Plates separate

• Plates that separate have constructive boundaries. New crust is created. Plates move apart from each other and a gap forms. Magma rises out the mantle to fill that gap. Magma cools and hardens to form new crust. When this happens under the sea it’s called sea-floor spreading. Plated that seperate form volcanic mountains, islands and mid ocean ridges. e.g iceland formed by Eurasian and North American plate separating.