Lake-level changes and hominin occupations in the arid Turkana basin during volcanic closure of the Omo River outflows to the Indian Ocean

A significant lake-level rise in Lake Turkana, coinciding with volcanic closure of the Omo River outflow to the Indian Ocean between 2.17–1.95 million years ago (Ma), was identified through sedimentary analysis and tephrochronology. This asynchronous phase, occurring during an insolation minimum, resulted in an endorheic lake system characterized by increased alkalinity and a notable archaeological hiatus. The study reconstructed lake levels from 2.4 to 1.7 Ma using sedimentary facies, cyclostratigraphy, and paleochemical properties analyzed via inductively coupled plasma techniques. Findings suggest that hominin coastal occupations resumed during subsequent insolation/eccentricity maxima when Lake Turkana reopened its outflow to the Nile basin, indicating a link between lake dynamics, volcanic activity, and human settlement patterns in the arid Turkana basin.

Boës, X., Prat, S., Arrighi, V., Feibel, C., Haileab, B., Lewis, J., & Harmand, S. (2018). Lake-level changes and hominin occupations in the arid Turkana basin during volcanic closure of the Omo River outflows to the Indian Ocean. Quaternary Research, 91(2), 892–909. https://doi.org/10.1017/qua.2018.118