Exposures of Plioce
ne a
nd Pleistoce
ne deposits i
n the Ileret regio
n i
nclude all eight members of the Koobi Fora Formatio
n a
nd represe
nt at least 533 m of sectio
n from the base of the Lo
nyumu
n Member to the top of the Chari Mb. This thick
ness is more tha
n twice that reported by earlier workers (
![]()
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not, vert, similar"" border=0>260 m) a
nd compares well with the composite sectio
n of the Koobi Fora Formatio
n (525 m). Thus the Ileret regio
n provides a very complete a
nd represe
ntative outcrop of the Koobi Fora Formatio
n. As Koobi Fora Formatio
n member bou
ndaries are placed at the base of specified tuffs,
not all member bou
ndaries ca
n be recog
nized i
n the Ileret regio
n. For this reaso
n, the stratigraphy is described i
n terms of the followi
ng members (thick
nesses i
n pare
ntheses): Lo
nyumu
n (110 m), u
ndiffere
ntiated Moiti a
nd Lokochot (104 m), Tulu Bor (54 m), Burgi (55 m), KBS (74 m), Okote (45 m), a
nd Chari (93 m). Moreover, the bou
ndary betwee
n the Okote Member a
nd the KBS Member i
n the Ileret regio
n is placed at a promi
ne
nt caliche which must closely approximate the age of the Okote Tuff i
n its type sectio
n.