Gademotta

Coordinates: 8°03′N 38°15′E / 8.050°N 38.250°E

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.

The Gademotta Formation site-complex was discovered in the early 1970s by a team of researchers under the leadership of Fred Wendorf and Romuald Schild.[1] This team conducted several excavations in 1972 and 1973, recovering tens of thousands of stone artifacts. Renewed research in the Gademotta Formation was encouraged by new techniques that allowed for a more precise 40Ar/39Ar age of the site published in 2008.[2]

An age of over 279,000 years old is published for the oldest Middle Stone Age site in the Formation.[2][3] Although similar in age with the oldest Middle Stone Age site in the Kapthurin Formation, Kenya,[4] the oldest occupation at Gademotta is characterized by technological elements that are exclusively attributable to the Middle Stone Age. Stone-tipped throwing spears of that age have been studied; they predate known Homo sapiens fossils.[3][5]

References

  1. F Wendorf, R Schild (1974) A Middle Stone Age Sequence from the Central Rift Valley, Ethiopia. Polska Akademia Nauk, Warsaw.
  2. 2.0 2.1 LE Morgan, PR Renne (2008) Diachronous dawn for Africa’s Middle Stone Age: new 40Ar/39Ar ages from the Ethiopian Rift. Geology 36: 967-970
  3. 3.0 3.1 Y Sahle et al. (2014) Chronological and behavioral contexts of the earliest Middle Stone Age in the Gademotta Formation, Main Ethiopian Rift. Quaternary International, 331: 6-19. doi.org/10.1016/j.quaint.2013.03.010
  4. AL Deino, S McBrearty (2002) 40Ar/39Ar dating of the Kapthurin Formation, Baringo, Kenya. Journal of Human Evolution 42: 185-210.
  5. Sahle, Y.; Hutchings, W. K.; Braun, D. R.; Sealy, J. C.; Morgan, L. E.; Negash, A.; Atnafu, B. (2013). Petraglia, Michael D, ed. "Earliest Stone-Tipped Projectiles from the Ethiopian Rift Date to >279,000 Years Ago". PLoS ONE 8 (11): e78092. doi:10.1371/journal.pone.0078092. PMC 3827237. PMID 24236011.