Oceanic crust is continuously created at mid-ocean ridges and destroyed (recycled) at convergent boundaries. The age of oceanic crust, therefore, varies according to its distance from the mid-ocean ridge. Near the mid-ocean ridge, the crust is typically less than 1 million years old. Crust that is farther away from the ridge is progressively older. On average, the age of the Earth's oceanic crust is estimated to be about 70-80 million years.

Here's a simplified breakdown of the average age of oceanic crust in different regions:

- At the mid-ocean ridges: less than 1 million years

- Within a few hundred kilometers from the mid-ocean ridges: < 20 million years

- Pacific Ocean basin: ~100 million years (the oldest due to the large size and slower tectonic activity of the Pacific)

- Atlantic Ocean basin: ~60-80 million years

- Indian Ocean basin: ~70-100 million years

It is important to note that these are just average age estimates, and there can be local variations and exceptions.