... the Omo–Turkana Basin at the time was low. Thus the record of climatic influence on deposition in the Omo–Turkana Basin, previously shown for the Kibish Formation (≤200 ka), extends at least to early Pleistocene time. 17 6 2005 14 12 2004 Fifteen different tuffs have been analysed...

...Figure 2 Stratigraphic relations between the Kibish Formation in its type area and at Natodomeri I, where KNM-ND 59673 was recovered. ...

...J. L. Ballais GeoRef, Copyright 2004, American Geological Institute. 1979 Africa Cenozoic cuestas East Africa erosion features Ethiopia fault scarps geomorphology Holocene Kibish Formation landform evolution lower Pleistocene Nakwas Neogene Omo River Omo Valley...

... - 168 , doi: 10.1016/j.quascirev.2016.09.020 Brown FH , McDougall I , Fleagle JG ( 2012 ) Correlation of the KHS Tuff of the Kibish Formation to volcanic ash layers at other sites, and the age of early Homo sapiens (Omo I and Omo II) . Journal of Human Evolution 63 : 577...

... c . 32 m above the base of the Shungura Formation ( de Heinzelin 1983 ). On the basis of glass analyses, Brown & Fuller (2008) showed that the Lokochot (= A) Tuff also occurs in the Nkalabong Formation ( Butzer 1971, 1976 ) in the Kibish area ( Fig. 1 ), and there it contains pumice clasts...

..., 2008 ). The apparently oldest fossils assigned to H. sapiens are from the Kibish Formation in the Omo, bracketed by 40 Ar/ 39 Ar dates to between 104 ± 14 ka and 196 ± 4 ka, with an inferred age of 195 ± 10 ka ( McDougall et al., 2005 ). H. sapiens from Herto are dated by 40 Ar/ 39 Ar to between 160...

.... , Roeland , J.C. , and Guiot , J. , 1990 , Temperature and rainfall estimates for the past 40 000 years in equatorial Africa : Nature , v. 346 p. 347 – 348 . Butzer , K.W. , Brown , F.W. , and Thruber , D.L. , 1969 , Horizontal sediments of the lower Omo valley; the Kibish...

... in appearance, others pale grey. These pumice clasts have abundant anorthoclase phenocrysts, readily separated for dating purposes. The Chibele Tuff is overlain by about 2 m of mudstone and followed upward disconformably by about 5 m of sediments assigned to the much younger Kibish Formation ( Butzer...

... a significant hiatus, and that for the Nachukui Formation is derived from Harris et al. (1988) with minor modification. The sequence at Kanapoi, to the east of Loperot, is after Leakey et al. (1998) and Feibel (2003) , and the sequence at Kibish to the north of Lake Turkana is after Brown & Fuller...

... Foundation, the National Geographic Society, and the L. S. B. Leakey Foundation to F. H. Brown for work on the Koobi Fora and Nachukui formations, by grants to John G. Fleagle and F. H. Brown for work on the Kibish Formation, and by grants to Meave G. Leakey for work at Koobi Fora, Lothagam and Kanapoi...

... , pp 285 – 312 Brown FH , Fuller CR ( 2008 ) Stratigraphy and tephra of the Kibish Formation, southwestern Ethiopia . Journal of Human Evolution 55 : 366 - 403 , doi: 10.1016/j.jhevol.2008.05.009 Campisano CJ , Feibel CS ( 2008 ) Depositional environments...

... the region into four approximately north-south–trending, fault-bounded valleys comprising two or more basins ( Figs. 3 and 4 ). The Kibish basin marks the northward extent of the West Turkana rift of northern Kenya, which contains Eocene(?)–Oligocene to Pliocene volcanic strata interbedded...

... (Pangani), and southwestern Tanzania (Rukwa-Malawi) also show evidence for renewed faulting and exhumation at 60–45 Ma. The brown ellipse outlines an area of ~7-Ma magmatism and platform formation in the Indian Ocean between Africa and Madagascar. Nm indicates the Nyamuragira Volcano, and Ng indicates...

... that precipitation levels greater than 80 mm/yr could not have persisted for periods longer than tens to hundreds of years ( Amit et al., 2006 ). Thus, the wet episodes were too short to cause the development of calcite horizons in the soils but long enough to allow the formation of thin speleothem laminae...

... ; Gebregiorgis et al. 2021 ), the Pleistocene Naivasha Basin, Kenya ( Trauth et al. 2001 ), and the Pliocene–Pleistocene Chemeron Formation of the Baringo Basin, Kenya ( Minkara 2017 ). Analcime indicates more saline conditions because it is favored by a higher Na/K ratio, typical of more saline conditions...

... Ar experimental results from four tuff beds Isochron Analysis* Apparent Ages* Name (formation) mineral analysis type location n SUMS (N – 2) 40 Ar/ 36 Ari ± 2 σ Isochron Age (Ma) ± 2σ‡ average K/Ca ± 2σ MSWD Weighted Mean Age (Ma) ± 2σ‡ ±2σ§ ±2σ|| Notes...