How do features formed in deep ocean basins and abyssal ridges
wind up on top of the continental crust? Wouldn't plate tectonics subduct them back into the mantle?
I was always under the impression the deep ocean basins were extruded from mid-ocean ridges and eventually slid under the continents, and the continents were made up of lighter rocks that floated on top of the basaltic abyssal plains.
If you can visit these sites on foot, they somehow must have found themselves lifted up onto the continents.