The graphic shows the vast swathe of our planet that geologists call the Younger Dryas Boundary Field. Across this huge "fingerprint" spanning North America, Central America, parts of South America and most of Europe, the tell-tale traces of multiple impacts by the fragments of a giant comet have been found. Some of these fragments, were TWO KILOMETRES or more in diameter and they hit the earth like a blast from a cosmic scatter-gun around 12,800 years ago. This was near the end of the last Ice Age, from which our world had been emerging into a pleasant warming phase, but the impacts set in train a kind of "nuclear winter" and plunged the planet back into a period of deep cold and darkness that lasted until around 11,500 years ago. It is this period of extreme cold that is referred to as the Younger Dryas (after a characteristic Alpine tundra wildflower, Dryas octopetala) but it is only now, with conclusive evidence of the comet impact, that we can be sure what caused it. For the past seven years academics have been involved in such an intense dispute about whether or not a comet impact actually occurred 12,800 years ago that the implications of what it might have meant for the story of civilisation have not yet been considered at all. But every attempt to refute the impact evidence has in turn been refuted and the case for the Younger Dryas comet is now so compelling that it is time to widen the debate. It is clear now that some of the largest fragments of the comet hit the North American ice cap, which was still a mile deep 12,800 years ago, and caused cataclysmic flooding (I had the opportunity to explore some of the extraordinary effects of this on the ground in September 2014 when I drove from Portland, Oregon, to Minneapolis, Minnesota, with catastrophist researcher Randall Carlson). Simultaneously other large fragments hit the northern European ice cap with the same cataclysmic effects. The result was a global disaster that lasted for 1,300 years. It is, I believe, the "smoking gun" that made us a species with amnesia and wiped out almost all traces of a former high civilisation of prehistoric antiquity. But there were survivors, who preserved at least some of the knowledge of the civilisation that had been destroyed with the intention of transmitting it to future generations, so it is not an accident that the first traces of the re-emergence of civilisation, in the form of the earliest known megalithic architecture and the re-promulgation of agricultural skills, occur at Gobekli Tepe in Turkey 11,500 years ago -- a date that coincides exactly with the end of the Younger Dryas and the return to a more congenial global environment. Everything we have been taught about the origins of civilisation occurs AFTER 11,500 years ago -- in other words AFTER the radical punctuation mark of the Younger Dryas. It is what happened before that we desperately need to recover. These are amongst the mysteries that I am exploring in "Magicians of the Gods", the book that I have been researching for the past three years and am now in the midst of writing.
Graphic from Kinzie, Firestone, Kennett et al. "Nanodiamond-Rich Layer across Three Continents Consistent with Major Cosmic Impact at 12,800 Cal BP", The Journal of Geology, 2014, volume 122, p. 475–506.