the subduction of tectonic plates may cause magma to surface from underneath & the oceanic plate is a kind of tectonic plate ->  the subduction of an oceanic plate may cause magma to surface from underneath  the subduction of an oceanic plate may cause magma to surface from underneath & magma cools down when it comes to the surface from underneath ->  the subduction of an oceanic plate will cause magma to surface and cool down  the subduction of an oceanic plate will cause magma to surface and cool down & magma cooling can form volcanic mountains -> the subduction of an oceanic plate can form volcanic mountians