Lab 4: The

movement of the Earth’s

Lithospheric Plates

•One Plate Subducts•A trench forms above the subduction

zone in water•A volcanic island arc forms on the

plate that is not subducted

Ocean – Ocean Convergence

•Ocean plate is subducted below continent.•A trench forms above the subduction zone

in water•A volcanic mountain chain forms on land

Ocean – continent Convergence

•No subduction because continents are less dense than the mantle

•Continents collide and fold up (crunch) to form mountains

continent – continent Convergence

Ocean – Continent Convergence

1. A. When an ocean plate converges with a

continental plate, what happens? (Which plate subducts?) Explain.

B. What is a subduction zone?

C. What feature is found on the earth directly above the subduction zone?

D. What feature forms on land? Explain.

Ocean – ocean Convergence

2.A. When two ocean plates collide, what happens?

B. What feature is found on the earth’s surface directly above the

subduction zone?

C. What feature forms on the ocean plate

that is not subducted? Explain.

Continent– Continent Convergence

3.A. When two continents collide, what happens?

B. What feature forms on the earth’s surface because of the collision?

C. Why don’t continents go down at the

subduction zones?

Lab 4: VOCABULA

RY

11. Continental CrustThicker, less dense, older lithospheric

plate

49. Oceanic CrustThinner, more dense, younger

lithospheric plate

15. Continent-Continent Collision Zones

Areas where two plates of the same density (continental crust) move toward each other

and collide

46. Subduction

The movement when one plate (oceanic crust) dives below another plate into the

mantle