The Nazca Plate is an oceanic plate. This means it is made up of oceanic crust, which is denser and thinner than continental crust.

Oceanic crust is typically composed of:

* Basalt: A dark-colored, fine-grained igneous rock.

* Gabbro: A coarse-grained igneous rock similar in composition to basalt.

These rocks are formed from the cooling and solidification of magma that erupts at mid-ocean ridges.