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How does new oceanic crust form at mid-ocean ridges?

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Watch Earth's Continents Move — paleogeography Watch a time-lapse of Earth changing through geologic time, from the Cambrian Era to the projected period of Pangea Proxima.

In the context of paleogeography and plate tectonics, new oceanic crust is created at mid-ocean ridges through a process known as seafloor spreading.12

This process occurs at divergent plate boundaries where tectonic plates move apart. As the plates diverge, the underlying mantle—specifically the asthenosphere—rises toward the surface. Due to the decrease in pressure as the mantle material ascends, it undergoes partial melting to produce magma. This molten material wells up into the rift zone at the ridge crest, where it cools and solidifies to form new oceanic crust.1324

The resulting crust is composed of several layers, including basaltic lavas, sheeted dikes, and gabbro layers. As spreading continues, the newly formed crust is pushed laterally away from the ridge axis, causing the ocean basin to widen over time. This mechanism is sustained by gravitational forces and mantle convection, which continuously provide the space and material necessary for the ongoing creation of the seafloor.52416