Looks like a good outline for a supercontinent.

Have you thought about your climate? I'm thinking that unless your planet's very small, the interior of the supercontintent is likely to be pretty dry, especially the eastern parts. Obviously where you put your mountains will have a big impact. The northernmost regions of the supercontinent could be an ice cap, or the planet could be ice-free and then warmer and wetter overall. Of course the cataclysm will change the climate a lot; the newly-created sea could bring rains to formerly dry regions.