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[clarification needed] 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.[3][5]
References
^F Wendorf, R Schild (1974) A Middle Stone Age Sequence from the Central Rift Valley, Ethiopia. Polska Akademia Nauk, Warsaw.
^ abMorgan, LE; Renne, PR (2008). "Diachronous dawn for Africa's Middle Stone Age: new 40Ar/39Ar ages from the Ethiopian Rift". Geology. 36 (12): 967–970. Bibcode:2008Geo....36..967M. doi:10.1130/g25213a.1.
^ abSahle, Y; 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. Bibcode:2014QuInt.331....6S. doi:10.1016/j.quaint.2013.03.010.
^Deino, AL; McBrearty, S (2002). "40Ar/39Ar dating of the Kapthurin Formation, Baringo, Kenya". Journal of Human Evolution. 42 (1–2): 185–210. doi:10.1006/jhev.2001.0517. PMID11795974.
