The Stone Age was a broad prehistoric period during which stone was widely used to make stone tools with an edge, a point, or a percussion surface. The period lasted for roughly 3.4 million years and ended between 4,000 BC and 2,000 BC, with the advent of metalworking. It therefore represents nearly 99.3% of human history. Though some simple metalworking of malleable metals, particularly the use of gold and copper for purposes of ornamentation, was known in the Stone Age, it is the melting and smelting of copper that marks the end of the Stone Age. In Western Asia, this occurred by about 3,000 BC, when bronze became widespread. The term Bronze Age is used to describe the period that followed the Stone Age, as well as to describe cultures that had developed techniques and technologies for working copper alloys into tools, supplanting stone in many uses.
Stone tools have been used throughout human history but are most closely associated with prehistoric cultures and in particular those of the Stone Age. Stone tools may be made of either ground stone or knapped stone, the latter fashioned by a craftsman called a flintknapper. Stone has been used to make a wide variety of tools throughout history, including arrowheads, spearheads, hand axes, and querns. Knapped stone tools are nearly ubiquitous in pre-metal-using societies because they are easily manufactured, the tool stone raw material is usually plentiful, and they are easy to transport and sharpen.
The Olduvai Gorge or Oldupai Gorge in Tanzania is one of the most important paleoanthropological localities in the world; the many sites exposed by the gorge have proven invaluable in furthering understanding of early human evolution. A steep-sided ravine in the Great Rift Valley that stretches across East Africa, it is about 48 km long, and is located in the eastern Serengeti Plains within the Ngorongoro Conservation Area in the Olbalbal ward located in Ngorongoro District of Arusha Region, about 45 kilometres from Laetoli, another important archaeological locality of early human occupation. The British/Kenyan paleoanthropologist-archeologist team of Mary and Louis Leakey established excavation and research programs at Olduvai Gorge that achieved great advances in human knowledge and are world-renowned. The site is registered as one of the National Historic Sites of Tanzania.
Acheulean, from the French acheuléen after the type site of Saint-Acheul, is an archaeological industry of stone tool manufacture characterized by the distinctive oval and pear-shaped "hand axes" associated with Homo erectus and derived species such as Homo heidelbergensis.
The Oldowan was a widespread stone tool archaeological industry (style) in prehistory. These early tools were simple, usually made by chipping off one, or a few, flakes off using another stone. Oldowan tools were used during the Lower Paleolithic period, 2.9 million years ago up until at least 1.7 million years ago (Ma), by ancient Hominins across much of Africa. This technological industry was followed by the more sophisticated Acheulean industry.
Herto Man refers to human remains discovered in 1997 from the Upper Herto member of the Bouri Formation in the Afar Triangle, Ethiopia. The remains have been dated as between 154,000 and 160,000 years old. The discovery of Herto Man was especially significant at the time, falling within a long gap in the fossil record between 300 and 100 thousand years ago and representing the oldest dated H. sapiens remains then described.
The Lower Paleolithic is the earliest subdivision of the Paleolithic or Old Stone Age. It spans the time from around 3.3 million years ago when the first evidence for stone tool production and use by hominins appears in the current archaeological record, until around 300,000 years ago, spanning the Oldowan and Acheulean lithics industries.
The Levallois technique is a name given by archaeologists to a distinctive type of stone knapping developed around 250,000 to 300,000 years ago during the Middle Palaeolithic period. It is part of the Mousterian stone tool industry, and was used by the Neanderthals in Europe and by modern humans in other regions such as the Levant.
Koobi Fora refers primarily to a region around Koobi Fora Ridge, located on the eastern shore of Lake Turkana in the territory of the nomadic Gabbra people. According to the National Museums of Kenya, the name comes from the Gabbra language:
In the language of the Gabbra people who live near the site, the term Koobi Fora means a place of the commiphora and the source of myrrh...
The Middle Stone Age was a period of African prehistory between the Early Stone Age and the Late Stone Age. It is generally considered to have begun around 280,000 years ago and ended around 50–25,000 years ago. The beginnings of particular MSA stone tools have their origins as far back as 550–500,000 years ago and as such some researchers consider this to be the beginnings of the MSA. The MSA is often mistakenly understood to be synonymous with the Middle Paleolithic of Europe, especially due to their roughly contemporaneous time span; however, the Middle Paleolithic of Europe represents an entirely different hominin population, Homo neanderthalensis, than the MSA of Africa, which did not have Neanderthal populations. Additionally, current archaeological research in Africa has yielded much evidence to suggest that modern human behavior and cognition was beginning to develop much earlier in Africa during the MSA than it was in Europe during the Middle Paleolithic. The MSA is associated with both anatomically modern humans as well as archaic Homo sapiens, sometimes referred to as Homo helmei. Early physical evidence comes from the Gademotta Formation in Ethiopia, the Kapthurin Formation in Kenya and Kathu Pan in South Africa.
Olorgesailie is a geological formation in East Africa, on the floor of the Eastern Rift Valley in southern Kenya, 67 kilometres (42 mi) southwest of Nairobi along the road to Lake Magadi. It contains a group of Lower Paleolithic archaeological sites. Olorgesailie is noted for the large number of Acheulean hand axes discovered there that are associated with animal butchering. According to the National Museums of Kenya, the finds are internationally significant for archaeology, palaeontology, and geology.
The Bouri Formation is a sequence of sedimentary deposits that is the source of australopithecine and Homo fossils, artifacts, and bones of large mammals with cut marks from butchery with tools by early hominins. It is located in the Middle Awash Valley, in Ethiopia, East Africa, and is a part of the Afar Depression that has provided rich human fossil sites such as Gona and Hadar.
The Gregory Rift is the eastern branch of the East African Rift fracture system. The rift is being caused by the separation of the Somali plate from the Nubian plate, driven by a thermal plume. Although the term is sometimes used in the narrow sense of the Kenyan Rift, the larger definition of the Gregory Rift is the set of faults and grabens extending southward from the Gulf of Aden through Ethiopia and Kenya into Northern Tanzania, passing over the local uplifts of the Ethiopian and Kenyan domes. Ancient fossils of early hominins, the ancestors of humans, have been found in the southern part of the Gregory Rift.
The Gademotta Formation in the Main Ethiopian Rift Valley is known for its Middle Stone Age archaeological sites. It is located west of Lake Ziway. In addition to the type-site, which assumes the same name, the formation contains a cluster of sites at Kulkuletti, some 2.5 kilometres (1.6 mi) away. The near-lake environment and locally available obsidian may have attracted the continuous/repeated occupation of the area by Middle and Late Pleistocene hominins.
Anna Katherine "Kay" Behrensmeyer is an American taphonomist and paleoecologist. She is a pioneer in the study of the fossil records of terrestrial ecosystems and engages in geological and paleontological field research into the ecological context of human evolution in East Africa. She is Curator of Vertebrate Paleontology in the Department of Paleobiology at the Smithsonian Institution's National Museum of Natural History (NMNH). At the museum, she is co-director of the Evolution of Terrestrial Ecosystems program and an associate of the Human Origins Program.
The KBS Tuff is an ash layer in East African Rift Valley sediments, derived from a volcanic eruption that occurred approximately 1.87 million years ago (Ma). The tuff is widely distributed geographically, and marks a significant transition between water flow and associated environmental conditions around Lake Turkana shortly after 2 Ma.
The geology of Uganda extends back to the Archean and Proterozoic eons of the Precambrian, and much of the country is underlain by gneiss, argillite and other metamorphic rocks that are sometimes over 2.5 billion years old. Sedimentary rocks and new igneous and metamorphic units formed throughout the Proterozoic and the region was partially affected by the Pan-African orogeny and Snowball Earth events. Through the Mesozoic and Cenozoic, ancient basement rock has weathered into water-bearing saprolite and the region has experienced periods of volcanism and rift valley formation. The East Africa Rift gives rise to thick, more geologically recent sediment sequences and the country's numerous lakes. Uganda has extensive natural resources, particularly gold.
The geology of Virginia began to form at least 1.8 billion years ago. The oldest rocks in the state were metamorphosed during the Grenville orogeny, a mountain-building event beginning 1.2 billion years ago in the Proterozoic, which obscured older rocks. Throughout the Proterozoic and Paleozoic, Virginia experienced igneous intrusions, carbonate and sandstone deposition, and a series of other mountain-building events which defined the terrain of the inland parts of the state. The closing of the Iapetus Ocean formed the supercontinent Pangaea, and created additional small landmasses, some of which are now hidden beneath thick Atlantic Coastal Plain sediments. The region subsequently experienced the rifting open of the Atlantic ocean in the Mesozoic, the development of the Coastal Plain, isolated volcanism, and a series of marine transgressions that flooded much of the area. Virginia has extensive deposits of coal, oil, and natural gas, as well as deposits of other minerals and metals, including vermiculite, kyanite and uranium.
Gona is a paleoanthropological research area in Ethiopia's Afar Region. Gona is primarily known for its archaeological sites and discoveries of hominin fossils from the Late Miocene, Early Pliocene and Early Pleistocene. Fossils of Ardipithecus and Homo erectus were discovered there. Two of the most significant finds are an Ardipithecus ramidus postcranial skeleton and an essentially complete Homo erectus pelvis. Historically, Gona had the oldest documented Oldowan artifact assemblages. Archaeologists have since found older examples of the Oldowan at other sites. Still, Gona's Oldowan assemblages have been essential to the archaeological understanding of the Oldowan. Gona's Acheulean archaeological sites have helped us understand the beginnings of the Acheulean Industry.
Chesowanja is a Kenian archaeological site located in the north of the Kenya Rift Valley, east of Lake Baringo. The Chesowanja sites consist of quaternary sediments. The sites are home to various discoveries like fossils, evidence of human activity over a period of 2 million years and the remains of Australopithecus. Also, artefacts belonging to Oldowan technology, Acheulean tradition and later stone industries have been found.
