Answer;
-Sea-floor spreading
Sea floor spreading is process that takes place at mid-ocean ridges, evidence is found in magnetic minerals on the ocean floor.
Step-by-step explanation;
-Seafloor spreading is a geologic process in which tectonic plates; large slabs of Earth's lithosphere; split apart from each other.
-Seafloor spreading and other tectonic activity processes are the result of mantle convection. Mantle convection is the slow, churning motion of Earth’s mantle. Seafloor spreading occurs at divergent plate boundaries. As tectonic plates slowly move away from each other, heat from the mantle’s convection currents makes the crust more plastic and less dense.