Environment and collapse: Eastern Anatolian obsidians at Urkesh (Tell Mozan, Syria) and the third-millennium Mesopotamian urban crisis

► Examines exchange and social networks during a North Mesopotamian urban/arid crisis. ► Geochemical and magnetic sourcing of 97 obsidian artefacts from Tell Mozan, Syria. ► Before the crisis, six Eastern Anatolian obsidian sources represented among artefacts. ► Such diversity of Eastern Anatolian obsidians at a Syrian site is previously unknown. ► Dramatic changes during the crisis as obsidians came from two of the closest sources.