What evidence supports the theory of sea-floor spreading? There are three things?

Several things support the theory of seafloor spreading: 1. The measured radiometric ages of the sea floor become progressively older as you go from the middle of the ocean to the edges of the ocean, suggesting that new oceanic crust is created in the middle and then spreads to the side, like a conveyor belt. 2. We can directly observe lava coming out of mid-ocean ridges, creating new rock. 3. The direction of the earth's magnetic field is recorded in the rocks that make up the sea floor. There is a striped pattern parallel to mid-ocean ridges all along the ridge, that record a series of oscillations in the earth's magnetic field and suggest that oceanic crust that is equidistant from the ridge is also the same age (since it has identical magnetic properties). 4. Continental shelves on opposite sides of an ocean match up very closely with each other like puzzle pieces, suggesting that they were at one time joined. 5. Fossils found on the coasts of continents on opposite sides of an ...  more