what property allows magma to rise through the crust?
If oceanic and continental crust collides the denser one which is the oceanic crust will be subducted, go underneath, the continental crust. The high heat of the mantle causes the oceanic crust to melt into magma. If the crust gets cracked this allows magma to rise and come out of the crust as lava which will form Volcanoes. When two continental crusts collide, the crust is forced to go upwards which forms mountains.