Question

Volcanoes are often formed at plate boundaries. This is a convergent plate boundary. From the choices listed, pick the correct description of what happens before the volcano forms.

Answer 1

Options

A) Denser continental plate pushes oceanic plate down. Oceanic plate melts deep in the Earth, Magma rises up through weak spot.

B) The less dense oceanic plate subducts under the denser continental plate. Subducted plate melts due to heat and pressure. Melted plate, now magma, rises up to the surface.

C) As the more dense oceanic plate subducts under the less dense continental plate, it pulls the front edge of the less dense plate down, creating a deep zone or oceanic trench.

D) The more dense oceanic plate subducts under the less dense continental plate. Subducted plate melts due to heat and friction. Melted plate, now magma, rises up to the surface.

Answer:

D.

Explanation:

Formation of volcanoes may be at any plate boundaries; whether it's a convergent plate boundaries or it is divergent.. Collision of two tectonic plates gives rise to a convergent plate boundaries. The dense oceanic plate (one of the converging plates) will move beneath the other, which is the less dense continental plate a process as subduction.

The subduction zone is the region where geological process that takes place at convergent boundaries of tectonic plates where one plate moves under another and is forced to sink due to high gravitational potential energy into the mantle, take place.

As a result of non stop movement, frictions between the plates that are in subduction zone begins and continue to melts the Earth's crust causing the underneath rocks to turn into magma.

The magma then creates great pressure and rises towards the surface of the earth, and on reaching the surface it is called lava, and a volcano is formed.