In North America the evidence is that hunter-gatherers bounced back quite successfully within less than a millennium of the onset of the Younger Drya… - Graham Hancock

We can no longer think of the so-called Fertile Crescent of Sumeria as the cradle of civilization. What seems more likely from the large body of evidence I have compiled is that there were a number of cities built before this time which were submerged by rising sea levels at the end of the last ice age... It proved that the methods I was using, the combination of deciphering ancient myths and new technology, actually worked. Of course I still keeping an open mind, but it does suggest I am on the right track after all. Its mainstream archaeology and science that are blinkered.

As the discoverer and principal excavator of Murray Springs, [...] Haynes deserves credit for drawing attention to a very curious aspect of the site — a distinct dark layer of soil draped 'like a shrink-wrap,' as Allen West puts it, over the top of the Clovis remains and of the extinct megafauna — including Eloise.
Haynes has identified this 'black mat' (his term) not only at Murray Springs but at dozens of other sites across North America, and was the first to acknowledge its clear and obvious association with the Late Pleistocene Extinction Event. he speaks of the 'remarkable circumstances' surrounding the event, the abrupt die-off on a continental scale of all large mammals 'immediately before deposition of the ... black mat,' and the total absence thereafter of 'mammoth, mastodon, horse, camel, dire wold, American lion, tapir and other [megafauna], as well as Clovis people.'
Haynes notes also that 'The basal black mat contact marks a major climate change from the warm dry climate of the terminal Allerod to the glacially cold Younger Dryas.'
From roughly 18,000 years ago, and for several thousand years thereafter, global temperatures had been slowly but steadily rising and the ice sheets melting. Our ancestors would have had reason to hope that earth's long winter was at last coming to an end and that a new era of congenial climate beckoned. This process of warming became particularly pronounced after about 14,500 years ago. Then suddenly, around 12,800 years ago, the direction of climate change reversed and the world turned dramatically, instantly cold — as cold as it had been at the peak of the Ice Age many thousands of years earlier. This deep freeze — the mysterious epoch now known as the Younger Dryas — lasted for approximately 1,200 years until 11,600 years ago, at which point the climate flipped again, global temperatures shot up rapidly, the remnant ice sheets melted and collapsed into the oceans, and the world became as warm as it is today.

It was Cesare Emiliani who first drew serious attention to the possibility of post-glacial superfloods. In a paper published in Science magazine in 1975, he and a group of colleagues presented startling evidence from deep-sea cores from the north-eastern part of the Gulf of Mexico. The evidence revealed 'a 2.4 per cent isotopic anomaly between 12,000 and 11,000 years ago', which the authors correctly interpreted as having been caused by 'the occurrence of major flooding of ice meltwater into the Gulf of Mexico ... centring at about 11,600 years before the present'.