The earliest Oldowan stone tools were first produced 2.6 million years ago at Gona in the Afar region of Ethiopia. These tools lasted for roughly 1 million years with little technological/behavioural changes. Following the Oldowan, Acheulian stone technology, which employed large cutting tools, appeared about 1.75 million years (Ma) ago in East Africa. Investigating the timing and technological shift in uninterrupted archaeology-rich deposits is crucial, prompting the GONA PROJECT (The Oldowan-Acheulian transition and the emergence of the Acheulian industry, field and laboratory investigations at the Gona Plio-Pleistocene archaeological sites, Ethiopia) to study this important behavioural issue in human evolution. Detailed surveys and excavations were carried out targeting deposits dated to the 2.0-1.6 Ma interval, and freshly exposed stone artefacts and fauna (including bone/tooth fragments) were recovered. Seven bone/tooth fragments and 50 artefacts were excavated in a 13-square-metre area, with several cores that allow assessment of the stone technology of the toolmakers of that period. Faunal specimens collected from the sites could also be useful in providing behavioural and palaeo-environmental information. Volcanic ashes and palaeomagnetic samples were collected to resolve the age of the sites. Samples were taken back to Spain and to the United States for analysis. The team conducted surveys in order to look more closely at the sources of the raw materials associated with the archaeological sites for experimental knapping and also for planned brain imaging studies. Results indicate that the Oldowan-Acheulian transition was both complex and rapid. The toolmakers at this time sought out stone tools, placing major emphasis on their heavy weight and large size, with minimum effort put in to standardising their shape. The work can be useful for prehistorians and other archaeological studies in the future.
Tool technology, Oldowan, stone tools, Ethiopia, Acheulian, GONA PROJECT