Physical Science:

Oceanic-continental plate collision: When an oceanic plate collides with a continental plate, the denser oceanic plate is usually subducted under the less dense continental plate. This process can lead to the formation of subduction zones, where the oceanic plate is forced downward into the mantle, creating a deep oceanic trench [Figure 11.4.4]. As the oceanic plate is subducted, it heats up and begins to melt. This melt rises up to the surface in the form of magma and can cause the volcanic activity. This volcanic activity can create a line of volcanoes known as a volcanic arc on the continental plate side of the subduction zone. The collision between the oceanic and continental plates can also cause folding and faulting of the continental crust, leading to the formation of mountain ranges. This collision can also cause earthquakes as the plates grind against each other and release energy. One well-known example of an oceanic-continental plate collision is the Andes Mountains in South America.

Oceanic-oceanic plate collision: When two oceanic plates collide, one plate usually subducts beneath the other, creating a subduction zone. The subducted plate is forced down into the mantle, creating a deep trench, while the overriding plate forms an island arc, a curved chain of volcanic islands. As the subducted plate sinks deeper into the mantle, it heats up and begins to melt. This process can also lead to volcanic activity. This volcanic activity can contribute to the growth of the island arc. Over time, the volcanic activity can also lead to the formation of a new oceanic crust, as magma solidifies and builds up on the seafloor. One example of an oceanic-oceanic plate collision is the collision between the Pacific Plate and the Philippine Sea Plate, which has created the Marianas Trench and the Mariana Islands, a volcanic island arc in the western Pacific Ocean.

Continental-continental plate collision: When two continental plates collide, neither plate is subducted because both plates are too buoyant to sink. Instead, the collision can lead to the formation of massive mountain ranges and intense deformation of the continental crust. As the two continental plates collide, they crumple and fold, leading to the formation of complex mountain belts. The collision can also cause extensive faulting and fracturing of the crust that leads to the formation of deep basins and rift valleys. One example of a continental-continental plate collision is the collision between the Indian Plate and the Eurasian Plate, which has led to the formation of the Himalayan mountain range, the tallest mountain range in the world. The collision between these two plates is ongoing, and the Himalayas continue to grow taller each year.