* Density: Oceanic crust is denser than continental crust. This is because oceanic crust is primarily made of basalt, which is a denser rock than the granite that makes up continental crust.
* Plate Tectonics: The Earth's surface is divided into large plates that move and interact. When an oceanic plate collides with a continental plate, the denser oceanic plate bends and slides beneath the continental plate in a process called subduction.
Here's what happens during subduction:
1. Collision: The oceanic plate collides with the continental plate.
2. Bending: The denser oceanic plate bends downwards.
3. Subduction: The oceanic plate slides beneath the continental plate, sinking into the mantle.
4. Melting: The subducting oceanic plate melts as it descends deeper into the Earth's mantle due to increased pressure and temperature.
5. Magma Formation: The melted rock rises to the surface, forming magma.
6. Volcanoes: The magma often erupts on the surface, creating volcanic mountain ranges along the edge of the continent.
Examples of subduction zones:
* The Andes Mountains in South America are a result of the Nazca Plate (oceanic) subducting under the South American Plate (continental).
* The Cascade Range in the Western United States is formed by the Juan de Fuca Plate (oceanic) subducting under the North American Plate (continental).
Let me know if you'd like to know more about subduction zones or plate tectonics!
