Answer:
Convergent and divergent plate boundaries
Explanation:
In a convergent plate boundary, two plates move towards each other. Due to the impact, the heavier tectonic plate subducts beneath the lighter plate. This results in the formation of a subduction zone, and there forms a trench above this zone. The rocks at greater depths, melts and mixes up with the magma and eventually rises upward, towards the surface in the over-riding plate, giving rise to the formation of volcanoes and volcanic arcs.
In a divergent plate boundary, two plates move away from one another. Due to this opposite motion of plates, there occur cracks on the seafloor and land areas, from where the magma comes out. With continuous spreading, there forms a ridge, which is commonly known as the mid-oceanic ridge. This type of plate boundary is responsible for the formation and expansion of the ocean basin. For example, the mid-Atlantic ridge.
