The Site
The culture that was discovered at Olduvai Gorge is known as Oldowan culture. Olduvai Gorge is a very important site located in Tanzania, on the Great Rift Valley, a wide flat plain formed approximately 20 to 25 million years ago. The site is situated on the Serengeti Plain within the boundary of Ngorongoro crater through the great lake region in east Africa. Olduvai Gorge is made famous by Louis S. B. Leakey, a British Palaeoanthropologist, born in Kenya, Africa, trained in Cambridge University, in Anthropology and Archaeology. Olduvai Gorge yielded more than 60 hominid fossils and countless stone tools made by early men.
The Gorge and its Geological Features
On the upper reaches of Olduvai River a steep gorge is formed along the banks of the river. Wall of the gorge is over three hundred feet high. This has exposed geological layers from a time called by geologists as Tertiary into Quaternary periods. From the exposed beds biological and cultural remains of early men are found in a datable context. Large number of fossil and cultural remains suggests that the area was inhabited by early man. The water bodies of the lakes of the rift valley is considered as “pluviometer; meaning that climatic condition and its changeover could be measured by the water levels in the lakes. Olduvai Gorge presents an excellent cross section of Kamasian pluvial deposit belonging to Middle Pleistocene time period. Fossils and artifacts were found from all the layers. On the basaltic base of the Gorge, several superposed beds were laid. Olduvai Gorge is divided into seven successive formations (Bed I to Bed VII).
Bed I(average thickness is 60 meters)
This is the lowest and the thickest deposit and consists of Lava. Bed I is dated by Potassium-Argon method. All the tool bearing areas and faunal remains came from the upper part of Bed I, belonging to dates ranging between 1.85 to 1.7 Myrs. Bed I is divided into five strata or layers. These are made up of clay stone and volcanic ash deposit of Ngongoro volcano. Bed I yielded tools belonging to Oldowan industry. This industry is divided into four evolutionary stages. 11.1.2.2 Palaeoecology of Bed I At the time of formation oflower part of Bed Iforested environment prevailed around the lake. By the time of deposition of middle portion of the bed mosaic environment with open woodland replaced the forest. Trees mingled with grassland surrounded the lake. This indicated that climate was changing to drier condition. Early hominines roamed the land at this time. Farther drying trend was found towards the upper part of Bed I, with open landscape which announced the beginning of a dry period.
Oldowan Culture
Homo habilis appeared in Bed I and lived up to the lower part of Bed II. Environment was mostly dry savannah type grassland. Tools of the industry were simple pebble tools, produced with the use of percussion, stone hammer or block on block technique. These are mostly choppers and chopping tools. These were simple, crude, multipurpose tools used for chopping, scraping and cutting. Mary Leakey classified Oldowan industry on the basis of their probable function. She classified them into (i) Heavy duty, (ii) Light duty, (iii) Utilized pieces and (iv) Debitages or waste materials. i) Heavy duty tools are mainly choppers. Those worked only on one surface is called unifacial chopper and those worked on both the surfaces to produce an edge is called bifacial. Discoids are tools with edges along the circular periphery. Polyhedrons are called as polyhedral and spheroids were probably used as hammer stones. ii) Flakes were classified into Light duty categories. These are scrapers, awls and burins. The first one is for scraping; the second for boring holes and last one is for engraving. iii) Utilized pieces were mostly without retouch but were used according to need. iv) Debitages are flakes without any retouch or use mark and probably were manufacturing waste products.
According to current method of classification Oldowan industry belongs to Mode 1 type but subdivisions are made into classic Oldowan and developed Oldowan. Classic Oldowan artifacts are found from Bed I and Lower part of Bed II and are dated to around 1.9 to 1.6 Myrs ago. Tools are made by detaching flakes from a pebble core with the help of hammer stone. Utilized materials were hammer stones and anvils. Developed Oldowan culture flourished around 1.6 million years ago. Tools include protohandaxes. These are trimmed more along the lateral sides and represented types between a chopper and a handaxe. Oldowan people could have used wood but no wooden item is preserved at Olduvai Gorge. Bone tools are found. Oldowan industry persisted for about 1 million years before the advent of Acheulian industry. Oldowan culture started almost 2 million years ago and developed through time into advanced forms and gave rise to bifacially worked handaxes and cleavers of the succeeding Acheulian culture. Acheulian culture with true handaxes and developed technologies are found from upper part of Bed II. Subsistence pattern of Oldowan hominid may be compared with those of chimpanzees. Like the apes they too lived mainly by collecting fruits and other vegetable food. They probably scavenged upon medium to large games. It is important to note that though the makers of Oldowan culture were Homo habilis but they also lived at the same time with some Austrlopithecines at Olduvai Gorge.
