What is oceanic crust and continental crust?
It is the solid rock layer upon which we live. It is either continental or oceanic. Continental crust is typically 30-50 km thick, whilst oceanic crust is only 5-10 km thick. Oceanic crust is denser, can be subducted and is constantly being destroyed and replaced at plate boundaries.
What is continental plate and oceanic plate?
Continental crust is composed of granitic rocks which are made up of relatively lightweight minerals such as quartz and feldspar. By contrast, oceanic crust is composed of basaltic rocks, which are much denser and heavier.
Which plates are oceanic and which are continental?
An example of an oceanic plate is the Pacific Plate, which extends from the East Pacific Rise to the deep-sea trenches bordering the western part of the Pacific basin. A continental plate is exemplified by the North American Plate, which includes North America as well as the oceanic crust…
What is oceanic continental convergent?
When oceanic crust collides with a continent, an oceanic-continental convergent boundary forms. The oceanic plate is denser, so it undergoes subduction. This means that the oceanic plate sinks beneath the continent, forming a deep ocean trench.
Why is oceanic crust made of basalt?
Magmas generated by melting of Earth’s mantle rise up below the oceanic crust and erupt on Earth’s surface at mid-ocean ridge systems, the longest mountain ranges in the world. When the magma cools it forms basalt, the planet’s most-common rock and the basis for oceanic crust.
How is continental crust formed?
Continental Crust Through the Ages Present-day continental crust is formed by magmatism at volcanic arcs above subduction zones, like the Aleutian Arc off Alaska, the Izu-Bonin-Mariana Arc in the western Pacific, and the Andes in South America.
How is oceanic crust formed?
Oceanic crust is constantly formed at mid-ocean ridges, where tectonic plates are tearing apart from each other. As magma that wells up from these rifts in Earth’s surface cools, it becomes young oceanic crust. The age and density of oceanic crust increases with distance from mid-ocean ridges.
Where is the oceanic plate?
oceanic plates are formed at divergent boundaries mainly at mid ocean ridges. The material that is poured out are basaltic lave in nature. Basalt is denser and heavier than the granite that makes up continental plates.