Pangaea
Pangaea was the supercontinent that existed about millions of years ago. The continent covered about one-third of the Earth’s surface. It consisted of all the continents which are known today. The supercontinent was formed about 300 million years ago as a result of the Earth’s tectonic plates’ movement. These plates pushed together to form the supercontinent, but the further movement of tectonic plates 100 million years ago caused the breaking of Pangaea into parts along the volcanic rift zones.
Subduction of Tectonic Plates
Subduction is the process of one plate’s moving or sliding under the other one. This process is typical for the regions of convergent boundaries. The oceanic lithosphere subducts, but the continental lithosphere does not subduct in any cases. The reason is in the fact that the oceanic lithosphere is characterized by a higher density. As a result, the older oceanic lithosphere can slide beneath the continental lithosphere when the continental lithosphere is not as dense as the oceanic lithosphere is, and it rides up causing the possible destruction of the older oceanic lithosphere.
A Convergent Plate Volcanic Belt vs. A Hot Spot Series of Volcanic Islands
Volcanoes usually form the belt along the convergent plate boundaries because of the subduction processes. The result of subduction is the older oceanic plates’ sinking to the mantle to form volcanoes as weak spots there because the magma breaks the ocean floor. As a result, the volcanic belt is created. On the contrary, a hot spot series of volcanic islands are formed not because of the subduction process, but because the Earth’s mantle has hot spots through which magma rises to the surface to form volcanoes. Thus, the volcanic mountains appear to form volcanic islands.
Transform Faults
A transform fault can be discussed as a specific fault or a boundary within the subduction zones. According to this type of fault, the tectonic plates slide past one another without destroying the lithosphere. This horizontal type of sliding is often the result of the processes observed in the subduction zones. Many transform faults are also observed in the ocean to be associated with the parallel movements of tectonic plates.
Sea-Floor Spreading
When volcanic activity is observed in oceans, the floor of the ocean begins to spread because of the impact of the volcanic energy. As a result, the oceanic crust becomes formed due to volcanic processes that are observed at mid-ocean ridges. The effects of the volcanic activity are the motions of the oceanic crust to spread from the ridge. The fractures appearing during the volcanic activity are also associated with the changes in the lithosphere and sea-floor spreading which causes the formation of the new floor of the ocean.
The Ring of Fire
The Ring of Fire is the name used to determine a series of volcanoes observed in the Pacific Ocean. This string of volcanoes is a result of the significant seismic activity of these territories because this is the region where several tectonic plates form different types of boundaries such as a convergent boundary, a divergent boundary, and a transform boundary. Different tectonic plates found in the Ring of Fire can crash into each other or pull apart from each other to form subduction zones and volcanoes in the first situation and sea-floor spreading in the second situation.