An international team of scientists has discovered new evidence of the cosmic impact in Abu Hureyra, Syria, at the beginning of the Young Dryas 12,800 years ago. The site consists of two settlements, two villages that archaeologists call Abu Hureyra 1 and Abu Hureyra 2, and which span over a chronological period of 4,000 years from the Epipalaeolithic, 13,000 to 9,000 years ago, to the Neolithic period.
The place where humans became farmers
Abu Hureyra witnessed the moment when the ancient nomadic people first settled and began to cultivate: they became farmers. Today the settlement is located under Lake Assad, bound by a large mound. However, before the 525 square kilometres, an artificial lake was formed by the construction of the Tabqa dam that would submerge the site, archaeologists were forced to excavate it urgently and were able to extract and carefully describe a lot of the materials found, including parts of houses, food and tools, a great deal of evidence that allowed them to identify the transition to agriculture nearly 12,800 years ago. It was undoubtedly one of the most important events in the cultural and environmental history of our Earth.
Archaeologists found melted glass among grains and cereals, as well as in early building materials and animal bones. According to experts, the characteristics of the melted glass indicate that it was made at extremely high temperatures, much higher than humans could reach at that time, so it was caused by... an object from space.
"Just so you can get an idea of how hot it was, such high temperatures would completely melt a car in less than a minute," said James Kennett, professor emeritus of geology at the University of California, Santa Barbara. Such intensity could only have been the result of an extremely violent, high-energy, high-speed phenomenon, something on the order of a cosmic impact.
Experts say Abu Hureyra is the first place to document the direct effects of a fragmented comet's collision on a human settlement. All of these fragments are part of the same comet that probably hit the earth at the end of the Pleistocene and exploded into the atmosphere. This influence contributed to the extinction of most large animals, including mammoths, horses and camels, the disappearance of the North American Clovis culture and the abrupt appearance of the first Ice Age.
"Our new findings are much more significant evidence of very high temperatures that can only be associated with a cosmic influence," Kennett says.
The cosmic impact hypothesis has grown in importance in recent years due to many recent discoveries, including a very young impact crater under the Hiawatha glacier of the Greenland ice sheet, as well as high-temperature melting glass and other similar evidence at an archaeological site in Pilauco in southern Chile.
"The village of Abu Hureyra would have been violently destroyed," Kennett said, thanks to this direct evidence of catastrophe in this early human settlement. An impact or explosion had to happen close enough to send massive heat and molten glass to this human settlement.
The researchers analyzed the glass for geochemical composition, shape, structure, formation temperature, magnetic properties and water content. The results showed that it formed at very high temperatures and contained minerals that were rich in chromium, iron, nickel, sulfides, titanium and even platinum and iridium-rich cast iron, all formed at temperatures above 2200 ºC.
According to the study, the melted glass was created "from the almost instantaneous melting and evaporation of regional biomass, soils and flood deposits, followed by immediate cooling".
Reference: Andrew M. T. Moore, James P. Kennett, William M. Napier, Ted E. Bunch, James C. Weaver, Malcolm LeCompte, A. Victor Adedeji, Paul Hackley, Gunther Kletetschka, Robert E. Hermes, James H. Wittke, Joshua J. Razink, Michael W. Gaultois, Allen West. Evidence of Cosmic Impact at Abu Hureyra, Syria at the Younger Dryas Onset (~12.8 ka): High-temperature melting at >2200 °C. Scientific Reports, 2020; 10 (1) DOI: 10.1038/s41598-020-60867-w