Question

Does an oceanic-oceanic plate form island arcs and does an ocean-continental form volcanic arcs?

Answer 1

Yes, an oceanic-oceanic plate boundary forms island arcs, while an oceanic-continental plate boundary results in volcanic arcs.

Step-by-step explanation:

Oceanic-oceanic plate boundaries occur when two oceanic plates converge. In this scenario, one plate is typically subducted beneath the other, creating a subduction zone. As the subducted plate melts in the mantle, magma rises to the surface, forming a series of volcanic islands known as an island arc. This process is exemplified by the Pacific Ring of Fire, where several island arcs, such as the Aleutian Islands and the Japanese archipelago, are located.

On the other hand, oceanic-continental plate boundaries involve the collision of an oceanic plate with a continental plate. The denser oceanic plate is subducted beneath the lighter continental plate. The melting of the subducted plate generates magma that ascends through the continental crust, resulting in the formation of volcanic arcs on the continent's edge. A classic example of this is the Andes mountain range in South America, where the Nazca Plate subducts beneath the South American Plate, giving rise to a volcanic arc with numerous active volcanoes.

Answer 2

Yes, oceanic-oceanic plate boundaries can form island arcs, and ocean-continental plate boundaries can form volcanic arcs.

Step-by-step explanation:

Yes, an oceanic-oceanic plate boundary can form island arcs. This occurs when two oceanic plates converge, and one plate subducts beneath the other. As the subducting plate sinks into the mantle, it generates magma, which rises to the surface and forms a chain of volcanic islands known as an island arc. The classic example of an island arc is the Japanese archipelago.

On the other hand, an ocean-continental plate boundary can form volcanic arcs. This occurs when an oceanic plate collides with a continental plate, and the denser oceanic plate subducts beneath the less dense continental plate. As the oceanic plate sinks into the mantle, it generates magma, which rises to the surface and forms a line of volcanic mountains known as a volcanic arc. The Andes Mountains in South America are an example of a volcanic arc formed by the subduction of the Nazca Plate beneath the South American Plate.