Using paleosols to reconstruct past environments before, during and after periods of Anatomically Human Migration at Gona, Ethiopia

Environmental change is thought to have driven dispersals of Anatomically Modern Humans (AMH) out of Africa, yet the precise landscape context of these migrations remains unclear. Furthermore, river-based archives of paleoenvironment during periods of dispersal are scarce. Gona, an area in northeastern Ethiopia with one of the most continuous records of East African Paleolithic and Neolithic archaeology, contains abundant Middle to Late Pleistocene river deposits interbedded with volcanic ash. This study examines the physical and chemical changes of 11 fossilized soils (paleosols) extracted from Gona’s paleoanthropological sites that range in age from the Middle to the Late Pleistocene (~380-11 ka). The paleosols from Gona yield insight into the landscapes with which our earliest direct ancestors interacted, as they are a dynamic biogeochemical archive of weathering, related to the surrounding environment at the time of formation. We focus on paleo-Vertisols or paleosols with vertic features that formed in distal floodplain settings to provide a control on landscape position. The paleosols at Gona record evidence of wetter paleoclimates during periods of AMH migration and suggest that this terrestrial record is a unique source for paleoenvironmental data. This localized dataset complements additional regional-scale paleoenvironmental records when interpreting the forcing and responses of Out-of-Africa migrations