Changes

At constructive plate margins two plates are pushing away from each other and therefore opening a large gap between then. [[Magma]] then rises from deep in the earth in the [[mantle]] to fill this gap and new [[crust]] is formed. [[Volcano]]s are often found at constructive plate margins as the rising [[magma]] often creates [[Volcanic Eruption|eruptions]]. A key example of a constructive plate margin is the [[mid-Atlantic ridge]] where the new crust that has formed is visble in the form of a long ridge of land under the [[Atlantic Ocean]].