Plate Boundaries - Geology for Kids
Some lithospheric plates consist of both continental and oceanic crust. Subduction initiates as. Covers convergent plate boundaries where an oceanic plate meets If both plates meet with continental crust, there will be mountain building. Convergent boundaries -- where crust is destroyed as one plate dives under . two continents meet head-on, neither is subducted because the continental rocks .
When the two crustal plates converge the oceanic plate always bends and subducts beneath a continental plate. Subduction zones that occur on the coastline of Alaska are areas of frequent large and small earthquakes.
The plates lock and break apart creating these earthquakes which occasionally send tsunami waves traveling across the Pacific Ocean to distant shores. Ocean crusts collide When two oceanic plates meet the older and colder plate like the Pacific Ocean Plate is heavier and denser. The leading edge of the plate bends and slips beneath the younger oceanic plate. Off the island of Guam is the Mariana Trench the deepest area on our planet.
In this area the leading edge of the Pacific Plate is forced beneath the smaller and lighter Mariana Plate. The trench that has formed between the two plates includes the Challenger Deep. Collision boundary land forms Each of these boundaries are associated with specific land forms. Collision boundaries form great mountain chains on Earth. The European Alps and the Himalaya Range are examples of the land forms visible on Earth where continental crusts came together.
Ocean-Ocean Convergent Plate Boundaries ( Read ) | Earth Science | CK Foundation
Great volcanic mountains like Mount Rainier form in a subduction zone on the continental side of a subduction zone. The Aleutian Islands in the North Pacific are an example of a volcanic island arc that has formed above a subduction zone. More Facts About Earth Links.
Subduction zones occur when one or both of the tectonic plates are composed of oceanic crust. The denser plate is subducted underneath the less dense plate. The plate being forced under is eventually melted and destroyed. Where oceanic crust meets ocean crust Island arcs and oceanic trenches occur when both of the plates are made of oceanic crust.
Zones of active seafloor spreading can also occur behind the island arc, known as back-arc basins.
These are often associated with submarine volcanoes. Where oceanic crust meets continental crust The denser oceanic plate is subducted, often forming a mountain range on the continent. The Andes is an example of this type of collision.
Tectonic Plates and Plate Boundaries
Where continental crust meets continental crust Both continental crusts are too light to subduct so a continent-continent collision occurs, creating especially large mountain ranges. The most spectacular example of this is the Himalayas.
Divergent boundaries — where two plates are moving apart. The space created can also fill with new crustal material sourced from molten magma that forms below.