New ocean crust erupts in the void, creating an ocean between continents. When two plates converge, the result depends on the type of lithosphere the plates are made of. No matter what, smashing two enormous slabs of lithosphere together results in magma generation and earthquakes. Figure 6. Subduction of an oceanic plate beneath a continental plate causes earthquakes and forms a line of volcanoes known as a continental arc.
When oceanic crust converges with continental crust, the denser oceanic plate plunges beneath the continental plate. This process, called subduction , occurs at the oceanic trenches figure 6. The entire region is known as a subduction zone. Subduction zones have a lot of intense earthquakes and volcanic eruptions. The subducting plate causes melting in the mantle.
The magma rises and erupts, creating volcanoes. These coastal volcanic mountains are found in a line above the subducting plate figure 7. The volcanoes are known as a continental arc. Figure 7. The movement of crust and magma causes earthquakes. Look at this map of earthquake epicenters at subduction zones.
This animation shows the relationship between subduction of the lithosphere and creation of a volcanic arc. The Juan de Fuca plate is created by seafloor spreading just offshore at the Juan de Fuca ridge. Figure 8. The Cascade Mountains of the Pacific Northwest are a continental arc. If the magma at a continental arc is felsic, it may be too viscous thick to rise through the crust.
The magma will cool slowly to form granite or granodiorite. These large bodies of intrusive igneous rocks are called batholiths , which may someday be uplifted to form a mountain range figure 9.
Figure 9. The Sierra Nevada batholith cooled beneath a volcanic arc roughly million years ago. The rock is well exposed here at Mount Whitney. Similar batholiths are likely forming beneath the Andes and Cascades today. When two oceanic plates converge, the older, denser plate will subduct into the mantle.
An ocean trench marks the location where the plate is pushed down into the mantle. The line of volcanoes that grows on the upper oceanic plate is an island arc. Do you think earthquakes are common in these regions figure 10?
Figure Check out this animation of an ocean continent plate boundary. Continental plates are too buoyant to subduct. What happens to continental material when it collides? Magma cannot penetrate this thick crust so there are no volcanoes, although the magma stays in the crust. Metamorphic rocks are common because of the stress the continental crust experiences.
With enormous slabs of crust smashing together, continent-continent collisions bring on numerous and large earthquakes. Check out this short animation of the Indian Plate colliding with the Eurasian Plate. Watch this animation of the Himalaya rising. The Appalachian Mountains are the remnants of a large mountain range that was created when North America rammed into Eurasia about million years ago.
At the northern end of the picture, the transform boundary turns into a subduction zone. Transform plate boundaries are seen as transform faults , where two plates move past each other in opposite directions. Transform faults on continents bring massive earthquakes figure California is very geologically active. What are the three major plate boundaries in or near California figure 13?
This map shows the three major plate boundaries in or near California. A brief review of the three types of plate boundaries and the structures that are found there is the subject of this wordless video. Geologists know that Wegener was right because the movements of continents explain so much about the geology we see.
Most of the geologic activity that we see on the planet today is because of the interactions of the moving plates. In the map of North America figure 14 , where are the mountain ranges located? Using what you have learned about plate tectonics, try to answer the following questions:. About million years ago, the Appalachian Mountains of eastern North America were probably once as high as the Himalaya, but they have been weathered and eroded significantly since the breakup of Pangaea.
Remember that Wegener used the similarity of the mountains on the west and east sides of the Atlantic as evidence for his continental drift hypothesis. Why does karst topography only exist in some geographic locations.
Geology 20 cards. Types of convergent boundaries. As erosion removes the tops of mountains the crust will rise upwards This is an example of. In which era do you live today. A fault in which the hanging wall moves down relative to the footwall is a. Plate Tectonics 20 cards. Most earthquakes happen. What is is it called when plate movement causes rocks to break. Where are ocean ridges generally located.
Which of earths mechanical layers contains the seven major plates. Q: What boundary is normally devoid of volcanism? Write your answer Related questions. What are the characteristics of divergent-boundary volcanoes and convergent boundary volcanoes? Was Mount Tambora formed by a convergent plate boundary or a divergent plate boundary?
At which type of plate boundary does rift volcanism occur? What type of boundary produces volcanoes? At which type of plate boundary does rift-volcanism occur? What are the common effects of plate boundary movement? What kind of plate boundary causes volcanism?
Is Yellowstone a intraplate volcanism? Why are there no volcanos or earthquakes in Britain? Where does spreading volcanism occur? Describe the volcanic activity that forms at a divergent boundary? What is formed when an ocean plate converges with a continental plate? How volcanism causes earthquake? What type of volcanism occurs underwater along the mid-oceanic ridge?
What type of boundary produces volcanoes? The hawaiian isand and Yellowstone national park are associted with which of the three zones of volcanism? Why is volcanism common in subduction zones? Does Uranus have volcanism? What plates caused the volcano Kilauea to form?
What are the 2 major ways an island is formed? The most common way for mountain to form is when? What is intra plate volcanism? Is volcanism found at convergent and divergent boundaries of tectonic plates?
What is volcanic activity? What is intrusive volcanism? Is it true or false volcanism occurs on planets whose interiors have completely cooled? What is the meaning of bulkanismo? What is volcanic activity called? What is volcanism? What is a hot spot and why do volcanoes often form here? What is the most common way for mountains to form?
What is the relationship between volcanism and geysers and hot springs? Study Guides. Trending Questions. What can you hold in your right hand but not in your left hand? Still have questions? Find more answers. A convergent B transform C divergent. Answer: a B, b C, c A 68 If you could time travel back to the s and meet Alfred Wegener, who was the original proponent of the continental drift hypothesis, what could you tell him about our modern idea of plate tectonics?
Answer: The Earth is divided into different layers. The outermost rocky layer the lithosphere is broken into plates of various sizes. There are multiple lines of evidence that support plate tectonics such as the ages of the seafloor proportional to the distance from the ridge, magnetic stripes of the oceanic floor parallel to oceanic ridges, and hotspots. The plate boundaries and earthquakes are closely linked. For instance, the region around the Peru-Chile trend experiences great earthquakes.
Convection in the mantle is a process that still needs to be fully understood. It was only after WWII that oceanographers began exploring the ocean floor.
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