oa Ecosystem and Hydroclimate Conditions from a New Early Human Site at Olduvai Gorge (AGS, BED I, 1.84 Ma)

In this study, we focus on a newly discovered Early Pleistocene archaeological site – AGS (Alberto Gómez Site) – at Olduvai Gorge in Northeast Africa to identify coeval landscape resources via a multi-proxy perspective. We explore the distribution of four major compound classes (n-alkanes, n-alcohols, n-alkanoic acids, and sterols) and leaf-wax δ13C-δD compositions of 24 paleosoil samples excavated from a 24 m2 archaeological transect at AGS. Our multi-proxy geochemical interpretations of the Olduvai Zinj-Paleolandscape at 1.89 Mya reveal that AGS was located near the river/lake margins and was dominated by C3 aquatic plants and C4 grasses. Given the mosaic patchy ecosystem across the Zinj-Paleolandscape soil horizon and the molecular fossils studied here at AGS, we hypothesize that hominins at Olduvai Gorge, 1.9 ma years ago, selected the locations for their main activities conditioned by the presence of water resources within the landscape.