Theory of Plate Tectonics - Earth’s crust is divided into several big rigid plates that are made up of continental and oceanic crust - These plates move around by floating on top of the liquid layer of the Earth; mantle. This process is driven by convection currents within the mantle where hot magma near the core rises towards the surface - The top of the heated column spread sideways & cooling occurs. During cooling, the density increases & the material sinks, also due to gravitational pull, forming a current that causes the plates to move - As a result of this movement, it causes 3 types of plate boundaries to occur o Divergent ♣ As tectonic plates move apart, magma from the mantle well up form ridges of the Earth, causing new rocks to be made (aka constructive boundaries) ♣ mid-ocean ridges & underwater mountains are formed o Convergent ♣ Plates move together ♣ Plates meet at a subduction zone, (aka destructive boundaries) because rock is destroyed ♣ Volcanoes, mountains & earthquakes are formed o Transform ♣ Plates slide past each other ♣ No new rock is being made (aka conservative boundaries) ♣ Very strong earthquakes produced due to jagged crust that jolts & scraps past each other