The theory of plate tectonics is supported by the eurasian and african plate are pushed away from the north and south american plates at the is where rocks are carried back into the mantle of the earth. iron can be magnetized by the magnetism of the earth. subduction of the ocean floor occurs in respond to the following based on your reading. why have rocks older than 200 million years never been found in the oceans? explain how the movement of tectonic plates is responsible for this recycling of the ocean floor.