Yes, V discusses the "Mount Sinai a Volcano" book (which at first actually sounds reasonable, pillar of fire by night, pillar of cloud during the day), the author of which hiked all over the Sinai and elsewhere trying to find a volcanic peak as a candidate. He failed.
Velikovsky's Planets in Collision hypothesis finally bit the dust when the Venera series of Venus landers found no oil on Venus. I had already decided against the wandering planets because there appears to be no mechanism for Mars, earth and Venus to have been flying around in wild orbits so recently and then to be in fairly circular orbits now.