Here's why:
* Continental crust is thicker and less dense than oceanic crust, meaning it's less likely to be recycled back into the Earth's mantle through subduction.
* Continental crust is constantly being renewed, but the process happens much slower than the formation and destruction of oceanic crust.
* Some of the oldest rocks on Earth are found in continental shields, ancient and stable parts of continents that have been largely untouched by tectonic activity for billions of years.
So, there is no single answer to how old continental rocks are because their ages vary widely. However, they can be significantly older than rocks found in the Earth's oceans.
