The volcanic activity refers to the eruption of magma at the surface of the ocean floor and continental land areas, forming volcanoes.
Some of the tectonic settings that are associated with volcanic activity are as follows-
Mantle plumes- These are the large uprising bodies of magma that are generated due to the formation of convection current in the mantle. These are localized body and are located away from the tectonic boundaries. For example, Hawaii is formed as the plates moved over the mantle plumes.
Continental rifts- This refers to the eruption of magma at the surface of the continents, due to the divergent motion of two continental plates. It results in the formation of a rift, rift valley and then later forms an ocean.
Island arcs- These are formed due to the collision of two oceanic plates, where the volcanoes are formed on the lighter oceanic plate due to the rising up of magma.
Continental arcs- These are formed due to the collision between an oceanic and a continental plate, where the volcanoes are formed due to the uprising of magma in the lighter continental plates.
When sedimentary rock go to the bottom of a seafloor it sticks together over time and turns into metamorphic rock. Then metamorphic rock melts and when it cools down it turns into igneous rock. This process happen over and over and its called rock cycle.
