Studies of rock samples from sites spanning a portion of North America from the Channel Islands of Pacific California to the Midwestern creeks of Oklahoma failed to turn up any evidence of the 'Younger Dryas Impact Hypothesis', says Doctor Tyrone Daulton of Washington University in Saint Louis USA. The missing evidence? Diamonds.
     For a decade, the impact theory has posited a period of sudden cooling around 12,900 years ago (known as the Younger Dryas event), caused by dust in the atmosphere resulting from widespread wildfires after the impact of a meteorite, comet, or other celestial object, leading to the extinction of animals such as the mammoth and the mastodon, and the decline of the Clovis culture.
     Experts don't dispute that the cold snap occurred. The most widely held theory is that it was caused by changes in ocean currents and climate patterns following a rapid influx of fresh water from the melting of glaciers at the end of the Ice Age.
     Supporters of the impact hypothesis argue that proof can be found at a microscopic scale, in the form of nano-sized diamond crystals, produced by the energy of the impact.
     Dr Daulton - known for his research into the formation of diamonds in space (such as during the birth of stars) - decided to do his own research, concluding that the "nano-diamond" evidence reported by impact proponents is not true diamond, but hypothetical phases of carbon called "n-diamonds" or "i-carbon" whose very existence is controversial.
     Daulton says his observations of the tiny spheres may explain why they may have been misidentified. Rather than being made of pure carbon, they contain nanoparticles of copper and copper oxide which can scatter light and electrons into diffraction patterns nearly identical to those attributed to the hypothetical carbon structures.

Edited from Western Digs (9 February 2017)