I am a big fan of Graham Hancock. He has been given a very hard time by mainstream scientific community. Almost like the Inquisition and Gallileo. Yet many are now saying similar things. Always meant to write a piece on him. The asteroid theory has much credibility & serious scientific evidence to some sort of impact but something very extreme caused colossal ice shelfs & sheets to suddenly melt causing floods and worldwide firestorms.
After having written it and posted it I had the same afternoon an alert from 'Archaeology World' which I follow thatthe Cerutti Mastodon site in San Diego had confirmed that remains were CUT by humans 130,000years ago. Their findings are controversial ever since the find in 1990 suggested such a possibility. But they have double-downed on their original supposition with further evidence.
Graham Hancock gave a great interview with Joe Rogan on youtube a few yearsago. Worth a listen.
It is mind-blowing stuff.
Marc