I believe in the continental drift theory. I believe this because the continental plates are still moving. back the the ice age was an important role in this i believe . Because the water froze up then when it melted there was a huge rush of water . that rush of water may of impacted on the athosphere or crust causing it so shatter. then with the shock wave of the shatter they / the continants rode their way outta here. and that is my theory. thanks bye.