The "new" recycled oceanic crust is formed by subduction at diverging limits.
Subduction occurs when a tectonic plate infiltrates under the other tectonic plate. When this occurs, the slow movement of the heavier plate causes an increase in temperature in the oldest rocks on the seabed. It also causes increased pressure. In this area, the melted earth crust (due to the temperature) is able to rise to the surface, forming the "new" oceanic crust.
