Name: ______Date ______Hour ______

Study Guide - Plate Tectonics

______1. The youngest part of the ocean floor is found ______

a. along deep sea trenches b. where ocean sediments are thickest

c. near ocean ridges d. where Earth’s magnetic field changes polarity

______2. At oceanic-oceanic convergent boundary, ______

a. new crust is created b. old crust is deformed or fractured

c. old crust is recycled by subduction d. plates side past one another

______3. Convection currents transfer thermal energy _____

a. between continents b. from cooler regions to warmer regions

c. from warmer regions to cooler regions d. as a result of buoyancy

______4. The downward part of a convection current causes a sinking force that _____

a. pulls tectonic plates toward one another b. moves plates apart from one another

c. lifts and splits the lithosphere d. creates a divergent boundary

______5. What happens to ocean floor as is moves farther away from a rift valley?

a. it gets older b. it gets wider c. it gets younger d. it gets thinner

______6. Compared to ocean crust near deep-sea trenches, crust near ocean ridges is _____

a. younger b. older

c. the same age d. magnetically reversed

______7. Divergent boundaries ______happen at oceanic-oceanic boundaries.

a. always b. sometimes c. never d. mostly

______8. Convergent boundaries move______

a. past each other b. towards each other c. away from each other d. next to each other

______9. Each cycle of spreading and intrusion of magma during seafloor spreading results in _____

a. magnetic reversals b. new ocean crust

c. subduction d. plates colliding

______10. Features found at divergent boundaries include _____

a. ocean ridges b. deep-sea trenches

c. crumpled mountains d. island arc volcanoes

______11. Continental-continental plate collisions produce _____

a. island arcs b. rift valleys

c. deep-sea trenches d. very tall mountain ranges

______12. Crust is neither destroyed nor formed by which of the following boundaries?

a. convergent b. divergent

c. transform d. magnetic

______13. The driving forces of tectonic plates are related to convection currents in Earth’s _____

a. crust b. mantle

c. inner core d. outer core

______14. A vast, underwater mountain chain is called a(n) _____

a. deep-sea trench b. ocean ridge

c. oceanic crust d. ocean floor sediments

______15. Elongated, sometimes arc-shaped depressions in the seafloor is called a(n) _____. They are the deepest part of the

ocean.

a. deep-sea trenches b. oceanic crust c. ocean ridge d. ocean floor sediment

16. Listed below are the steps involved in the process of seafloor spreading. Sequence the steps in the correct order.

The seafloor contracts and sinks
Crust spreads along an ocean ridge and magma fills the gap that is created
New seafloor moves away from the ridge, cools, and becomes more dense than the material beneath it
Hot magma which is less dense than surrounding material, is forced toward the crust
New ocean floor forms as the magma hardens

17. Complete the table below.

Type of Boundary / Plates Involved / Direction of Movement / Resulting Feature or Phenomena
a / Divergent / Ocean Ridges & rift valley
b / Moving apart / Rift valley
c / Convergent / Toward one another / Deep-sea trench
volcanic island arc
d / Toward one another / Volcanic mountain range
trench
e / Convergent / Uplifted mountain range
f / Oceanic-oceanic and continental-continental / Slide past one another

Match the letter that appears in the diagram with the appropriate feature listed below.(A-G)

18. ______trench 19. ______mountain range 20. ______mid-ocean ridge

21. ______volcanic island arc 22. ______volcanic mountain range 23. ______rift valley

24. ______subduction zone

Match the boundary with its name. (1-5)

25. ______divergent boundary 26. ______transform boundary

27. ______convergent: oceanic-oceanic 28. ______convergent: oceanic-continental

29. ______convergent: continental-continental