What is it called when a heavier plate moves under a lighter plate?

At some convergent boundaries, an oceanic plate collides with a continental plate. Oceanic crust tends to be denser and thinner than continental crust, so the denser oceanic crust is bent and pulled under or subducted under the lighter and thicker continental crust. This forms what is called a subduction zone.

What happens when one tectonic plate slides under another?

When an oceanic plate collides with another oceanic plate or with a plate carrying continents, one plate will bend and slide under the other. This process is called subduction. As the subducting plate plunges deep into the mantle, it becomes so hot that it melts the surrounding rock.

Where does subduction occur?

Subduction zones are where the cold oceanic lithosphere sinks back into the mantle and is recycled. They are found at convergent plate boundaries, where the oceanic lithosphere of one plate converges with the less dense lithosphere of another plate.

What happens when two tectonic plates of different density collide?

When two tectonic plates of different density collide due to convection currents produced by the heat in the asthenosphere, a plate boundary (convergent) is formed. Deep trenches are usually formed where one of the plates slides under each other (a process called subduction).

What happens when two tectonic plates collide in a subduction zone?

Where two tectonic plates meet in a subduction zone, one bends and slides under the other, arching down into the mantle. (The mantle is the warmer layer below the crust.) At a subduction zone, the oceanic crust usually sinks into the mantle beneath a lighter continental crust.

What happens to the tectonic plates during subduction?

There, this chemically active fluid enters an energetic cycle of volcanism and tectonic activity. This process forms arc volcanism and is sometimes known as the subduction factory. The rest of the plate continues to fall, leaving the realm of plate tectonics. Subduction also creates some of Earth's most powerful earthquakes.

What happens when two plates slide along the side of each other?

Transform plate boundaries occur when two plates slide next to each other. The theory of plate tectonics consists of the theory of continental drift and seafloor spreading, which states that the Earth is divided into giant plates which move due to mantle convection.

What is a weaker layer in plate tectonics?

The asthenosphere is a weaker layer extending from approximately 150 to 400 km depth on which the lithospheric plates move and from which magmas that form the oceanic crust originate. Heat from the Earth's core creates circulation patterns (convection currents) in the mantle that drive the movements of the overlying plates.

What happens when oceanic plates and continental plates collide?

When an oceanic plate collides with a continental plate, it typically slides beneath it. If two identical plates collide, they crush together at the point of collision and lift up broken material from both plates.