As to the big blast are what ever caused an extension event, I believe it to be BS and it is not supported by fossil records..
“it is not supported by fossil records.”
I strongly urge you to read Firestone’s book. It does a very good job of describing the careful scientific process by which the scientists who wrote the book collaborated in examining a number of different types of evidence from different sub-branches of science to develop the book. They also traveled thousands of miles to examine the evidence, all of which points to the idea that something terrible came out of the heavens 13,000 years ago, and triggered the Younger Dryas world wide cooling. It is well written for a non-technical but educated reader.