.... Stratigraphically higher tuffs and their ages include the Ninikaa Tuff, 3.06 ± 0.03 Ma; the KBS Tuff, 1.88 ± 0.02 Ma; the Malbe Tuff, 1.86 ± 0.02 Ma; the Chari Tuff, 1.39 ± 0.02 Ma, and the Silbo Tuff, 0.74 ± 0.01 Ma, near the top of the sequence. The geochronology and geological data indicate at least three...

.... Feldspars from pumice clasts in about 15 tephra within the stratigraphic interval from the KBS Tuff to the Silbo Tuff have yielded precise ages that allow much finer definition of the numerical time framework for the sedimentary sequence between the KBS Tuff (1.869 ± 0.021 Ma) and the Chari Tuff (1.383...

... green thinly bedded claystones with ostracodes and molluscs (Cleopatra sp. dominant). This (10-30 cm) sandstone 300 F. H. BROWN & C. S . FEIBEL Table 1. Compositional data on tuffs of the Koobi Fora Formation Fe,03 CaO Ba Mn Nb Ti Y Zn Zr Chari Member Silbo Tuff 82-880 82-845 82-834 81-605 Chari Tuff...

... as young as the Nariokotome Tuff (1.33 Ma), and the Silbo Tuff (0.74 Ma). At Kalochoro, at least 350 m of motion is necessary in the past 1.3 Ma to bring the Kokiselei Tuff in contact with the Nariokotome Tuff. North of the Kokoi, at least 450 m of motion is necessary in the past 0.74 Ma to bring the Silbo...

... Suregei Isolate (SI; Williamson, 1980, see also Van Bocxlaer et al., 2008 ), a term no longer used in modern stratigraphic terminology; 4) between about 2.0 and 1.5 Mya the Turkana Basin held Lake Lorenyang, which is the focus of the present study; and 5) Lake Silbo is the fifth lake around 0.7 Mya...

..., Nachukui Formation) to 0.750 ± 0.006 (2 σ ) Ma (Silbo tuff, Chari Member, Koobi Fora Formation) ( McDougall and Brown 2006 , 2008 ) ( Fig. 1 ). The first tuff to be identified in the Turkana Basin was the KBS Tuff, which defines the lower boundary of the KBS Member ( Brown et al. 2006 ) ( Fig. 1...

... of Pliocene age, the Silbo Tuff (0.75 Ma), of Pleistocene age, has also been identified. One other correlation seems likely, and demonstrates very well the difficulties involved. Analyses of the Nabelete Tuff and the Akait Tuff of the Nachukui Formation compare favourably with an analysis of the Hope Tuff...