1. How does sea-floor spreading occur? A. New materials are being added to the asthenosphere. B. Earthquakes brake apart the ocean floor. C. Sediments accumulate at the area of spreading. D. Molten material beneath Earth's crust rises
New seafloor rock is continually being formed at mid-ocean ridges and old seafloor rock is continually removed at ocean trenches. If the rock on the continents compare with the age of the oldest rocks on the seafloor ?