Explanation: The vast majority of volcanic activity on the planet occurs along the mid-ocean ridge, and it is the place where the crust of the Earth is born. The material that erupts at spreading centers along the mid-ocean ridge is primarily basalt, the most common rock on Earth.
Two processes ridge-push and slab-pull, are thought to be responsible for spreading at mid-ocean ridges. Ridge-push refers to the gravitation sliding of the ocean plate that is raised above the hotter asthenosphere, which creates a body force causing sliding of the plate down-slope.
