Super interesting read from Graham Hancock on the cataclysmic events that shook the earth at the onset of the Younger Dryas 12,800 years ago. North America payed a heavy price...

...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.4 ...

...The coauthors of the 2017 platinum paper chose North America, the suspected epicenter of the Younger Dryas cataclysm—and also their home turf—to test this prediction by establishing “whether or not a Pt anomaly exists in terrestrial sediments of YD age that is similar to that reported from the GISP2 ice core.”6

It sounds low-key, but much was at stake. If soil samples showed platinum to be at normal background levels in the YDB layer across North America, then Petaev’s prediction would be false and the Younger Dryas Impact Hypothesis would suffer serious collateral damage. On the other hand, if elevated levels of platinum were found, it would vindicate Petaev and give further strong support to the hypothesis that cosmic impacts caused the Younger Dryas cataclysm.

....The Nebraska Rainwater Basins are not as well known as the Carolina Bays but their elliptical shape is so similar that it is necessary to consider that they formed contemporaneously with the Carolina Bays by the same mechanisms. … The objective of the Glacier Ice Impact Hypothesis is to examine the characteristics of the Carolina Bays and Nebraska Rainwater Basins to determine whether these geomorphological features could have been created by secondary impacts from terrestrial material, such as glacier ice, ejected by an extraterrestrial impact.11

Zamora is the first to acknowledge that his “Glacier Ice Impact Hypothesis” depends heavily on prior work done by two other investigators, Michael E. Davias 12 and Thomas H. S. Harris,13 the former a specialist in “geospatial big data, data mining, computer graphics and algorithms” and the latter a dynamics and flight science expert at Lockheed Martin Corporation...
https://exploringrealhistory.blogspot.com/2020/11/part-11america-before-key-to-earths.html