Oceanic Crust:
* Basalt: A dark-colored, fine-grained volcanic rock rich in magnesium and iron. It's the dominant rock type in the upper layers of the oceanic crust.
* Gabbro: A dark-colored, coarse-grained intrusive igneous rock that's the deeper, denser equivalent of basalt.
* Peridotite: A greenish, coarse-grained rock found in the mantle beneath the oceanic crust. It's primarily composed of olivine and pyroxene minerals.
* Sediments: Oceanic crust is covered by a layer of sediments, mainly made up of tiny particles of shell, plankton, and sand.
Continental Crust:
* Granite: A light-colored, coarse-grained igneous rock that's rich in quartz and feldspar. Granite is common in the upper layers of continental crust.
* Diorite: A medium-colored, coarse-grained intrusive igneous rock, similar to granite but with less silica and more sodium and calcium.
* Gneiss: A metamorphic rock formed from granite or other igneous rocks under intense pressure and heat.
* Schist: Another type of metamorphic rock, often formed from shale, that has a layered or foliated appearance.
* Sedimentary rocks: These rocks form from the accumulation and cementation of sediments. Common types include sandstone, limestone, and shale.
Key Differences:
* Composition: Oceanic crust is denser and richer in magnesium and iron, while continental crust is less dense and more rich in silica and aluminum.
* Thickness: Continental crust is significantly thicker than oceanic crust.
* Age: Oceanic crust is much younger than continental crust, as it is constantly being recycled through plate tectonics.
Important Note: While these are the major components, the actual composition of both oceanic and continental crust can vary significantly based on location and geological history.
