Incredibly, Robert E. Howard's fictional account of the Thurian Age, cataclysm and Hyborian Age are eerily similar to what actually has happened.
BTW the Richat structure, or the Eye of the Sahara is almost certainly Atlantis. Yes....it is real and of the former age. Strabo indicates the usual date of about 12,500 BC for its demise.....along with the Giza and other megalithic highly advanced civilizations.
I assume this cataclysm to be the Tower of Babel judgment/disaster.