If you are interested in the grim geological future of New York, check this out. Africa is going to smash Manhattan like—oh, like the 1980s, you mean, but with continents mugging continents rather than oppressed individuals mugging people with jobs?

This documentary is a bit melodramatic but does explain plate tectonics effectively. If you are writing a far future sci-fi or fantasy setting you may want to view this as a prelude to your geological research.