Cosmic impact, the Younger Dryas, Abu Hureyra, and the inception of agriculture in Western Asia
Andrew M. T. Moore & Douglas J. Kennett A.J. Ammerman & T. Davis (eds), Island Archaeology and the Origins of Seafaring in the Eastern Mediterranean, Eurasian Prehistory 10 (1-2) (2013): 57-66
The Younger Dryas was a major environmental event in the transition from Pleistocene to Holocene. The onset of this 1,200 year episode of cold, dry climate ca. 12,900 cal BP was sudden and swift. Recent evidence suggests that it was triggered by the impact of a comet or asteroid that fragmented in the Earth’s atmosphere. The effects of this impact were felt over a wide area of the northern hemisphere. It appears to have destabilized the Laurentide ice sheet, causing a pulse of meltwater to flow into the North Atlantic, which precipitated the Younger Dryas. The onset of the Younger Dryas was the catalyst for the transition from foraging to farming at Abu Hureyra, an early village in Syria. New evidence from the site suggests that the same cosmic event caused an airburst near Abu Hureyra. The evidence comes from soil samples dated to ca. 12,900 cal. BP, which contain glass impact spherules and scoria-like objects that formed at temperatures above 2,200°C. These are comparable to melt products from cosmic impacts elsewhere on Earth. The airburst would have destroyed the settlement and many of its inhabitants. Yet occupation resumed there, apparently immediately afterwards. Following the airburst and associated inception of the Younger Dryas, the environment around the site changed to an arid open steppe. This obliged the inhabitants of Abu Hureyra to alter their economy. Accordingly, they adopted farming and also modified their foraging practices to suit the new ecological circumstances.