sophisticated handaxes of the Acheulean industry and made by Homo erectus. This layer dates to around 1.5 million years ago.
Beds III and IV have produced Acheulean tools and fossil bones with Neandertal characteristics which were used until around 600,000 years ago.
Beds above these contained tools from a Kenya-Capsian industry made by modern humans and are termed the Masek Beds (600,000 to 400,000 years ago), the Ndutu Beds (400,000 to 32,000 years ago), and the Naisiusiu Beds (22,000 to 15,000 years ago).
Also located on the rim of the Gorge is the Olduvai Gorge Museum. This Museum presents exhibitions pertaining to the Gorge's history.
Olduvai is the location of the first monolith in Arthur C. Clarke's 2001: A Space Odyssey series of books.
Olduvai is also the theme of the Olduvai theory, which states that industrial civilization will have a lifetime of less than or equal to 100 years.
[edit] References
- Cole, Sonia. Leakey’s Luck. Harcourt Brace Jovanvich: New York, New York, 1975
- Joanne Christine Tactikos (2006) A landscape perspective on the Oldowan from Olduvai Gorge, Tanzania ISBN 0542156989
- Leakey, L.S.B., By the Evidence: Memoirs 1932-1951, Harcourt Brace Jovanavich, New York, 1974, ISBN 0-15-149454-1.
- Leakey, M.D., 1971: Olduvai Gorge: Excavations in beds I & II 1960- 1963, Cambridge University Press, Cambridge; Disclosing the Past, Doubleday & Co., New York, 1984, ISBN 0-385-18961-3.
[edit] External links
