Oceanic crust is primarily composed of basaltic volcanic rock, which is formed from the solidification of molten lava from the Earth's mantle at mid-ocean ridges. Other components of oceanic crust include diabase, gabbro, and peridotite.

The oceanic crust is primarily made up of basaltic rocks. Basalt is a dark-colored, fine-grained rock that is formed from the rapid cooling of lava from volcanic eruptions. The oceanic crust is also composed of sediments that have been deposited on the ocean floor over time. These sediments can include sand, mud, and the remains of marine organisms.

Here are the typical compositions of the oceanic crust:

- Basalt: 60-70%

- Gabbro: 10-20%

- Peridotite: 10-15%

- Sediments: 5-10%

Continental crust

Continental crust is more complex in composition, comprising various rock types such as granite, gneiss, and schist. These rocks are primarily formed through the process of continental collision and mountain building over millions of years. The continental crust also includes sedimentary deposits, such as limestone, sandstone, and shale.

The continental crust is primarily made up of granite and other felsic rocks. Granite is a light-colored, coarse-grained rock that is formed from the slow cooling of magma deep within the Earth's crust. The continental crust is also composed of metamorphic rocks, which are rocks that have been changed by heat and pressure. These rocks include gneiss, schist, and marble.

Here are the typical compositions of the continental crust:

- Felsic rocks (granite, rhyolite): 60-70%

- Metamorphic rocks: 20-30%

- Sedimentary rocks: 10-15%