Convergence zone. Image by Coft.edu

Convergence zone. Image by Coft.edu

ZIMSEC O Level Geography Notes: Plate tectonics: Convergence Zone.

Convergence zone

  • Are also know as destructive plates (zones) or the zone of subduction.
  • This is when two plates move towards each other as shown on the diagram above.
  • An Ocean crust moves towards a continental crust but being heavier,
  • It (the oceanic crust) sinks (is subdued by the continental crust hence the name zone of subduction) and is destroyed into the mantle forming deep-sea trenches and
  • Island arcs with volcanoes.
  • Since one plate (the oceanic plate) and sediments are being destroyed the zone is termed the destructive zone.
  • Thus when two plates move towards each other, their leading edges are destroyed as they collided and push one another.
  • For example the Nazca plate (near Peru South America) an oceanic plate sinks under the South American plate (the Andes)
  • The Juan de Fuca sinks under the North American plate (Rockies) forming the Island arc of the West Indies.

Collision zone

Collision zone. Image Classromatsea

Collision zone. Image Classromatsea

  • This is when two continental crust collide and as neither can sink
  • they are formed into fold mountains.
  • For example the India Plate collided with Eurasian Plate forming the Himalayas
  • The African Plate collided with the Eurasian Plate forming the Alps.

To access more topics go to the Geography Notes page.

 


Quick NetOne, Telecel, Africom, And Econet Airtime Recharge

If anything goes wrong, click here to enter your query.