Question

Explain how subduction zones are formed.

I'm trying to study from a book but it doesn't explain well.

Answer 1

subduction is the process of which two plates collide against each other and one is forced under the other into the mantle. so like take your hands and pretend to left one is sliding under the other one after you force them against each other L→←R to L←R ⊕ ⊕
↓ ·-__-·

Answer 2

A subduction zone arises from the clash between the continental crust and the oceanic crust.

The oceanic crust is the part of the earth's crust that forms the oceans and is much less thick than the continental crust. And the continental crust is what continents and continental platforms are made of and is much thicker than the oceanic crust.

Being much thicker, the continental crust forces the oceanic crust to sink beneath it, and exerts a downward force causing it to sink to a depth of up to 160 km.

While it reaches depth, it is getting hotter and the liquids and materials inside it are released. All these materials melt and form magma and as they come out again towards the surface steep volcanoes form.

These areas are characterized by having large chains of volcanoes due to this process.