* Formation Process: Oceanic crust is constantly being created at mid-ocean ridges where magma rises from the mantle and cools. This process is called seafloor spreading.
* Subduction: Older oceanic crust is denser than the mantle and is subducted (pulled down) beneath continental crust at subduction zones. This process destroys the oceanic crust.
Age Comparison:
* Continental Crust: The oldest continental crust is about 4.03 billion years old, found in the Nuvvuagittuq Greenstone Belt in Canada. This makes it nearly as old as the Earth itself.
* Oceanic Crust: The oldest oceanic crust is only about 200 million years old. This is because it is constantly being recycled through the subduction process.
In summary:
Continental crust is much older than oceanic crust because:
* Continental crust is not constantly being created and destroyed like oceanic crust.
* Oceanic crust is recycled through subduction, while continental crust is generally more stable.
