The geological and faunal context of Late Miocene hominid remains from Lukeino, Kenya

Hominid fossils have been recovered from four localities within the Late Mi ocene Lukeino Formation, Tugen Hills, Kenya. The sediments from which the f ossils came consist of fluvial and shallow lacustrine deposits. Some of the specimens are coated in a thin layer of carbonate of organic origin, sugge sting deposition and preservation in slightly alkaline water, while others are riddled with superficial cracks indicating exposure at the surface prio r to burial, Radioisotopic age determinations from lavas underlying and ove rlying: the Lukeino Formation, and from crystals from the sediments themsel ves, indicate an age of ca 6 Ma for these hominids. (C) 2001 Academie des s ciences / Editions scientifiques et medicales Elsevier SAS.