Sea floor spreading/Divergent translation
The creation of new oceanic basaltic crust at divergent plate boundaries called mid-ocean ridges. Material from the asthenosphere becomes molten as convection currents cause it to rise toward the thin upraised boundary between plates there. /as it solidifies, it becomes new crust. Because new oceanic crust is being created there, older oceanic crust is being destroyed at trenches, where the colder, more dense oceanic crust is being drawn into the asthenosphere, completing the roughly 200 million year oceanic crust recycling period.