In Velikovsky's Worlds in Collision, he basically says that meteor or astroid strikes (or near strikes) may have knocked the earth of its axis in fairly short and violent order.
Lets hear it for Velikofsky.
Velikovsky was a kook. He also wrote a book "Twelfth Planet (I think)" that contends that there is a planet in an excentric orbit that brings it close to earth every 10,000 years. The inhabitants of this planet visit us at that time. They are Von Daniken's gods in space-ships. Velikovsky, like Von Daniken, never worries about evidence, or science when it comes to proposing his theories."