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 (48 km) long. The gorge is named after the Maasai word for the wild sisal plant Sansevieria ehrenbergii, commonly called Oldupai.
Chasing a fancy butterfly in the green wilds of Tanganyika 50 years ago. a German entomologist named (Wilhelm) Kattwinkel tumbled off a rocky ledge and nearly killed himself. When he regained his senses, he found himself in an anthropologist's dream world: an erosion-created rift with layer after layer of fossils, bones and ancient artifacts. The find was named Olduvai Gorge, and Kattwinkel's heirs ever since have been scrambling up and down its sun-baked sides in search of clues to man's earliest awakening. (Time, Friday 10 March 1961)
Excavation work there was pioneered by Louis and Mary Leakey beginning in 1931 and continued into the twenty-first century by Professor Fidelis Masao of the Open University of Tanzania supported by Earthwatch; there have also been teams from Rutgers University. 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 geology of Olduvai Gorge and the surrounding region was studied in detail by Richard L. Hay, who worked at the site between 1961 and 2002.
The stratigraphy is extremely deep and layers of volcanic ash and stones allow radiometric dating of the embedded artifacts, mostly through potassium-argon dating and Argon–argon dating. The base of the Olduvai sediments dates to slightly older than 2 million years, with the first artifacts (pebble tools and choppers) appearing slightly above. Nearby site Laetoli has a much older fossil record.
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 site of Frida Leakey Korongo North (commonly known as FLK North and named after Louis Leakey's first wife) bears the distinction of having the oldest known evidence of Elephant consumption, attributed to Homo ergaster around 1.8 million years ago. A nearly complete skeleton of the extinct Elephas recki was found in the lowest of its six occupation levels along with stone tools such as choppers and flakes. Large numbers of bone fragments of smaller animals found with it clearly identify FLK North as an early butchering site.
Above this, in Bed II, pebble tools begin to be replaced by more sophisticated handaxes of the Acheulean industry and made by H. ergaster. This layer has not yet been successfully dated, but likely falls between 1.75 and 1.2 million years.
Beds III and IV have produced Acheulean tools and fossil bones from more than 600,000 years ago.
During a period of major faulting and volcanism roughly 400,000 to 600,000 years ago, the Masek Beds were made.
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 also the theme of the Olduvai theory, which states that industrial civilization will have a lifetime of less than or equal to 100 years.
The variant "Oldupai" is the Maasai word for the wild Sisal plant that grows in the gorge; some claim the more common spelling "Olduvai" is the result of a mis-hearing of the word by colonial visitors. The latter spelling is not used locally.
Seven Views of Olduvai Gorge is a 1994 novella by science fiction author Mike Resnick. It won the year's Nebula Award for Best Novella and the 1995 Hugo Award for Best Novella. The story concerns an archaeological expedition sent to Earth after humanity's alleged extinction.
Olduvai is used in the science-fiction movie Doom as a name of research facility on Mars. It was built around the ancient subspace gateway, linked with a similar device that was excavated on Earth. The plot is based on the theory that life on Earth originated from Mars.
In Arthur C. Clarke's novel , the monolith that led to the creation of Homo sapiens is discovered in Olduvai.
In Larry Niven's book Protector, one of the aliases used by Jack Brennan after his conversion into a Pak Protector is "George Olduvai".
