Table of Contents
What is it called where the continental crust and oceanic crust meet?
Ocean-Continent Convergence. When oceanic crust converges with continental crust, the denser oceanic plate plunges beneath the continental plate. This process, called subduction, occurs at the oceanic trenches. The entire region is known as a subduction zone.
What can occur between continental and oceanic crust?
When oceanic crust converges with continental crust, the denser oceanic plate plunges beneath the continental plate. This process, called subduction, occurs at the oceanic trenches (figure 6). The subducting plate causes melting in the mantle. The magma rises and erupts, creating volcanoes.
Is oceanic or continental crust denser?
Oceanic crust is generally composed of dark-colored rocks called basalt and gabbro. It is thinner and denser than continental crust, which is made of light-colored rocks called andesite and granite.
What events occur during the convergent of continental plates and oceanic plates?
When a continental plate meets an oceanic plate, the thinner, denser, and more flexible oceanic plate sinks beneath the thicker, more rigid continental plate. This is called subduction. Subduction causes deep ocean trenches to form, such as the one along the west coast of South America.
Where are trenches usually form?
In particular, ocean trenches are a feature of convergent plate boundaries, where two or more tectonic plates meet. At many convergent plate boundaries, dense lithosphere melts or slides beneath less-dense lithosphere in a process called subduction, creating a trench.
What are found in continental crust?
Continental crust is mostly composed of different types of granites. Geologists often refer to the rocks of the continental crust as “sial.” Sial stands for silicate and aluminum, the most abundant minerals in continental crust.
What are the found at the oceanic crust?
The oceanic crust is primarily composed of mafic rocks, or sima, which is rich in iron and magnesium. The crust uppermost is the result of the cooling of magma derived from mantle material below the plate.
What are the found at the continental crust?
What are facts about continental crust?
The continental crust is the layer of granitic, sedimentary, and metamorphic rocks which form the continents and the areas of shallow seabed close to their shores, known as continental shelves. It consists mostly of sialic rock. It is less dense than the material of the Earth’s mantle, which consists of mafic rock.
Where would the crust be the thickest on Earth?
The thickest crust can be found in mountain ranges, notably the Tibetan Himalayas where it is 70km deep. The thinnest crust is oceanic crust where it is about 5km deep at places along the mid Atlantic ridge .
Where is the youngest crust on Earth is found?
The youngest crust occurs near the west coastline of North America near the North American and Juan de Fuca Plates. The oldest crust is along the Japan Trench and Marianas Trench. This is the outermost layer of the Earth.
Where is the oldest continental crust on Earth?
Most of the continental crust is much older. The oldest continental crustal rocks on Earth are cratons between 3.7 and 4.28 billion years old. These have been found in the Narryer Gneiss Terrane in Western Australia, in the Acasta Gneiss in the Northwest Territories on the Canadian Shield ,…