1. Oceanic Crust:

* Composition: Primarily composed of basalt, a dark-colored, fine-grained igneous rock. It also contains gabbro, a coarse-grained igneous rock.

* Density: Denser than continental crust.

* Thickness: Relatively thin, averaging about 7 kilometers (4 miles) thick.

* Age: Younger than continental crust, typically less than 200 million years old.

* Location: Found beneath the ocean basins.

2. Continental Crust:

* Composition: More diverse, containing a variety of rocks, including granite, sedimentary rocks, and metamorphic rocks.

* Density: Less dense than oceanic crust.

* Thickness: Thicker than oceanic crust, averaging about 35 kilometers (22 miles) thick, but can reach up to 70 kilometers (43 miles) in some areas.

* Age: Older than oceanic crust, with some parts dating back billions of years.

* Location: Forms the continents and the shallow areas around them.

It's important to note that both types of crust are part of the lithosphere, which is the rigid outermost layer of the Earth.