All this truth is very, umm, impressive without data.
But 5000 years ago, seems to be more likely when the ‘great deluge’ was: 8’ of river mud that dates to 5000 ya in the Persion Gulf region, the (admittedly disputed) Burkle crater, the sudden worldwide attempts at pyrimid construction by cultures near the ocean; the Epic of Gilgamesh; the Biblical Noah story, tree ring dating… all seem to point to an asteroid strike in the Indian Ocean.
13 kya seems to more point to the flooding of the Black Sea, a minor if very impressive event.
12 kya, there was some event in the Americas that caused the Clovis Culture extinction and the extinction of American horses and other species: possibly an asteroid strike in Alaska; but who knows?
But if a story can’t get its recent history right, what are the chances it would get its modern history right?
I’m inclined to think the gold theory is better explained in other ways. Conspiracy theories would seem a more rational choice.