http://www.users.on.net/~mkfenn/page9.htm

This long article (I have only included a small portion of this article, in order to really understand it, you have to read it from the site, or print it out) makes an incredible suggestion, borne from the studies of land and sea topography, along with the newer findings, as well as older, or the true beginnings of the America's. It is a long article, but I would suggest to print this out and read it all. I will post it here, and highlight the area where the author suggest the place name "Aztlan" comes from and where that place actually is:

The Golden Age

13,600 years ago In Aztec legends, was the beginning of the Age of the Second Sun - the “Golden Ageâ€