Converging Boundaries

Converging Boundaries : - When things converge, it means that they come together. For example, cars entering a busy freeway need to converge, and join to form one flow of traffic. Converging boundaries occur when two plates are colliding head-on into each other. Rock is destroyed at converging boundaries, and so these boundaries are also known as destructive boundaries. These collisions form an assortment of land features such as mountains chains of islands and underwater trenchers. The features that are formed depend on what types of crust collide.

Mountains, Volcanoes and Trenches : - It oceanic crust is colliding with continental crust, then the denser oceanic plate sinks under the lighter continental plate. This is subduction, and can be seem in Figure, 10.2.6. The continental plate becomes distorted, forming fold mountains and volcanoes. Fold mountains form when plates collide and the crust crumples upwards. Where the oceanic plate subducts ocean floor called a trench is formed. A good example is where the Nazca Plate collides with South America. The Andes Mountains have been formed along the west coast of South America, and the 8000-metre deep Peru-Chic French has formed.

The plate that subducts dives down deep into the mantle, which is extremely hot. The friction of the plates colliding also generates heat. This heat is enough to melt the crust and form magma. So crust is being destroyed as it subducts.

High Mountain Systems : - When two continental plates collide, both are pushed upwards because both have similar densities. This upwards push forms ranges of very high mountains. The best-known example of this is where the Indian Plate is colliding with the Eurasian Plate (Figure 10.2.7). This has formed the Himalayas, the highest mountain range on Earth. Its highest mountain is Mt. Everest at 8,848 metres above sea level.

Island Arcs : - When two oceanic plates collide, the faster-moving plate always subducts under the other . This forms a deep trench. The descending plate melts and is destroyed, forming magma. The magma rises to the surface creating a chain of volcanic islands called an island arc.

The Mariana Trench is the deepest ocean trench yet discovered. It occurs where the Pacific Plate collides with a small plate called the Mariana Plate (part of the Philippine Plate). The trench is 10,911 metres deep- A string of volcanic islands forms an island are along the boundary.

Sample Questions

(More Questions for each concept available in Login)

Question : 1

Underwater trenches formation occur due to which type of movements ?
A. Diverging movements		B. Converging movements
C. Transforming movements		D. None of the above
Right Option : B
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Question : 2

Which of the following structures are formed due to the Converging boundaries movement ?
A. Formation of Himalayan range		B. Formation of deep trenches
C. Formation of fold mountains		D. All of the above
Right Option : D
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Question : 3

Formation of Andes mountains is an example of which type of boundary movement ?
A. Converging movements		B. Transforming movements
C. Diverging movements		D. None of the above
Right Option : A
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