image: Harcha Valley in the Bale Mountains with today's vegetation. During the Middle Stone Age occupation, a valley glacier blocked the access to the central Plateau. Nevertheless, prehistoric humans extracted (at 4240 masl: the ridge on the left-hand side of the photo) obsidian to produce their tools. This material relates to a paper that appeared in the August 9, 2019, issue of Science, published by AAAS. The paper, by G. Ossendorf at University of Cologne in Cologne, Germany, and colleagues was titled, "Middle Stone Age foragers resided in high elevations of the glaciated Bale Mountains, Ethiopia." view more
Credit: A.R. Groos