* Composition: Continental crust is primarily made up of felsic rocks, which are rich in silica (SiO2) and have a lower density than oceanic crust. These rocks are typically granite, rhyolite, and andesite. Oceanic crust, on the other hand, is composed of mafic rocks, which are rich in magnesium (Mg) and iron (Fe). These rocks are typically basalt and gabbro.
* Density: Continental crust is less dense than oceanic crust, which is why it floats higher on the mantle. This is why continents are elevated above sea level, while the ocean floor is below it.
* Thickness: Continental crust is thicker than oceanic crust, ranging from 25 to 70 kilometers thick, while oceanic crust is only about 5 to 10 kilometers thick.
* Age: Continental crust is generally older than oceanic crust. Oceanic crust is constantly being created at mid-ocean ridges and destroyed at subduction zones, leading to a much younger average age. Continental crust, on the other hand, is much more resistant to destruction and can survive for billions of years.
Here's a quick analogy: Imagine a block of wood floating in water. This block represents the continental crust. Now imagine a thin sheet of metal also floating in the water. This sheet represents the oceanic crust. The wood is thicker and less dense, allowing it to float higher than the metal.
In summary, continental crust is the older, thicker, and less dense layer of Earth's crust that makes up the continents.
