The Karari Escarpment is part of the Koobi Fora Formation, which records stages in human evolution over a 3 million period, from ca. 4 to 1 million years ago. We surveyed and excavated mainly in the Upper KBS and lower Okote Members around the crucial age of human evolution of 1.6 million years ago. The stratigraphy is composed of "Member" strata of sediments which derive their names from volcanic ash layers deposited by fluvial activity and dated by various techniques including radiometric (Potassium-Argon and Argon-Argon) and magnetic reversal. The meandering proto-Omo river with its shifting delta and associated floodplains dominated the region at 1.6 million years and provided the backdrop of important transitions in human evolution. To better understand the context in which human ancestral populations lived, we collected a large number of fossils of extinct fauna for the purpose of further paleoenvironmental reconstruction.
