1) Occurs when a concentrated radioactive area creates a mantle plume under the tectonic plate
2) The mantle plume starts to heat the upper mantle and lithosphere and eventually it will start to melt and magma becomes less dense and starts to rise up.
3) Once magma rises it forms an underwater volcano which overtime more basaltic magma accumulates allowing the voclano to build up and rise to the surface forming an island volcano.
4) Due to convenction currents in the mantle the plate moves but the mantle plume hotspot remains in its original position.
5) Therefore as the plate moves the volcano moves with it so the volcano loses its source of magma and becomes extinct.
6) On the new area above the hotspot the whole process occurs again and another volcano forms. This cycle happens over millions of years and forms a chain of hotspot volcanoes
7) Overtime the older volcanoes start to become eroded due to geomorphic processes like weathering causing them to become sea mountains.
Example - Hawaii
-Oldest one is calle Kauai and is 3.8m years old
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